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Proyecto Final de Carrera Abastecimiento de agua de consumo en Rønde, Dinamarca. Autor José Antonio Alba Hernández Director Javier Lanaja Especialidad Química Industrial Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 2 B6PMI2 PROJECT 2011 GROUP 3 José Antonio Hernández Marcin Sozanski Mehmet Can Güclü Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 3 1. Abstract “Water can be without the company of humans but we as humans can only be without water for a few days." This quotation shows the whole truth about the importance and meaning of water as the main source of nourishment. Its value cannot be overestimated. It is essential for all life on this planet. The water is our most wealthy treasure, our life depend on the quality of the water we use for drinking, and even for washing clothes, dishes etc. Ground water can be a very important source of water. The problem is that is difficult and/or expensive to find where we can get water from. However, in a priory point of view this water is more likely to be cleaner or freer of pollutant than the surface water, and then its treatment is cheaper and/or easier. Therefore is important to know the characteristics of the water and of the aquifer the water is being taken from. Once this is known, a treatment process can be designed to improve the water status and get then, optimal conditions for its consumption. Moreover, in this world where the dollars are the most important thing, it was impossible not to think about this factor. Then if a network is about to be built, ways of saving money and providing water have to be thought. The network modeling will be an essential part of this proyect. Group 3 Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 4 2. Preface The project, and this report has been written by a group of 3 people, as part of the Spring International Semester on Environmental Engineering Studies at the University College of Aarhus for the subject B6PMI2 (20 ECTS credits). The project is based on knowledge obtained from the BTWSPL course. As a part of a consulting company, we are asked to check the drinking water network status of a Danish village called Rønde, give solutions to the hypothetical problems which can appear and to get an accurate idea of the plant performance, aquifer conditions, the chemistry of the water and of the way the water is supplied to the city and to the new area which is about to be built. We would like to thank the three supervisors, Michael Rosenberg Pedersen, Peder Maribo and Rasmus Bundegaard Eriksen who helped us whenever any doubt came up. It is our desire to give special thanks to Peder Maribo, for all his help during the writing of the report, and especially during the optional part experiments. Thank you. We would also like to thanks Hans Rixen, from the Waterworks, for allowing us to take samples in the sand filters. The members of the Group 3: Marcin Sozanski West Pomeranian University of Technology. Mehmet Can Guclu Uludag University José Antonio Alba Escuela Universitaria Ingeniería Técnica Industrial Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 5 Point INDEX Pag. 1. Abstract 1 2. Preface 2 3. Introduction 7 4. Intake aquifer 9 4.1 Geological profile 9 4.1.1 Analysis of geological profile of the Rønde Aquifer 9 4.2 Abstration area 11 4.2.1 Transmissivity 11 4.2.1.1 Calculation of transmissivity 12 4.2.2 Potentiomatric map 14 4.2.3 Precipitation an infiltration 15 4.2.4 Calculations of abstraction area 16 4.2.4.1 Resultant of wells locations 18 4.2.5 Maps of abstraction area 19 4.3 possible location of the new borings 21 5. Intake wells 23 5.1 wells technical specifications 23 5.1.1 well 321 24 5.1.2 well 217 25 5.1.3 well 352 26 5.1.4 well 272 28 6. Water chemistry 29 6.1 Description 29 6.2 Comparation to drinking water criteria 29 Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 6 Point INDEX Pag 6.3 Calculations 30 6.4 Parameters 30 6.4.1 Ion Exchange 30 6.4.2 Degree of weathering 31 6.4.3 Hardness 31 6.4.4conductivity 32 6.4.5 Organic matter 32 6.4.6 Pyrite oxidation 32 6.4.7 Calcite saturation index (Log SI) 32 6.4.8 Sulphate reduction 33 6.4.9 Acid/base Water types 33 6.4.10 Redox condition 34 6.4.11 Ion balance 34 6.5 Identification of critical parameters and effects of health 34 6.5.1 Salt 35 6.5.2 Nitrate 35 6.5.3 Arsenic 35 6.5.4 Fluorite 36 6.6 Four Critical Compounds of over the criteria 6.7 Contamination of groundwater 37 6.8 Conclusion 38 7 .Water treatment description 39 7.1 Aeration 39 7.2 Reaction basin 40 Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 7 Point Pag. 7.2.1 Basin retention time 41 7.3 Filtration 42 7.3.1 Backwash 45 7.3.2 Settling time 45 7.4 Storage tank 46 7.4.1 Storage tank design 46 7.5 Conclusion 47 8. Water consumption 47 8.1 Description 47 8.2 Present consumption 47 8.3 Evaluation of future consumption 43 8.4 Assessment: Present and Future Consumption 49 8.5 Evaluation of borings 50 8.6 Time Varying demands 50 8.7 Conclusion 51 9. Network 51 9.1 Aquis model 51 9.2 Water demands for Rønde 51 9.3 Calibration 52 9.3.1 Lack of water in reservoirs 53 9.3.2 Too high pressure in nodes 53 9.3.3 Demands Zone weighting factors 53 9.4 New water network in Følle 54 1. Optional part 56 Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 8 1.1 Main aim 56 1.2Introduction 56 1.3First experiment 58 1.3.1Materials 58 1.3.2 Sampling device for water 58 1.3.3 Sampling device for sand 61 1.3.4 Method 62 1.3.4.1 The disinfection procedure 64 1.3.4.2 Placing the tubes 64 1.3.4.3 Tanking samples 65 1.3.4.4 Possible problems and risk 66 1.3.5Experimental hydraulics in the filter 68 1.3.6 Conclusion 69 1.3.7 Sampling error 72 1.4 Second experiment 74 1.4.1 Introduction 74 1.4.2 Materials 74 1.4.3 Process 75 1.4.4 Incidences 76 1.4.5 Conclusions 80 1.4.6 Possible improvements 83 2. Enclosures 84 3. Literature 148 Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 9 3. Introduction The drinking water for the village of Rønde comes from 2 well fields which are placed in the same region of the city. Rønde is a city located 37 km from Aarhus in a northern direction. It is part of the municipality of Syddjurs. Its population is 2213 according to the GeoNames geographical database (09-08-2010). The average elevation of the village is 57 meters. The waterworks in charge of treating the water extracted from the wells only can clean the water by standard treatment, this is: Aeration and filtration. There is a storage tank right next to the water works and two more down in the town. These last two tanks are built in high. Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 16 4.2.2. Potentiometric map. A Potentiometric map shows the elevation of a potentiometric surface which belongs to an aquifer by means of contour lines. It gives information about direction of groundwater flow, because water always flows from the higher potential point to point with lower potential. Potentiometric map of Rønde will be used as a base to create abstraction area. The direction of the groundwater flow shows the place where the abstraction area is located. Gradient of terrain will be used in calculation of abstraction area. figure 3.2 shows the potentiometric map of Rønde and direction of water flow. Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 17 4.2.3. Precipitation and infiltration The precipitation is a product of the condensation of atmospheric water vapor that falls under gravity. The Precipitation for Rønde is approximately 700 mm / year figure 3.3 shows the precipitation in Denmark. The fraction of the precipitation, that does not evaporate or run off as surface water, is infiltration (other name: groundwater recharge). This gives information about the amount of water recharged per m 2 of ground. This parameter affects the size of abstraction area. The infiltration is in Denmark typically 1/3 or 1/2 of precipitation. It depends on climatic and geological factors as well as land use and vegetation. To calculate the aquifer abstraction area were used infiltration of 1 / 3 of precipitation. Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 18 4.2.4. Calculations of Abstraction area Danish law say: “only 35% of groundwater can be abstract from the aquifer”. If more water than 35% is abstracted, groundwater level will drop down, which will cause drying of lakes and streams. Therefore calculated two abstraction area, normal, and large for the water intake of about 35% from aquifer. In order to calculate a large area of water abstraction, amount of water intake was divided by 0,35. Knowing the amount of abstraction water, transmissivity of aquifer and gradient of terrain is possible to calculate the dimensions of abstraction area. Abstraction area for wells 80.321, 80,217, 80,352. Point of stagnation XL= 94,20500021 m Width of abstraction area by the well YL= 295,8037006 m Width of the abstraction area up stream YL,opl= 328,6707785 m Abstraction area A= 800200 m2 Abstraction area for wells 80.321, 80,217, 80,352. (for abstraction only 35% of water) Point of stagnation XL= 269,1571434 m Width of abstraction area by the well YL= 845,1534304 m Width of the abstraction area up stream YL,opl= 939,0593671 m Abstraction area A= 2286285,714 m2 The second abstraction area is almost 3 times bigger than first one. Knowing XL,YL,YL,opl is possible to calculate X which is length of abstraction area: X= 2503m X 0,35 = 2392m Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 19 In the result of calculation, length of "35%" abstraction area is shorter than the length of "100%" abstraction area. In reality it is impossible. Therefore length of “35%” abstraction area were increased to length of “100%” abstraction area. Theoretical model of abstraction area were used to calculate size of real abstraction area. figure 3.4 shows the theoretical model of abstraction area. Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 20 4.2.4.1. Resultant of wells location. Abstraction area are made for three wells, therefore need to calculate the resultant point of wells location. Data of wells location were taken from JUPITER database. Calculation also takes into account volume of water extracted by each well. figure 3.5 Shows the localization point of resultant of wells location. Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 21 4.2.5. Map of abstraction area The performed Abstraction area shows places from which water is taken to Rønde waterworks. The area is located northwest from Rønde. This place should be protected from contamination, because it is risky, otherwise the contamination may get to groundwater, and later during abstraction to waterworks. In the area of abstraction, there are mostly fields. The biggest risk is connected with fertilizers. Some part of abstraction area is urbanized, therefore it should be looked for potential contamination e.g. gas station, old wells. Picture in the next page. Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 22 igure 3.6 Shows shape and location of abstraction area. Red color shows abstraction area for 100% use of Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 23 groundwater. Blue color shows abstraction area for only 35% use of groundwater. 4.3. Possible location of the new borings To increase water intake capacity e.g. in reason of connects new homes to Rønde water mains, there are 3 possibilities: a) Restore the well number 80.272 This well didn't work because of accident with pump which fell down in the bottom of well. Probably, there is some way to remove this pump, and resume water extraction even though this procees can be very expensive.. b) Make new boring near to well 80.352 Huge water level drop ( 33,7 m ) suggests that well 80.352 don't work properly. Probably the problem is with the screen which is not enough deep in layer of sand and gravel. New boring with screen located more deep in aquifer, will help to extract more water from this aquifer. c) Find new aquifer To find new well protected aquifer it should be made geophysical surveys, like CVES to know upper layer of soil and TEM to know better deeper zones in ground . Figure 3.6.1 Possible new abstraction area Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 24 Figure 3.7Shows the suggested location of new borings. Pipes which transport raw water to the waterworks are very expensive. Therefore the new wells should be located close to the waterworks. Suggested area of new exploration is located north from well 80.352. This area keeps a distance from farms main buildings, houses, and surface water reservoirs, so the risk of contamination is lower. The problem can be pesticides. Additional problem can be get permission from landowners to make new well, so it is good that the searching area is located on several different fields. Moreover well located in this area will have different abstraction area than existing wells, some part of area can be the same but most of abstraction area will be different. Which means that the bigger amount of water can b Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 25 5. Intake Wells Intake wells are used to collect water. The raw water is pumped to the waterworks, and after standard treatment it goes to individual and industrial customers. To understand better raw water quality and risk of contamination is important to know construction and location of the wells. Also the volume of water which we can abstract is related with sizes of the screen in well. Rønde Vandvær currently uses 3 intake water wells to extraction of ground water, fourth well (80.272) is currently not used. Well 80.352 is about 360m away from water treatment station, other wells are located next to water treatment station building. figure 2.1 shows the location of intake water wells in Rønde. 5.1. Wells technical specifications : Information of each well will be presented below. This information will be used in calculations. Geological data collected during making boreholes will be used to made geological profile of the aquifer, and to evaluate aquifer vulnerability to contamination. Information about wells was got from Jupiter databases and Google Earth. Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 32 6.3. Calculations The following table parameters were calculated and it is possible to find formulas in the Water Chemistry Enclosure . Parameters were evaluated according to Danish water criteria. WELL NUMBERS UNITS PARAMETERS Symbol 80.217 80.272 80.321 80.352 - Date 2009 1996 2009 2009 - Ion Exchange ( I ) I 1,53 1,72 1,34 1,54 ION EXCHANGE ION EXCHANGE ION EXCHANGE ION EXCHANGE - Degree of Weathering (F) F 0,85 0,73 0,83 0,36 - Hardness (dH) Middle dH 12,54 10,8 12,82 11,65 - Conductivity 84 83,2 110 95 mS/m Organic Matter NVOC 1,4 1,2 1,5 1,5 mg/L Pyrite Oxidation None None None None - Calcite Saturation Index (logSI) log SI 0,65 0,46 0,59 0,54 - Sulphate Reduction Yes Yes Yes Yes - Acid/Base Water Type Buffered Buffered Buffered Buffered - Redox Conditions D D D D - Ion Balan ce Ca,Mg,Na,K - HCO3 ,Cl,SO 4,NO3 CATIONS 8,59 8,3 11,08 9,51 meq/l ANIONS 8,39 8,28 10,11 9,57 meq/l Charge Balance Deviation % 2,36 0,24 9,16 -0,63 meq/l Figure: Comparing of Parameters 6.4. Parameters Parameters were evaluated according to existing information which was given of the region of Rønde. 6.4.1. Ion Exchange (I) Ion Exchange is occurring by ions that are loosely bound to aquifer solids exchange with ion dissolved in the groundwater. Groundwater becomes enriched in sodium and depleted in calcium by the way changing ions when is ion exchange, and it will be the opposite, when reverse ion exchange is found. This process is a key factor in evaluation groundwater age and vulnerability. Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 33 Aquifer solids with a high density of charges and wide surface areas have the largest ion exchange capacities. All the wells present ION EXCHANGE, which means;  Ion Exchange is still taking place and the system has not reached equilibrium yet  Therefore, the groundwater is old and well protected from surface contamination  High CEC (Cation Exchange Capacity): Clay minerals have large capacities and all the wells are surrounded by clay, meters of clay.  There are limited groundwater flow  Recent freshening  Water is becoming softened because calcium is removed 6.4.2. Degree of Weathering (F) Knowing this parameter is essential to guess if pyrite oxidation exists. It was found that this process is not taking place in any wells. This assumption was made analysing F (Degree of Weathering). Hence, it turned out that F is lower than 1, which is the lower limit to have pyrite oxidation. But not only the pyrite oxidation can change F, some other processes might affect Degree of Weathering which are pyrite oxidation, sulphate reduction and ion exchange. As it can be checked in the Water Chemistry Enclosure F depends on Mg 2+ , Ca 2+ and HCO 3- concentration. Then, any process that affects these concentrations will modify the F as well. It will increase because of pyrite oxidation, hydrolysis and it will decrease because of ion exchange, sulphate reduction. 6.4.3. Hardness (dHº) The kind of hardness identified in all the wells is middle hardness, which matches with the interval of 8-18 dHº. As it can be checked in the Water Chemistry Enclosure hardness depends on the Mg 2+ , Ca 2+ , and some other divalent cations concentration. The long chain is not soluble in water but adequate to dissolve in organic compounds. However, the carboxyl group is able to be dissolved in water. Hardness assignments are used in the control of softening processes. Because, this processes is made with a certain amount of calcium and magnesium. Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 34 6.4.4. Conductivity All results are above Danish water criterion for the all wells. In spite of exceeding this criteria, if the classification of different conductivities given by the Bibliography // is checked, all of them are type of typical. (30-130) Conductivity measures the ability of the water to conduct the electricity, then the more ions we have in the water, the easier the electricity goes through the water and hence, the higher will be the conductivity. High values can be caused by salt water intrusion or landfill leakage. Low values can be found in many rock aquifers or sedimentary aquifers where salt have been leaching out since before last ice age. 6.4.5. Organic Matter ( Non-volatile Organic Carbon ) The wells types are identified according with the Bibliography//, as typical. The highest value is 1.5 mg C/L which is in the typical range. Dissolved organic matter is often measured as non-volatile organic carbon or NVOC, which may give the groundwater a colour ranging from weak tea to black coffee. Also, organic matter is most important parameter ion exchange in the top soil. All of wells’ values are between 1-4 so that, it is type of typical. 6.4.6. Pyrite Oxidation As it was already said before, there is no pyrite oxidation in none of the 3 wells. Pyrite oxidation has taken place by following these parameters:  Sulphate increases to >30 mg/l or higher  Hardness increases above background if carbonates are present  pH may drop if no carbonates are present  Nickel present in the pyrite may dissolve in the groundwater  I value is usually low 6.4.7. Calcite Saturation Index (log SI) By analysing the Calcite Saturation Index it is possible to know if the water is aggressive or not. To identify, if water is aggressive, laboratory measurements may be carried out by simply adding and excess of calcium carbonate to the sample and measuring if there is increasing in the water. If the water is not aggressive, the Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 35 CaCO3 won’t dissolve and aqueous concentrations will remain same. The three Log SI were calculated instead of getting them experimentally. To check how Log SI was calculated, please go to Water Chemistry Enclosure The water extracted from the 3 wells is non-aggressive due to the Log SI > 0. It should be kept in mind that in order to use that formula, some assumptions were made and then the accurate of the equation is ±1. For more accurate results, a geochemical model must be done. 6.4.8. Sulphate Reduction In order to determine if sulphate reduction has already taken place, knowing that the water type is D, it is assumed that the background sulphate concentration in the area is 30 mg/l. The sulphate concentration in all the three wells is less than 30 mg/l. If it would decrease then it could be guessed that the sulphate reduction in fact,is taking place. However, this concentration decrease could be also because the sulphate reacts with the iron in water, and form FeS, so the reason of the decrease should be checked. In order to be sure that this assumption is correct, other parameters such as, degree of weathering or HCO 3- , H 2 S concentration, which can be affected by the sulphate reduction should be checked. Then, If the concentration of hydrogen carbonate is higher than 300 mg/l, the Degree of weathering, F, decreases usually to below 1 values or there is hydrogen sulphide and methane in the water, then that will say there is sulphate reduction. There is no data about methane or hydrogen sulphite concentration in water, so no presence of these gases in the water can be guessed. Nevertheless, hydrogen carbonate concentration is higher than 300 mg/ l and F is in fact smaller than 1. The conclusion is there could be sulphate reduction in the three borings. 6.4.9. Acid/Base Water Types In order to know the kind of water which is extracted from the wells, it is necessary to take a look at the water ph. The result is the water is Buffered which means that the pH is between7-8.5. (For more information about buffered in the Water Chemistry Enclosure). It is OK for each wells and it is proper for treatments. Buffered water type is characterized by:  Neural pH  Saturated with calcite  Medium to high hardness Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 36 They are buffered so that, groundwater used for drinking water typically has a near neutral pH. If there is calcite in the soil layers, the acid may be neutralized. In time, the buffer may be used up, and the aquifer material loses it is buffer capacity . 6.4.10. Redox Conditions To know the redox condition of the water, an algorithm was used. It is possible to find it in the Water Chemistry Enclosure. All of wells are type of D which means ‘’strongly reduced’’ which is correspond to sulphate reduction. 6.4.11. Ion Balance If Ion Balance value (the charge balance deviation) is less than 5%, the sample is suitable and there is no ions problem . It is possible to find more information about this calculation in the Water Chemistry Enclosure. Therefore, wells of 80.217, 80.272 and 80.352 have not ions problem, but well of 80.321 has ions problem. It means that here, the charge balance deviation more than <5. Thus, the calculation shows inaccurate results. 6.5. IDENTIFICATION OF CRITICAL PARAMETERS AND EFFECTS OF HEALTH It is enough to take information about groundwater which is about stable or not, by looking at nitrate, sulphate as well as calculated parameters degree of ion exchange and degree of weathering. Depending on the severity of the contaminant, different treatment will be used. We can find the some critical parameters below in the Figure. Figure: Potentially critical parameters Advanced: Naturally- Occurring Parameters Advanced: man-made Contaminants Standard Treatment Salt Nitrate Iron Fluoride Chlorinated Solvents Manganese NVOC Pesticides Hydrogen Sulphide Arsenic Methane Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 37 All categories are not equally serious. Critical parameters are categorized under 3 titles. One of them is naturally-occurring parameters, man-made contaminants and treatment. Naturallyoccurring and contaminant parameters are very important because, it is very hard to remove it from water but, iron, manganese, hydrogen sulphide and methane, which are treated in standard treatment. 6.5.1. Salt Salt problem is occurring by high values of sodium and chloride. It is one of the most common quality problems in groundwater. Danish criteria are set to avoid a salty taste. It is very important parameter for drinking water because consumers don’t want to drink tasteless water. According to criteria , value of sodium has to be lower than 175 mg/l and chloride has to be lower than 250 mg /l. For the present water, all results are showing good quality about salt content. Present water quality is not including bad property, but it is important to follow pressure between drinking water and salty water. Additionally, it has caused to some important healthy problems like hypertension, cardiovascular, kidney disease. Also, using of salty water in industrial processes may result in corrosion. Because of this reasons, the amount of salt should be controlled. 6.5.2. Nitrate It is very basic compound for nitrification processes so that control is necessary because it is the part of natural cycle. It is possible to find more information in the Enclosure of water chemistry Exceeding of 50 mg/l Nitrate is undesirable, also our results are very low according to this criteria. According to results, nitrate level is below 0.05. It is possible to find information about contamination of nitrate in the section of 6.6. A possible explanation for such a low concentration is that the aquifers are quite well protected, and the intrusion of nitrates by filtration is very difficult. 6.5.3. Arsenic Today, naturally-occurring arsenic is perhaps the most serious health threat found in groundwater. It is affecting to millions of people in the world. This compound is reasons of some significant diseases like heart problem, cancer, kidney disease and mental problems. According to our results, one of the wells is above the criteria. It is not too much which is 5,7 and criteria is 5, but it should be checked for future. Actually, İt will be removed in standard treatment , therefore it is not occurring problem for now. Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 38 6.5.4. Fluoride Fluoride has low values for all wells. It is available to find more information about fluoride in the Enclosure According to results; all results are below the criteria but, for number of 80.352 which is very close to criteria. Amount of fluoride is about 1.4 for the well but criteria is 1.5. For preventing of some health problems in the future, we have to continue to control it carefully. 6.6. Four critical compounds of over the criteria According to results of groundwater, iron, manganese, ammonium and total-P are higher than criteria for all wells. These are key compounds for various processes and treatments. So that control is necessary for substances. WELLS 80.217 80.321 80.352 DANISH CRITERIA STANDARD TREATMENT SUBSTANCES IRON 2 2,1 1,1 0,02 Filtration MANGANESE 0,12 0,11 0,061 0,05 Filtration AMMONIUM 0,68 0,78 0,64 0,05 Filtration TOTAL - P 0,18 0,19 0,054 0,15 Biological or Advanced Figure: Comparing of 4 compounds according to Danish criteria Total-P is over the Danish criteria, but it is very close to limit. So that it does not necessary to use Biological or Advanced Treatments only for these low upper-amounts. A standard filtration is enough to get rid of this phosphorous. If the concentration were increased, some advanced treatment would be necessary. All of these compounds are removed in standard treatment. There is no need advanced treatment with present water values. Additionally, it is necessary to treat arsenic for wells of 80.321. You can find more information in the part of Treatment. Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 39 6.7. Contamination of groundwater It is the one of the reasons to change quality of groundwater. Among the main causes of groundwater contaminations are: agriculture (nutrients and pesticides), industry (chlorinated solvents), the military (explosives), the energy sector (hydrocarbons and radioactive materials), municipalities (landfill organics) and even home owners (fuel oil from leaky underground Storage tanks) Figure: Area of contamination around the wells As shown in picture, there is available some buildings near the wells. Therefore, firstly their wastes should be kept under control. Secondly, area seems like suitable for agriculture so that a certain part of region’s water supply, agricultural activities are prohibited or allowed in part. For the animal effects, precautions should be taken with signboards and fences. Finally, all the wells are well-protected which means, that is difficult to change their chemical properties by filtration of pollutants from the surface. Furthermore all the area was taken under control to prevent changing of water quality. It is possible to find more details in the Geography part of the project Contamination of Nitrate: It is available to see where, is nitrate density of contamination. We can see there are 3 kind of density of nitrate and red point is describing to Rønde Waterworks. There is exist of class of nitrate 1 around Rønde Waterworks, south-east is class of three and north-east is not including nitrate contamination. Class 1 means which requires about % 15 reduction in the flow. Also, class of three requires % 50. Figure: Nitrate contamination regions Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 40 Contamination of Phosphorus: Brown area is describing contamination but other regions do not show any contamination about phosphorus. Figure: Contamination areas of phosphorus Also, there is a central built which is for heating of Rønde and it may be depended on oil tank so that some problems can be occurred like leakage into the soil so that it is necessary to control it. 6.8. Conclusion Generally, according to comparison of parameters, region is very useful area. Results are showing stable water with time series. Exactly, it is not enough to give decision stable or not. Also, for all the samples were checked for the other years. There was not a big change in the results. Some parameters were above the Danish criteria. These parameters are iron, manganese, nitrate and total-P. They are not like naturally-occurring or man-made parameters. It is not hard to remove them water, they will be removed after standard treatment. Contamination is very low around Rønde waterworks, but there is a field near waterworks and it has a potential risk for contamination about contamination of pesticides. Also, there is a factory which is central heating for Rønde. It is necessary to know what kind of production of heating available there. Additionally, area is well-protected with fences and aquifers. Additionally, because of the sand aquifer, there is low contamination. As a result, result of water quality, abstraction area and region is fit for water supply. Denmark is an advanced country about groundwater in the world. Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 41 7. Water Treatment description The water is pumped up from the well with a pump whose model is unknown. Once it is in the surface, it’s driven to the aeration system through a pipe network. There, oxygen is added making the water to fall down through a cascade, which is composed of four steps, this way water is enriched with oxygen and gasses are stripped from it. Underneath, there is a small reaction basin, to give the water and its components time to react with the oxygen. From this basin the water goes through three filter beds by gravity. In this stage, iron, manganese, some phosphorous and other metals are removed. This is the last step from all the circuit, after this process the water is taken by pumping to one storage tank in the plant, and from there to two others storage tanks located in down town. Figure 7.0 Flow Diagram of the waterworks 7.1. Aeration In the aeration stage, oxygen is supplied to the water to ensure that it contains the minimum oxygen necessary for the bio-chemical and chemical reactions which take place in the sand filters. Furthermore, aeration has some other benefits for the water quality as improving the taste of the water, preventing the bacteria growth, stripping gases which are not desirable to have dissolved and it ensures aerobic conditions in the pipe lines. Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 48 7.4. Storage Tank Clean water from water work can be delivered into the storage tank in the water work or into the reservoir (water tower) down in the city. There are many reason to install a Storage tank: • Create 2 systems almost independent, the network before and after the storage tank. By doing this, a decrease of the fluctuating demand from consumers by reserving water for periods of high demand is got. When there is a low demand, water gets stored in the tank then, if there is a high demand the pumps from the wells don’t need to work to its maximum power. • Supply water for backwashing the filters. • As a safety agent in case a treatment failure takes place. Then it could still supply water to the costumer for a period of time. • Provide a supply of water during short periods of extreme demand, ie during a fire. Then, a storage tank must include volume for water for fire fighting, for backwashing and to supply to the costumers always keeping in mind a security volume for leakage. Design of volume of drinking water depends on production of water work and numbers of consumers. 7.4.1. Storage Tank Design STORAGE TANK Units m 3 m 3 V com 281,75 285,75 fire 150 150 BW 16,2 20 Tot 447,95 455 Table 7.6 Volumes of the storage tank Then a storage tank with a volume of 455 m3 is needed. The calculation can be checked in the WaterWorks Enclosure. It is known that the shape of the tank is in “L”, however, the dimensions for a rectangular prism were guessed, and presented below: Lenth: 9,7 m Width: 9,7 m High: 4,838 m Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 49 7.5. Conclusion The plant works fine, and can remove all the pollutants in the water by standard treatment with a good efficiency. Then, parameters such as iron, manganese, ammonium phosphorous are removed from the water, and the water which goes out of the waterworks is way below than the Danish criteria for drinking water. However, if more consumers were added, then there would be more water consumption and it could create a problem basically in the filters. If the consumption is increased, the peaks would be higher, and the average flow would also be bigger making the residence time in the filters shorter. Therefore, the pollutants wouldn’t be removed from the water and it wouldn’t pass the drinking water control. Probably the fourth filter would be needed and even they might need a rebuilding to increase its capacity. 8. Water Consumption 8.1.Description In the following of this chapter, we will see that how much water needs for consumption for the present and future in Rønde, Følle and for 500 new consumers. There is possible to find some basic information about water consumption in this section about consumption area, additionally more specific information in the Water Consumption enclosures. There is no problem about available water consumption about current system, but have to be sure about future what it needs, which likes new borings, reservoirs, pipes or pumps. All of these consumption, Rønde waterworks will be used for treatment of groundwater and it is important to know its capacity enough or not. There are 4 wells in Rønde, which are ensuring water for the consumption area . But, one of these wells was closed. So that, there are 3 wells as active. It is an important problem that 3 wells will be enough for future structuring. 8.2 Present Consumption At the moment there is 1500 consumers, also they are consuming about 168.042 m 3 per year. Plus, we have to calculate for future consumption which is for new 500 consumers. It is possible to calculate present and future consumption using by formulas which are below:  The Daily consumption Q = Q m xf d (It is possible to find tables in the Water Consumption enclosures) Q = daily consumption Q m = mean (average) daily consumption f d = day factor (we can take between 1,5-2 also we took 1,75) Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 50 Q m = Q y /d Q y = yearly consumption d = number of days/year Q m = 168.042 m 3 / 365 = 460,389m 3 Q=547,945 m 3 * 1.75 = 805.680 m 3  The Hourly Consumption q = q m * f h q= hourly consumption q m = mean (average) hourly consumption f h = hour factor, we can choose between 1,5 and 2,5 . q m = Q/24 q m = 805,680/24 = 33.670 m 3 q = 33,670 * 2 =67,140 m 3 The Daily consumption 460,389 m 3 The Hourly Consumption 33,670m 3 Figure: Present water consumption (Average) The Daily consumption 805,608 m 3 The Hourly Consumption 67,140 m 3 Figure: Present water consumption (maximum) 8.3.Evaluation of Future Consumption • 500 new consumers: There exists general information which are personal and general consumption from chart of Danish norm values. As we can see that for villages and small industries, person per house is 2,0 -2,7 and water consumption is 150 -180 Liters/person/day. We can calculate two capacity which are minimum capacity and maximum capacity. Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 51 In the future,we will have 500 new consumers and we can reach minimum and maximum population. (Value to be added present population) 500 x 2 = 1000 person (minimum population) 500 x2.7 = 1350 person (maximum population)  The yearly consumption for future Q min =155 Liters/person/day x 1000 person x 365day/year x 1m 3 /1000 Liters =56.575 m 3 Q max= 180 Liters/person/day x 1350 person x 365day/year x 1m 3 /1000 Liters =88.695 m 3 The yearly water production is approximately 168.042 m3/y. This means that: Q min.future = 168.042 + 56.575 =224.617 m 3 /year Q max.future = 168.042 + 88.695 = 256.737 m 3 /year It was accepted average of results. About 70.000m 3 /y • Følle: Existing Waterwork and demand is 9000m 3 /y for Følle Totally, future water demand is about70.000+9.000=79.000 ~ 80.000m 3 /year Figure: Chart of future consumption 8.4. Assessment: Present and Future Consumption In the future, it needs providing about 70.000m 3 /year water more for new 500 consumers in Rønde and 9.000m 3 /year for Følle.Totally, water demand will be about 168.042 m 3 /year water. It is necessary to know there is enough capacity of borings. Location of future consumption Capacity ( m 3 /year) 500 new consumers 70.000 Følle 9.000 Total 80.000 ( 79.000 ) Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 52 8.5. Evaluation of Borings According to chart below, total pumping of water is similar with calculation of hourly demand. It means that water consumption is proper for present demand. Borings Pumping(m 3 /h) 80.217 40 80.321 21,6 80.352 16,3 Total 77,9 Figure: Present pumping water capacity of wells According to geology part, there is enough water capacity for future consumption. It is possible to find more information in the //Geology part. 8.6. Time-varying Demands Water usage in distribution systems is unsteady because of the varying demands. The temporal variation in water usage for municipal watersystems typically follows a 24 hour cycle. However, it is not only changes with daily, also weekly and yearly . Figure: Fluctuation of Consumption in Rønde According to diagram, we can see that what is the maximum consumption and what is the daily capacity of consumption. In the picture, there is relatively low usage at night when most people sleep, increase usage during the early morning hours as people wake up and preparing for the day, decreased usage during the middle of Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 53 day .Finally, increasing usage again in the early evening, because people return home from their works. Therefore, mean that there is two picks and water demand will be maximum in this 2 times. 8.7. Conclusion As a result, there is no problem for ensuring of water to new structuring from wells. But, it is necessary to control wells and protecting them. It can be provided with a well water distribution modelling. In this project, Aquis was used for providing of water distribution. 9. Network Network system delivers water from water station to customer. Water must be delivered at right pressure, and without any contamination. Network system consists of pipes, valves, pumps, reservoirs and control equipment. Combination of all these elements together in a well working network is no so easy, requires experience and big knowledge. 9.1. AQUIS model . AQUIS program is used to simulate the waterworks network. With this program can design new networks and also check the operation of existing networks. The program is very complex therefore it's able to show potential problems with newly designed water network. 9.2. Water demands for Rønde. Calculate water demand for Rønde is necessary to calibrate network system. Calculations were made using a database of water demand for each address in Rønde. First step was to find the biggest water customers, then find the nearest node for each customer, and enter their demand into the node. Big customers were assumed to be costumers using more than 500 m3 of water per year. Afterwards the remaining amount of water was split equally between other nodes. Then offline simulation was begun. Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 54 9.3. Calibration For the beginning the problem was with negative pressure in pipes 174 and 162. The reason was bad location of the pumps. The pumps were on higher level than the water reservoir, so there were a negative pressure between pumps and water reservoir. Problem was solved by making additional nodes, at the same lever like water reservoir and placing the pumps between new nodes. figure 9.1 shows change location of the pumps, new location on right. This problem seems impossible to conceive out of the model, an explanation for this high difference was searched. The reason found was that in the reality both pumps are on top of the reservoir, and when the model was created whoever did it, made a mistake. It was also necessary to connect pumps with water reservoirs, so pumping water will began when water lever in reservoirs will be to low. Third pump in waterworks station was switched off because in real world it was never used. Next step was to close down the connection with old water station, and made new pipe to connect two networks in one system. Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 55 figure 9.2 shows new connection between the nodes which connects to networks in one. 9.3.1. Lack of water in reservoirs Lack of water in reservoir caused low water pressure in network during peak hours. This problem was solved by the calibration of the pumps. Pumps in waterworks station start working when the water level in reservoir 283 is lower than 1,8 m and stops when the water level is 2 meters. And pumps located in reservoir 284 start working when water lever in reservoir 83 is lower than 1m, and stop working when level is higher than 1,5m. 9.3.2. Too high pressure in nodes In nodes 122,111,204,116 there was a problem with too high pressure. The problem was solved by adding PRV valve, which reduced pressure in the pipes. Very interesting is that after the addition of several valve next to nodes with high pressure. The pressure increase in the whole network , even the new part in Følle. It suggests that the nodes with high pressure reduce the efficiency of the whole network. 9.3.3. Demand zone weighting factor Calibration was made for demand zone weighting factor 1,0. For factor 1,2 (20% extra just in case) was a problem with negative pressure, because pumps in water station have not enough flow. Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 56 Problem solved changing the pumps but it was modification of network system. Therefore, decided use demand zone weighting factors 1,0 and don't change the network elements. 9.4. New water network in Følle To make the project of a new network, first step is to look at location of roads and buildings to know were various networks elements can be located. Next step is to found a way to transport water to the network. In this project the main pipe will be located in or next to Aarhusvej, because it allows for easy connection to a Rønde network . Følle is a village which used 9000 m3 of water in year. New water network will supply each house in Følle. The pipes and nodes are arranged in way as to be able to supply water to every customer. The dimension of pipes is changing from bigger in the main pipe, to smaller in the end of network branch. Følle will be supplied by Rønde waterworks. figure 9.3 shows new water network in Følle. In the very first moment the new part was created, the pressure in some pipes was too low. It was lower than the minimum required by the Danish legislation. However, after placing the PRV valve in the nodes whose original pressure were too high, the pressure in the rest of the model was within the legal range. Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 57 From figure below it is able to see that there is no pipes with low pressure in Følle, which mean that the network was designed properly and works well. figure 9.4 shows the water pressure in network in Følle. The minimum pressure in nodes and pipes was 12 mcw, and the minimum one established by the Danish criteria is 10 mcw. Furthermore the maximum pressure possible is not reached in anywhere. Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 64 1.3.4.Method The sizes of the filters are 2,7m x 1,8 m and it has a depth of 1,8 m. However, the filter bed depth is 1,0 m. It would be desirable to take samples of water representatives of all the area of the tanks. Five sampling points would be chosen per layer. However, due to lack of material, only one point will be used. This spot should be at least 20 cm away from any wall to avoid any flow disturbance. The temperature of the water is to be measured, because nitrification is highly dependent of it. However, this measurement wouldn’t change a lot from the temperature measurement done before the water enters in the waterworks. This will be chosen as the water temperature. It would also be advisable to take samples every 10 cm of depth, but as it was said before, due to lack of material, samples will be taken in this way: - Outlet (filtered water) - 20 cm from bottom of the bed filter. - 30 cm from the previous point. -60 cm from first point. -Inlet (raw water) There will be 2 samplings day, the first one; right after backwashing the filters. The second one; the day after backwashing. The same amount of samples is to be taken in both days. Legend: -Circle: Sampling place Fig.1.5 Sampling method I Fig.1.6 Sampling method, filter profile. Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 65 Fig 1.7 Sampling method II Having the sample taken, there are two options: 1. Make the measurements in situ 2. Take the samples to a laboratory and make the measurements there. it’s highly recommended to make the measurements in situ because more reliable results are obtained on fresh samples, however, if no car is available it may be difficult to take all the equipment to the waterworks and then the best choice would be to make the measurements in the lab. If the measurement has to be postponed, the samples have to be treated. This treatment consists of: The first aim is to destroy residual chlorine to prevent its reaction with ammonia. To achieve this, 0.8 ml conc. H 2 SO 4 /L sample should be added and then, keep it at 4ºC. The pH of the acid-preserved samples should be between 1,5 and 2. After this treatment the sample can last 28 days before getting spoiled. The recipient to keep the water can be plastic made, or glass. If acid preservation is used, neutralize samples with NaOH or KOH immediately before making the determination. Reference Finally despite of having to take all the equipment to the waterworks, the analysis will be carried out in situ, what makes it easier than treating the samples to take them to the laboratory. It should be at least tested once the sampling and disinfecting procedure before going to the waterworks, in order to be fast and to know how to react for possible unforeseen events. In the waterworks, the disposal suits are to be put on and then, prepare the working area. Place the protective plastic on the floor. Having all the tools disinfected is the previous step to introduce them in the filter. The disinfection should get started as soon as possible because it takes some time to disinfect with the Vikron S and then it should be flushed several times with water to get rid of this agent. Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 66 1.3.4.1.The disinfection procedure The second steel rod must be introduced into the tube where the first steel bar is. Once this is done, the whole set is to be introduced in the disinfecting tube with the rubber cap at the end. With a funnel, approximately 1,5 l of Vikron S are introduced in the tube and from 10 to 15 min are waited. The rubber cap should be watched, because if there is too much weight it will blow up flushing all the disinfecting agent without any control. Once this time has passed by, the flushing is begun. The epoxy stuffed plastic is to be removed and aiming properly to the Vikron S bottle, all the disinfectant is flushed. The same steps must be repeated four times but using tap water to remove all the remaining Vikron S in the tube. To disinfect the steel bars for taking the sand the same procedure is to be followed. The plastic glass to take the sand and the pins are put in a plastic box full of disinfectant for the same time. Then, after 10-15 min tap water. Fig.1.8 desinfectant recipients 1.3.4.2 Placing the tubes After the disinfection, it is time to introduce the sampling device in the filter. As trying to introduce the tubes with the water going down is impossible because the sand is very compacted, the backwash in necessary. The backwash in Rønde starts first with air going up and then water. During the air time, to introduce the tube is fairly easy, so then, the sample device should be placed in the appropriate spot before backwashing and when the air is going through the filter it has to be pushed down until reaching the bottom. Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 67 Fig.1.9 Placing the sampling tool 1.3.4.3.Taking Samples At the same time than placing the tubes, the sample of sand will be taken. Once the bars and the plastic glass are disinfected, they should be mounting together using the bridles and the pins to join de three parts. After this, while the backwashing is taking place, the glass in the extreme of the steel bar is put in the filter and moved to catch the sand. Then the glass is lifted and the sand is kept in a clean plastic glass for posterior experiments. After the backwash period, 10 min later than when the water starts to get filtered; the sampling of water can begin. There can be two sampling directions, from bottom to top, and from top to bottom. The concentration of ammonia in the water is lower in the bottom than in the top. As only one syringe is used, to minimize its contamination due to some remaining water in the syringe, the sampling process is started from the bottom. To homogenize the tubes, they need to be flushed once before taking the sample. The extraction rate cannot be too high, otherwise not only water from this level would be extracted but from many points around the screen. This is not good for the experiment, because it’s desired to know the variation with the depth, then if water from many levels is extracted, a mistake would be made. It was decided that create vacuum every 6 sec was enough fast. For knowing the wanted extracting rate, the filtration speed should be checked. The pumping rate should never be higher than the filtration because a too high negative pressure would be created around the screen and the effect above explained would happen. However, it is impossible to know our extracting rate, then the pumping of the water is done slowly and carefully. As explained before, the vacuum hand pump is used for flushing and pumping up the water and the syringe is used to take the sample. Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 68 Fig. 1.10 taking samples From each sample 2 analysis are made; ammonium detecting and iron detecting. These detections are made in situ with the Kit HACH LCK 304 for iron and ammonium. - For ammonium, 5 ml of water are needed - For iron, 2 ml of water are needed. The concentration obtained by this method will be noted down. To know more about this method, please go to Optional Part 1 enclosures All the samples must be marked properly right after being taken to avoid confusions. The first day only 1 measurement was repeated to check the accurate of the method. The second day, it was decided to start from the top to the bottom. In order to avoid contamination in the syringe, it was flushed once before taking the samples. Then, there were two flushing, one for the cleaning the tube and the other one to wash the syringe, before taking the sample. The flow is to be checked to calculate the HRT of the filters those days. 1.3.4.4.Possible problems and risks Before going to the waterworks, lists with possible problems, risks and solutions for these problems were made. Sampling in the waterworks is not an easy job. There is a big responsibility when a sampling tool is introduced in the sand filter (or in any place inside the waterworks where there is a contact with the water) because many things can happen and there is a risk of polluting the water. This would affect many people due to a possible shut down of the water supply until the water accomplishes the drinking water criteria again or even due to some health problems. Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 69 Here below the lists can be found: • Problems which may happen: 1. Impossibility of putting the sampling tubes in the filter or to the end of the filter bed. 2. Clogging of the small screen. 3. Loss of some parts of the tool when introducing or taking out. 4. Drop of some items (watch, rings, bracelets..) in the water. 5. Rupture of some parts of the sampling tool. 6. High variations in the ammonia analyzed. 7. Analysis of the water carried out wrongly. 8. Disassembling of different parts. 9. Break down of the syringe/pump 10. Entrance of air through the joints 11. Contamination of the sample due to a bad cleaning of the syringe 12. Holes along the tubes • Possible solutions to the problems: 1. The sampling tubes will be placed during the backwash, when the sand is being loosened. If it s still impossible to do, a screwing movement could make it easier 2. Let go some of the water which is in the tube, this way there will be a loss of pressure and the particles in the screen can go out of the slots. 3. Handle the tube very carefully, and having something ready to pick up the possible thing which can fall down nearby, just in case. 4. All the personal items should be left in a bag before handling the tube. 5. It will depend on what part is broken, it could be replaced, removed and go on without it and as the worst possible case, take out all the tube and renew it. 6. Measure ammonia in more than 1 sample, so average can be calculated. It is also possible to take samples again. 7. Take new samples and start the measurements over again. 8. Make sure that all the parts are correctly assembled with clamps. Lift the tube slow and carefully. In case some part disassembles, if it occurs inside of the sand filters, wait to next backwash when it would come to the surface. If it’s out of the filter, we would be in point 3. 9. Renew it or just pump up the water using the other method. (only syringe or just vacuum hand pump) 10. Make sure all the joints are properly well closed and isolated. 11. The sampling should be started in the spot which is the deepest due to the lowest concentration of the 3 points. After every sampling the syringe should be shacked and flushed to try to get rid of all the water remaining inside of it. 12. Patch it. Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 70 • Hypothetical risks during sampling. 1. Contamination of the water. 2. Bad filtration while the tubes are inside of the sand filters. 3. Bad filtration due to the extraction speed used. 4. Some part of the sampling tool stays stuck in the filter and cannot be floated. With all these for risks a chart evaluating them was made: Risk Probability Impact Result 1 Low Hig h Medium 2 High Very low Low 3 Medium Very low Low 4 Very low Medium Low Table 1.1 Risk evaluation As it can be seen, all the risk had a small importance. Please note that this evaluation was done since a subjective point of view, it can change with the person doing it. 1.3.5.Experimental Hydraulics in the filter Day 1 Day 2 Flow(m3/h) 34 32,4 FR (m/h) 6,99 6,67 Real Velocity (m/h) 17,49 16,67 EBCT (h) 0,143 0,15 T res (min) 3,431 3,6 Table 1.2 Experimental hydraulics in filters For checking the calculations, go to Optional Part 1 enclosures The extraction speed should never be faster than the real velocity, because then water from everywhere next to the sampling place will be extracted and the result wouldn’t be representative of that level. However, it was impossible to know if it was being pumped up faster or slower than this real velocity. Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 71 1.3.6.Conclusions Water was taken from inlet, outlet and from three different levels in the filter. The three levels were called I, II, III according to the sampling order. Therefore, (I) was used to call the lowest point, (II) middle point and (III) was the point the closest to the surface. Here below, the concentration obtained as results can be checked in the Optional Part 1 enclosures As the flow in both days were different, in order to compare the capacity of the filter right after backwashing and one day later to remove ammonia and iron, all the concentration should be changed into mass flow: - First Day: Spot Fe (g/h) NH 4 + (g/h) Fe (g/h) NH 4 + (g/h) Raw 64,26 17,612 3 10,574 0,748 2 17,068 4,59 14,178 4,046 1 11,016 0,306 Outlet 4,012 0,51 Table 1.3 first day concentrations - Second Day: Spot Fe (g/h) NH 4 + (g/h) Fe (g/h) NH 4 + (g/h) Raw 68,364 17,172 3 27,3132 8,6184 16,9128 8,424 2 12,1824 3,8232 9,6228 3,1104 1 4,4064 0,0324 5,508 0,0324 Outlet 3,8556 0,0648 Table 1.4 second day concentratios During the sampling the first day, only one sample could be taken twice and spot (II) was chosen as sampling point. The reason why this level was chosen is because it was in the middle of the filter and there would be less possible interferences there. However, in the second day, a second sampling round was done to see how accurate the sampling system was. Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 72 The representation of these data can be seen right below. Graph 1.1 Mass flos vs spot Graph 1.2 Mass flow vs spot II Day X.Y means in what day the samples were taken, and if it was the first or second time in that day. As it can be seen in the graph, there is a reduction of ammonia and iron while the water goes deeper just as it was supposed theoretically at the beginning of the experiment. One of the things should be marked is the iron speed removal in the filters, it has a high iron removal speed at the beginning of the filter. From the raw water to the first point, which is only 20 cm under the surface, there are 40 g of iron less. However this velocity gets slower and slower. The graph could fit a exponential curve. Despite of the fast change in the mass of iron, the variation of the mass of ammonium is not very big with depth, the concentration of ammonium doesn’t change fast, or at least not as fast as in iron removal. From the raw water to the Spot III around of 9 mg of ammonium is lost. It gets proved then, that the concentration of either ammonium or iron gets reduced with the depth. However, the nitrification rate variation is not very big with depth, the concentration of ammonium doesn’t change fast. However in the spot III as it can be seen, some strange thing happens, the concentration of both, iron and ammonium, are very low. Some explanations for this effect were thought: 1. As all the sand particles were loosened the flow between particles doesn’t go straight, the paths where the water goes the easiest through are not done yet, then it could be that the water taken during sampling of Spot II was running around a bigger area than normally and that is why this sample has a less concentration of ammonium. 2. The extraction rate was too high, too much water was extracted in a short period of time during sampling, and due to a high negative pressure, water from much under the screen was taken, having this water less concentration as it should the water in this spot. That’s why the concentration is more similar to the next point. Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 73 3. It is known that the pumps stopped and resume working at least twice during sampling. This can affect the concentration of ammonium and iron because is straight related with the residence time. Then, it could happen that one of the pumps stopped working in some time before taking the samples in III (15 min earlier), so the residence time of the water taken in III was higher than for II or I. As it was wanted to compare the nitrification two graphs were made to compare adequately the amount of ammonia and iron between days: - For Ammonium: Graph 1.3 ammonium comparetion between days Analysis of the graph: If a one hour period is to be analyzed, then as it has been said before, is quite evident that the mass of ammonium obtained per level gets reduced going deeper in the filter. It can be seen that in the first day, the day when the backwash took place, there is always more mass of ammonium than in the second day. Only one spot breaks this fact, the Sport III has more mass of ammonium in second day than in the first one. The possible explanation for this is explained in the previous page. However, the ammonium found in the raw water is also higher. Then it cannot be said 100% sure that the nitrification rate was higher the second day than the first one. The difference of mass is almost constant in all the spots, even the same in the raw water and treated water. Hence, the relation between backwash and nitrification is certainly not clear enough to get a conclusion. Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 80 Then, if it is believed that the turbidity is a constant in the eight samples, the parameter which is changing is the concentration of ammonia what makes the color to change. As it has been said before, to get inside of the range, all the samples were diluted. The volumes of the nine samples were taken to 20 ml what makes the samples four times more diluted than the original dissolution. Then, 5 ml of the new concentration were taken and measured in the spectrophotometer. t(min) C(mg/l) C real (mg/l) 0 3,02 12,08 12 2,81 11,24 20,5 2,52 10,08 37 2,03 8,12 57,7 1,85 7,4 88 1,65 6,6 128 1,52 6,08 193 1,43 5,72 380 1,41 5,64 Table 1.5 Concentratios and time As it can be observed, the concentration which was measured is much higher than the original one, what doesn’t make sense, unless the original dissolution had then a fake concentration. Then, a failure in the scale was more likely than in the spectrophotometer, hence, the original concentration was decided to be 12,08 mg N /l. In the table from above, the increment of the waiting time between samples, which was described before, can be observed. To know if it was made an error diluting the samples, it was decided to dilute one of the samples even more, and see if it made sense. The sample of 12’ was driven to a volume of 40 ml, what makes it to be 8 times more diluted than the original and twice more diluted than the first dilution. The result: C v=20 = 2,81 mgN/ l C v=40 = 1,52 mg N/l Theoretical concentration: 1 · 1 · 2 · 2  20 · ,   2 · 40; C 2 = 1,405 mgN/l As it can be seen the real actual concentration is a bit higher than the theoretical one. But it was decided to say that the error wasn’t too high to reject the method. This problem is assigned to the error which is caused by the turbidity. Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 81 To check if there was any problem with the spectrophotometer, some pure water was introduced to analyze its ammonia. The result was 0 mg N/l, so a hypothetical failure in the machine was rejected. Three days later, the tube samples were found with a light brown precipitate (iron and manganese loosened in the sand filters). This light brown precipitate is the agent which caused all the turbidity in the samples and made impossible to know the exact concentration of ammonia. Fig1.15 Sand Settled As the beam used in the spectrophotometer goes through the dissolution some higher than the precipitate, it was possible to determine in a more accurate way the concentration of ammonia. However, as three days had passed by, the concentration of nitrogen then was not the same as the beginning, but measuring the absorbance with the sand both settled and in suspension could give us an idea of how big was the error due to the turbidity and apply a corrector factor to the concentration obtained the first day, being the result: t(min) Creal (mgN/l) 0 12,08 12 10,2273874 20,5 9,408 37 7,35073684 57,7 6,61647059 88 5,57806452 128 5,15751724 193 4,54235294 380 4,48704425 Table 1.7 time vs Real Concentration Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 82 1.4.5. Conclusions Plotting all those results in a graph: Graph 1.5 Concentration real vs time Graph 1.6 Concentration vs time theoretical As it can be seen, the graph has approximately the shape of an exponential curve, which is the kind of form that belongs to a 1 st order kinetic equation. Then it could be assumed that the nitrification process which took place in the sand matches with a kinetic 1 st order equation. However, as it can be checked in the Optional Part 2 Enclosure.many calculations assuming this 1 st order were made, and none of them fitted the assumptions. Furthermore, the equation of the curve was calculated by approximation, and as it can be seen in the formula below, it is different than the typical formula of a 1 st order. How this equation was got is explained in the Optional Part 2 Enclosure.   0,23   ,  4,45 Formula 1.2       Formula 1.3 It should be kept in mind that the results aren’t completely right. They are always approximated to the real ones. A comparison between the graph obtained with the results and a graph extracted from another experiment, but with the same aim, was made. In that experiment, the objective was to know the hydraulic characterization of the filters in a waterworks in Flanders, the northern part of Belgium. In order to accomplish this, a tracer test (Froment and Bishoff, 1990) performed on one of the biofilters was used to determine the hydraulic behavior of the biofilter. With this tracer test the number of (perfectly mixed) tanks in series that correspond to the actual reactors hydraulic behavior is determined. For this tracer test a pulse of 4 mgN/ℓ ammonium was added to the influent of one of biofilters. Over a period of 2 h the effluent ammonium concentration was measured every 2.5 min. Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 83 Graph 1.5 Concentration real vs time Graph 1.6 Concentration vs time theoretical If the nitrification process was first order equation, the half-life time, which is the time it takes to get the half of the original concentration of the reactive agent, would be the same, independent of the reactive agent original concentration. Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 84 However, it is not like this: Half - life T ime (t 1/2 ) Theoretical Flanders Experiment 15,47 min. 35 min 74,47 min Table 1.8 Half life time If the different t (1/2) were to be compared, the conclusion would be that the half life time from the experiment is higher, what means that the nitrification rate is slower. If the formula for the 1 st order of the half life time is used, the K of the process is easily calculated: T 1/2 = !   " #  !  $/& = 0, 00931min -1 Formula 1.4 It can be checked that the K calculated by this procedure, is different than the K calculated in the equation of the curve. This is another reason to say that it is not a first order kinetic equation. Furthermore, the results from the experiment were tried to fit in a 2 nd order equation, but neither had they fit. Hence, it can be concluded that the nitrification order reaction n, is 2 < n >1. It easily appreciate that there is a big difference between the two practical graph and the theoretical one, while this last one tends to 0, the two firsts, tend to something less than their 50% concentration. This could be caused by the inhibition of the bacteria in charge of the nitrification either by a pH drop due to the oxidation of the ammonium and the consumption of the alkalinity of the water or because there was a high ammonium concentration. It was calculated that in around 2 hours the ammonium in water should be in a very low concentration, but as it was seen in the experiment, the last sample was taken 6 hours later than the beginning and the concentration seemed still high. One possible explanation for this effect could be that the ammonia concentration in the water from the wells is 10 times lower than the dissolution which was made, and too high concentrations of ammonium can inhibit the process. Another inhibitor can be the lack of oxygen, but it needs to be less than 1 mg/l of oxygen, and it is very unlikely that this could happen in the experiment. Then, it can be said as a conclusion that the real nitrification rate in the sand is much slower than the theoretical calculated. Despite all this, the main point would be that there was a fact which hadn’t been taken into consideration, the iron and manganese rests which were in the sand and that interfered in all the measurements. The entire conclusion depends on this, what makes it a critical factor. Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 85 1.4.6.Possible improvements If this experiment has to be done, there would be some things which are to be changed. • In order to reduce the particles in suspension in the water, the mixing of the water in the last 4 samples was done 5 min before taking the sample. During the mixing of the water, all the particles which had settled in the sand are in suspension again. By giving them some time to settle again, it is possible to reduce the turbidity in the water which will go inside of the cuvette. It could be a good idea to increase the time between mixing the water and taking the sample, being always careful of not mixing it too much time ahead of the sampling moment because then the water wouldn’t be representative of the concentration in the filter. If the time between samples is one hour, 10 min before sampling a mixing could be a good idea. • One way to minimize the turbidity could be making the sampling water to go through a filter paper and therefore, holding the particles in the paper. To do this, it would be necessary then, to take more water. • For trying to reduce the impact of the iron and manganese rests in the sand, more water could be used. Instead of using 0,2 l sand and 0,2 l water, it could be helpful to use 0,2 l sand and 0,4 l water. However, doing this the oxidation of all the ammonium would be even slower due to the increment of it. This can also be done by adding a dissolution more diluted than the original, but instead of just 0,2 l putting the volume needed to reach the total mass of ammonium which is in the original dissolution. • Instead of using the kit LCK 304 whose capacity was a bit small, maybe it could be better to dispose of some other materials and for example use the Nessler reactive to analyze ions of ammonium. More details in Optional Part 2 Enclosure. • In general, it would be great to have some more material to use, such as more testing tubes, glasses, and any tool used to measure volume. • It would be a good idea to measure the pH of the dissolution over time. • Measure the temperature should be done at least once during the experiment. A compilation of pictures taken during the second part of the experiment can be found in the end of the enclosures or in the attached CD-ROM. Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 86 General conclusions • Well protected aquifers. This was checked by 2 different ways, the geological profile and the analysis of the water. • To provide more water: • Restore old well (80.272) • New wells next to the (80.352) • Investigate new abstraction area • Water status: quite stable. • Main contaminants: Fe, Mn, NH4, P, Ar. • Waterworks work fine. • There might be possible bottlenecks in: reaction basin, sand filter and storage tank if the water demand increases ( and it is expected to do so). To increase the capacity of the waterworks, a new reaction basin should be built, the 4 th filter bed should be open and if the demand is too big, a new storage tank should be planned. • The simulated network works properly. However the model creator did a quite bad work. There are many mistakes in the model provided. • Adding extra costumers in the area of Folle doesn’t have a negative influence in the whole network . Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 87 2. Enclosures Geology Transmisivity calculations Transmissivity was calculated using following formula: Calculation for wells: figure 1.1 shows the calculation of transmissivity for well 80.321 Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 88 figure 1.2 shows the calculation of transmissivity for well 80.217 Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 89 figure 1.3 shows the calculation of transmissivity for well 80.272 Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 96 figure 2.8 shows the construction of the well 80.352, and geological profile Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 97 figure 2.10 shows the construction of the well 80.321, and geological profile. Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 98 figure 2.3 shows the construction of the well 80.321, and geological profile . Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 99 Water chemistry Enclosures 1 ……………. Evaluation of Water Enclosures 2 ……………. Processes in Groundwater Enclosures 3 ……………. Parameters Enclosures 4 ……………. Calculations Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 100 Evaluation of Water Quality 1. Comparison of Parameters WATER QUALITY PARAMETERS WELL FIELD 1 WELL FIELD 2 Units Danish Water WELL NO. 80.217 80.272 80.321 80.352 Criteria DATE 2009 1996 2009 2009 CONDITION PARAMETERS Symbol Conductivity 84 83,2 110 95 mS/m 30 pH 7 ,7 7,6 7, 6 7 ,6 pH units - Temperature T 9 ,3 --- 9.1 9, 8 ºC - CHEMICAL MAIN COMPONENTS Ammonium NH3+N H4 0,68 0,73 0,78 0,64 mg/l 0,05 Calcium Ca 70 57 72 62 mg/l - Carbondioxid,Aggr. CO2 < 2 <2 < 2 < 2 mg/l 2,00 Carbon,org. NVOC NVOC 1,2 1,2 1,5 1,5 mg C/l 4,00 Chloride Cl 93 90 150 120 mg/l 250,00 Fluoride F 0,9 1 1,1 1,4 mg/l 1,50 Hydrogen Carbonate HCO3 323 320 344 352 mg/l - Evaporation E 480 490 610 540 mg/l - Iron Fe 2 1,7 2,1 1,1 mg/l 0,20 Potassium K 4,2 4,7 4,8 5 mg/l 10,00 Magnesium Mg 12 12 13 13 mg/l 50,00 Manganese Mn 0,12 0,1 0,11 0,061 mg/l 0,05 Sodium Na 92 100 130 120 mg/l 175,00 Nitrate NO3 <0.5 < 0,5 < 0,5 < 0,5 mg/l 50,00 Nitrite NO2 <.005 0.012 < 0.005 < 0.005 mg/l 0,10 Oxygen Content O2 < 0,1 1,10 < 0,1 < 0,1 mg/l 5,00 Total-P P 0,18 0,12 0,19 0,054 mg/l 0,15 Sulphate SO4 23 24 23 20 mg/l 250,00 INORGANIC TRACE ELEMENTS Arsenic Ar 0,4 --- 5,7 2,50 µg/l 5,00 Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 101 Barium Ba 74 --- 110 58 µg/l 700,00 Bor B 430 --- 590 610 µg/l 1000,00 Nickel Ni 1,6 < 2 0,18 0,36 µg/l 20,00 PARAMETERS Ion Exchange ( I ) I 1,53 1,72 1,34 1,54 - Degree of Weathering (F) F 0,85 0,73 0,83 0,36 - Hardness (dH) Middle dH 12,54 10,8 12,82 11,65 Conductivity 84 83,2 110 95 mS/m Organic Matter NVOC 1,4 1,2 1,5 1,5 mg/l Pyrite Oxidation None None None None - Calcite Saturation Index (logSI) log SI 0,65 0,46 0,59 0,54 - Sulphate Reduction Yes Yes Yes Yes - Acid/Base Water Type Buffered Buffered Buffered Buffered - Redox Conditions D D D D - Ion Balance CATIONS 8,59 8,3 11,08 9,51 meq/l ANIONS 8,39 8,28 10,11 9,57 meq/l % 2,36 0,24 9,16 -0,63 meq/l Theoretical Oxygen Demand 80.217 80.272 80.321 80.352 Oxygen Oxygen Oxygen Oxygen PARAMETERS (SUBTANCES) Concentration ThOD Requirement Requirement Requirement Requirement Units mg/L mg O2 mg O2/L mg O2/L mg O2/L mg O2/L Iron 2 0,14 0,28 0,238 0,294 0,154 Manganese 0,12 0,29 0,0348 0,029 0,0319 0,01769 Ammonium 0,68 3,60 2,448 2,628 2,808 2,304 Methane 0 4 0 0 0 0 Hydrogen Sulphide 0 0,51 0 0 0 0 Oxygen (Residual) --- - -- 5,50 5,50 5,5 5,5 Total Oxygen Reguirement --- - -- 8,26 8,40 8,6339 7,97569 Figure: Chart of the comparison of Parameters Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 102 Variations of Elements NH 4 (Ammonium) Figure : Variation of Ammonium Generally, changings are resembling each other. They are making pick at the same time. Fe (Iron) Figure: Variation of Iron Results are unstable for 80.217 but it is not too high. For other wells, variations are watching same way but values are different. Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 103 P (phosphorus) Figure: Variation of phosphorus For phosphorus, wells of 80.217 and 80.352 results are very close to the limit. (0,2- Danish water criteria). Also, for 80.321, results are low and stable. Mn (Manganese) Figure: Variation of Manganese 80.217 and 80.321 are close to limit also little above criteria. 80.352 is under the limits. Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 104 Ar (Arsenic) Figure: Variation of Arsenic For arsenic, limit is 5 for Danish drinking criteria. 80.217 and 80.352 are under the limit but they are almost increasing year to year. Also, 80.321 is over limit and it is increasing. It is necessary to know that why it is increasing. This element is occurring very important health disease so that it has be controlled. Additionally, it is mentioned in the mandatory part. Conclusion Generally, results are showing a stable case, but some section increases requires control. 2. Processes in Groundwater The quality of groundwater is the result of processes in solids react with one another. Some of groundwater processes: 1. Ion Exchange 2. Pyrite Oxidation 3. Dissolution of Minerals 4. Sulphate Reduction Figure: Processes in groundwater Rønde Drinking Water Marcin The quality of groundwater is the result of processes in which gasses, dissolved constituents and solids react with one another. Some of groundwater processes: Pyrite Oxidation Dissolution of Minerals Sulphate Reduction Processes in groundwater Rønde Drinking Water B6PMI2 Marcin -Mehmet- José Antonio 105 which gasses, dissolved constituents and Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 112  HARDNESS • Results: Figure: Categories of hardness  CALCITE SATURATION INDEX WELL NO. 80.217 80.272 80.321 80.352 Hardness 12,54 10,8 12,82 11,65 Interval Category 0-8 Soft 8-18 Middle 18-32 Hard >32 Very hard Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 113 • Results  ION BALANCE The charge balance deviation = According to formula, if result is lower than 5, it means that the calculation indicates somewhat inaccurate results. • Results: % 2,36 0,24 9,16 -0,63 meq/l * % = The charge balance deviation  Conductivity Figure: Categories of conductivity  Organic Matter Interval Value (mg C/L) low <1 Typical 1-4 Elevated 4-10 Brown water >10 Figure: Categories of organic matter WELL NO. 80.217 80.272 80.321 80.352 Log SI 0,65 0,46 0,59 0,54 Interval Value (mS/m) Low salt content < 30 Typical 30-130 Elevated salt content >130 Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 114  pH Conditions Acid/Base Water Type Value (pH Units) Acidic <4.5 Aggressive 4.5-7.0 Buffered 7.0-8.5 Alkaline >8.5 Figure: Categories of pH conditions  Fluoride (F) Chemistry Fluoride is a halogen, defined as corrosive, pale greenish-yellow gaseous chemical element, the most reactive non-metallic element known, forming fluorides with almost all the know elements, organic and inorganic. Health Effects Dental fluorosis appears in a very small percentage when fluoride in drinking water is in the range of 1 -2 mg/l Long term intake of fluoride in concentrations higher than 4 mg/l may cause asymptomatic osteosclerosis in a small percentage of persons. Crippling fluorosis has been detected in individuals exposed to fluoride levels from 10-40 mg/L No carcinogenicity or other adverse effects have been detected. Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 115 WATER CONSUMPTION 1. Description Water consumption is basically the use of water in any form for any reason. It used in irrigation, cleaning, cooking and some cases...etc. There is two ways for consumption. One of them is in-stream use; this includes hydroelectric power, boating and swimming like that. For example; if there is no in-stream activities don’t use up the water. It is possible to degrade the water quality through pollution. The second one is the withdrawal of water, which is valid for us in this project. Also, it is including: • Household Use • Industry Use • Consumption in institutions • Additional consumption (backwash, leakage/pipe burst, fire fighting, pipe flushing ,cleaning) • Irrigation • Nuclear Power The amount of water that is taken (or withdrawn) from the source is called the water intake, and the amount that is returned is called the water discharge. The difference between the water intake and the water discharge is the amount consumed.  Consumption = Water intake – Water discharge The total amount of water that is used is called the gross water use. The difference between the gross water use and the water intake is equal to the amount of water that is recirculated. The recirculated amount is expressed as a recycling rate and is a good indicator of water efficiency.  Amount recirculated = Gross water use – Water intake What is the cause of high level of water consumption? That is why environmental and economic problems. About environmental, which is occurring because of high consumption places stress on rivers, lakes and groundwater aquifers and may require dams and flooding with serious ecological impacts. On the economic side, high-level of consumption requires increasing expensive systems. These systems are like dams, reservoirs, water treatment facilities, distribution networks and sewage treatment. Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 116 According to chart, Denmark uses very less water than other countries per person. Also, other information is that water use is increasing some other OECD countries (Canada25.7 %, United States, Japan and Mexico) but, Denmark was able to decrease overall water use since 1980. (these researches from // environmentalindicators.com ) Figure: Freshwater abstractions per Capita in cubic meters 2. Type of Consumptions and Charts 2.1 Data, Households It means that water consumption in buildings primarily used for housing. Also, minor industries or minor institutions can be accepted in this group. There is 2 types of household consumption is available: 1. Personal Consumption 2. General Consumption 1. Personal Consumption: It is including drinking, cooking, hygiene, cleaning, watering) 2. General Consumption: It is including in offices, shops, minor industries) Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 117 Figure: An example of single household Personal and general consumption between 2.0 – 2.7 person per house (Danish Norm Values) Figure: Data for Household 2.2 Data, industries (norm values) In this type, water consumption in buildings that primarily is used for business and industry. Consumption may be changeable business to business, even though in the same line of production. Single households in an industry building may therefore count as industry consumption. Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 118 Figure: Data for industries 2.3 Variation in Consumption If there is no available data about consumption, the following day factor and hour factors can be used: f d Figure: Day and hourly factors according to category of consumption Note: These factors are generally too high! Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 119 2.4 Additional Consumption Consumption in waterworks for backwash, pipe flushing and cleaning of fire fire-fighting. Leaks and pipe bursts: Waste measured as %, if waste of water is over %10 then a penalty tax is imposed. 3. Demand Types Baseline demands during a steady-state simulation do not change over time. But, in reality water demand varies continuously over time according to time scale. This scale is occurring of daily, weekly, seasonal and long-term time series.  Daily - Water use varies depends on course of a day.  Weekly - Weekend patterns are different from weekdays.  Seasonal – It depends on seasonal changes, such as tourism, consumption is very changeable season to season.  Long-term – Depends on changing in population and area. Some examples of demand types: • Average Day Demand: The average rate of demand for an average day. • Maximum Day Demand: The average rate of use on the maximum usage day. • Peak Hour Demand: It depends on maximum rate of usage. • Maximum Day of Record: The highest average rate of demand for the historical demand. Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 120 Figure: An example of variation for consumption We can see the pick point which means that point is rate of maximum consumption in a day. (Q max. = 5.8 m 3 /y). Also, a line is dividing variation which is giving us average demand. (Q middle = 2.5 m 3 /y) NETWORK – WATER DISTRIBUTION MODELLING 1. Description Model-based simulation is a method for mathematically approximating the behavior of water distribution systems. Water distribution models have many different types of nodal elements, including junction where pipe connect, storage tank and reservoir nodes, pump nodes and control valve nodes. Also, it is possible to create a chart below about elements of network. Element P rimary Modelling Purpose Reservoir Provides water to the system Tank Stores excess water within the system, and release that water at times of high usage Junction Removes ( demand) or adds (inflow) water from/to the system Pipe Conveys water from one n ode to another Pump Raises the hydraulic grade to overcome elevation differences and friction losses Control Valve Controls flow or pressure in the system based on specified criteria Figure: Common network modelling elements The goal of Modelling  A common database structure to ensure data can be correlated and cross referenced.  One database to contain all data Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 121  Well defined structure and outline  Easy to expand  No information is to be registered twice (or thrice..)  Easy update and use of data  Reduced need for conversion of data Figure: Cycle of Network Modelling To give an example of the network model: AQUIS EPANET Differences between them, AQUIS is more up to date. Also, project was carried out according to AQUIS . 2. Definitions of Common Network Elements 2.1 Reservoir Reservoir can supply or accept water with such a large capacity that the hydraulic grade of the reservoir is unaffected and remains constant. Reservoirs are used to model any source of water where the hydraulic grade is controlled by factors other than the water usage rate. For a reservoir, two things are required; 1. Hydraulic grade line Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 128 Figure 1.3 shows calculation of water demand for each node. Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 129 Figure 1.4 shows calculation of water demand for each node in Følle. Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 130 RISK ASSESSMENT OF NETWORK Many conditions exist that may result in degradation of water quality in the distribution system. It is possible to have problems like cross-connections, corrosion, biological growth, bursting pumps, closed valves, pumping failures etc. Using a model, operator can simulate what is occurring at any location in the distribution system under the full range of possible conditions. There are some programmes, which are monitoring programmes for following of distribution. Also, maps are helping for identifying problem and location. But, it is not available for each point. In this case, it is needed to make local measurements. First of all, measures should be taken to protect equipment. Figure: Maintenance Source of Contamination: Physical Chemical Biological Shavings Plastics Dust Radioactive fallout Pesticides Natural substances Solvents Coliform Animals/insects Pollen Pathogenic bacteria Figure: Sources Some points to consider There is possible some critical problems and need to control:  Leakage in distribution system  Power failure Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 131  Contamination of supply facilities  Threats of sabotage  Fire and explosion Figure: Pipe burst Technical problems It is possible to have some kind of technical problems in network. These problems can be occurred in a wide variety of network elements like; reservoir, tank, pipe, pump, valve, intersections etc. Reservoir  Generally, reservoir can be built strong against risk of earthquake and vibration of some reasons (exactly, very low probability of earthquake in Denmark)  The need to secure against the risk of sabotage  For preventing of problems, need covering and protecting reservoirs. For example reservoir’s inlet and outlet using for sampling so that we have to protect these points.  We have to check; access hatch, ventilation, filters and concrete.  Cleaning sludge in sedimentation basin Figure: Reservoir in Rønde Pipe Pipes are like vessels in distribution system. It needs to be clean, steady and safe. Sometimes, it canbe damaged due to leaks, water quality, microorganisms, sabotage, earthquake etc. For example, ‘’red water ‘’ problem is due to iron which should be checked for preventing corrosion. Location of leaks Rarely, forces water to surface so that it is sometimes hard to find location. A leak gives a hissing sound therefore sometimes it is possible to hear its voice. Generally, the leakage water of region should be closed for repairing pipes and night hours must be chosen. Also, a special material can be chosen for leakage location. Firstly, trouble place can be cut and this material will be used for that point. Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 132 Repairing of pipes Firstly, turn the water off as soon as you release there is a problem. Valve is possible to use for turning water off. Pump Check:  Controlling yield (Q), pressure and power consumption  Protection against outside influences  Flow-meters  Valves  Pressure transmitter  Pressure switch Figure: Pump in Rønde Reservoir Valve It is necessary to control valve is opened or closed. Otherwise, some problems may occur;  It has to be closed while flushing pipe  Also, while pump is running, the necessary valve must be open Low pressures It is very significant and widespread problem in distribution systems. Because, low pressure can be occurred because of the some reasons. In general, poor pressures tend to be caused by inadequate capacity in a pipe or pump, high elevations, or some combination of the two. To be followed such a problem:  Making operational changes such as opening valves  Changing pump settings  Locating and repairing any leaks  Cleaning pipes  İnstalling new tank Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 133 WaterWorks Theoretical oxygen demand (mg O2/mg) Concentration mg O2/l mg O2/l mg O2/l mg O2/l Well 217 272 321 352 Iron 0,14 2 0,28 1,7 0,238 2,1 0,294 1,1 0,154 Mn 0,29 0,12 0,0348 0,1 0,029 0,11 0,0319 0,061 0,01769 NH4+ 3,6 0,68 2,448 0,73 2,628 0,78 2,808 0,64 2,304 H2S 0,51 CH4 4 TOD 2,7628 2,895 3,1339 2,47569 mg O2/l Maximum Oxygen demand: 3,1368 Minimum Oxygen Demand: 2,47569 Average Oxygen Demand: 2,79079667 Volume of oxygen needed: '()  *  +,-- ./ 0123  6440 2/5 Mass flow of air: 677 , 30666,7 2 9:; /5 Reactions in filters In the filters, some chemical reactions take place: Fe 2+ + 0 2 + H 2 O  Fe(OH) 3 + ½ H + 2 Mn 2+ + O 2 + 2 H 2 O  2MnO 2 + 4 H + NH 4+ + 2 O 2  NO 3- + H 2 O + 2 H + Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 134 Hydraulic in filters There are the formulas used to calculate the different parameters: .<  = > ;,  ?@ ! AB'  >C = ';-  AB'  3 Where: Q= Flow A= Area n = Porosity = 0,4 D= Depth Backwash period Concentration of Iron in raw water c Fe [mg/l] was taken from Jupiter database. Surface area of sand filter Area [m 2 ] was calculated. Flow of raw water Flow [m 3 ] was taken from Appendix 1 CFe TotalArea Flow Fe Load Run lenght Period Per iod Units mg/l m2 m3/h kg Fe/m 2 /h kg Fe/m 2 d m 3 Average 1,73 14,58 32,9 3.9 ·10 - 3 0,5 5,3 4213,62 Water needed for backwash: 40 m/h · 4,86 m 2 · 5min · 1/60 = 16,2 m 3 Storage Tank Dimension To calculate the Volume for the consumers: Q max,day = 805 m3/day  V com = 0,35 · 805 = 281,75 m 3 To calculate the volume of water needed for backwash please go to enclosure . Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 135 The water for case of fire is set up as 150m 3 . The Authorities should say if it is enough. m3 m3 Vcom 281,75 285 fire 150 150 BW 16,2 20 Tot 447,95 455 Optional Part: Experiment I Screen test Three different kinds of screens were provided to the group. To know which one was the best, a recreation of the sampling situation in the waterworks was done. To do this, 2 m of tube with a diameter equal to the tube which would be used in the waterworks was used. In one of its extremes the screens were plugged and in the other the syringe to extract the water. The side of the tube with the filters was introduced in a test tube half-full of sand and water. The first conclusion obtained was the difficulty of introducing the tube in the tube and with only 7 cl of water above it. The sand got very compact really fast and it made impossible to put the tube inside of it. The first screen tested was the one with the biggest separation between cuts: - It wasn’t difficult to extract water - It didn’t clog fast The second screen was the other cut tube: - It wasn’t difficult to extract water at the beginning, 2 syringes later it became more and more difficult - When the tube was taken out of the test tube, the screen was with lot of particles, it was almost clogged. The pierced tube: - It wasn’t difficult to extract water, and actually, it was easier than with the first one. - It didn’t clog and when it was taken out, it was completely clean. The tube chosen was the pierced one. It was checked that there wasn’t any problem of extracting water with the syringe having a headloss of 2 m. A problem was found during the test, a piece of soft plastic used to avoid the inlet of air while flushing the syringe failed when it was used 4 or 5 times. Bridles should be used to avoid this problem. Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 136 Virkon S Key Information Virkon® S, the premier broad spectrum virucidal veterinary disinfectant, is recognised by industry and governments worldwide as a disinfectant of choice for livestock disease prevention and control. Virkon® S has a unique formulation; no other disinfectant has the same powerful composition. In terms of efficacy Virkon® S has been proven highly effective against 65 strains of virus in over 19 viral families, 400 strains of bacteria and over 100 strains of fungi. This list of proven efficacy includes the major OIE List A diseases of concern; Avian Influenza (H5N1), Newcastle Disease, Classical Swine Fever (Hog Cholera) and Foot and Mouth Disease. Virkon® S’ versatility provides the flexible solution for; surface, water and aerial disinfection, in hard water, on porous surfaces, at low temperatures and in the presence of organic challenge. UK DEFRA Approved - Foot and Mouth Disease, Swine Vesicular Disease, Diseases of Poultry and General Orders Powerful - independently proven effective against viral, bacterial and fungal disease causing organisms including the lethal H5N1 Avian Influenza Virus. Fast-acting - a one percent solution of Virkon® S is independently proven to kill bacteria with contact times as low as five minutes and the tough to kill parvovirus in ten minutes or less. Versatile - surface, equipment, vehicle, footdip, water delivery system and aerial disinfection. Independently proven effective on porous surfaces, in hard water, at low temperatures and in the presence of organic challenge. Readily soluble in tap water , Virkon® S dissolves into a pink solution. An environmentally acceptable product with an exceptional safety profile towards man and animals when used and disposed of as instructed on the label. Transport and storage - being a powdered disinfectant formulation Virkon® S can be swiftly transported by air and can be stored for long periods making it the ideal choice for stockpiling in bulk. Mode of Action DuPont™ Virkon® S does not elicit a specific toxicological effect on the target organism, instead it achieves deactivation and/or destruction of the target organism through general oxidative disruption of key structures and compounds vital to normal activity (e.g. proteins and lipids). Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 137 There is no evidence to suggest that bacterial disease causing organisms develop resistance towards Virkon® S as opposed to other disinfectant types. Composition Virkon® S is meticulously controlled during the manufacture process to be a balanced, stabilized blend of peroxygen compounds, surfactant, organic acids and an inorganic buffer system. Disposal Do not allow Virkon® S disinfectant solutions to enter watercourses. Dispose of Virkon® S, disinfectant solutions directly to foul sewer. Independent studies have shown that diluted Virkon® S should not, when used as directed, pose any threat to sewage treatment facilities. Kit HACH LCK 304 Determination of Nitrogen: 5 ml of water are needed. It is added into a cuvette with the two others reactive agents. It needs to be shaking for 15 min to complete the chemical reaction, and then the absorbance of the remaining substance is measured. Principle: Ammonium ions react at pH=12,6 with hypoclorite ions and salycilate ions in the presence of sodium nitroprusside as a catalyst to form idophenol blue It should work in a pH 4-9 and in a 20ºC temperature. Determination of Iron: 2 ml of water are needed. It is added into a cuvete with the other reactive agent. It needs to be shaking for 15 min to complete the chemical reaction, and then the absorbance of the remaining substance is measured. Principle: Iron(II) ions form an orange-red complex with 1.10-phenanthroline. Any Iron(III) present in the water sample are reduced to iron(II) by Ascorbic acid before the complex is formed. Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 144 When 15 min were taken, the graph was slightly different. However taking 10 min, the equation of the graph was exactly the same. Then it was decided that the waiting time between samples should be inside of the 10-15 min range. Furthemore, as only 10 kit were available to take samples, it fits perfectly to take a sample every 10 min. Water in sand calculation. Some sand is taken from the recipient where it was kept. It’s weight is measured in an accurate scale. (Remember to tare first the recipient where the sand is going to be hold) After 4 days it’s weight is measured again. All the water is supposed to have evaporated. This sample of sand can also be put into a oven, to ensure that all the water is gone, but one have to be careful because more elements in the sand, such as organic matter, can burn too and then it will be a mistake to think that all the difference in the weight is because of water. W o –W 4d = W water `J`7a `J · 100  % weight of water in the sand. Where: W o = Sands weight at the beginning 6,NR, `6,NJ · 100  24,92% W 4d =Sands weight after drying the sample W water =Weight of water. Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 145 Calibration of the results To try to avoid the problem of the turbidity, the results were calculated in base of the raw water analysis. The operation made: U,:d;.  2,76 2/ · ;, 12,08 2/ t(min) C(mg/l) Creal (mg/l) Ccalibr . (mg/l) 0 3,02 12,08 2,76 12 2,81 11,24 2,56807947 20,5 2,52 10,08 2,30304636 37 2,03 8,12 1,85523179 57,7 1,85 7,4 1,69072848 88 1,65 6,6 1,50794702 128 1,52 6,08 1,38913907 193 1,43 5,72 1,30688742 380 1,41 5,64 1,28860927 The graph Ccalibr. Vs. Time was plotted: However, all this wasn’t used for further calculations. Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 146 Nessler method to measure Ammonium in water The Nessler reactive agent (potasium iodium mercuriate) in presence of ammonium ions gets discomposed, and it forms di-mercury ammonium iodine, what allows a colorimetric determination of ammonium ions. Reactive Agents: • Extra demineralised water, without any ammonium ions. • Nessler Reactive agent: Weigh the following quantities for 100 ml: o Mercury II red iodine(HgI 2 ) 10 g o Potassium iodine (KI) 7,5 g o Sodium hydroxide (Na(OH)) 20 g The KI should be added over the HgI 2 and the 100ml water. Once it is dissolved, the NaOH is to be added. All this mixing should be done under an extractor fan due to the mercury; it is really toxic and easy to inhale. • 1 g/l nitrogen Standard solution: Weigh 3,82 ammonium chlorine and reach 1000 ml with demineralised water. • 0,01 g/l nitrogen Standard solution: Take 10 ml from the previous standard solution and reach 1000 ml with demineralised water. Calibration Curve: Take six 50ml volumetric flasks: Flasks 1 2 3 4 5 6 Std 2 (ml) 0.5 1.0 2.0 3.0 4.0 5.0 Deminer. Water (ml) 49.5 49 48 47 46 45 mg N/l 0.1 0.2 0.4 0.6 0.8 1 Nessler (ml) 2 2 2 2 2 2 Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 147 Let all the dissolution to rest 10 min. Make all readings in a spectrophotometer in a 425 nm wavelength. There should be also a white sample, what is the same as before but instead of adding some nitrogen standard solution only 50 ml demineralised water. After all the measurements are done, a calibration curve is to be done, always including all the results in base the white sample. This curve will give the concentration of nitrogen expressed in mg/l. To get the results in mg NH4+/l, they should be multiplied by 1,29. Rønde Drinking Water B6PMI2 Marcin-Mehmet- José Antonio 148 3. References http://kort.arealinfo.dk/ http://www.sc.ehu.es/ Google Earth GEUS Jupiter Database http://airy.ual.es/fisica/Seminario.pdf P.E., Zuane D. J., Drinking Water Quality Walski, T. M. ,Chase D. V. and Savic D. A. ‘’Water Distribution Modelling ‘’(First Edition), HAESTAD PRESS, Waterbury, CT , U.S.A. http://www2.dupont.com/DAHS_EMEA/en_GB/products/disinfectants/ http://www.selba.org/EspTaster/Ecologica/Agua/ http://www.stanford.edu http://www1.uprh.edu/quimgen/Cinetica.pdf Literature from lectures Standard Methods for the examination of water and waste water, American Public Health Association.