The Contribution of Engineering in Advancing Sustainable Urban Infrastructure and Environmental Impact Assessments in Nigeria and South Africa: A PRISMA Systematic Review

449 Nigerian Research Journal of Engineering and Environmental Sciences 10(2) 2025 pp. 449-464 p ISSN: 2635-3342; e ISSN: 2635-3350 Review Article The Contribution of Engineering in Advancing Sustainable Urban Infrastructure and Environmental Impact Assessments in Nigeria and South Africa: A PRISMA Systematic Review 1Samuel-Ekpe, I.N., *2Afabor, A.M., 3Olaye, M., 3Onyiruika, O.F., 4Ikikiru, D.F. and 1Ufuoma, O.G. 1Department of Civil and Water Resources Engineering, Southern Delta University, Ozoro, Nigeria. 2Department of Materials and Metallurgical Engineering, Southern Delta University, Ozoro, Nigeria. 3Department of Industrial and Production Engineering, Southern Delta University, Ozoro, Nigeria. 4Department of Agricultural Engineering, Southern Delta University, Ozoro, Nigeria. *afaborm[email protected]g http://doi.org/10.5281/zenodo.18061487 ARTICLE INFORMATION ABSTRACT Article history: Received 29 Sep. 2025 Revised 11 Oct. 2025 Accepted 20 Oct. 2025 Available online 30 Dec. 2025 The rapid urbanisation of cities presents both opportunities and challenges for sustainable urban infrastructure development. This systematic review explores engineering contributions to sustainable urban infrastructure in Nigeria and South Africa, focusing on environmental impact assessments. Given the unique hurdles faced by African nations, including limited resources and infrastructure, innovative engineering solutions are essential. The review highlights engineering's vital role in minimising environmental impacts, reducing carbon footprints, and promoting resource efficiency within urban development projects. By analysing existing literature and identifying gaps relevant to Nigeria and South Africa, this study aims to understand how engineering practices and policies influence sustainable infrastructure development and environmental assessments. Key research questions include the extent of engineering contributions to sustainable urban infrastructure, the ecological consequences of these initiatives, and best practices for addressing sector challenges. The findings indicate that South Africa concentrates on equitable urban infrastructure development postApartheid, while Nigeria's investment aims at resilient urban infrastructure driven by rapid population growth and urbanisation. These insights are designed to support policymakers, engineers, and stakeholders in promoting resilient urban ecosystems and attaining the United Nations' Sustainable Development Goals. © 2025 RJEES. All rights reserved. Keywords: Sustainable urban infrastructure Nigeria South Africa Environmental impact assessment Systematic review 1. INTRODUCTION The rapid urbanisation of cities as centres for economic growth and cultural diversity presents significant challenges for urban infrastructure, encompassing power, electricity, and the handling of 450 I.N. Samuel-Ekpe et al. / Nigerian Research Journal of Engineering and Environmental Sciences 10(2) 2025 pp. 449-464 waste (Unegbu et al., 2024). Sustainable urban development is critical to meet the demands of current and future generations while protecting the environment, in sync with the United Nations' goals for sustainability, specifically the 11th Goal (Sustainable Cities and Communities) and the 9th Goal (Industry, Innovation, and Infrastructure) (Unegbu et al., 2024). Engineering is vital in this context, offering innovative solutions in reducing environmental impacts and enhancing resource efficiency (Banso et al., 2023). By developing resilient urban infrastructure, engineers can significantly contribute to economic development and social well-being (Ikiriko and Dapa, 2023). Effective town planning can also address the pressures of urbanisation and improve residents' quality of life. African nations, particularly Nigeria and South Africa, confront unique hurdles in sustainable urban infrastructure, including rapid urbanisation, limited resources, and inadequate facilities. Despite advances in infrastructure development, many nations confront issues such as inadequate finance, inadequate maintenance, and environmental damage (El-bouayady and Radoine, 2023). Current research on sustainable urban infrastructure has primarily focused on developed countries, leaving a gap in understanding the specific issues faced by African nations (Lindley et al., 2018; Nnaemeka-Okeke, 2016). There is a need for comprehensive studies comparing the experiences of Nigeria and South Africa regarding sustainable urban infrastructure and environmental impact. This systematic review will explore: (i) the role of engineering solutions in developing urban infrastructure in Nigeria and South Africa, (ii) the environmental consequences of these developments, and (iii) how engineering practices and policies affect sustainable infrastructure development. The review aims to identify best practices, challenges, and provide recommendations for policymakers and stakeholders. 2. THEORETICAL FRAMEWORK 2.1. Overview of Sustainable Urban Infrastructure Development Urbanisation strongly influences the restructuring of urban infrastructures across multiple aspects. With a projected global population increase of 26% from 2019 to 2050, most of this growth will take place in cities. Although urbanisation rates are rising across all continents, only Africa is anticipated to continue growing over the next 50 years. Rural-to-urban migration, rising birth rates, settlement reclassification, and demographic transitions are all driving this development forward (El-bouayady and Radoine, 2023). Africa, which has over 1 billion people, is currently facing severe issues as a result of an increase in urban population, which puts strain on existing infrastructures (UN-Habitat, 2025). As urban systems develop, the need for sustainable urban planning becomes vital (UN-Habitat, 2025). This approach stresses balancing economic, environmental, and social factors to ensure urban environments meet current needs while conserving resources for future generations (El-bouayady and Radoine, 2023). Sustainable urban planning aims to use resources efficiently and maintain economic growth without harming the environment. 2.2. Engineering Solutions in Sustainable Urban Infrastructure Engineering contributes significantly to sustainable urban development by creating infrastructure projects that minimise environmental impact, lower carbon footprints, and enhance resource efficiency. This approach supports local economic growth, reduces energy consumption through innovative designs, and fosters green industries (El-bouayady and Radoine, 2023). The aim is to reduce carbon dioxide emissions in metropolitan areas by lowering emission levels and enhancing energy conservation, while also encouraging the utilisation of green energies. Green infrastructure, including natural and semi-natural networks, is crucial for sustainability, as is the protection of natural ecosystems and the establishment of green spaces (Lixu et al., 2025). Green roofs and urban landscaping are examples of key efforts, as is boosting sustainable mobility alternatives such as cycling and transit systems (El-bouayady and Radoine, 2023). Socially, sustainable urban design aims to offer equal accessibility to basic services such as medical care, schooling, and shelter for everyone, irrespective of their economic background (El-bouayady and Radoine, 2023). 2.3. Environmental Impact Assessment in Urban Infrastructure Development Environmental impact assessment (EIA) is essential for resilient urban facilities construction, as it evaluates potential impacts and identifies mitigation strategies. In Nigeria and South Africa, EIA has been utilised to 451 I.N. Samuel-Ekpe et al. / Nigerian Research Journal of Engineering and Environmental Sciences 10(2) 2025 pp. 449-464 assess the impacts of urban projects on the health of the public and ecology. However, it's important to examine the burdens and ecological impacts associated with the materials and processes used in sustainable practices to achieve optimal outcomes. Life Cycle Assessment (LCA) (Figure 1), recommended by ISO 14040, is a valuable method for quantifying ecological issues, collecting material impact data, and aiding in sustainable design and construction (Reyhani et al., 2024). Despite its effectiveness, the limited studies on LCA within African contexts, especially Nigeria and South Africa, present challenges in demonstrating the sustainability of these systems. Figure 1: Life cycle impact assessment methods overview (Hou et al., 2024) 2.4. Challenges and Opportunities in African Countries Poor execution, insufficient agency collaboration, and little public involvement have historically plagued urban planning in African countries (Ikiriko and Dapa, 2023). Problems like political unpredictability, corruption, and a lack of technological know-how make these problems worse. Many cities prioritise shortterm economic gains over sustainable development, leading to disorganised expansion, traffic congestion, pollution, and declining urban living standards (Nnaemeka-Okeke, 2016). In Nigeria, urban planning is particularly challenged by underfunded infrastructure, insufficient public transportation, and a lack of skilled personnel, undermining the execution of urban policies (Unegbu et al., 2024). Public involvement in the planning process is minimal, often resulting in plans that don’t reflect community needs. Additionally, weak enforcement of regulations leads to illegal developments and unplanned settlements, exacerbated by bureaucratic inefficiencies and corruption. Water supply and sanitation facilities are inadequate, with frequent shortages and poor sanitary conditions. Waste management systems are inefficient, contributing to environmental and health issues due to accumulated waste (Lixu et al., 2025). Housing shortages force many into slums lacking basic services, compounding the challenges of urbanisation (Reyhani et al., 2024). In South Africa, urban issues are influenced by the legacy of apartheid, yet many are similar to those faced across Africa. With a rapidly growing number of residents living in cities, expected to increase from 62% to 71.3% by 2030, the country grapples with unsustainable urbanisation and its associated challenges (Helen and Gumbo, 2022). The rapid and unplanned urbanisation in South Africa poses significant sustainability challenges, particularly in managing the utilisation of resources to satisfy the accommodation and physical amenities demands of urban dwellers. The country's colonial and apartheid histories have led to inequitable urban development and continue to influence planning practices since 1994. The apartheid system, rooted in white supremacy, systematically oppressed the black majority and restricted their development (Van der Berg, 2017). Because of this, many South African cities still exhibit the effects of this planning system, which include growing 452 I.N. Samuel-Ekpe et al. / Nigerian Research Journal of Engineering and Environmental Sciences 10(2) 2025 pp. 449-464 poverty and marginalisation, insufficient basic services, and socioeconomic and geographical segregation (Helen and Gumbo, 2022). 3. METHODOLOGY 3.1. PRISMA Methodological Approach A widely recognised framework that promotes reproducibility, clarity, and transparency in systematic scientific reviews is the PRISMA approach (Olaniran et al., 2025). The PRISMA Protocol provides researchers with a comprehensive guide and process model to aid in identifying, screening, and selecting studies for inclusion in a systematic review (Page et al., 2021). The structured methodology of PRISMA significantly enhances reviews in the fields of engineering and energy, enabling a thorough and objective integration of various research studies. (Alberha et al., 2020) To afford academics, policymakers, and industry stakeholders a detailed and dependable evaluation of the contribution of engineering in the longterm growth of urban infrastructure in African nations, particularly Nigeria and South Africa, following the PRISMA 2020 standards will facilitate the creation of a robust and transparent synthesis of the existing literature. 3.2. Search Strategy and Inclusionary/Exclusionary Guidelines To ensure a comprehensive review of engineering's role in sustainable urban infrastructure and environmental impact assessments in African countries, particularly Nigeria and South Africa, specific inclusion and exclusion criteria were established. The inclusion criteria focused on research published in the last ten years (2015–2025) to capture recent advancements. Only peer-reviewed journal articles and professional sources were considered for their reliability and quality, while English-language publications or translations were required for consistency. Non-peer-reviewed materials, editorials, articles in press, notes, opinion pieces, and theses citing data primarily from before 2019 were excluded. The main sources for this review were two databases: Web of Science and ScienceDirect, chosen for their extensive collection of high-quality research. The search employed keywords such as "Sustainable urban infrastructure development," "Environmental impact assessment," "Nigeria," and "South Africa," yielding 1,298 results. After removing duplicate entries with the Zotero reference management tool, 1,170 articles were retained for the initial stage of the systematic review. The data represented in Figures 2 and 3 were derived from this analysis. Figure 2: Distribution of items by database Figure 3 illustrates the annual growth of publications, indicating a notable interest in the topic in 2025, which underscores the significance of this research. The number of publications has consistently increased from 50 in 2015 to 302 in 2025, demonstrating a growing scholarly attention and advancements in sustainable urban infrastructure development. Likewise, Figure 4 shows the distribution of publications by subject area, with Environmental Science, Engineering, and Medicine and Dentistry having the highest number of publications. 652 (50.23%) 503 (38.75%) 143 (11.02%) ScienceDirect Web of Science Other Search Engines 453 I.N. Samuel-Ekpe et al. / Nigerian Research Journal of Engineering and Environmental Sciences 10(2) 2025 pp. 449-464 The research team conducted a thorough double evaluation of all articles based on established inclusion and exclusion criteria to minimise bias. Key data points extracted included urban infrastructure development, challenges, opportunities, efficiency, and renewable integration. Following a full-text review to find relevant papers, the first stage of screening entailed evaluating abstracts, titles, and keywords for relevancy. The selection process was IN or OUT, where IN denotes complete adherence to the inclusion criteria and OUT denotes non-adherence. This straightforward grading process enhances consistency in article assessment. Any discrepancies in scoring among reviewers were resolved through discussion. Ultimately, 420 articles (35.9% of the total) met the inclusion criteria, with only twenty-one advancing to final evaluation. The process stages are outlined in Figure 5, detailing the journey from research discovery to the final selection of high-quality publications. Figure 3: Allocation of items according to year of publication Figure 4: Distribution of items by subject area 3.3. Data Extraction and Analysis Methods 3.3.1. Study design The systematic research techniques discussed in this article consist of thematic assessments and comparisons. This article uses a comparative case study methodology and focuses on urban infrastructure 454 I.N. Samuel-Ekpe et al. / Nigerian Research Journal of Engineering and Environmental Sciences 10(2) 2025 pp. 449-464 projects in large South African cities like Johannesburg and Cape Town, as well as important Nigerian cities like Lagos and Abuja. Figure 5: The Study’s flowchart based on the PRISMA 2020 protocol 3.3.2. Data gathering The core information for this study was collected through interviews with urban planners, engineers, and policymakers in Nigeria and South Africa to examine project implementation and challenges. Additional information came from government reports, academic research, and publications from international organisations like the UN and World Bank regarding infrastructure projects and environmental assessments. According to Fei et al. (2021), 12 interviews are sufficient for qualitative research, as this number typically reaches a saturation point. The interviews included eleven senior academics with knowledge of the SDGs and the building sector, as well as nine industry professionals. Out of about 29 experts approached, 14 agreed to participate. Key data sources included reputable publications, regulatory legislation from Nigerian governing bodies, and reports from global bodies. Notable documents like the Nigerian Urban and Regional Planning Act and the National Physical Development Plan offer vital insights into Nigeria's urban planning regulatory framework. 3.3.3. Data analysis This paper examines the contribution of engineering in the advancement of resilient metropolitan infrastructure in Nigeria and South Africa. It examines the strategies and policies used in engineering, while also assessing their environmental impacts through metrics such as carbon emissions and energy efficiency. Additionally, the study investigates specific projects related to Sustainable Development Goal 11 in both countries, emphasising innovation, scalability, cost-effectiveness, and environmental outcomes. 3.4. The study's limitations Although this study offers insightful information, it is crucial to recognise several important constraints. The research depends on available data that can be affected by issues such as incomplete information and variations in reporting standards between Nigeria and South Africa. To promote transparency, consent was obtained from relevant authorities before conducting interviews. Additionally, potential biases in data from government sources cannot be overlooked. In larger or more diverse areas, analysing data at the municipal 455 I.N. Samuel-Ekpe et al. / Nigerian Research Journal of Engineering and Environmental Sciences 10(2) 2025 pp. 449-464 level may obscure regional differences. Notwithstanding these drawbacks, this study serves as a useful beginning point for comprehending regional sustainability in Nigeria and South Africa, and it can lay the groundwork for future, more focused research and policy development. 4. CASE STUDIES: NIGERIA AND SOUTH AFRICA With an estimated citizenry of approximately nine million, Lagos, once the capital of Nigeria, is the largest metropolis in Africa and one of the rapidly developing towns in the world; thus, this figure will inevitably increase (www.statista.com/statistics). There are a number of densely populated cities in South Africa and Nigeria, two of the continent's most densely populated countries. Nigeria also contains the major cities of Kano and Ibadan, each of which has a population of around 3.5 million and is a major city by all accounts. Around 3.5 million individuals live in Cape Town, South Africa, and Durban, with 3.1 million, is not far behind. Johannesburg is home to two million people, whereas Soweto and Pretoria are home to around 1.6 million people each (www.worldpopulationreview.com). This research analysed urban infrastructure development by examining each country individually, with a specific emphasis on public transportation, green infrastructure, and waste management practices/facilities (Emmanuel, 2022). 4.1. Nigeria More than 70% of Nigeria's greenhouse gas (GHG) emissions come from the country's power sector, mostly from the burning of fuel. The Nigerian government has initiated a project aimed at developing a National Appropriate Mitigation Action (NAMA) for its power sector, focusing on solar energy to achieve the goal of generating 20 GW from solar sources. The initiative builds on existing national policies to enhance private sector participation through public de-risking instruments. It plans to establish the NAMA framework and supportive conditions, validated by implementing a 100 MW solar power plant, ultimately de-risking green energy in the country's energy industry. Additionally, with over 70% of the population relying on biomass for fuelwood, leading to significant deforestation, the project seeks to reduce GHG emissions from fuelwood usage. It promotes sustainable biomass production and the use of improved stoves and kilns, thereby enhancing health, reducing fuelwood demand, and securing multiple environmental benefits through carbon storage and sequestration. 4.1.1. Public transport systems To increase connectivity and reduce traffic, the administration of Lagos State has started a number of infrastructure projects, such as the Lagos Light Rail and motorway extensions. The goal of Abuja's Public Transit Project is to build an integrated Bus Rapid Transit (BRT) network that would improve urban mobility, ease traffic, cut greenhouse gas emissions, and give locals access to reasonably priced transportation (Unegbu et al., 2024). The BRT has significantly reduced the duration of travel and increased the effectiveness of public transportation, making it an excellent example for other Nigerian communities dealing with the same problems. Furthermore, centred-around communities projects like the revitalisation of Oshodi, a significant transportation hub, have resulted in the building of contemporary bus terminals, footbridges, and green areas, substantially improving the area's use and appeal (Unegbu et al., 2024). 4.1.2. Innovations and ongoing projects driving Nigeria’s green transition Renewable energy solutions: With a predicted compound annual growth rate of 9.88% from 2024 to 2034, Nigeria's clean power sector is expanding at an impressive rate. Expected to increase from 3.13 gigawatts in 2024 to 5.01 gigawatts by 2029, the nation's renewable energy capacity will mark a dramatic shift in the energy sector. As reported by Nkalo (2025), Nigeria's solar capacity reached approximately 112 MW in 2023, reflecting a substantial increase over recent years. The country's vast land resources and plentiful sunshine make solar energy a promising solution for meeting energy demands and reducing carbon emissions. By 2050, renewable energy sources, including hydropower, windmills, and solar power, may supply around 60% of Nigeria's energy needs, according to future projections. As part of its promise to reach emission-free status by 2060, the nation is making progress in shifting away from oil and toward renewable forms of energy, especially petroleum gas (liquified natural gas (LNG), compressed natural gas (CNG), and liquefied petroleum gas (LPG)). Important infrastructure projects, including the approximately three billion dollars Kano-Kaduna-Ajaokuta (KKA) pipeline, helped the CNG industry attract over $500 million in investments in 2024 (Ibrahim, 2025). The 456 I.N. Samuel-Ekpe et al. / Nigerian Research Journal of Engineering and Environmental Sciences 10(2) 2025 pp. 449-464 government’s flagship initiative, the Pi-CNG, aims to convert one million vehicles to CNG by 2027, with over 100,000 conversions completed as of April 2025. CNG provides considerable cost benefits, with prices around ₦230 per standard cubic meter, and reduces emissions by 73%. Vehicles powered by CNG also emit 30% lower GHGs than gasoline vehicles (Augusto and Co., 2025). According to experts, using CNG instead of gasoline can save operational costs by 70%. For a journey that formerly cost ₦50,000 with gasoline, commercial carriers estimate reduced expenses of up to ₦38,000. There are still issues, though, such as poor infrastructure (there are just 53 service outlets in operation) and expensive conversion costs (up to ₦1.6 million per car) (Augusto and Co., 2025). The change to green energy extends beyond ecological advantages; it presents significant economic opportunities. The International Energy Agency (2023) highlights Nigeria’s National Renewable Energy and Energy Efficiency Policy, which is expected to increase the proportion of renewable electricity to 23% by 2025, thereby creating thousands of jobs in areas like installation, maintenance, and manufacturing. Nigeria is positioned to take the lead in Africa's renewable energy revolution on this trajectory. A notable advancement in green technology includes Nigeria’s growing investments in renewable energy, especially in solar electricity. The Nigeria Electrification Project (NEP), backed by the World Bank and executed by the Rural Electrification Agency (REA), seeks to connect over 2.5 million people in off-grid regions using tiny solar power plants and residential systems. The Solar Power Naija Initiative, also from the REA, seeks to install 5 million additional connections for 25 million people living in off-grid areas, emphasising energy access for the underserved (Benedicta, 2023). In the commercial and industrial sectors, the Wood Factory Hybrid Solar Project in Abuja features a 600 kW rooftop solar PV system with battery storage, showcasing an innovative model for commercial and industrial clients. It aims for a substantial 44% reduction in energy costs and ensures 95% uptime through a DisCo-enabled project (Folawiyo, 2024). Green building: The Lagos-based Eko Atlantic City project is among the most ambitious and well-known projects. In order to solve ongoing land shortages and environmental issues, including eroding coastlines and floodwaters, this project aims to create a new metropolitan area on land that has been recovered from the Atlantic Ocean. Sustainability is central to the project, which features energy-efficient structures, ample green areas, and a strong transportation system (Ibrahim, 2025). The construction industry in Nigeria is slowly adopting green building and sustainable construction methodologies, acknowledging their long-term environmental and economic advantages. Established in 2010, the Green Building Council Nigeria (GBCN) plays a crucial role in fostering sustainable building practices throughout the nation. Through advocacy, education, the creation of regional green building standards, and certification, GBCN seeks to steer Nigeria's infrastructure toward environmental, social, and economic sustainability (GBCN, 2025). High sustainability standards are demonstrated by projects like the Nestoil Tower in Lagos and Primetech's headquarters in Abuja, which were planned and built in compliance with Leadership in Energy and Environmental Design (LEED) accreditation (Julius Berger, 2022). The African Leadership University in Lagos boasts a large green roof, while the Lagos Court of Arbitration features a vertical green wall, showcasing innovative methods to improve energy efficiency and visual appeal in urban architecture (Jackie, 2023). These examples illustrate how green building principles can be effectively applied within the Nigerian framework. The National Building Energy Efficiency Code (BEEC) seeks to lower overall energy use in Nigeria by encouraging energy-efficient technologies and design practices for both residential and commercial properties. This code places emphasis on passive design principles, which take into account local climate conditions, building orientation, and materials to reduce reliance on mechanical cooling and lighting (Julius Berger, 2022). Water treatment and sanitation: Solar energy is emerging as a highly efficient solution for delivering clean water, particularly in regions lacking access to the electricity grid. In Oyo State, Guinness Nigeria PLC teamed up with WaterAid to establish three large-capacity solar-powered motorised water systems, supplying safe drinking water and sanitation to more than 11,000 individuals (ESI Africa, 2023). This initiative underscores the dedication of private sector players to sustainable development. Additionally, Nigerian scientists have created a solarpowered biosensor filtration device capable of detecting and eliminating harmful bacteria from water, providing a remedy for water contamination issues in both rural and urban settings (Jesusegun, 2025). Community-Led Total Sanitation (CLTS) initiatives are being executed as a vital approach to address open 457 I.N. Samuel-Ekpe et al. / Nigerian Research Journal of Engineering and Environmental Sciences 10(2) 2025 pp. 449-464 defecation in Nigeria. CLTS seeks to inspire collective behavioural changes within communities, resulting in greater ownership and utilisation of improved sanitation facilities (Abramovsky et al., 2019). 4.1.3. Waste management and recycling innovations Nigeria produces more than 32 million tonnes of solid garbage per annum, yet less than 20% of this waste is properly managed (World Bank, 2020). Green start-ups like WeCyclers in Lagos have introduced innovative waste collection and recycling systems using low-cost cargo bicycles to serve urban slums. Their model rewards households with points that can be exchanged for essential goods, thereby incentivising recycling behaviour while addressing urban pollution. Over time, Lagos has started a number of projects to address the trash problem. Through cooperation with commercial organisations and government-led strategies, programmes such as the Cleaner Lagos Initiative (CLI) and the "Waste-to-Wealth" projects aim to enhance collection efficiency, promote recycling, and explore opportunities for recovering valuable resources. In recognition of the difficulties and financial advantages associated with trash management, the Lagos State government launched the "Waste-to-Wealth" initiative as a complete approach. By encouraging resource conservation techniques like green manure processing, recycling, and waste-to-energy conversion, this programme aims to divert garbage from landfills (Okposin, 2021). It also aims to create economic opportunities within the waste management sector, ultimately generating jobs. Promoting public involvement is a crucial component of the program, and this includes efforts to establish redemption schemes and promote the separation of waste at the source. In Abuja, a pilot project has introduced locally fabricated Reverse Vending Machines (RVMs) in key locations such as the Central Park and the National Assembly Complex (UNIDO, 2024). This initiative, a collaboration between the United Nations Industrial Development Organisation (UNIDO) and the Abuja Environmental Protection Board, aims to automate the collection of plastic waste, boost recycling rates, and support Nigeria's transition to a circular economy. The RVMs encourage public engagement in recycling activities by offering rewards to those who deposit aluminium cans and plastic bottles. This project's computerised data collection will also help shape trash control strategies in the future. Garbage-to-energy initiatives are becoming more popular as a way to generate electricity and manage garbage. At the Epe landfill, the Lagos State Government has teamed up with the Dutch-based Harvest Waste Consortium to construct a very efficient energy-from-waste facility (ESI Africa, 2023). This plant will process 2,250 tonnes of waste daily and is expected to generate 60-75 MW of electricity annually, enough to power approximately 40,000 homes. Additionally, the project aims to significantly reduce CO2 emissions and divert a substantial percentage of waste from landfills. Another notable example is the organic garbage electricity generator at the University of Nigeria, Nsukka. This 100 kVA refuse-derived fuel gasification plant utilises organic waste generated on campus to produce electricity, demonstrating the potential for decentralised WtE solutions within institutions (Fidelis, 2019). Efforts to promote recycling and material recovery are also vital for establishing a circular economy. Lafarge's Geocycle Initiative in Nigeria utilises co-processing technology in its cement kilns to manage industrial, agricultural, and municipal waste (Larfarge Geocycle, 2025). This process involves using waste as both a substitute for raw materials and as a fuel source in cement production, achieving high rates of recycling and recovery without generating residue. Geocycle manages over 80,000 tons of waste annually and partners with various sectors, including food and beverage, pharmaceuticals, and oil and gas, to provide sustainable waste management solutions. Initiated in 2021, the National Policy on Plastic Waste Management outlines an explicit plan to lessen plastic pollution and waste while encouraging sustainable practices in plastic usage and recovery (Oumar, 2025). Initiatives like ReflexNG in Lagos, supported by Next Generation Recycling Machines, focus on recycling specific waste streams, such as used water sachets, into new high-quality packaging applications. This is coupled with awareness campaigns and training for local waste entrepreneurs (Next Generation Recycling (NGR), 2025). 4.2. South Africa 4.2.1. Public transport systems Cape Town's MyCiTi system is expanding, with R5.2 billion allocated for Phase 2A over the next three years. This project will include the construction of high-quality pedestrian and bicycle transport infrastructure as well as improved transportation services. South Africa is promoting electric vehicles through various initiatives, including an electric bus pilot project. A total of 39 electric buses have been introduced in the municipalities of Tshwane and eThekwini, supported by a $4.7 million grant from the 464 I.N. Samuel-Ekpe et al. / Nigerian Research Journal of Engineering and Environmental Sciences 10(2) 2025 pp. 449-464 Okposin, A. (2021). Nigeria and the Sustainable Development Goal on 'Energy Access' by 2030: Prospects and Challenges. In book: Law, Democracy and National Development (pp.441-469). Faculty of Law, University of Nigeria, Nsukka, Enugu Campus, Enugu, Enugu State, Nigeria. https://www.researchgate.net/publication/360141247_Nigeria_and_the_Sustainable_Development_Goal_on_'Energy_ Access'_by_2030_Prospects_and_Challenges Olaniran, Temitope Olufolahan, and Aule, Thomas Terna (2025). Systematic approach to sustainable urban development: reviewing challenges of informal settlements and peri-urban growth in sub-Sahara Africa. Urban, Planning and Transport Research, 13(1), pp.1-20, https://doi.org/10.1080/21650020.2025.2495660 Oumar, F. (2025). Nigeria steps up efforts in plastic waste management. Accessed on September 10, 2025, https://www.packaging-gateway.com/features/nigeria-steps-up-efforts-in-plastic-waste-management/ Page, M. J.; McKenzie, J. E.; Bossuyt, P. M.; Boutron, I.; Hoffmann, T. C.; Mulrow, C. D.; Shamseer, L.; Tetzlaff, J. M.; Akl, E. A.; Brennan, S. E. Chou R.; Glanville J.; Jeremy M. Grimshaw, J. M.; Hróbjartsson A.; Lalu, M. M.; Tianjing, T.; Loder, E. W.; Mayo-Wilson, E.; McDonald, S.; McGuinness, L. A.; and David Moher, D. (2021). The PRISMA 2020 statement: An updated guideline for reporting systematic reviews. International Journal of Surgery, 88, pp. 1-9. https://doi.org/10.1016/j.ijsu.2021.105906 Reyhani, M., Santoli, E., Michael, N. R., Babaresi, A., Tassinari, P., and Torreggian, D. (2024). Environmental assessment of green wall: A comparison between Australia and Italy. Science of the Total Environment 957, pp. 1-14. https://doi.org/10.1016/j.scitotenv.2024.177699 UNDP (2025). The Leapfrogging South Africa’s markets to high-efficiency LED lighting and high-efficiency distribution transformers. Accessed on September 10, 2025. https://www.undp.org/south-africa/ Unegbu, H., Yawas, D. S., Dan-asabe, B., and Alabi, A. A. (2024). Sustainable urban planning and development: A systematic review of policies and practices in Nigeria. Journal of Sustainable Development Innovations, 1(1), pp. 3853. https://doi.org/10.61552/JSI.2024.01.005 UNIDO (2024). Nigeria automates plastic waste management with locally fabricated. Accessed on September 10, 2025, https://www.unido.org/news/nigeria-automates-plastic-waste-management-locally-fabricated-reverse-vendingmachines-boosting-recycling-efforts-federal-capital-territory Van der Berg, A. (2017). South Africa’s integrated urban development framework and sustainable development goal 11: policy mismatch or success? Obiter 38(3), pp. 557-573 https://doi.org/10.17159/obiter.v38i3.11424 World Bank. (2020). Solid Waste Management. https://www.worldbank.org /en/topic/urbandevelopment/brief/solid-waste-management.