Sustainability Evaluation of Municipal Solid Waste Management System for Hanoi (Vietnam)—Why to Choose the ‘Waste-to-Energy’ Concept

Municipal solid waste management challenges in developing regions: A comprehensive review and future perspectives for Asia and Africa

The rapid urbanization witnessed in developing countries in Asia and Africa has led to a substantial increase in municipal solid waste (MSW) generation. However, the corresponding disposal strategies, along with constraints in land resources and finances, compounded by unorganized public behaviour, have resulted in ineffective policy implementation and monitoring. This lack of systematic and targeted orientation, combined with blind mapping, has led to inefficient development in many areas. This review examines the key challenges of MSW management in developing countries in Asia and Africa from 2013 to 2023, drawing insights from 170 academic papers. Rather than solely focusing on recycling, the study proposes waste sorting at the source, optimization of landfill practices, thermal treatment measures, and strategies to capitalize on the value of waste as more pertinent solutions aligned with local realities. Barriers to optimizing management systems arise from socio-economic factors, infrastructural limitations, and cultural considerations. The review emphasizes the importance of integrating the study area into the circular economy framework, with a focus on enhancing citizen participation in solid waste reduction and promoting recycling initiatives, along with seeking economic assistance from international organizations.

Insight into heavy metal chemical fractions in ash collected from municipal and industrial waste incinerators in northern Vietnam

This investigation involved the collection of fly ash and bottom ash specimens from seven waste incinerators situated in the northern provinces of Vietnam, aimed at assessing the composition and distribution patterns of five chemical fractions of heavy metals (Pb, Cr, As, Cd Cu, and Zn) present in incinerator waste ash. The outcomes reveal that fly ash exhibited a relatively elevated concentration of industrial waste metals (25-66%) such as As, Cd, and Pb primarily in exchangeable (F1) and carbonate fractions (F2), which are mobile forms susceptible to environmental dissolution and consequential bioaccumulation posing health risks to humans. The predominant states of the metals Cr, Cu, and Zn were identified as residual, Fe-Mn oxide, and carbonate, respectively, with their relative proportions showing minimal variation. Conversely, heavy metals were predominantly present in residual residue and Fe-Mn bound form (F3) in bottom ash derived from both residential and commercial waste incineration operations. The non-carcinogenic hazard indices (HI) associated with the examined metals, ranked for both adults and children, were as follows: Pb > Cr > As > Cd > Cu > Zn. Notably, the HI values for Pb, Cr, and As exceeded the permissible threshold (HI > 1) for children. However, the risk of As, Cd, and Pb-related cancer via exposure pathways remained within acceptable limits for both age groups. Conversely, the probability of carcinogenic effects attributable to Cr surpassed the permissible threshold (>10-4), indicating significant health concerns associated with heavy metals in waste incinerators for humans, particularly children.

Environmental Sustainability Impacts of Solid Waste Management Practices in the Global South

Solid waste management (SWM) is one of the key responsibilities of city administrators and one of the effective proxies for good governance. Effective SWM mitigates adverse health and environmental impacts, conserves resources, and improves the livability of cities. However, unsustainable SWM practices, exacerbated by rapid urbanization and financial and institutional limitations, negatively impact public health and environmental sustainability. This review article assesses the human and environmental health impacts of SWM practices in the Global South cities that are the future of global urbanization. The study employs desktop research methodology based on in-depth analysis of secondary data and literature, including official documents and published articles. It finds that the commonplace SWM practices include mixing household and commercial garbage with hazardous waste during storage and handling. While waste storage is largely in old or poorly managed facilities such as storage containers, the transportation system is often deficient and informal. The disposal methods are predominantly via uncontrolled dumping, open-air incinerators, and landfills. The negative impacts of such practices include air and water pollution, land degradation, emissions of methane and hazardous leachate, and climate change. These impacts impose significant environmental and public health costs on residents with marginalized social groups mostly affected. The paper concludes with recommendations for mitigating the public and environmental health risks associated with the existing SWM practices in the Global South.

Risk Analysis of Public–Private Partnership Waste-to-Energy Incineration Projects from the Perspective of Rural Revitalization

In China, more and more waste-to-energy (WTE) incineration plants are being delivered through public–private partnership (PPP) schemes in rural areas, which are focused on rural revitalization. These can not only deal with the ever-increasing solid waste but also provide renewable energy and thus benefit local societies. However, they usually endure a lot of risks due to long concession periods and complex contractual relationships. This research investigates the risk management of PPP WTE incineration projects from the perspective of rural revitalization. First, a preliminary list of 36 risks was derived based on a literature review. Second, a focused group discussion with eight experts was held to obtain the final list of 36 risk factors, taking into account rural revitalization. Third, a structured questionnaire survey was conducted to consult the risk frequency and risk severity. A total of 100 valid questionaries were collected. Finally, risk analysis and discussion were provided on the basis of the survey. The top 10 risks are rural appearance, payment risk, local employment, local economic development, local government succession, operation cost overrun, waste supply, construction cost overrun, revenue risk and price change risk. It indicates that (1) PPP WTE incineration projects can effectively promote rural development; (2) government authorities play a significant role in the sustainable development of PPP WTE incineration projects; and (3) the risk preference of rural PPP WTE incineration projects is social, economic and environmental risks.

Growth of the Black Soldier Fly Hermetia illucens (Diptera: Stratiomyidae) on Organic-Waste Residues and Its Application as Supplementary Diet for Nile Tilapia Oreochromis niloticus (Perciformes: Cichlidae)

The black soldier fly, Hermetia illucens (BSF, Diptera: Stratiomyidae) is an insect with high protein value and a potential feed agent for animals aimed for human consumption. The growth parameters of BSF larvae reared on four substrates—restaurant-waste, fruit-waste, fish-waste, and commercial tilapia food—for 41 days before processing for inclusion into Oreochromis niloticus (Perciformes: Cichlidae, Nile tilapia) commercial fry diets at 30% (70:30) were determined. On fly larvae, the food substrate based on restaurant waste yielded the greatest larval weight and length. BSF larvae fed a fish-waste diet showed the shortest developmental time. The fruit-waste diet induced the lowest weight and length in the fly larvae/pre-pupae (immature stage). The pre-pupal protein values were similar to commercial food. On fry-fish, the diets with pre-pupae grown on fish waste showed the greatest yields regarding weight (biomass), length, and nutritional content. These results suggest the BSF has the potential to be used in fish feed and provides an alternative for commercial cultivation.

Composting Strategy Instead of Waste-to-Energy in the Urban Context—A Case Study from Ho Chi Minh City, Vietnam

The waste-to-energy programs that have taken place in recent years present a daunting picture in terms of sustainable material management. The incineration of much organic and unorganized waste in metropolitan waste treatment facilities is not meet with sustainable development. The solution to this problem may be to increase urban composting programs in the future, which is a sustainable treatment option but also a serious technical challenge. Our research question is whether composting programs can play a key role in rapidly evolving urban ecosystems in Asia, due to the specificities associated with the waste rates outlined and developmental differences outlined. Instead of the waste-to-energy or waste-to-landfill strategies often used today, can central composting focusing on high organic matter content be a suitable alternative? Using the AHP method (Analytical Hierarchy Process), the following alternatives were examined to clarify the issue: Wastes are commingled and processed at the treatment facilities; Classification of organic and non-organic waste at source for composting; Totally separating waste at source before processing at the treatment facilities. We have found that the use of central composting (separation of organic and non-organic waste at source) strategies to support circular development is one of the most innovative development strategies in the fast-growing cities of Asia, in line with E.U. targets.

Characteristics of municipal fresh solid wastes from the selected large urban centres in Uganda: Implication for re-use and soil amendment strategies

In Uganda, the municipal solid wastes are generally a menace to the environment, ranging from indiscriminate dumping, open burning, and landfills, which would be utilized to augment agricultural fields through organic manure. The National Environment Management Authority (NEMA) of Uganda, however from 2009 to 2012 initiated and implemented a Clean Development Mechanism project. This project was established and conducted in nine urban centers with the key objective of reducing methane and other environmental nuisances while generating compost manure. The in-coming fresh municipal wastes at composting facilities were sorted into six categories; i) wood and wood products, ii) food and food wastes, iii) textiles, iv) garden, yard and park wastes, v) paper and pulp, and vi) glass, plastics, and metals. These were laboratory analyzed based on standard procedures, characterized and investigated for the pH, total organic carbon (TOC), total nitrogen (TN), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) (g kg^-1). Statistical analyses were performed based on One-Way ANOVA, implemented in the SPSS program. The results indicate that the municipal fresh solid wastes were mainly dominated by biodegradable organic matter; garden, yard, and park wastes (49%), food and food wastes (43.2%), and the other wastes falling below 5.4%. Overall, the pH was 7.7 ± 0.02, TOC 318.2 ± 2.90, TN 12.1 ± 0.10, C/N 26.7 ± 0.20, P 4.4 ± 0.04, K 35.0 ± 0.49, Ca 38.9 ± 0.51, and Mg 5.8 ± 0.09. The concentration of the fresh wastes and macro-nutrients varied per municipality and were congruent with the economic activities and population lifestyles. We detected the effect of season/month on the concentration of wastes which corresponded with the various agronomical activities. The results from this study suggest that the notion of composting is potentially a viable organic waste management strategy in the country which can ultimately generate sufficient organic manure for agricultural input and thus enhanced carbon sequestration.Implications: In this study, we characterized the in-coming fresh municipal solid wastes and investigated the pH, total organic carbon (TOC), total nitrogen (TN), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) (g kg^-1). We found that the municipal fresh solid wastes were mainly dominated by biodegradable organic matter (>90%). The results from this study suggest the notion of composting to be potentially a viable organic waste management strategy in Uganda which can ultimately generate sufficient organic manure for agricultural input. This is typically vital for enhancing carbon sequestration towards minimizing greenhouse gas emissions.

Concentrations, profiles, emission inventory, and risk assessment of chlorinated benzenes in bottom ash and fly ash of municipal and medical waste incinerators in northern Vietnam

Concentrations and congener profiles of seven di- to hexachlorinated benzenes (CBzs) were characterized in bottom ash and fly ash samples collected simultaneously from one medical waste incinerator (MEWI) and one municipal waste incinerator (MUWI) in northern Vietnam. Total concentrations of seven CBzs in the fly ash samples ranged from 6.98 to 34.4 (median 19.1) ng g^-1 in the MEWI, and ranged from 59.1 to 391 (median 197) ng g^-1 in the MUWI. Concentrations of CBzs in the bottom ash samples of the MEWI (median 1.95; range 1.53-5.98 ng g^-1) were also lower than those measured in the MUWI samples (median 17.4; range 14.5-42.6 ng g^-1). Levels of CBzs in the fly ash samples were significantly higher than concentrations measured in the bottom ash samples, partially indicating the low-temperature catalytic formation of these pollutants in post-combustion zone. In general, higher chlorinated congeners (e.g., hexachlorobenzene, pentachlorobenzene, and 1,2,4,5-tetrachlorobenzene) were more abundant than lower chlorinated compounds. However, compositional profiles of CBzs were different between the ash types and incinerators and even between the same sample types of different sampling days, suggesting that the formation of CBzs in these incinerators is complicated and influenced by many factors. Emission factors and annual emission amounts of CBzs were estimated for the two incinerators by using actually measured data of CBz concentrations in the ash. Daily intake doses and cancer risks of ash-bound CBzs estimated for workers in the two incinerators were generally lower than critical values, but cancer risks caused by other relevant pollutants (e.g., polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and dioxin-related compounds) were not considered.

Raising Awareness on Solid Waste Management through Formal Education for Sustainability: A Developing Countries Evidence Review

Solid Waste Management (SWM) is a multifaceted problem comprising political, socioeconomic, institutional, and environmental aspects. Due to exponential urban growth, it has become one of the most significant issues faced by urban spaces in developing countries. The gap in environmental knowledge among the youth and the old within developing countries contribute to ecological issues or waste management problems, resulting in unsustainable development, with important consequences in low-income countries. For that matter, a systematic review was conducted aiming to identify and analyse environmental knowledge, awareness, attitudes, and practice studies on SWM from 2010 to 2019 in developing countries. The evidence suggests that students at both secondary and tertiary levels have positive environmental attitudes, and high awareness of environmental issues, but there is a lack of practical education of teachers to guide students to put SWM into practice. Student’s low environmental knowledge is related to a deficiency in teachers’ practical experience in SWM for environmental sustainability. A relationship between teachers’ and students’ knowledge and attitudes towards SWM, as well as differences in awareness, attitude, and practices of SWM linked with education and age, were also found. This review also revealed that the lack of environmental education in most developing countries is caused by fragilities in practical environmental curricula of teachers to respond to modern-day environmental issues for sustainable development and cleaner production (CP). To bridge the knowledge gap between the youth and older people in SWM, environmental sustainability education should be integrated into schools at all levels within developing countries.

On the Way of Policy Making to Reduce the Reliance of Fossil Fuels: Case Study of Iran

Nowadays, fossil fuels are well known as a predominant source of energy in the planet. Located in the Middle East region, Iran holds one of the largest fossil fuel reservoirs in the world. The country has abundant oil and natural gas fields in various regions; some of them are shared between other countries and have not reached their operational capacity yet. Meanwhile, during recent years and due to global warming followed by environmental global contracts such as Kyoto protocol, using fossil fuels is being criticized to a large extent around the world. Therefore, the global interest has been focused toward clean energy resources. Furthermore, endowed with sundry geographical pattern throughout its land, Iran has adequate renewable energy potentials. So, there will be a serious paradox affecting its whole energy policy: more exploration and extraction of conventional fossil fuels or take advantage of renewable and sustainable energy resources? In this paper, energy structure of Iran is generally overviewed, followed by study of renewable energy potentials in various parts of the country. Afterwards, policy making in renewable energy market, systems, and applicable strategies are elaborated. Furthermore, a number of barriers obstructing the development path of renewable energy schemes and initiatives are presented and discussed in detail.

Renewable Waste-to-Energy in Southeast Asia: Status, Challenges, Opportunities, and Selection of Waste-to-Energy Technologies

Rapid urban population growth that boosts increased waste generation and electricity demand has led to a possible alternative waste-to-energy solution in Southeast Asia. Despite some issues related to the development of the waste-to-energy sector such as public perception, all stakeholder involvement, public–private partnerships, funding, and climate factors, some Southeast Asian countries have made a reasonably successful step toward the developed technologies. Therefore, this study aimed to highlight an overview of the waste-to-energy sector in Southeast Asian countries to specify the status, challenges, opportunities, and selection of the technologies suited for the specific country. In order to achieve this aim, the study collected, synthesized, and evaluated data about waste resources, current waste management, waste-to-energy utilization, and its potential in the region based on published research papers and policy reports. It was found that the major waste-to-energy technologies in the region are incineration, landfills with gas capture, and anaerobic digestion. The total quantity of the waste-to-energy capacity from landfill biogas plants, incineration plants, and other waste-to-energy practices in the region accounts for over 323 MW at present and is expected to grow to double its current size by 2022. Meanwhile, by 2030, the realizable generation potential from renewable municipal waste in six Southeast Asian countries (Indonesia, Malaysia, Philippines, Singapore, Thailand, and Vietnam) amounts to 17.26 terawatt-hours (TWh). The study also specifies the requirements and considerations for the selection of waste-to-energy technologies, as well as the dimensions related to the development of the technologies. Additionally, four major aspects—technical, financial, environmental, and social and political—regarding the challenges and opportunities for the development of these technologies are considered. The challenges and opportunities related to the development of waste-to-energy in the region reveal how to overcome the drawbacks and to grasp the benefits at present and in the near future. Finally, the study is concluded with suggestions for the selection of the technologies in the region.

Sustainable Governance of Coastal Areas and Tourism Impact on Waste Production: Panel Analysis of Croatian Municipalities

The research problem this paper is concerned with is the effect of tourism on solid waste generation in Croatia’s coastal area. We are aware of the fact that this has not been thoroughly addressed, especially considering tourism’s share in the Croatian economy and the pressure it generates on sustainable coastal management. This is of particular importance considering the governing complexity of coastal areas. Thus, we ask a simple question regarding the role of the tourism industry in the solid waste generation in the Croatian coastal area: Do tourists generate relatively more solid waste than the domestic population? The falsifiable hypothesis is stated in terms of the difference in the production of communal waste between domestic population and tourists, taking into account local idiosyncratic factors, when such a difference is recoverable through statistical analysis of measurable tourist presence in panel data. The first hypothesis is thus: The amount of solid waste produced by local residents in Croatian coastal municipalities diverges significantly in statistical terms from the amount of solid waste produced by tourists. The second hypothesis is: The amount of waste-streams is influenced by local idiosyncrasies of coastal settlements, their economic structure, per capita GDP and/or cultural background of local people. Our dataset is a panel of 160 municipalities in the Croatian coastal area spanned across a time period of 12 months during 2019, giving us a total of 1920 panel observations. We performed a Panel Estimated Generalized Least Squares cross-section fixed effects analysis with Panel Corrected Standard Errors on domestic population and tourist overnight stays and their solid waste generation. We used the above mentioned method to achieve better results with higher significance, and lower Standard Errors than comparable methods. We complemented the analysis with a dynamic Panel Generalized Method of Moments First Differences test. Results show a relatively larger relative impact of tourist overnight stays on municipal solid waste generation than what is to be expected from the locals only. Our different methods of analysis ended with non-contradicting results. The number of tourist overnight stays in some municipalities shadows the overnight stays of the local population as an indicator of solid waste generation, exacerbating the problem of sustainability of waste disposal. We conclude that the relative waste disposal impact of the tourists is at least 22% greater and possibly up to 55% greater than the one of local inhabitants, contradicting some other research. We also found evidence of possible Environmental Kuznets Curve behavior.

Deploying Municipal Solid Waste Management 3R-WTE Framework in Saudi Arabia: Challenges and Future

The need for resilience and an agile waste management system in Saudi Arabia is vital to control safely the rapid growth of its municipal solid waste (MSW) with minimal environment toll. Similarly, the domestic energy production in Saudi Arabia is thriving and putting a tremendous pressure on its huge reserves of fossil oil. Waste to energy (WTE) plants provides a golden opportunity for Saudi Arabia; however, both challenges (MSW mitigation and energy production) are usually looked at in isolation. This paper at first explores the potential of expanding the WTE energy production in the eastern province in Saudi Arabia under two scenarios (complete mass burn with and without recycling). Secondly, this study analyzes the effect of 3Rs (reduce, reuse, recycle) practices implementation in a residential camp (11,000 population) to influence the behavior of the camp’s citizens to reduce their average waste (kg/capita). The results of the 3R-WTE framework show a potential may reach 254 Megawatt (MW) of electricity by year 2030. The 3R system implementation in the camp reduced MSW production from 5,625 tons to 3000 tons of household waste every year, which is considered lower than what the surrounding communities to be produced in the same area.