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With the increase in global population, industrialization, and urbanization, waste from construction, renovation, and demolition (CRD) activities has grown rapidly. There are some issues associated with the disposal of CRD waste in landfills. Depositing in landfills is still the main method for CRD waste disposal from the global perspective. The objective of this study is to comprehensively review the environmental impacts and management technologies for CRD waste in landfills. It includes the overview of the current CRD waste flow and relevant policies worldwide. The main environmental problems caused by CRD waste in landfills include leachate and H 2 S gas emission. This paper summarizes the primary environmental impacts caused by landfilling CRD waste and the available mitigation technologies. It also includes the use of CRD waste as an alternative material in landfill barriers. Although many technologies can help mitigate the environmental impacts caused by landfilling CRD waste, the optimal solution is to divert the waste flow from landfills using the “3R” principle. In the end, the existing research gaps in CRD waste and landfill management are also discussed. Graphical abstract

Thermal ignition of radioactive waste within a 55-gallon drum was simulated by using a pressure-dependent waste decomposition model (Hobbs et al. in Process Saf Environ Prot https://doi.org/10.1016/j.psep.2022.09.047, 2022) calibrated with data from full-scale drum experiments (Parker et al. in The thermolytic response of a surrogate RNS waste mixture at the drum scale. Los Alamos National Laboratory Report LA-UR-16-21760, 2016) and validated with experiments from multiple laboratories (Hobbs et al. in Thermal analysis of aged nitric acid-soaked kitty litter in TRU waste drums-23370.WM2023 Conference, Phoenix, AZ, 2023). The acceleration of nitric acid chemistry reacting with an organic cat litter leading to thermal ignition was likely triggered by a restricted vent in the drum. Here, we address whether the form of the rate equation in (Hobbs et al. in Process Saf Environ Prot https://doi.org/10.1016/j.psep.2022.09.047, 2022) is sufficient to extrapolate thermal ignition within aged drums of similar content that have been stored in Texas for over nine years by investigating four different reaction rate forms for waste decomposition. A critical reaction rate reduction analysis is performed on each of these models to determine if delayed thermal runaway within vented aged waste is possible after nine years. We found that a pressure-dependent first-order rate expression not only predicted the accidental ignition of the waste drum, but the form also matches multiple experiments from different laboratories. Even though the waste composition decreases over time, the model predicts that acceleration leading to thermal runaway is possible if the waste is confined, even after 9 years. In conclusion, waste containing oxidizers such as nitric acid should not be mixed with organic adsorbents, especially if the waste is confined.

Solid waste refers to the material that is discarded because of human activity. In developing countries like Ethiopia, rapid urbanization leads to the production of large amounts of solid waste in towns. As a consequence, it causes severe problems to human health, aesthetics, and the environment, particularly in Dangila Town. Therefore, this study aimed to assess household solid waste characteristics, quantity, and management practices. Data was collected for seven days in January 2020 from 73 households, which were divided into three income groups. Observations, interviews, field measurements, sorting, and open-ended questionnaires were used as data collection tools. The research showed that food waste and ash and dust were the most dominant fractions, comprising 41.04% and 26.18%, respectively. It was also revealed that 77.88%, 12.74%, and 9.38% of household solid waste was decomposable, recyclable, and disposable waste, respectively. Furthermore, the waste components showed a significant statistical difference among income groups, except for the metal and miscellaneous groups. The quantification result indicated that the per capita household generation rate was 0.26 kg/day. The management practice assessment found that most households did not practice integrated solid waste management options. They disposed of waste indiscriminately, leading to environmental pollution. The results of this study suggest that the municipality needs to create awareness among households regarding proper solid waste management practices. It is crucial to apply appropriate solid waste management mechanisms and establish a well-organized institution that will collect solid waste in the town and achieve a circular economy.

Varanasi, India’s historic cultural capital, struggles with efficient waste management practices. This impacts environment and human well-being in terms of waste generation that is estimated around 550–650 TPD with a generation rate of 0.42 kg capita −1  day −1 ( n  = 117). The present study aims to explore and characterize wastes, current practices, ecological profiling, and phytotoxicity of an abandoned open dumping site, and vermicomposting of organic fraction of municipal solid waste (OFMSW) as sustainable waste management approach. Compositional analysis of waste indicates organic fraction (46.13%) as a major component along with a considerable amount of heavy metals. The calorific value and moisture content of municipal solid waste (MSW) was 2351.4 cal g −1 and 34.72%, respectively. Ecological profiling of the dumping site revealed that floral diversity and ecological species/indicators were negatively affected. Likewise, phytotoxicity results displayed a negative impact on germination and physiology of maize ( Zea mays L . ) plants grown on dumping site soil. Vermistabilization of OFMSW showed a significant increase in N (56.10–89.48%), P (33.93–82.87%), and K (25.55–50.42%) and a decrease in total organic carbon (15.15–24.81%). Similarly, C/N and C/P ratios decreased by 1.89–2.51 and 1.72–2.18 folds, respectively. A survey of stakeholders suggested that open dumping was the main practice adopted by Varanasi Municipal Corporation (VMC) during 2013–2015. Recently (2017–2018), VMC adopted different methods, such as door-to-door collection and source segregation for effective waste management. Waste characteristics and nutrient profile of the vermicompost explains that vermicomposting could be used for efficient waste management in Varanasi, further reducing the collection, transportation, and disposal costs of waste, which enables to close the loop and move towards a circular economy. Moreover, implications of existing waste management practices and possible management options need to be addressed scientifically. Therefore, this research outcome will help in designing a successful waste management plan for Varanasi and other cities with similar waste characteristics.

Exponentially increasing population, industrialization, urbanization, etc., are the consequences of the unsolved problem of municipal solid waste management in India. Mismanagement of the generated solid waste has a negative impact on the public health and the environment. Effective recycling of solid waste is considered as one of the various approaches to overcome these problems. The review aims to provide an overview of the prevailing waste management scenarios across the globe and highlight the importance of recycling. The review assessed the key criteria of municipal solid waste management, and it includes a complete assessment of municipal solid waste creation, characterization, collection, and disposal in India. The inherent issues and driving possible solutions for successful solid waste management are examined. Unsorted garbage at the source, social hurdles, public perception, a lack of knowledge, unplanned expenditures, and inadequate execution of government laws were noted as the problems with solid waste management. The review found that the geographical position and economic status of a nation are important in dictating waste characteristics, and identified the recycling potential of solid waste. The review concluded that the various characterization techniques are important for the development of value-added products produced through the recycling of solid waste. Moreover, the review suggested the adoption of an integrated waste management approach for the socio-economic environmental development of nations. The findings and discussions of the review will help the relevant authorities for municipal solid waste management and researchers develop more efficient strategies for successful municipal solid waste management.

A huge accumulation of domestic waste has caused serious environmental contamination in rural areas of developing countries (RADIC). The characteristics and management of domestic waste are carefully discussed, based on field surveys and a literature review. The results indicate that the generation in most of RADIC is less than the median of 0.521 kg day −1 per capita in China, and much smaller than in rural areas of developed countries (RADEC). Organic waste and inert waste with an accumulative mass percentage of 72.31% are dominant components of domestic waste in the rural areas of China. There are trends of increasing amounts of kitchen waste, paper/cardboard, and plastic/rubber and a decreasing trend of ash waste. The RADIC composition of domestic waste had a high content of organic waste and a low content of recyclable waste compared to the RADEC. Domestic waste has good compressibility and a light bulk density ranging from 40 to 650 kg m −3 . The moisture, ash, combustible, and calorific values of domestic waste were 53.31%, 18.03%, 28.67%, and 5368 kJ kg −1 , respectively. The domestic waste has an abundance of nutrients including organic matter (39.05%), nitrogen (1.02%), phosphorus (0.50%), and potassium (1.42%). In RADIC, domestic waste can be used as an agricultural manure only after it has been collected and sorted for the potential risk of heavy metal accumulation. Based on these characteristics of domestic waste and the different situations of rural areas, four waste management modes including centralized treatment, decentralized treatment, group treatment, and mobile treatment are designed and discussed.

The fault in the method of collection of waste-related data which has resulted in ill-defined and unreliable waste-data has necessitated the modeling approach. Despite the benefits of artificial-intelligence modeling in solving waste management problems in recent years, its applications in modeling the physical composition of waste, which is an important waste characteristic critical to sustainable waste management decisions are still lacking. In this study, an adaptive neuro-fuzzy inference system (ANFIS) model optimized with evolutionary algorithms, particle swarm optimization (PSO), and genetic algorithm (GA) was developed to investigate the effect of seasonal variation on the physical composition of solid waste using the city of Johannesburg as a case study. Three clustering techniques vis-à-vis grid partitioning (GP), subtractive clustering (SC), and fuzzy c-means (FCM) with varying combinations of their hyper-parameters were tested. The best models for each output are as follows: PSO-ANFIS-FCM with five clusters for organic waste (RMSE = 2.864), PSO-ANFIS-SC with cluster radius (CR) of 0.25 and squash factors (SF) of 1.3 for paper waste (RMSE = 2.543), GA-ANFIS-SC with CR of 0.35 and SF of 1.2 for plastic (RMSE = 4.329) and GA-ANFIS-GP with triangular membership function for textile (RMSE = 2.065). The result of this study revealed that both PSO-ANFIS and GA-ANFIS had a good performance in predicting the physical composition of waste stream with only a marginal variation.

Recognizing the advantages of waste-to-energy (WtE) combustion over landfills, China is rapidly expanding WtE capacity nationwide to address the escalating urban waste crisis. This study compiles a comprehensive WtE facility-level database between 2000 and 2020 to examine waste–energy–carbon dynamics and improvement potential. Whereas WtE expansion has notably reduced greenhouse gas emissions and recovered energy compared with landfills, these facilities remain carbon intensive and are increasingly outperformed by coal-fired power plants within China’s electricity grid. The main challenges facing WtE are the growing plastic content in waste streams and limited advancements in energy efficiency. Given WtE’s dual role in waste management and the national grid mix, it is crucial to balance capacity expansion with carbon intensity reduction. The high-resolution database provides geographically tailored strategies based on local waste characteristics and facility performance, indicating that effective waste classification and equipment upgrades could decarbonize WtE power generation by half to natural gas levels by 2060. The expansion of China’s waste-to-energy combustion capacity offers great carbon and energy benefits over landfills but remains a carbon-intensive process due to plastic waste and low efficiency. Enhanced waste sorting and the adoption of high-efficiency devices could decarbonize the power generated by these facilities to match that generated by natural gas by 2060.

BACKGROUND AND OBJECTIVES: Population growth and economic activity in rural areas are factors driving the waste generation rate. Rural waste management generally still applies conventional patterns and has the potential to damage the environment and threaten human health. Challenges and remedial measures for solid waste management in rural areas differ from urban ones. The first step in planning a waste management system is to identify the generation and characteristics of waste. Unfortunately, data on waste generation and characteristics in rural areas in developing countries are still minimal. The problems are mainly caused by the development of the tourism industry, and it certainly requires waste management as the solution. However, due to the unavailability of waste generation data, this study aims to measure and analyze waste characteristics in the southern zone of Gunungkidul Regency. METHODS: Primary data collection was taken from 16 randomly selected villages in six sub-districts in Gunungkidul Regency. A door-to-door survey was carried to 110 residential and 160 nonresidential samples for eight consecutive days using the Indonesian National Standard 19-39641994 method. The processed data were analyzed using a quantitative descriptive method. FINDINGS: The results showed that the average waste generation was 0.29 kilograms per person per day. It shows that the waste generation in the study area is categorized in small-town classification. 75 percent of solid waste generated is food waste and leaves. Meanwhile, paper, plastic, glass, wood, other materials, and fabrics were calculated at 11.8 percent, 10.1 percent, 1.7 percent, 0.5 percent, 0.5 percent, and 0.4 percent respectively. Housing produced less recycled waste as indicated by a high density of 110.6 kilograms per cubic meter. Waste generation and composition are influenced by socioeconomic factors such as economic activity and lifestyle, geographic conditions, and downtown attractiveness. CONCLUSION: The characteristics of the waste produced by the southern zone of Gunungkidul Regency are not much different from most rural areas in developing countries. Rural waste management needs to see organic waste as the main management material. Organic waste processing through composting can be a future solution, but the active role of residents determines its success. In addition, this method can help extend the life of the landfill capacity because the volume of organic waste will be reduced by half.

One-third of food produced results as food waste, with no organized and sustainable disposal, and ends up in landfills. Garden waste is yet another significant waste experiencing improper disposal or burning. The present study aims to assess the effect of different pretreatment processes in biogas production from anaerobic digestion of food waste and its co-digestion with garden waste. Feedstock is subjected to thermal and or extrusion pretreatment. A combination of both is the proposed novel sequential hybrid pretreatment method. Feedstock is rich in cellulose I, II, and di/monosaccharides, where pretreatment altered the characteristics and morphology with a steady neutral pH indicating stability. The resultant feedstock exhibited the absence of cellulose II and reduced disaccharides. An average of 0.25 times increase in biogas production is observed with individual thermal and extrusion pretreatment than the conventional digestion. Sequential hybrid pretreated feedstock yielded maximum biogas of 730 and 430 mL/g VSfed in mono digestion and co-digestion over its conventional counterparts. In this study, the modified Gompertz model (R2 of 0.98) is suitable over the first-order kinetics model. Results conclude that sequential hybrid pretreatment leads to significant breakage of complex organic matter in substrates aiding in the efficient digestion process and biogas generation.