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• Demonstration of a whole-site flushing technique in an MSW landfill. • Use of bromide and water as tracers in landfill. • Verification of dual-porosity behaviour of MSW. • in situ field-scale estimates of block diffusion time. • Examination of different fill-and-draw flushing scenarios. A fill-and-draw flushing test on a landfill cell containing MSW waste was carried out to examine the operational viability of this method for accelerating the flushing of contaminants and landfill stabilisation. During the fill cycle, 800 m3 of water containing the tracer bromide was pumped into the base of a 0.44 ha landfill cell, resulting in the estimated saturation of 9,400 m3 of waste. Abstraction took place in two phases, during which 1,100 m3 of tracer/leachate was recovered. Samples of leachate were analysed for the tracer, electrical conductivity and indigenous solutes chloride and ammonia. Tracer recovery was between 63 and 72 % for bromide. An estimated 227 kg of ammonia and 575 kg of chloride were removed. Test data was used to calibrate a 1D, dual-porosity model involving advection in a mobile zone, and diffusion into 'blocks' of a less mobile zone. The model fitted well to the early time data, whereas later data appears to have been affected by recharge. The results of this trial demonstrate the possibilities of the 'fill-and-draw' concept using the basal leachate drainage system of landfills as a potential accelerated landfill remediation technique. However, modelling results suggest low contaminant removal efficiency. Including a pause between the fill and the draw cycles improves mass removal. [ABSTRACT FROM AUTHOR]

This study evaluates the efficacy of the Thiopaq bio-desulfurization system at the Daegu Bangcheon-ri Sanitary Landfill in Korea over 1 year focusing on operational insights and microbial dynamics. The system employs sulfur-oxidizing bacteria (SOBs) to convert hydrogen sulfide (H2S) in landfill gas (LFG) into elemental sulfur. Key findings include maintaining over 96% H2S removal efficiency despite operational challenges such as sulfur clogging and foam formation. Significant microbial community shifts were observed, with Thioalkalibacter halophilus remaining robust, Alkalilimnicola ehrlichii declining, and Halothiobacillus kellyi becoming more prominent, especially during new well installations with high thiol (methanethiol) concentrations. Scanning electron microscopy revealed distinct morphological characteristics of bio-sulfur under varying conditions contributing to process optimization. Our results underscore the necessity for continuous monitoring and adaptive management of microbial populations and system parameters to effectively handle fluctuating LFG compositions and operational conditions. This study provides substantial guidance for enhancing LFG quality and bio-sulfur production in large-scale landfills. [ABSTRACT FROM AUTHOR]

Municipal solid waste management (MSWM) is an exigent and emerging problem in India. Despite various MSWM options, landfill continues to be the ultimate disposal destination of solid waste leading to ecosystem damage and leachate generation. The appropriate MSWM options and landfill leachate treatment become a matter of great apprehension to avoid negative impacts on the surrounding environment. In the present study, three LCA-based potential scenarios of systematic solid waste management, including anaerobic digestion, composting and landfilling, were analyzed and compared. The life cycle assessment (LCA) model was created in the Gabi 17.00 software for analyzing the impact of every steps involved in the MSWM system. Further, the study also focuses on leachate management of the Bhandewadi landfill site, situated in Nagpur City, India, using five different types of adsorbents, viz. rice husk, granular activated charcoal, powdered activated charcoal, compost and fly ash. Among the different scenario's analyzed and various impact categories studied, the LCA of all the three scenarios highlights that the global warming potential and human toxicity potential of scenario one is comparatively lower than other scenarios. Further, the adsorbents used in the study have potential for the removal of containments. The diffusion profile analysis of leachate through different types of adsorbents used revealed that the chemical oxygen demand removal efficiency enhances with thickness of the adsorbent. The study emphasized that it is crucial for decision-makers associated with waste management sector to focus on environment friendly MSWM approaches. It is also recommended that the decision and policymakers adhere and follow the stringent implementation of laws and regulations associated to the MSWM system. [ABSTRACT FROM AUTHOR]

1,4‐Dioxane is a probable human carcinogen and a persistent aquatic contaminant. Cometabolic biodegradation of 1,4‐dioxane is a promising low‐cost and effective treatment technology; however, further demonstration is needed for treating landfill leachate. This technology was tested in two full‐scale moving bed biofilm reactors (MBBRs) treating raw landfill leachate with tetrahydrofuran selected as the cometabolite. The raw leachate contained on average 82 μg/L of 1,4‐dioxane and before testing the MBBRs removed an average of 38% and 42% of 1,4‐dioxane, respectively. First, tetrahydrofuran was added to MBBR 1, and 1,4‐dioxane removal was improved to an average of 73%, with the control MBBR removing an average of 37% of 1,4‐dioxane. During this period, an optimal dose of 2 mg/L of tetrahydrofuran was identified. Tetrahydrofuran was then fed to both MBBRs, where the 1,4‐dioxane removal was on average 73% and 80%. Cometabolic treatment at the landfill significantly reduced the concentration of 1,4‐dioxane received from the landfill at a downstream wastewater treatment and indirect potable reuse facility, reducing the load of 1,4‐dioxane from 44% to 24% after the study. Practitioner Points: Cometabolic degradation of leachate 1,4‐dioxane with THF in MBBRs is a feasible treatment technology and a low‐cost technique when retrofitting existing biological treatment facilities.The MBBRs can be operated at a range of temperatures, require no operational changes beyond THF addition, and operate best at a mass ratio of THF to 1,4‐dioxane of 24.Source control of 1,4‐dioxane significantly reduces the concentration of 1,4‐dioxane in downstream wastewater treatment plants and potable reuse facilities. [ABSTRACT FROM AUTHOR]

The health of the public and environment may suffer significantly when solid waste is dumped in unmanaged landfills. The primary concern is the risk of pollution caused by leachate from landfill sites migrating into surface waters, & groundwater. In India, handling the leachates from landfills is a significant environmental and financial issue. Owing to the rapid urbanization, industrialization, and population increase, a variety of by-products are produced from day-to-day living and are frequently disposed of carelessly, creating serious environmental issues. This study evaluates the environmental risks to groundwater that leachate from municipal solid waste landfills poses. In order to assess the degree and kind of groundwater contamination, the research uses a thorough analytical methodology that integrates hydrogeological, geochemical, and microbiological examinations. To ascertain the physicochemical characteristics of leachate, including heavy metal concentrations, three landfill sites in Deonar, Mulund, and Malad were chosen. Landfill leachate samples were taken from three municipal solid waste (MSW) landfills and examined for 22 trace contaminants that are frequently found in surface and municipal wastewater effluents. It was discovered that the Deonar dump site was far more polluted than the Malad and Mulund garbage sites. The leachate pollution index was used to assess the toxicity hazard of the dumpsites; values of 20.41, 23.42, and 23.52 were found for the landfill sites in Mulund, Malad, and Deonar, respectively. This study will provide valuable insights into the present state of groundwater contamination around Mumbai landfills. Furthermore, by identifying the precise contaminants causing groundwater degradation, thorough research will facilitate the development of tailored mitigation plans. The study's findings are anticipated to have a significant impact on urban planning and policy decisions about sustainable waste management techniques, with a particular focus on groundwater resource conservation and public health in Mumbai. [ABSTRACT FROM AUTHOR]

Nitrogen (N) and phosphorus (P) metabolism is becoming an increasingly complex process during urbanization due to increasing rates of consumption and emission worldwide. Understanding the urban N and P metabolism helps identifying production capacity, consumption demand, and the impact of N and P emissions on the environment, providing a scientific basis for decision‐making in sustainable utilization of N and P resources. Quantifying and mapping the source, path, and sinks of N and P in an urban system is the premise of controlling emissions. In this paper, we used the substance flow analysis (SFA) method to describe the N and P metabolism processes in the urban system of Dar es Salaam (Tanzania) in 2017, and used the scenario‐based analysis method to understand the impact of different N and P metabolisms on potentially recoverable N and P sources by 2030. The results showed that the urban system of Dar es Salaam receives a total input flow of 28,101.8 tN/year and 3,379 tP/year, with a total output flow of 18,859.6 tN/year and 1,849.3 tP/year with net stock changes of 9,242.2 t/year for N and 1,529.7 t/year for P, respectively. We noticed that increased human activities largely represented the city's waste released after the household consumption, and would become the main causes of N and P emissions. In addition to this, 59.38%, 31.25%, and 9.38% of N flow quantification quality were at high, medium, and low levels, respectively, while 74.07%, 11.11%, and 14.81% of P flow quantification quality were at high, medium, and low levels, respectively. Our results suggest that implementing integrated nutrient management measures, such as changes in people's diets and the use of washing products, and improved management and technologies of manure, sewage, and landfill leachate treatment, would be the most effective approach to resolve the urban nutrient emissions in Dar es Salaam. [ABSTRACT FROM AUTHOR]

Effective management of urban solid waste in the Metropolitan Region of Belém, State of Pará, Brazil is essential for conserving ecosystems and public health in eight cities, emphasizing the municipality of Marituba. Considering the vulnerability of underground water resources in Marituba to pollution due to the possible impact of leachate percolation from the landfill, this study evaluates the quality of groundwater captured in tubular wells from different adjacent locations potentially used for human consumption. For this purpose, the systematic methodologies of the groundwater quality index and human health risk assessment analysis: non-carcinogenic and carcinogenic risk to human health were used based on chronic daily intake of heavy metals by consumption and dermal adsorption of groundwater, measured through risk quotients, risk index, and incremental lifetime cancer risk. To evaluate the interrelationships of pollutants, analysis of variance, hierarchical cluster analysis, and principal component analysis were used based on the spatio-temporal quantification of pH, temperature, electrical conductivity, As, Al, Ba, Co, Cd, Cu, Cr, Fe, Hg, Ni, Pb, Sb, Se, U, and Zn. Residents of the study area are not at potential risk, as the results demonstrate that groundwater is within the potability standards of Brazilian legislation, except for aluminum concentrations, which ranged from 53.12 to 378.01 μg L−1 and 3.82 to 339.5 μg L−1 in the dry and rainy seasons, respectively, exceeding the established limit of 200.0 μg L−1. The quality index for groundwater and the heavy metal pollution index demonstrated that groundwater has good drinking quality with low metal contamination. The risk was considered low at all sampling sites in the non-carcinogenic risk assessment. Principal component analysis indicated that the sources of metal pollution are natural origins and anthropogeny. In this sense, they become worried because aluminum is a recognized neurotoxicant that can interfere with the central nervous system's critical physiological and biochemical processes. Furthermore, despite complying with potability standards, trace concentrations of highly toxic metals such as As, Pb, Cd, and Ni may indicate initial contamination by landfill leachate. [ABSTRACT FROM AUTHOR]

• A regional CDW landfill landslide risk assessment method is developed. • Most identified landfills located at city administrative borders. • Nearly 70 % of landfills in Shenzhen are at high landslide risk. • Landfills at city internal administrative junctions typically face high risks. In recent years, construction and demolition waste (CDW) landfills landslide accidents have occurred globally, with consequences varying due to surrounding environmental factors. Risk monitoring is crucial to mitigate these risks effectively. Existing studies mainly focus on improving risk assessment accuracy for individual landfills, lacking the ability to rapidly assess multiple landfills at a regional scale. This study proposes an innovative approach utilizing deep learning models to quickly locate suspected landfills and develop risk assessment models based on surrounding environmental factors. Shenzhen, China, with significant CDW disposal pressure, is chosen as the empirical research area. Empirical findings from this study include: (1) the identification of 52 suspected CDW landfills predominantly located at the administrative boundaries within Shenzhen, specifically in the Longgang, Guangming, and Bao'an districts; (2) landfills at the lower risk of landslides are typically found near the northern borders adjacent to cities like Huizhou and Dongguan; (3) landfills situated at the internal administrative junctions generally exhibit higher landslide risks; (4) about 70 % of these landfills are high-risk, mostly located in densely populated areas with substantial rainfall and complex topographies. This study advances landfill landslide risk assessments by integrating computer vision and environmental analysis, providing a robust method for governments to rapidly evaluate risks at CDW landfills regionally. The adaptable models can be customized for various urban and broadened to general landfills by adjusting specific indicators, enhancing environmental safety protocols and risk management strategies effectively. [ABSTRACT FROM AUTHOR]

This study investigated seasonal variations in the physico-chemical properties of leachate from the Kupferberg landfill site, examining the influence of landfill age and climatic factors. Data provided by the Windhoek Municipality during the years 2017 to 2022 facilitated the exploration of critical concerns related to groundwater protection and human health. Guided by two research questions and anchored in hypotheses tested at a 95% confidence level, the study employed Statistical Packages for Social Scientists (SPSS) for analysis. Significant temperature variations were observed across years [F (5, 21) = 4.493, p < 0.05], indicating a substantial relationship between landfill age and seasonal variations in leachate physico-chemical properties. Further ANOVA tests revealed temperature trends impacting leachate parameters, such as organic content and pH. While COD displayed a declining trend with landfill age, inorganic components like Cl- and alkalinity exhibited no distinct age-related pattern. Wet seasons demonstrated higher EC and Cl--mean values than dry seasons, correlating with elevated COD levels. The study underscored the incremental rise in parameter values over time and during the rainy season, attributed to solid waste degradation and rainwater percolation. Notably, climatic conditions significantly influenced seasonal variations in leachate physico-chemical properties (p < 0.05). Based on this outcome, null hypothesis 1 was rejected. The second null hypothesis was also rejected because climatic conditions do influence the seasonal variations in physico-chemical properties. These findings are crucial for emphasizing the need for effective leachate management strategies and providing valuable insights for arid regions. Future research can expand on a national scale, employing one-way ANOVA tests on other landfills in Namibia, and engaging local communities for comprehensive data collection on cross-contamination. [ABSTRACT FROM AUTHOR]

The reuse of waste materials has recently become appealing due to pollution and cost reduction factors. Using waste materials can reduce environmental pollution and product costs, thus promoting sustainability. Approximately 95% of calcium carbonate-containing waste eggshells end up in landfills, unused. These eggshells, a form of bio-waste, can be repurposed as catalytic electrode material for various applications, including supercapacitors, after being converted into CaO. Similarly, used waste battery electrode materials pose environmental hazards if not properly recycled. Various types of batteries, particularly lithium-ion batteries, are extensively used worldwide. The recycling of used lithium-ion batteries has become less important considering its low economic benefits. This necessitates finding alternative methods to recover and reuse the graphite rods of spent batteries. Therefore, this study reports the conversion of waste eggshell into calcium oxide by high-temperature calcination and extraction of nanographite from spent batteries for application in energy storage fields. Both CaO and CaO/graphite were characterized for their structural, morphological, and chemical compositions using XRD, SEM, TEM, and XPS techniques. The prepared CaO/graphite nanocomposite material was evaluated for its efficiency in electrochemical supercapacitor applications. CaO and its composite with graphite powder obtained from used lithium-ion batteries demonstrated improved performance compared to CaO alone for energy storage applications. Using these waste materials for electrochemical energy storage and conversion devices results in cheaper, greener, and sustainable processes. This approach not only aids in energy storage but also promotes sustainability through waste management by reducing landfills. [ABSTRACT FROM AUTHOR]

While in situ toxicity testing with caged organisms has been used to assess surface water and sediment contamination, no successful application to benthic organisms exposed to highly contaminated groundwater plumes discharging to surface waters has been reported. The objective of this study was to demonstrate and evaluate this application using four sets of tests performed at three previously reported contaminated groundwater sites, which include one river site affected by volatile organic contaminant plumes, and two sites, one pond and one small urban stream, impacted by landfill plumes. The study examined multiple cage designs and orientations and two test organisms: an amphipod (Hyalella azteca) and midge larvae (Chironomus riparius; only one study). Cages were deployed for between 5 and 28 days and assessed for organism survival and growth. At all sites and for some deployment conditions, cages exposed to high contaminant concentrations in the plume footprint had greater mortality compared to those exposed to lower or background concentrations. Organism growth was less clear as a metric of toxicity. Vertically oriented cages typically showed high mortality to plume contaminants, but some were also affected by other non-target groundwater conditions (e.g., low dissolved oxygen, other contaminant sources), while horizontally oriented cages were rarely responsive to either groundwater influence. A hybrid cage design showed much promise in its single study. Useful observations on the test organisms and on potentially problematic site conditions were also made. The informed use of in situ toxicity cages could be an additional beneficial tool for groundwater contaminated site assessments. [ABSTRACT FROM AUTHOR]

There is a lack of information on the level of microplastic (MP) contamination in leachate, which contains high levels of pollutants and has considerable complexity to treat, originating from landfills. In this review, the sources, abundance, and characteristics (polymer type, size, shape) of MPs in landfill leachates were presented. Subsequently, the limited number of studies on MPs released into the environment from the environment from the leachate of uncontrolled landfills were summarised. In the next section, possible remediation approaches (physical treatment processes, chemical treatment processes, biological treatment processes, and constructed wetlands) for MPs in landfill leachate were discussed. Finally, research gaps and recommendations for future studies on MPs in landfill leachates were presented. As a result of the review, it was determined that there is an urgent need for a standardized MP analysis method. Furthermore, the necessity for an increased number of studies on the removal of MPs from landfill leachate with high efficiency and low cost was highlighted. It was emphasized that reducing the amount of plastic waste in landfills and reducing the amount of MP in landfill leachate can be achieved by taking and implementing urgent measures through public policies. [ABSTRACT FROM AUTHOR]

Borehole samples were collected from a municipal solid waste (MSW) landfill in Xi'an, China, and subjected to a series of basic geotechnical and compression tests. This study aims to investigate the influence of composition, dry unit weight, moisture content, organic content, and landfill age on the compressibility of MSW. The results show that with increasing landfill age, the compressible components and organic content exhibit a decreasing trend while the dry unit weight increases. The moisture content does not vary significantly. There is also a linear trend between the logarithm of the primary compression strain and vertical stress. In addition, with an increase in compressible components content, moisture content, and organic content, the modified primary compression index (Cc') shows an increasing trend, whereas with an increase in dry unit weight and landfill age, Cc' shows a decreasing trend. Furthermore, regarding the 34 sets of data, authors only selected five data points for a detailed comparative analysis, this decision was made on the basis that these data points are representative. A modified primary compression index prediction model that considers the dry unit weight, moisture content, and landfill age of the MSW as influencing factors results in a fitting coefficient of 0.797. The Cc' values in this study are within the range of 0.12 to 0.36. These findings provide a reference for the vertical expansion design of existing landfills. [ABSTRACT FROM AUTHOR]

Surface water resources are the most precious, yet they are also the most vulnerable to pollution. Consequently, maintaining the sustainability of water supplies is critical for livestock support to achieve SDG goals. Landfill leachate poses a significant threat to water resources in developing countries. This study aims to determine how the Hosanna town landfill site affects the Jewie River by analysing the quality of the Alela and Ajew streams and the landfill leachate in both wet and dry seasons. Furthermore, assess the suitability of the water quality for agricultural purposes. The leachate pollution index (LPI), Canadian Council Member of the Environment Water Quality Index (CCMEWQI), and irrigation water quality indices (IWQI) were computed for both seasons using two composite leachate samples and five flow-pace composite river samples. In the wet season, the leachate pollution indices for L1 and L2 ranged from 20.87 to 22.47, respectively. During the dry season, the leachate pollutant index of L1 and L2 was found to be 24.42 and 27.98. Only the Ajew River stream was affected during the dry season because the landfill site is only 46 m away. Both the Ajew and Alela River streams are infested during the rainy season. Irrigation index concentrations revealed that the river water is suitable for cultivation. The early stages of landfill waste maturation are evident from the LPI results. Relocating the dump site is necessary to safeguard water resources because leachate has entered the river streams. [ABSTRACT FROM AUTHOR]

This research provides the first assessment of the leachate impact on water sources near the newly installed Landfill and Recovery Center (LRC) in Tangier, Morocco, which has been operational since the beginning of 2021. The investigation involved the analysis of microbiological and chemical parameters in water samples from four community wells and five surface water sources in the M'harar and Tahaddart Wadis during the dry season. Chemical analysis focused on detecting heavy metals, which were quantified using Atomic Absorption Spectrometry. Microbiological analysis involved assessing the presence of Fecal Indicator Bacteria utilizing the membrane filtration method. The findings reveal alarmingly high levels of fecal bacteria and distinct spatial water quality patterns, with a notable gradient of bacteriological contamination in groundwater sources surrounding the LRC. The highest concentrations were noted at well P.1, located about 3.6 meters from the LRC, while at well P.4, located 1 km away, there is a regression in bacterial and metal concentration, suggesting leachate percolation, likely due to construction faults and inadequate waste management. The heavy metal concentrations remained below the World Health Organization's maximum acceptable values. Nevertheless, the overall results of the M'harar and Tahaddart Wadis waters show no leachate runoff. The study highlights the urgent need to improve the installation of proper leachate collection tanks and treatment systems as well as robust environmental monitoring, to protect the ecological integrity of the Biological and Ecological Interest Site (SIBE) of the Tahaddart region and safeguard public health. This study is limited by its focus on a specific geographic area and the timing of sampling, which restricted the groundwater analysis to only four wells. Future research should include sampling across different seasons and a broader range of wells to provide a more comprehensive understanding of water quality dynamics.

This research provides the first assessment of the leachate impact on water sources near the newly installed Landfill and Recovery Center (LRC) in Tangier, Morocco, which has been operational since the beginning of 2021. The investigation involved the analysis of microbiological and chemical parameters in water samples from four community wells and five surface water sources in the M’harar and Tahaddart Wadis during the dry season. Chemical analysis focused on detecting heavy metals, which were quantified using Atomic Absorption Spectrometry. Microbiological analysis involved assessing the presence of Fecal Indicator Bacteria utilizing the membrane filtration method. The findings reveal alarmingly high levels of fecal bacteria and distinct spatial water quality patterns, with a notable gradient of bacteriological contamination in groundwater sources surrounding the LRC. The highest concentrations were noted at well P.1, located about 3.6 meters from the LRC, while at well P.4, located 1 km away, there is a regression in bacterial and metal concentration, suggesting leachate percolation, likely due to construction faults and inadequate waste management. The heavy metal concentrations remained below the World Health Organization’s maximum acceptable values. Nevertheless, the overall results of the M’harar and Tahaddart Wadis waters show no leachate runoff. The study highlights the urgent need to improve the installation of proper leachate collection tanks and treatment systems as well as robust environmental monitoring, to protect the ecological integrity of the Biological and Ecological Interest Site (SIBE) of the Tahaddart region and safeguard public health. This study is limited by its focus on a specific geographic area and the timing of sampling, which restricted the groundwater analysis to only four wells. Future research should include sampling across different seasons and a broader range of wells to provide a more comprehensive understanding of water quality dynamics. [ABSTRACT FROM AUTHOR]

Hydrothermal carbonization (HTC) emerges as a promising avenue for converting food waste into valuable resources while addressing environmental concerns. This study investigated the optimization of HTC parameters, utilizing landfill leachate as a sustainable moisture source and exploring methane recovery from process water. Employing the response surface methodology (RSM) and artificial neural networks (ANN), the influence of key process variables on HTC efficiency was meticulously analyzed. Notably, the superior predictive capability of ANN over RSM was demonstrated, with a lower mean-squared error and a higher correlation coefficient. The identified optimal HTC conditions were 193°C for 175 min at a solid/liquid ratio of 0.2; under these conditions, RSM and ANN predicted mass yields of 66.37 ± 1.15% and 65.68 ± 0.11%, respectively. Furthermore, under these conditions, process water exhibited a remarkable biomethane production rate of approximately 283.11 ± 13.5 mL/g COD, fitting well with the modified Gompertz model. This study advances HTC optimization strategies and underscores the potential of integrating landfill leachate and methane recovery into food waste valorization processes, thereby paving the way for sustainable resource management practices. [ABSTRACT FROM AUTHOR]

The waste produced around the world increases daily due to population increase and the fact that life expectancy is longer. Waste production is higher in urban environments; therefore, managing Urban Solid Waste must be more rigorous to avoid environmental problems and health effects. For this reason, standards are created to properly manage landfills so that each life cycle stage is managed responsibly. However, a solid commitment from the community and more management regulations from the government are needed to be focused on reducing, reusing, and recycling materials as much as possible. This commitment needs to be reinforced to the extent that regulatory policies are created at the household level as much as education and awareness programs are implemented. This study presents a method to evaluate how imposing waste management goals before they reach landfills can increase the lifetime of landfills and, consequently the suitableness of a treatment plant implementation. [ABSTRACT FROM AUTHOR]

This study investigated the electrooxidation (EO) of mature landfill leachate from the Brady Road Resource Management Facility, Winnipeg (Canada). EO using boron-doped diamond (BDD) electrodes were applied to treat real landfill leachate using a batch reactor. Response surface methodology (RSM) was used to determine the optimum process parameter levels. This research mainly focused on how different current densities (64, 95, and 125 mA/cm2) and operational time (30 min, 1, 1.5, 2, 2.5, and 3 hr.) influenced the optimisation of parameters such as chemical oxygen demand (COD), colour, ammonium, and phosphate removal in mature landfill leachate at varied pH. To attain a high percentage of removal for the parameters mentioned above, the optimal conditions were found to be a current density (J) of 125 mA/cm2 and a pH of 8. The optimum conditions resulted in removal percentages of 95.47%, 80.27%, 71.15%, and 47.15% for colour, NH4+, COD, and PO43- respectively, with an energy consumption of 0.05 kWh/dm3. The removal is related to a mechanism of the decomposition of water molecules to hydroxyl radicals and by direct anodic oxidation where the pollutants are transformed to CO2 and H2O. The novelty of this research lies in the optimisation of BDD electrode-based treatment for the simultaneous removal of COD, ammonium, phosphate, and colour from mature leachate collected from a severely cold climatic region of Canada. The BDD electrode showed excellent removal efficiencies for the targeted contaminants with lower energy consumption, making it a feasible method for on-site landfill leachate treatment. [ABSTRACT FROM AUTHOR]

Landfill leachate, which is a complicated organic sewage water, presents substantial dangers to human health and the environment if not properly handled. Electrochemical technology has arisen as a promising strategy for effectively mitigating contaminants in landfill leachate. In this comprehensive review, we explore various theoretical and practical aspects of methods for treating landfill leachate. This exploration includes examining their performance, mechanisms, applications, associated challenges, existing issues, and potential strategies for enhancement, particularly in terms of cost-effectiveness. In addition, this critique provides a comparative investigation between these treatment approaches and the utilization of diverse kinds of microbial fuel cells (MFCs) in terms of their effectiveness in treating landfill leachate and generating power. The examination of these technologies also extends to their use in diverse global contexts, providing insights into operational parameters and regional variations. This extensive assessment serves the primary goal of assisting researchers in understanding the optimal methods for treating landfill leachate and comparing them to different types of MFCs. It offers a valuable resource for the large-scale design and implementation of processes that ensure both the safe treatment of landfill leachate and the generation of electricity. The review not only provides an overview of the current state of landfill leachate treatment but also identifies key challenges and sets the stage for future research directions, ultimately contributing to more sustainable and effective solutions in the management of this critical environmental issue. [ABSTRACT FROM AUTHOR]

This study investigates the process of long-term (bio)degradation of polyethylene (PE) in an old municipal waste landfill (MWL) and its implications for environmental and human health. Advanced techniques, such as ICP–ES/MS and IC–LC, were used to analyze heavy metals and anions/cations, demonstrating significant concentration deviations from control samples. The soil's chemical composition revealed numerous hazardous organic compounds, further indicating the migration of additives from PE to the soil. Toxicological assessments, including Phytotoxkit FTM, Microtox® bioassay, and Ostracodtoxkit®, demonstrated phytotoxicity, acute toxicity, and high mortality in living organisms (over 85% for Heterocypris Incongruens). An unusual concentration of contaminants in the MWL's middle layers, linked to Poland's economic changes during the 1980s and 1990s, suggests increased risks of pollutant migration, posing additional environmental and health threats. Moreover, the infiltration capability of microorganisms, including pathogens, into PE structures raises concerns about potential groundwater contamination through the landfill bottom. This research underscores the need for vigilant management and updated strategies to protect the environment and public health, particularly in older landfill sites. [ABSTRACT FROM AUTHOR]

• VOCs components on the surface of large landfills were identified. • The NMHC of surrounding area was most affected by landfill in summer. • P + m-xylene was the key component that contributes to O 3 generation. • Ethylbenzenethe was the key component that contributes to SOA generation. Landfill disposal is a major approach of disposing municipal solid waste (MSW) in China. In order to explore the impact of volatile organic compounds (VOCs) generated by landfill on the air quality of regional environment, Jiangcungou landfill in Xi'an and its surrounding area were taken as a research object to analyze the spatial distribution and seasonal variation patterns of non-methane hydrocarbon (NMHC) and VOCs components through seasonal sampling of regional NMHC concentration and VOCs concentration (116 species). CALPUFF model was adopted to analyze the regional dispersion characteristics of NMHC on landfill. In addition, propylene equivalent concentration (PEC) and maximum incremental reactivity (MIR) methods were used to estimate O 3 formation potential of the landfill, while fraction aerosol coefficient (FAC) and SOA potential (SOAP) methods were used to estimate SOA formation potential of the landfill. It was indicated that, the component with the highest concentration of VOCs on the working surface and the surrounding area of landfill was p + m-xylene (41.0 μg/m3) and halohydrocarbon (111.2 μg/m3–156.3 μg/m3), respectively. The component with the greatest impact on the surrounding air was acetone, which accounts for 75 %–87 % of the corresponding substance concentration on the landfill. In summer, the surrounding area was affected most by NMHC from landfill, whose emissions contributed 9.5 mg/m3 to the surrounding area. The component making the largest contribution to O 3 formation was p + m-xylene (8 %–24 %), while ethylbenzene was the component making the largest contribution to SOA formation (20 %–24 %). [ABSTRACT FROM AUTHOR]

• Pressurised pyrolysis is performed on real mattress waste. • Consistent char yields with high energy content. • Yields of C 3 species similar to those of H 2 and C 2 compounds. • High-pressure conditions yield low heating value gas due to N 2 dilution. • Main compounds identified in the liquid fraction are benzonitrile and BTEX. Mattresses are a difficult waste to manage in landfills due to their large volume and low density. Pyrolysis treatment could reduce its volume while producing fuel or products valuable for the chemical industry. Pressurized pyrolysis at 400, 450, and 500 °C is carried out in a lab-scale autoclave at initial pressures 4.2, 8.4, and 16.8 bar. Product gas yield increases slightly along with elevated pressure as well as temperature. However, beyond 8.4 bar the initial pressure makes no discernible differences. CO and CO 2 are the major gas species followed by CH 4. CO contributes the most to the product gas energy content followed by C 3 species, C 2 H 6 , and H 2. Calculated energy content (heating value) is between 2 and 15 MJ·Nm−3. In terms of product gas energy content, low pressure pyrolysis is favorable over high pressure pyrolysis. According to integration areas of chromatographic measurements the liquid phase contains up to 25 % of N-compounds, with benzonitrile being the most abundant, followed by toluene, o-xylene, and ethylbenzene. The solid char maintains constant properties across operating conditions, with carbon and energy contents of approximately 75 wt% and 30 MJ·kg−1, respectively. [ABSTRACT FROM AUTHOR]

The water retention curve (WRC) of municipal solid waste (MSW) is the important hydraulic parameter for the study of unsaturated seepage analysis in landfills. Due to the compressibility and degradability of the waste, the search for a method to quickly and accurately test its water retention curve (WRC) is a current problem that needs to be solved. In this paper, considering the volume change of the waste specimens in test, the test principle of centrifuge testing of WRC is corrected to make it applicable to the testing of waste WRC. In addition, the WRCs of 20 MSW specimens with typical landfill compositions and porosities are measured using the corrected centrifuge test. The effects of compositions and porosities of waste specimens on WRC parameters were analyzed. The results are summarized as follows. Disregarding the height reduction of specimens resulted in overestimated matric suction values and underestimating volume water content values. By comparing uncorrected and corrected values, the maximum difference of the matric suction and volumetric water content reach 233 kPa and 11%, respectively. This study can provide a reference for accurately measuring the WRC of MSW using a centrifuge. For the waste specimen without kitchen and yard waste, composition had less of an effect on the WRC of waste compared to porosity. The effect of the content of the non-absorbable fraction on the residual volumetric water content θr and the parameter nv in the van Genuchten model was significant. The initial porosity n had a great effect on the parameter α. [ABSTRACT FROM AUTHOR]

Nitrate contamination has become an ecological and health issue in Quanzhou, a typical coastal city in Southeast China. Hydrogeological surveys reveal that NO3− is a major factor influencing the groundwater quality in Quanzhou City, Fujian Province, China. To protect public health, this study explored the geographical spatial distribution, contamination level, contamination sources, and noncancer risks of nitrates in the plain area of Quanzhou. Key findings are as follows: (1) The groundwater in Quanzhou's plain area exhibits a high detection rate and over-limit ratio of NO3− –N of 99.3% and 57.86%, respectively. This result suggests that the groundwater in the area has been extensively contaminated by nitrates, with relatively severe nitrate contamination occurring in the Quanzhou Taiwanese Investment Zone, Jinjiang City, and Shishi City; (2) NO3− has become a major anion in groundwater in Quanzhou's plain area, leading to significant geochemical changes in some groundwater. 26.4% of the groundwater samples exhibited a hydrochemical type of nitric acid (also referred to as NO3− type water), with X(NO3−) ≥ 25%; (3) The primary nitrate contamination in groundwater in Quanzhou originates from the infiltration of domestic and industrial wastewater or landfill leachate; (4) 42.86%, 43.57%, and 67.14% of the samples posed health risks to adult males, adult females, and children, respectively when they were subjected to the prolonged exposure in a high-concentration nitrate environment. Additionally, the noncancer risks of nitrates principally stem from oral exposure for drinking water. [ABSTRACT FROM AUTHOR]

This article presents a methodology for evaluating the susceptibility of landfill areas to develop landslides by analyzing Synthetic Aperture Radar (SAR) satellite products. The deformation velocity of the landfills is computed through the Persistent Scatterer Method on SAR imagery. These data, combined with a deformation model based on the shallow water equations (SWE), form the foundation for a Monte Carlo experiment that extrapolates the current state of the landfill into the future. The results of this simulation are then employed to determine the probability of a landslide occurrence. In order to validate the methodology effectiveness, a case study is conducted on a landfill in Zaldibar, Spain, revealing its effectiveness in estimating the probability of landfill landslides. This innovative approach emerges as an asset in large landfill management, acting as a proactive tool for identifying high-risk sites and preventing potential landslides, ultimately safeguarding human life and the environment. By providing insights into landslide probabilities, this study enhances decision-making processes and facilitates the development of intervention strategies in the domain of landfill risk assessment and management. [ABSTRACT FROM AUTHOR]

Disposal of landfill leachate is a critical environmental challenge due to its high pollution content. Effective treatment technologies are essential to mitigate the adverse impacts on groundwater and surrounding ecosystems. This paper employs bibliometric analysis and utilizes CiteSpace software to conduct a visual analysis of the knowledge graph of 959 research articles on "Disposal of Landfill Leachate" from the Web of Science core database for the period 1996-2022. The results indicate that the publication quantity has undergone three stages: the sprouting stage, the stable development stage, and the rapid development stage. In terms of international collaboration, China and the USA play an absolute core role. The journals Waste Management, Journal of Hazardous Materials, and Water Research are ranked among the top 3 publications in the field of landfill leachate treatment. The keyword co-occurrence clustering analysis revealed 7 clusters, including groundwater quality, heavy metals, hydrogeophysics, municipal solid, hydraulic conductivity, geochemical barriers and waste disposal, representing the primary research topics. This paper provides a comprehensive analysis of the research progress and development trends in the field of disposal of landfill leachate. It contributes to a better understanding of the key research areas and offers potential prospects for future investigations to researchers. [ABSTRACT FROM AUTHOR]

Landfill leachate contains a significant amount of organic matter, making it a valuable source for CH4 production. However, due to its liquid form, the mono-digestion of leachate could result in a reduced CH4 yield per unit reactor volume. This necessitates its utilization in anaerobic digesters alongside solid waste streams. The objective of this study was to evaluate co-digestion performance of landfill leachate with different wastes using biomethane potential test and assess the optimum combination in terms of CH4 productivity. Modified Gompertz model was used for kinetic characterization. Experiments were held under mesophilic conditions and lasted for 30 days. Among mono-digestion of substrates, landfill leachate exhibited the highest CH4 productivity and yield: 83.17 mL/gVS.d and 793 ± 6.85 mL/gVS, respectively. Fish waste was found to have the lowest energy potential with 350 mL/gVS CH4 yield and 18.24 mL/gVS.d CH4 productivity. CH4 productivities for co-digestion cases ranged from 5.48 to 67.85 mL/gVS.d. Mixing landfill leachate and chicken manure with the same amount on wet weight basis yielded the highest CH4 productivity. On the other hand, inclusion of fish waste consistently resulted in decreased CH4 yield and productivity for all incubations, which suggests that fish waste may not be suitable as a co-substrate for landfill leachate in terms of CH4 production. Monitoring of chemical parameters revealed that buffering capacity of the system and free ammonia formation were the main parameters governing CH4 production. [ABSTRACT FROM AUTHOR]

This paper investigates the optimal remediation process in an aquifer using Modflow 6 software and genetic algorithms. A theoretical confined aquifer has been polluted over a long period of time by unnoticed leakage in a pipeline conveying leachate from an adjacent landfill to a wastewater treatment plant. When the extended leakage and groundwater pollution are discovered, the optimal planning of the remediation strategy is investigated using the pump-and-treat method or/and hydrodynamic control of the pollution. The practical goal is to find the optimal locations and flow rates of two additional pumping wells, which will pump the polluted water or/and control pollution, protecting an existing drinking water pumping well, securing its fully operational mode even during the remediation process with the minimum possible cost, simply represented by the pumped water volume of the additional wells. The remediation process is considered complete when the maximum concentration in the aquifer drops below a certain limit. The Modflow software (handled by the Flopy Python package) simulates the flow field and advective–dispersive mass transport, and a genetic algorithm is used as the optimization tool. The coupled simulation–optimization model, Modflow-GA, complemented by a sophisticated post-processing results analysis, provides optimal and alternate sub-optimal remediation strategies for the decision makers to select from. [ABSTRACT FROM AUTHOR]

Due to the abundance of agrochemicals, feces, urine, and landfill leachates, nitrates ( NO 3 - ) are one of the most prevalent forms of inorganic pollutants in water bodies and groundwater. In this work, EC treatment was carried out in continuous flow with a Mg/Zn system for the treatment of a drinking water well near a landfill. The maximum efficiency of 93.15% was achieved at optimal operating conditions: current intensity of 0.6 A, flow of 2.9 mL/min and TRH of 86.81 min. In addition, 73% of silica was removed (from 65.05 to 17.76 mg/L), which interacts with magnesium and calcium to form silicates of both elements. EC is an efficient treatment technology with an operating cost of 2.65 US$/m3. In addition, Si causes interference in the EC system by prioritizing reactions with calcium and magnesium, and 72.69% Si was removed by EC. Finally, the inorganic ions were also significantly removed: 100% phosphates, 82.37% sulfates, 47% total hardness, and 42.28% chlorides. Conclusively, EC improved the water quality and thus minimized the health effects of consumers, and the drinking water studied in this work was used for the hydration of 212,500 L per day of milk formula for infant consumption and older adults. Highlights: Mg/Zn electrocoagulation was used for the treatment of drinking water polluted with nitrates. The maximum efficiency of 93.15% was achieved at 0.6 A, flow of 2.9 mL/min and TRH of 86.81 min. In addition, 73% of silica was removed from 65.05 to 17.76 mg/ L. EC is an efficient treatment technology with an operating cost of 2.65 US$/m3 EC improved the water quality minimizing the health effects of consumers. [ABSTRACT FROM AUTHOR]

Open dump landfills are recognised as potential sources of heavy metal (HM) contamination. Their migration to the wider environment is largely controlled by their speciation; and in this study, results from sequential extraction, pH values and organic matter contents in soils around an open dump landfill and sediments in a leachate collection ditch were investigated in order to study the attenuation processes that lead to a decrease in HM mobility. The results revealed that Cu and Zn leached from the landfill were largely retained by sediments in the collection ditch and mostly bound to organic fraction. A simple mass balance suggested that, in comparison to other sources, HM accumulation in soils that resulted from the landfill was relatively low for Cu and relatively high for Zn. The concentrations observed were within safe limits according to the Thai standard for non-residential soil. This study showed that a leachate collection ditch plays an important role in minimising HM migration. Monitoring and further studies on fate and migration pathways of pollutants from open dump landfills, in particular to those underlain by different geologic settings to our study are needed to develop cost-effective measures to prevent/minimise the effect of landfill leachate and ensure that the environment surrounding landfill sites is safe. [ABSTRACT FROM AUTHOR]

Landfill leachate forms when waste-inherent water and percolated rainfall transfer are highly toxic, corrosive, acidic, and full of environmental pollutants. The release of leachate from municipal solid waste (MSW) landfill sites poses a severe hazard to human health and aquatic life. This study examined the impact of leachate from Delhi's Ghazipur landfill on the nearby groundwater quality. Analysis of leachate samples was done to determine various parameters such as total dissolved solids (TDS), hardness, alkalinity, electrical conductivity, pH, BOD5, COD, nitrate, sulphate, chloride and iron, and presence of coliform bacteria. Significant dissolved elements (22,690–34,525 mg/L) were observed in the samples, indicated by the high conductivity value (1156–1405 mho/cm). However, a stable pH range (6.90–7.80) of leachate samples was observed due to high alkalinity concentrations between 2123 and 3256 mg/L. The inverse distance weighing (IDW) interpolation tool from QGIS 3.22.7 developed spatial interpolated models for each parameter across the Ghazipur area. The IDW interpolated graphs of various parameters over the whole study area confirmed these contaminations. In addition, leachate and groundwater samples were physio-chemically analyzed, and temporal fluctuation in landfill waste has also been studied. The temporal fluctuation results showed that when heat is produced, transmitted, and lost throughout the waste system, the maximum temperature position fluctuates over time. The findings of this study highlight the critical importance of landfill management in reducing groundwater contamination from MSW leachate. [ABSTRACT FROM AUTHOR]

The Anaerobic Baffled Reactor (ABR) is an effective solution for landfill leachate treatment using an anaerobic fermentation process, which helps to reduce operating costs and sludge volume. To better understand the biological, chemical, and physical processes involved, especially when combining the ABR with an aerobic component, the study aimed to investigate the performance of an Anaerobic–Aerobic Hybrid Baffled Reactor (AABR) that includes an Anaerobic Filter (AF) for treating landfill leachate. This research utilized two glass reactors. The first reactor, designated as AABR-AF, consisted of six independent rectangular glass chambers arranged side by side. The third and sixth chamber designed for aerobic treatment and AF, respectively. The second reactor was used as a control reactor and did not include any aerobic chamber. The highest Removal Efficiencies (REs) for turbidity, COD, BOD, TP, TKN, nitrate, TOC, and TSS in the AABR-AF and ABR-AF were found to be (65.4% and 56.3%), (98.3% and 94.1%), (98.1% and 93.2%), (86.4% and 65%), (89.2% and 76.7%), (81.2% and 64.4%), (88.2% and 79.4%), and (72.4% and 68.5%), respectively. These optimal REs were achieved at an HRT of 48 h and an OLR of 10 kg/m3.d. Also, the highest and the lowest REs in Heavy Metals (HMs) were 89.57% for manganese in AABR-AF and 6.59% for nickel in ABR-AF, in an OLR of 10 kg/m3.d, respectively. The effective removal of Organic Matters (OMs) from landfill leachate using the AABR-AF and ABR-AF was found to be strongly influenced by HRT and OLR. The AABR-AF configuration, featuring a single aerobic chamber in the reactor, exhibited a higher efficiency in removing OMs compared to the ABR-AF configuration. [ABSTRACT FROM AUTHOR]

Increasing production and wealth in industrialized countries led to an increase in waste production, part of which was clearly harmful to human and non-human health. Out of several intergovernmental organizations that addressed related questions, the NATO Commission on Challenges of Modern Society (CCMS) was the first to organize a specific project dedicated to the topic. Between 1973 and 1981, delegates from nine NATO countries studies aspects ranging from the organization and recommended procedures of waste management to landfills, transportation, various ways of disposal and chromium recycling. Thereby, the CCMS got to set the agenda for problematic wastes, effectively establishing 'hazardous waste' as a recognized category. It also framed the challenge as one of 'disposal,' discouraging systemic socio-economic reviews. Overall, this framing drew attention to the potential dangers of some forms of waste to human health and to the environment and the need for special protective measures, while normalizing and potentially diverting attention away from other forms of waste. At the same time, CCMS activities provided an important push towards international guidelines and regulations of hazardous waste management and trade. [ABSTRACT FROM AUTHOR]

Uncontrolled dumping of open landfills has been becoming a significant threat to developing countries. The areas where solid wastes are stored increase the risk of groundwater and environmental pollution. Groundwater pollution causes poisoning and even death in terms of public health. This study investigated the impact area of pollutants that pose environmental risks in the Hamamboğazı (Aksaray Turkey) landfill area. Six vertical electrical sounding (VES) measurements were made in the study area. The direction of the leakage water is southwest, and the penetration depth is 15 m. The electrical conductivity reaching high values such as 4160-7900 µS/cm shows the polluting effect of the leachate. Heavy metals detected in leachate were Cu (0.183 mg/dm³), Pb (0.234 mg/dm³), Zn (0.33 mg/dm³), and Fe (3.179 mg/dm³). [ABSTRACT FROM AUTHOR]

BACKGROUND AND OBJECTIVES: The utilization of stabilization pond system for landfill leachate treatment is hindered by its requirement for expansive land areas and extended retention periods. Although the system effectively removes organic compounds, its ability to eliminate nutrients such as nitrogen and phosphorus is comparatively limited. Consequently, the leachate subjected to treatment often falls short of meeting the mandated standards for effluent quality. In response to this challenge, a research study was undertaken to investigate the potential of utilizing a consortium comprising microalgae and bacteria in the treatment of landfill leachate. METHODS: The microalgae, bacteria, and leachate utilized in this study were sourced from a leachate treatment facility located at the Aceh regional domestic waste management unit in Blang Bintang, Aceh Besar, Indonesia. The two glass photobioreactors were operated batchwise, where the first was provided with a combination of air and carbon dioxide, and the other was solely exposed to air. The pollutant removal efficacy in the leachate effluent was assessed through the measurements of chemical oxygen demand, ammonia, nitrate, nitrite, and phosphate concentrations. Subsequently, macroscopic identification of microalgae and bacteria species was also conducted. FINDINGS: Utilizing a consortium of microalgae and bacteria has demonstrated efficacy in treating leachate, resulting in a notable reduction of contaminants within the effluent. The symbiotic association between microalgae and bacteria in the context of leachate waste treatment is evident. The bacteria's metabolic actions result in carbon dioxide emission, which subsequently serves as a substrate for the photosynthetic activities of the microalgae. The microalgae facilitate the transfer of oxygen, produced through photosynthesis, to the bacteria to support their metabolic processes. Therefore, introducing exogenous carbon dioxide to the consortium yields minimal discernible effects, given that the bacteria adequately fulfill the carbon dioxide requirements of the microalgae. This discovery enhances the efficacy of leachate treatment techniques by leveraging the utilization of pre-existing mixed cultures of microalgae and bacteria found in leachate facilities. CONCLUSION: This study evaluated the microalgae-bacteria consortium's effectiveness in reducing leachate pollutants. The consortium exhibited a significant capability, achieving a 75 percent reduction in chemical oxygen demand and successfully eliminating a range of contaminants. Additionally, it demonstrated effective removal of nitrogen compounds such as ammonia, nitrate, and nitrite, with removal rates reaching 75 percent. Notably, the consortium showed a 99 percent removal rate for phosphate compounds. Even with the introduction of carbon dioxide, the pollutant removal remained consistently high, suggesting that the addition of carbon dioxide did not significantly influence the overall process. [ABSTRACT FROM AUTHOR]

Urban waste management, including that of sanitary landfills, is an urgent matter worldwide. Scavengers at sanitary landfill sites face safety and health issues. Their human rights are often violated through social oppression, dehumanization, and exploitation. Numerous landfills have been closed by governments to address these issues. Although these closures may have brought safer, cleaner, and more equitable living environments, in some cases, the low incomes and living standards of former scavengers who continue to reside at these sites have been exacerbated. That is, there may exist different perspectives of justices for respective stakeholders (e.g., government officials and scavengers). Based on the foundation of urban social justice and the capabilities approach as a theoretical framework, and using observations and interviews, this case study examines and addresses the socioeconomic complications faced by the local residents in the post-landfill situation of Payatas in the Philippines in an attempt to work toward establishing a just city. [ABSTRACT FROM AUTHOR]

Globally, more than 2 billion tonnes of municipal solid waste (MSW) are generated each year, with that amount anticipated to reach around 3.5 billion tonnes by 2050. On a worldwide scale, food and green waste contribute the major proportion of MSW, which accounts for 44% of global waste, followed by recycling waste (38%), which includes plastic, glass, cardboard, and paper, and 18% of other materials. Population growth, urbanization, and industrial expansion are the principal drivers of the ever-increasing production of MSW across the world. Among the different practices employed for the management of waste, landfill disposal has been the most popular and easiest method across the world. Waste management practices differ significantly depending on the income level. In high-income nations, only 2% of waste is dumped, whereas in low-income nations, approximately 93% of waste is burned or dumped. However, the unscientific disposal of waste in landfills causes the generation of gases, heat, and leachate and results in a variety of ecotoxicological problems, including global warming, water pollution, fire hazards, and health effects that are hazardous to both the environment and public health. Therefore, sustainable management of MSW and landfill leachate is critical, necessitating the use of more advanced techniques to lessen waste production and maximize recycling to assure environmental sustainability. The present review provides an updated overview of the global perspective of municipal waste generation, composition, landfill heat and leachate formation, and ecotoxicological effects, and also discusses integrated-waste management approaches for the sustainable management of municipal waste and landfill leachate. [ABSTRACT FROM AUTHOR]

Summary: In this work, we present a mixed‐dimensional mathematical model to obtain the electric potential and current density in direct current simulations when a thin liner is included in the modelled domain. The liner is used in landfill management to prevent leakage of leachate from the waste body into the underground and is made of a highly‐impermeable high‐resistivity plastic material. The electrodes and the liner have diameters and thickness, respectively, that are much smaller than their other dimensions, thus their numerical simulation might be too costly in an equi‐dimensional setting. Our approach is to approximate them as objects of lower dimension and derive the corresponding equations. The obtained mixed‐dimensional model is validated against laboratory experiments of increasing complexity to show the reliability of the proposed mathematical model. Our tests also show that configurations with current and voltage electrodes on either sides of the liner confining the landfill may be effective in detecting damages of the membrane. [ABSTRACT FROM AUTHOR]

Changes in the activated sludge performance in an anaerobic/aerobic biological treatment system for leachate was discussed under the condition of tetracycline (TC) exposure. The results show that a low concentration of TC did not have an obvious effect on the removal of chemical oxygen demand (COD) while a high concentration of TC had a certain promoting effect. Under the stimulation of TC, the particle size distribution of anaerobic/aerobic sludge tended to be more uniform, the particle size of anaerobic sludge decreased while the settleability increased; however, the particle size of aerobic sludge increased due to bulking. With the addition of TC, the concentration of most heavy metal ions in sludge samples increased.TC exposure results in the release of a large amount of extracellular polymeric substances (EPS), thus leading to a smoother surface of anaerobic sludge and a rougher surface of aerobic sludge. The high removal efficiency of COD under the high concentration of TC was also presumed to be due to EPS promoting the microbial absorption of anaerobic substances in the leachate. The results clearly showed that TC had a bacteriostatic effect. After antibiotic exposure, the abundance and diversity index of bacteria in each reactor decreased obviously, the microbial community evolved, and the dominant species at the genus and phylum levels of anaerobic/aerobic reactors changed. This study provides a better understanding the effect of TC on activated sludge and has reference value for the management of antibiotic exposure in leachate treatment facilities. [ABSTRACT FROM AUTHOR]

Cracking behavior can reduce soil hydraulic and mechanical properties and is a preferential pathway for water flow and pollutant transportation, resulting in polluted environment, such as application to landfill liners and capping. Recently, researchers have advocated the use of waste materials for clay mixtures using various measurement and analysis methods. Therefore, this study aims to conduct a bibliometric analysis of the scientific literature published between 2002 and 2021 obtained from Scopus to quantitatively identify research trends, key research areas, and future research paths in this field on desiccation and crack behavior using waste materials as landfill liners. The VOS viewer software was used to analyze 41 articles in which the paper selection process was filtered. The results showed that the fly ash mixture's application as a landfill liner could reduce cracking significantly. Furthermore, fractal analysis and X-ray computed tomography measurements have proven to be good candidates for measuring cracks because they are the most accurate for calculating the crack value. Waste materials such as fly ash can be applied as landfill liners with other materials, such as bentonite and coconut coir fibers. This study is beneficial for improving the design and selecting the appropriate materials for landfill liners. [ABSTRACT FROM AUTHOR]

Landfill leachate is a mixture of highly concentrated organic and inorganic pollutants and needs to be treated properly due to their toxicity and serious adverse effects on the environment. Recently, advanced oxidation processes have been successfully applied for leachate treatment. In this study, the removal of chemical oxygen demand (COD), total organic carbon (TOC) and absorbable organic halogens (AOX) in waste leachate stabilized by the electro-Fenton (EF) process, which is one of the advanced oxidation processes, was investigated. For this purpose, a jacketed reactor in which the electrochemical process takes place was designed and iron electrodes were used for maintenance and cost efficiency in this process. Within the scope of the study, the efficiency of the important process parameters, such as pH, current density, catalyst amount, oxidant dose and electrolysis time, was determined and their values were optimized. Optimum values were found to be as pH 3, current density 150 A/m2, hydrogen peroxide amount 500 mg/L and electrolysis time 10 min. The best removal efficiencies were obtained as 71.7% COD, 97.4% AOX and 90.87% TOC under optimum conditions. In addition, within the scope of this study, the collapsibility and operating costs of the sludge having formed as a result of the EF process were also examined. It has been observed that especially the sludge formed as a result of the EF process has good settling properties. When the results were evaluated, it was confirmed that the EF process can be used efficiently to break down leachate organics in terms of wastewater quality and discharge limits. [ABSTRACT FROM AUTHOR]

[Display omitted] • Estimated amount of ∑ 26 PFAS released from landfills (M ̇ SW) was 36.8 g/ha-yr. • 97% and 3% of M ̇ SW was found in leachate and stormwater, respectively. • Less than 1% of M ̇ SW was found in gas condensate and groundwater. • ∑ 8 PFAA-precursors/∑ 26 PFAS was consistent in the leachate released. • PFAS from landfills will be released for an estimated period of over 40 years. Per- and polyfluoroalkyl substances (PFAS) have been found at high levels within landfill environments. To assess PFAS distributions, this study aimed to evaluate PFAS mass flux leached from disposed solid waste and within landfill reservoirs by mass balance analyses for two full-scale operational Florida landfills. PFAS mass flux in different aqueous components within landfills were estimated based on PFAS concentrations and water flow rates. For PFAS concentration, 26 PFAS, including 18 perfluoroalkyl acids (PFAAs) and 8 PFAA-precursors, were measured in samples collected from the landfills or estimated based on previous studies. Flow rates of aqueous components (rainfall, evapotranspiration, runoff, stormwater, groundwater, leakage, gas condensate, and leachate) were evaluated through the Hydrologic Evaluation of Landfill Performance model, water balance, and Darcy's Law. Results showed that the average PFAS mass flux leached from the solid waste standardized by area was estimated as 36.8 g/ha-yr, which was approximately 1 % to 3 % of the total amount of PFAS within the solid waste. The majority of PFAS leached from the solid waste (95 % to 97 %) is captured by the leachate collection system, with other aqueous components representing much smaller fractions (stormwater system at 3 % to 5 %, and gas condensate and groundwater at < 1 %). Also, based on the results, we estimate that PFAS releases will likely occur at least over 40 years. Overall, these results can help prioritize components for waste management and PFAS treatment during the anticipated landfill release periods. [ABSTRACT FROM AUTHOR]

This article presents the results of the study of the morphological composition of municipal solid waste (MSW) from the landfill of Atyrau city, and the waste's energy characteristics and presence of microorganisms, including bacteria, fungi and viruses. This study was carried out under a government order to determine the feasibility of recycling accumulated and incoming waste into electricity and its hazard to the environment and the workers involved in handling it. At the moment, there is no MSW recycling in Kazakhstan, which has led to the accumulation of more than 125 million tons of waste with an annual increase of 5 million tons. The research included four major cities (Almaty, Shymkent, Atyrau and Astana), which were selected not only on the basis of population, but also because the cities were located in different climatic zones. Samples were collected at the city landfills: 10 samples with an average distance of 100 m from each other were collected to provide a maximum coverage of both recently received waste and long-time stored waste. The research showed that neither climatic conditions nor the population size had a significant impact on MSW density, the values of which ranged from 120.1 kg/m3 to 145.4 kg/m3, as this indicator directly depends on the quality of life. The mass of the combustible fraction ranged from 39.41% to 54.62% and was mainly represented by plastic, textile and paper waste. The average value for the four cities was 50.30%. The higher calorific value fell in the range of 24.22–30.49 MJ/kg, with an average value of 26.71 MJ/kg. Microbiological studies showed little difference in average composition regardless of climatic conditions. Thus, no sharp differences in MSW composition, its energy characteristics and microbiological composition were found. The results of this study may be useful for optimising MSW recycling and disposal processes, as well as for developing measures to reduce their negative impact on the environment and human health. [ABSTRACT FROM AUTHOR]

The characteristics of the hydrogeology of the municipal solid waste landfill in Ivano-Frankivsk are given. Accumulation of waste in landfills causes environmental problems due to pollution of the atmosphere, water resources, and soil. It was established that there is practically no contamination of the water horizon with infiltrate. Commissioning of the leachate pipeline, which feeds part of the leachate to the city's treatment facilities, solves the problem of the accumulation of leachate at the landfill, however, creates an additional burden on these facilities. The composition of the infiltrate was analyzed. It was confirmed that the main harmful pollutants of infiltrates are oil products, nitrogen-containing compounds, dyes, humic compounds, and heavy metals. The main methods of cleaning of infiltrates abroad and in Ukraine are characterized. Based on the analysis of the available impurities, for the purification of the infiltrate, it is proposed to use the technology of physical-electrochemical wastewater treatment, which includes their treatment in electrocoagulators and the separation of coagulated impurities in a thin-layer settling tank. Our studies showed that during infiltrate purification up to normative indicators of its discharge to treatment plants are not reached and it is worth using additional treatment of the infiltrate with oxidizers. As a result of exploratory studies, it is proposed to carry out additional treatment with hypochlorite ions, which can be obtained during the electrolysis of the infiltrate on an inert anode. Cleaning the infiltrate using the described technology will reduce environmental pollution, which means increasing the level of environmental safety of the solid waste landfill. [ABSTRACT FROM AUTHOR]

Expanded polystyrene (EPS) foam (thermocol waste) is produced at a rate of several million tons annually and poses serious environmental challenges due to its widespread use and lack of biodegradability. The present research is to design an effective Malachite Green (MG) dye adsorbent, RBT (Recycled polystyrene (RPS)—Benzophenone-3,3′,4′,4′-Tetracarboxylic dianhydride (BPTCDA)) by the chemical modification of RPS with BPTCDA via two-step reactions (namely the Friedel–Crafts followed by amidation reactions). The adsorbent's characteristics were studied using the Scanning Electron Microscope (SEM), X-Ray diffraction analysis (XRD), and Fourier-transform infrared spectroscopy (FTIR) techniques. Solution pH, contact duration, initial dye concentration, adsorbent dose, and temperature of the adsorption process were individually optimized. The adsorption is well matched (R2 > 0.955) with pseudo second-order kinetics, and Freundlich isotherm was identified as most fitting with research findings. Thermodynamic analysis suggests that the adsorption is spontaneous and endothermic. The probable mechanism behind adsorption was predicted between adsorbent and adsorbate through FT-IR analysis. Finally, MG adsorbed RBT, was converted into 3D printing filaments by the extrusion process. When MG leaching of 3D filaments was evaluated, there was no evidence of MG leaching, which could imply that this approach is an environmentally benign way to remove toxic pollutants as well as reduce landfill polymer waste. Based on the adsorption experiment results, RBT is suitable for the adsorption of MG dye from a water-based medium; also the final product was converted into value-added products. [ABSTRACT FROM AUTHOR]

Banana peels can be a valuable adsorbent for reducing heavy metals in water. This study investigated the effect of chemical activators on Nipah banana peel (Musa acuminata balbisiana) on their ability to reduce Pb and Cd metals in landfill leachate. Before the adsorption test, the banana peels were treated with a different chemical activator, including detergent, NaOH, KOH, and H3PO4. The results showed that H3PO4 adsorbs relatively high amounts of metals (Pb-75.800%, Cd-18.491%) in landfill leachate among these activators. FTIR analysis showed that banana peels treated with H3PO4 produced sharper carbonyl or carboxyl group peaks. These groups are very influential in the metal adsorption process. SEM-EDS analysis of the H3PO4-treated banana peels showed an increase in carbon and oxygen elements in the banana peels and changes in the pore surface that enhanced the adsorption process on Pb and Cd metals. From this study, banana peels activated with H3PO4 showed great potential to be developed into adsorbents to reduce heavy metal concentration. [ABSTRACT FROM AUTHOR]