Landfill leachate is a hazardous by-product of municipal solid waste (MSW) and chemical oxygen demand (COD) is a key indicator for evaluating its pollution strength and treatment needs. This study aimed to predict leachate COD concentrations from the Nigde Municipal Solid Waste Landfill Site using a Multilayer Perceptron Artificial Neural Network (MLPANN). 52 weekly leachate samples were collected and analyzed for physicochemical indicators, including pH, the ambient temperature, total solids (TS), oil and grease (OG), electrical conductivity (EC), arsenic (As), cobalt (Co), and cadmium (Cd). The principal component analysis (PCA) identified three significant components that explained 77.84% of the total variance. pH, temperature, Cd, Co, and OG had significant loading scores among other parameters. Four models were tested with different input selections. Before running the models, the data set (n = 52) was split with season strata to 70% as the training set and 30% as the testing set. After cross-validation, the best model was selected based on the lowest error metrics. The best-performing model, which incorporated variables selected via PCA performed the best during cross-validation and generalization. Its final architecture (5-21-1) was used for the testing set and achieved a correlation coefficient of 0.864. This study also represents the first application of the brulee engine within the tidymodels framework for leachate COD prediction, offering a reproducible modeling approach for environmental monitoring studies.

Numerical modeling of settlement and gas generation in biodegrading municipal solid waste: a systematic review for sanitary landfill applications.

Geoelectrical imaging and cluster analysis for leachate mapping in a municipal solid waste landfill: A case study in Brazil.

Changes in the pore structures of municipal solid waste samples with different abilities to provide support to the landfill structure during degradation: Analysis of synthetic waste using X-ray computed microtomography.

Integrated resiliency and sustainability assessment of biogeochemical cover system to mitigate landfill gas emissions.

The scarcity of space in urban areas poses significant challenges for the disposal of solid waste. Conducting an Environmental Impact Assessment (EIA) is essential for the sustainable management of municipal solid waste landfills. In Mettur Municipal Corporation (MMC), continuous use of existing landfill sites has shown signs of environmental degradation. In this context, MMC was selected for a landfill site suitability assessment using Remote Sensing and GIS technologies. In the initial phase, eleven key landfill-related factors were identified for analysis. A weighted overlay analysis was performed using a GIS platform to determine the most suitable locations for landfill development. Thematic maps were prepared for various parameters, including land use/land cover, geomorphology, geology, soil, lineament density, groundwater table, water bodies, roads, major rivers, slope, and drainage. Each thematic layer was reclassified using the reclassification method based on its relevance to landfill suitability. Euclidean distance analysis was also conducted for road and railway track proximity. The selection of criteria was guided by the specific regional needs and environmental considerations of the study area. All factors were assigned appropriate ranks and weights based on their importance in determining landfill suitability. These were then integrated into a weighted overlay index to generate the final landfill suitability map. Environmental factors such as proximity to residential areas, road networks, and water bodies also influenced the suitability of the selected sites. Furthermore, the availability of surrounding vacant land provides potential for future landfill expansion. The results indicated that only 4.5% of the study area is highly suitable for landfill development, emphasizing the need for sustainable land use planning to support long-term environmental management.

Landfills contain significant amounts of nitrogenous substances and serve as important sources of nitrous oxide (N2O), with emissions primarily concentrated on the working face. This paper developed a semiempirical model based on the logistic principles to simulate the temporal dynamics of landfill N2O emissions. Results showed that the model successfully captured the S-shaped N2O emission pattern observed at a landfill site (R2 = 0.54). Both field and laboratory data indicated that the key model parameter , which represented the rate of N2O emission potential change with O2 availability, was strongly correlated with waste nitrogen content, landfill operation practices, and temperature. The model output representative N2O emission factors for three typical landfill scenarios─waste sorting (WS), business as usual (BAU), and enhanced emission (EE)─with values of 0.51, 5.20, and 10.97 mg N·kg-1 waste, respectively. Under the BAU scenario, the representative emission factor was used to estimate historical N2O emissions from Chinese landfills over the past two decades, yielding a total of 12.25 Gg N. In contrast, WS achieved a 90% reduction in N2O emission by diverting high-nitrogen waste (e.g., food waste), while EE resulted in a 111% increase even exceeding those from composting and incineration. The study demonstrates that that the semiempirical model enables robust estimation of landfill N2O emissions at both site- and national- scales. This can supplement the current IPCC guidelines on greenhouse gas inventories.

The drawdown performance of conventional leachate pumping wells in municipal solid waste (MSW) landfills is often variable and sometimes unsatisfactory. The integration of vacuum-assisted vertical leachate pumping wells has shown significant potential for improving leachate drawdown performance. However, the improvement in the hydraulic response of MSW during leachate drawdown using vacuum pumping wells has not been quantified. In this study, laboratory-scale model tests were conducted to investigate the desaturation of synthetic MSW using vacuum pumping wells. Both continuous and cyclic vacuum applications with a pressure range from 0 to −10 kPa were tested. The results demonstrated the occurrence of gas bubble instability during leachate drawdown, with a critical pore water pressure for gas bubble destabilisation of approximately 6 kPa. High vacuum pressures could either increase the hydraulic conductivity of the synthetic MSW by way of enhanced gas bubble expulsion or decrease it because of increased MSW compression. The cyclic vacuum application may provide an energy-saving strategy for lowering leachate levels using vacuum pumping wells, as it resulted in nearly the same leachate pumping capacity as that of constant vacuum. The optimal leachate pumping capacity for both constant and cyclic vacuum applications ranged from −6 to −8 kPa.

The study evaluates the long-term environmental performance of natural filtration dams for leachate treatment at a municipal solid waste landfill. Field measurements of a system operating for 24 years, equipped with natural clay-loam filtration barriers, provide empirical validation for assessing the effectiveness and durability of natural material-based treatment approaches. Hydrogeological studies, including well drilling, water sampling, and comprehensive chemical analysis, demonstrate that the cascade filtration system achieves pollutant removal efficiencies of 80–95% for major contaminants. Physical property measurements reveal progressive density reduction from 1005 to 994 kg/m3 and viscosity decreases from 1.048 to 1.011 cSt across the treatment system. Numerical simulations demonstrate that contaminant transport under actual site conditions remains diffusion-dominated over multi-decadal timescales, with aquifer concentrations remaining below 1% of source values after 50 years. Parametric studies reveal that density-driven convective fingering develops only at source concentrations exceeding 100 g/L. The findings validate the long-term viability of natural geological barriers combined with cascade filtration systems for cost-effective leachate treatment, demonstrating that preliminary treatment through natural filtration effectively suppresses gravitational instabilities and protects underlying aquifers.

The authors would like to make the following corrections to the published paper [...]

Lithium-ion batteries (LiBs) are widely used in electronic devices and renewable energy systems. Fluorochemicals are essential components of LiBs, as a component of electrolytes, electrodes, and coatings. However, there are concerns about the environmental release of fluorochemicals, especially within landfills after disposal, due to the fact that landfill leachate is typically treated in facilities not designed to attenuate fluorochemicals. We have evaluated the occurrence of fluorochemical compounds in commercial LiBs and fluoropolymer binders and the release of LiB-derived fluorochemicals in simulated municipal solid waste (MSW) leaching experiments. Our survey of 19 LiBs found per- and polyfluoroalkyl substances (PFAS) including bis(perfluoroalkyl)sulfonimide (bis-FASI, up to 36 mg) and inorganic fluorochemicals such as hexafluorophosphate (PF6-, up to 1.4 g) and bis(fluorosulfinyl)imide (bis-FSI, up to 250 mg). PFAS were also measured in fluoropolymer binders in the range of 2-2000 ng/g. Nontargeted analysis resulted in detection of diverse fluorinated sulfonimides and organic phosphofluoridates in batteries as well as 6 novel PFAS in fluoropolymer binders. Analysis of MSW landfill leachates indicated the presence of LiB-derived fluorochemicals up to 76 μg/L. Simulated MSW leaching experiments showed that LiBs released PFAS (up to 100 mg/L) and inorganic fluorochemicals (up to 1.4 g/L) into the landfill leachate over a period of 220 days. Furthermore, PF6- and bis-FSI transformed in landfill leachate to form organic phosphofluoridates and novel amino sulfonyl fluorosulfanomides. This is the first report of PFAS and fluorochemical release from LiBs and transformation under landfill leaching conditions.

Antibiotic resistance is a growing global concern, with municipal solid waste (MSW) landfills recognized as significant reservoirs of antibiotic-resistant bacteria and antibiotic resistance genes (ARGs). This review focuses on the emergence and spread of antibiotic resistance within landfill ecosystems and its consequent environmental impacts. It synthesizes research findings from 2018 to 2024, highlighting the persistence of resistance genes in landfill leachate, soil, air, and water. Particular emphasis is placed on the role of landfill environmental conditions in facilitating horizontal gene transfer and enhancing microbial adaptation. The review discusses how ARGs enter MSW landfills primarily through pharmaceutical waste, health care activities, agricultural runoff, and industrial discharges. Additionally, it examines current mitigation strategies, including engineered landfill designs, bioremediation using microbial consortia, development of environmentally sustainable pharmaceuticals, and enforcement of global regulatory frameworks. The analysis identifies critical research gaps, particularly in low- and middle-income countries, underscoring the urgent need for enhanced surveillance, standardized monitoring, and stringent regulations. The study recommends a multidisciplinary approach that integrates expertise from waste management, environmental science, microbiology, and public health to effectively tackle antibiotic resistance in landfill environments.

This study assessed the microbial populations and physicochemical properties of soils from active, dormant, and control municipal solid waste landfills in Port Harcourt, Rivers State, Nigeria. Standard sampling and analytical methods were employed to determine the Total Heterotrophic Bacterial Count (THBC) and Total Fungal Count (TFC) at 0–5 cm and 5–10 cm soil depths. Results showed a consistent trend of microbial abundance across sites, with the first active dumpsite recording the highest in THBC (7.80) and TFC (5.20) 106 CFU/g, while the control site had the lowest counts of 1.6 and 0.4 respectively. At 0–5 cm depth, values for temperature (Oc ), pH, carbon (%), nitrogen (mg/kg), and phosphorus (mg/kg) were 43, 6.2, 4.6, 0.18, and 48 respectively, while at 5–10 cm depth the corresponding values were 40, 6.2, 4.2, 0.08, and 42. These findings indicate that waste disposal significantly influenced soil microbial communities and nutrient dynamics with important implications for soil quality, contamination risks, and ecological sustainability. Conclusively, effective management and remediation strategies are therefore essential to mitigate adverse impacts and restore soil health in waste-impacted areas.

The United Nations has identified municipal solid waste (MSW) landfills as significant reservoirs of antibiotic resistance genes (ARGs). Although ARG profiles, their primary drivers, and associated hosts have been well characterized in landfill leachate, such information remains limited for MSW landfills, which are the original source of the resistome. This knowledge gap impedes effective ARG monitoring at the source and poses challenges for public health management. Herein, we investigated the profiles of ARGs, their potential drivers, and associated hosts in refuse samples collected from a large-scale landfill using metagenomic sequencing and quantitative polymerase chain reaction analysis. Our findings revealed that landfills harbor diverse ARGs, with multidrug resistance genes (MDRGs) emerging as the dominant class, accounting for 39.78% of all ARGs detected. Notably, MDRGs exhibited high mobility potential (associated with plasmids, phages, and mobile genetic elements (MGEs)) and were frequently colocated with virulence factors. Pseudomonas, Acinetobacter, and Brevundimonas were identified as key MDRG hosts. Partial least-squares path modeling analysis indicated that MDRG variation was driven by multiple factors (i.e., MGEs, metal resistance genes (MRGs), hosts, and environmental factors). Additionally, metagenome-assembled genomes were found to carry multiple MDRGs. Collectively, these results underscore the role of landfills as critical hotspots for MDRGs.

Over 292 million tons of municipal solid waste (MSW) are generated annually in the United States, with more than half disposed of in landfills. Municipal solid waste landfills (MSWLFs) are stationary sources of air pollution and potential health risks for nearby communities. The Agency for Toxic Substances and Disease Registry (ATSDR) has completed over 300 public health assessments (PHAs) and related investigations at MSWLFs and open dumps since the 1980s. This paper reviews the ATSDR's evaluations of air pathway concerns at 125 MSWLF sites assessed between 1988 and early 2025, with many being evaluated during the 1990s. Most sites were located in the Midwest and Northeast, and only 25% remained active. The ATSDR found no air-related public health hazard at 86% of sites. At sites where hazards were identified, common issues included elevated outdoor or indoor toxicants (e.g., hydrogen sulfide, benzene, trichloroethylene, and mercury) and unsafe methane accumulations. Contributing factors included older site designs, inadequate gas-collection, subsurface fires, and distance from nearby residences. Corrective actions effectively reduced exposures at the affected sites. Results suggest that well-located and maintained landfills minimize public health hazards, while aging or poorly managed sites pose risks. Continued monitoring and research are warranted as waste management shifts toward reducing, reusing, recycling, composting, and energy-recovery technologies to improve efficiency, advance technologies, and address systemic public health challenges.

The identification of locations for both municipal solid waste (MSW) landfill and construction and demolition waste (CDW) disposal necessitates a comprehensive spatial planning strategy, particularly in environmentally sensitive and physically constrained areas. Gökçeada, an island characterized by limited developable land and seasonal population variations due to tourism, requires integrated planning for MSW and CDW. This research utilized a multi-criteria decision-making model (MCDM) that integrates the Analytic Hierarchy Process (AHP) with Geographic Information Systems (GIS) to determine appropriate sites for both forms of waste. The findings indicate that merely 3.61% of the island is appropriate for municipal solid waste landfill and 3.67% for CDW disposal site, with extremely favorable regions accounting for 1.04% and 0.61%, respectively. 3 locations; Area 1, Area 2, and Area 3 were recognized as feasible choices, each presenting unique spatial and logistical benefits. Moreover, the designated locations align with the anticipated MSW accumulation volume by 2058. This dual evaluation facilitates optimal land utilization, mitigates environmental repercussions, and offers a reproducible framework for sustainable waste management in island regions.

Studies of water bodies near MSW landfills are usually limited to hydrochemical parameters. However, since hydrochemical parameters are subject to frequent variability, and the negative effects of MSW landfills can occur over a long period of time, it is necessary to use the most "constant" indicators. It is proposed to expand the list of the studied parameters at the expense of hydrobiological ones, since hydrobionts are good bioindicators of the environment, and the use of various indices makes it possible to more accurately determine the nature and consequences of pollution by filtration waters of MSW landfills of water bodies. The article presents the results of a qualitative and quantitative study of zooplankton and zoobenthos from three water bodies (one background and two likely to be adversely affected) as part of the environmental monitoring of the impact of the Kaliningrad MSW landfill on aquatic ecosystems. The qualitative composition of zooplankton and zoobenthos revealed typical representatives for this area, mostly eutrophic organisms. An assessment of the contamination of the studied water bodies has also been carried out using the Pantle-Bucca method of indicator organisms modified by Sladechek, which is quite simple and often used in application. The calculations have made it possible to identify the state of aquatic ecosystems, in which water bodies retain high species diversity and biomass of zooplankton and zoobenthos. The studied water bodies, according to the gradation, can be characterized as "medium pollution". The most "polluted" is the nearest water body to the MSW landfill (a second-hand pond 400 m from the landfill), which is essentially a "buffer zone" between the MSW landfill and the Kaliningrad Bay.

Revealing hidden methane mitigation opportunities from legacy dumping and landfilling of municipal solid waste in rural China.

Heavy metal(loid) hazards in landfill groundwater: An assessment using self-organizing maps and 2D Monte Carlo modeling.

Life cycle environmental and economic assessment of co-combustion strategies for raw and landfilled municipal solid waste.