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At the end of 2020, Talang Gulo Landfill Site 1 in Jambi City was officially closed due to overcapacity. Municipal solid waste disposal has shifted to the Talang Gulo site 2 with a life expectancy of ± 90 years based on the design plan. However, this is difficult to realize because segregation and composting are not optimal, so more than 90% of the waste transported to the final processing site (TPA) is in a landfill. Thus, landfill mining was executed to utilize excavated landfill waste as a material and energy. It was carried out at depths of 3, 5, and 7 meters with an estimated sample age of > 9 years. The mixed landfill samples contained 55.6-66.2% moisture content, 50.3-80.6% volatile content, 19.4-49.7% ash content, 2.6-4.2% fixed carbon, and 3.5-5.7 MJ/kg calorific value. Furthermore, the landfill waste was dried using the biodrying method, combining fresh and landfill waste in the pile composition. The ratio of landfill waste to the addition of fresh waste is 1:0 (control pile), 1:1, 1:2, 1:3, and 1:4. The drying method reduced moisture content of 9-29.1% with a lower calorific value of 5-6.8 MJ/kg. Based on statistical analysis, it is known that waste ratio has a significant effect on moisture content. Based on the weighting results, the optimum mixture ratio is 1:1 (pile 2). [ABSTRACT FROM AUTHOR]

This study is a critical review of municipal solid waste (MSW) hydraulic conductivity that includes investigation of the influence of vertical stress, dry unit weight and degradation. A total of 56 studies were compiled that included laboratory-, pilot- and landfill-scale hydraulic conductivity experiments. Compacting waste and increasing vertical stress reduce MSW hydraulic conductivity via reshaping the pore networks throughout the waste matrix, reducing the void ratio and increasing tortuosity. However, the magnitude of reduction in hydraulic conductivity is dependent on stress, waste composition and decomposition. Solid waste decomposition can have opposing effects on hydraulic conductivity. Some studies have indicated that an increase in MSW decomposition results in particle size reduction and settlement that reduces the void ratio and decreases hydraulic conductivity. Conversely, some studies indicate that waste decomposition reduces the solid mass, which increases the void ratio and creates larger flow paths that increase hydraulic conductivity. The data compilation, observations and key findings from this study are beneficial for solid waste practitioners to improve design, analysis and operation of MSW landfills. [ABSTRACT FROM AUTHOR]

• Estimates of modeled CH 4 emission (E) data for 1,325 U.S. landfills were reviewed. • Operators use two methods to estimate E from landfills with a gas collection system. • First-order decay (FOD) method shows increasing emissions. • Collection efficiency assumption method shows decreasing emissions. • FOD method shows some agreement to remotely sensed national estimates. As part of its commitment to the United Nations Framework Convention on Climate Change, the U.S. annually develops a national estimate of methane emissions from municipal solid waste (MSW) landfills by aggregating activity data from each facility. Since 2010, the U.S. has reported a 20 % decrease in MSW landfill emissions despite a 21 % increase in tons disposed. Operator-submitted data were investigated to understand the causes of this decline. In the U.S., operators of landfills with a gas collection and control system (GCCS) calculate their facility's emissions via two separate approaches – (1) first-order decay (FOD) and (2) collection efficiency assumption (CEA) − and select either result to feed into the annual inventory. The FOD model predicts methane generation proportional to waste disposal and that approach calculated a 19 % increase in total methane generated from 2010 to 2022, whereas generation via the CEA approach decreased by 8.9 %. The amount of measured methane collected has increased 7.5 % for the same years. Discrepancies between the two models' generated methane, assumed gas collection efficiencies, and oxidized methane compound into substantive differences in national estimates. Operators more frequently select the CEA method, which results in decreased national estimates. If only the FOD method was used, U.S. MSW landfill emissions would be 1.3-1.7 times greater than current estimates which is similar to recent extrapolations from remote sensing campaigns in the U.S. Both models contain parameters with large inherent uncertainty. Without measurement methods that continuously quantify both point-source and diffuse emissions, an assessment of either equation's accuracy cannot be made. [ABSTRACT FROM AUTHOR]

Landfill siting is a major problem in solid waste management. Many aspects should be considered when selecting an appropriate site for a landfill in any particular region. In the current research, seventeen criteria were considered, including rivers, water bodies (lakes), geology, slope, elevation, power lines, groundwater depth, major district roads, archaeological sites, urban centers, infrastructure, villages, pipelines, quarrying, forests, aspect (wind), and agricultural areas. Several random open dump waste disposal sites are dispersed throughout the Ranya District, Iraq. This research employed the integration of a Geographic Information System (GIS) and Analytical Hierarchy Process (AHP) to identify the optimal sites for the establishment of sanitary landfills. The seventeen criteria were mapped and assigned subcriteria within GIS software. Subsequently, the normalized weights from the AHP were identified for each measure to generate the final Land Suitability Index (LSI) map for the site. Consequently, approximately 0.34% of the entire study area, equivalent to roughly 2,396,000 square meters, is estimated to be suitable for locating a landfill. Additionally, the suitable sites were categorized into moderately suitable, suitable, and mostly suitable. The normalized weight analysis revealed that groundwater depth significantly influences the selection of the best landfill site [ABSTRACT FROM AUTHOR]

Long-term monitoring and treatment of landfill leachate (LFL) and landfill gas (LFG) is required until landfilled municipal solid waste (MSW) is sufficiently stabilized and post-closure care can be terminated. Monitoring data of methane (CH4) emissions in LFG from a marine landfill over 30 years were compared with the IPCC first order decay (FOD) model estimates. The observed changes in CH4 showed a similar attenuation trend to the estimates, but the observed CH4 emissions were only about 30% of the estimate over 30 years; LFL is considered to be another pathway for organic carbon to be released to the environment, but the total organic carbon in discharged LFL was only about 0.2% of CH4 carbon in LFG emission over the same period. The increase in the CO2/CH4 ratio in LFG over time suggests that the discrepancy between estimated and observed emissions is due to methane oxidation in the overlying soil, in addition to the high coefficient values used in the FOD model. Total organic carbon (TOC) in LFL discharged as effluent reached a maximum value in the early stages of the landfill and gradually decreased, but only to about one-third of the maximum value after more than 30 years and a decrease in the amount of effluent. As incineration of MSW is expected to reduce organic carbon and nitrogen, the CH4 reduction effect of incineration of business and household waste and sewage sludge was investigated using FOD model estimates. [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]

Abstract 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.

Landfill leachate contains antibiotic resistance genes (ARGs) and microplastics (MPs), making it an important reservoir. However, little research has been conducted on how ARGs are enriched on MPs and how the presence of MPs affects pathogens and ARGs in leachates and soil. MPs possess the capacity to establish unique bacterial populations and assimilate contaminants from their immediate surroundings, generating a potential environment conducive to the growth of disease-causing microorganisms and antibiotic resistance genes (ARGs), thereby exerting selection pressure. Through a comprehensive analysis of scientific literature, we have carried out a practical assessment of this topic. The gathering of pollutants and the formation of dense bacterial communities on microplastics create advantageous circumstances for an increased frequency of ARG transfer and evolution. Additional investigations are necessary to acquire a more profound comprehension of how pathogens and ARGs are enriched, transported, and transferred on microplastics. This research is essential for evaluating the health risks associated with human exposure to these pollutants. [ABSTRACT FROM AUTHOR]

This study is mainly aimed at exploring effects of the aging-induced chemical decomposition of Municipal Solid Waste (MSW) on the shear response and physical properties of locally available MSW of Fars province, Iran, at its in-situ condition. To this end, a large direct shear device (1×1×1.1 m3) is designed, fabricated and employed to evaluate the parameters of the failure envelop at plane strain condition representing slopes of engineered landfills. Bulk disturbed samples of fresh MSW are exhumed from an operational disposal site to be implemented into the study and subsequently remolded in the large-scale shear box. Four drained shear tests are performed under a variety of vertical stresses. Next, intact components of MSW are landfilled over a period of 3, 6, and 9 months. Similar shear experiments are conducted at the end of each mentioned time interval. Mechanical behavior of MSW is completely frictional and internal friction angle of the studied MSW non-linearly increases with time from 44.2º to 55.7º. The stress-strain response is almost bilinear over a wide range of displacement. The decomposition process is further clarified in light of results of pH tests conducted on the leachate of the MSW at the end of various landfilling time intervals. [ABSTRACT FROM AUTHOR]

The article presents the stability analysis of two adjacent waste landfills located in a potentially unstable territory. One of the waste landfills is reclaimed and consists of ash. Municipal solid waste is actively deposited in the second landfill. In the space between the landfills, the expansion of the municipal solid waste landfill is planned, with a partial overlap of the reclaimed ash landfill. The instability of the area where the landfills are located is due to its susceptibility to the formation of landslides. The article presents the results of experimental verifications of the peak shear strength parameters of the ashes and the peak and residual shear strength of the soils forming the subsoil of both landfills and serve as input for stability analyses. The shear strength parameters of municipal waste are defined on the basis of literature research. The potential instability of both waste landfill territories was taken into account using the parameters of the residual shear strength of the subsoil. The stability analysis of waste landfills is expressed using both the peak and residual shear strength parameters of the subsoil of waste landfills. In addition, the effect of seismic loading on both landfills is considered in the stability analysis. [ABSTRACT FROM AUTHOR]

The dynamic changes in dissolved organic matter (DOM) during the transport of landfill leachate (LL) in porous medium should be explored, considering the high levels of DOM in the LL of municipal solid waste. Column experiments were carried out at 25 °C at a Darcy's flux of 0.29 cm/h for 2722 h to compare the transport of Cl−, ultraviolet absorbance at 254 nm (UV254), chemical oxygen demand (COD), and dissolved organic carbon (DOC) in the simulated porous medium by using the CXTFIT2.1 code. Results showed that the convection–dispersion equation (CDE) could describe Cl− transport well. The high levels of λ and D could be highly correlated with the physicochemical properties of the porous medium. The transport of the studied DOM with evident aromatic character could be described appropriately by the CDE model with the first-order reaction assumption, considering the similar variation trends of UV254, COD, and DOC in the effluent during experiments. Specifically, the values of retardation factor (R) were in the following order: DOC > UV254 > COD, whereas the low values of the first-order decay coefficient (k1) for DOC and COD were still higher than that for UV254. High contents of humic-like substances in the DOM with complex toxic components resulted in the natural low removal efficiencies of COD, DOC, and UV254 (≤ 23%), which could be confirmed by the variations of fluorescence index (FI) and humification index (HIX) in the effluent. The results should be helpful in evaluating the environmental risk induced by the LL leakage in a landfill site. [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]

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]

• Collection efficiency estimates are necessary for accurate emissions modeling. • Measured collection efficiency data categorized and compared with current defaults. • Cover type was statistically significant indicator of collection efficiency. • Results: 41% efficiency for daily cover, 69 % for intermediate, and 71 % for final. • New defaults greatly reduce discrepancy between modeled and measured estimates. Landfill methane emissions are commonly estimated using cover-type dependent default collection efficiency values, with a first-order decay model or measured gas collection. Current default collection efficiencies used in the United States were predominately derived from 4 studies conducted during or prior to 2007 that relied on flux chambers. Flux chambers are limited by small sample sizes, placement restrictions, and the inability to measure emissions from gas or leachate collection systems. Since 2007, over 14 new studies have been completed using more advanced technologies that allow for direct measurement of methane plumes from most or all of a landfill's surface. On average, these measurements are 2–3 times greater than emissions predicted by current models and collection efficiency defaults. In lieu of measuring emissions from all landfills, updating collection efficiency defaults can bring modeled emissions into better alignment with measurements. To this end, collection efficiency estimates derived from measured data were categorized into cover types and then adjusted to account for cases where whole plume measurement was an amalgamation of multiple cover types. The resultant adjusted default values were 41% for daily cover, 69% for intermediate cover, and 71% for final cover. Direct measurement of landfill methane emissions is preferrable to account for the full range of variables driving landfill emissions, including collection system design and operation. However, applying these updated defaults back into the landfill emission models eliminates underprediction of landfill emissions for the dataset reviewed, and would provide a more accurate estimate of landfill gas emissions where measurements are unavailable. [ABSTRACT FROM AUTHOR]

The world is currently facing significant environmental challenges due to increasing urbanization and globalization. Human activities can produce greenhouse gases (GHGs) such as CO2 and CH4. One of the contributors to GHG generation is the open dumping of Municipal Solid Waste (MSW), particularly because much of the waste is organic. It undergoes anaerobic decomposition, leading to the formation of GHGs, particularly methane. However, CH4 has a high potential for energy generation, and if harnessed properly, it can be highly beneficial. This study aims to assess the total air pollutants emitted from the landfill gas (LFG), including methane (CH4), carbon dioxide (CO2), and nonmethane organic compounds (NMOC) at the Regional Piyungan landfill in D.I. Yogyakarta province. The study also projected the year when the production of these gaseous pollutants would peak and when they are expected to be exhausted. Additionally, the study aimed to identify the potential health problems and clinical codification caused by these gaseous pollutants. To achieve these objectives, the LandGEM 3.03 version of the model developed by USEPA was used for the period 2023-2071. Clinical coding used the 2019 version of the ICD-10 reference. The estimated values for total LFG were 1.648E+04 (2024) and 1.584E+04 (2025) Mg/year, while CH4 was estimated at 4.403E+03 (2024) and 4.230E+03 (2025) Mg/year. CO2 was estimated to be 1,208E+04 (2024) and 1,161E+04 (2025) Mg/year, and NMOC was projected at 2,839E+01 (2024) and 2,727E+01 (2025) Mg/year. Some of the toxic effects that can occur cause respiratory, visual, and mental disorders with a variety of clinical codes. [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]

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]

This study examines the effect of landfill scarcity on the cost of municipal solid waste (MSW) disposal. We find the evidence that a decrease in the remaining capacity of landfill sites increases the unit cost of waste disposal. We also find that landfill scarcity impacts intermediate disposal costs (the cost of MSW disposal methods other than landfill disposal) more than landfill disposal costs. Based on the results of previous studies that estimated the external costs of landfills, the cost reduction effect of having a landfill site may overwhelm the external costs. Our results demonstrate that having its own landfill site not only provides the final recipient of MSW but also reduces the cost of MSW disposal. The latter type of benefit has been overlooked in previous studies on MSW disposal. [ABSTRACT FROM AUTHOR]

Landfilling is one of the predominant methods of municipal solid waste (MSW) disposal worldwide, while the generation of leachate, a kind of toxic wastewater, is among the primary factors behind landfill instability and environmental contamination problems. Precise prediction of leachate production is crucial to landfill safety evaluation and design. This paper presents a comprehensive review of methods for predicting leachate production from MSW landfills. Firstly, compositional characteristics of MSW and leachate generation mechanism are analysed. Factors influencing leachate production are summarised based on the generation mechanism, including the components of MSW, climatic conditions, landfill structure, and environmental factors. Then, we classified the existing methods for predicting leachate production into four categories: water balance formula, water balance model, empirical formula, and artificial intelligence model methods. Advantages, disadvantages, and applicability of different leachate production prediction methods are compared and analysed. Furthermore, limitations in the existing leachate production prediction methods for MSW landfills and scope for future research are discussed. [ABSTRACT FROM AUTHOR]

[Display omitted] • Three PFAS leached from biochar derived from construction/demolition (CDD) wood. • 5:3 FTCA was reduced by CDD wood biochar in landfill leachate batch leaching. • Low biochar surface area and high matrix organic matter hinder PFAS sorption. • CDD wood biochar not recommended for in-situ landfill leachate PFAS reduction. With regulations for per-and polyfluoroalkyl substances (PFAS) impending, the abundance of these chemicals of emerging concern in municipal solid waste (MSW) landfill leachate increasingly challenges landfill operators to seek on-site leachate pre-treatment options. This two-staged study explores the potential reuse of biochar derived from construction and demolition debris (CDD) wood as an in-situ PFAS sorbent for application within MSW landfill leachate collection systems. Batch leaching tests were first used to examine the feasibility of capturing PFAS from landfill leachate using two sources of CDD-wood-derived biochar. Then, columns were used to test the in-situ sorption capabilities of the same biochars under simulated landfill conditions. All leachates were characterized for pH, chemical oxygen demand, ammonia-nitrogen, and 92 PFAS. Seventeen PFAS were detected in the batch leaching experiment, and nine PFAS were detected in column leachates. In the batch leaching scenario, Biochar 1 achieved a maximum of 29% PFAS reduction compared to controls. Columns containing Biochar 1 generated leachates with PFAS concentrations 50% to 80% higher than those in control columns for the duration of the experiment. Columns containing Biochar 2 generated leachates with PFAS concentrations 44% less than controls in week 1 and similar concentrations in weeks 2, 3, and 4. In this study, PFAS removal from landfill leachate using biochar derived from CDD wood was not significant. Further research on biochar derived from CDD wood is needed before it can be recommended as an in-situ landfill leachate pre-treatment method. [ABSTRACT FROM AUTHOR]

Here, we analyzed the utilization efficiency of methane (CH4) gas from landfill sites associated with its power generation potential in different systems; in addition, we analyzed the reduction in the amount of CH4 emitted from landfills of untreated waste, proposed an effective method for site selection, and investigated the environmental issues caused by landfilling solid waste. Furthermore, we evaluated the geographical and chemical characteristics, iteration variables of landfill operations, application of CH4, efficiencies of energy-converting systems, and reduction in the CO2 emissions from other energy sources, with the landfill gas (LFG) being considered as the fuel. For efficient and quality extraction of CH4 from LFG, we investigated the ideal landfill conditions (e.g., construction, geometry, weather, temperature, moisture, pH, and biodegradable matter) and hydrogeological parameters that influence the generation of LFG and landfill leachate. The first order decay equation was used to predict the CH4 generation from a single bulk municipal solid waste stream for various characteristic interims of geography and CH4 generation capacity and potential. More CH4 is generated in the conventional clean air act condition than wet and arid conditions. Based on the analysis, we suggest efficient and economical power generation systems for using the CH4 emissions from landfills. [ABSTRACT FROM AUTHOR]

Due to rapid urbanization, industrialization, and population explosion, there is an increase in the generation of solid waste, which is then disposed of by dumping it into a landfill. Municipal solid waste (MSW) growth and improper disposal have become important environmental problems in metropolitan areas day to day. The present study area is located in Coimbatore district. The solid waste, which is being collected from Coimbatore city is being dumped into the study area. Despite the corporation's efforts, proper municipal solid waste management is not implemented in the Coimbatore district. In the present study, the soil characteristics were analysed to form a green belt in the dumpsite through LFMR techniques. The process of Landfill Mining and Reclamation (LFMR) involves the excavation and treatment of solid waste materials, which have been previously disposed of in landfills. Hence, considering the outcomes, obtained from both the on-site and controlled experimentation, it has been ascertained that the soil quality exhibits high levels of fertility, thereby augmenting the financial viability of undertaking landfill mining activities in the said area. [ABSTRACT FROM AUTHOR]

As an attempt to enhance landfill capacity and extend its lifespan, this research explores the effect of slope inclination on landfill storage capacity and its implementation on the safety factors using numerical simulations. A geometric approach was used to determine the capacity change with inclination, and a new probabilistic calculation method, which accounts for the heterogeneity of waste layers, was employed to analyze the safety factor for different slope angles. Over 100 conducted calculations for each inclination were used to investigate the effect of slope variation on landfill safety. The results show that increasing inclination leads to a significant increase in landfill capacity. The safety factor results indicate that the conventional method, assuming homogenous waste, classifies 1:3 and 1:2 slopes as safe, while the new suggested method showed that a 2:3 inclination could be considered safe, especially since the calculation is not considering the safety-enhancing effect of daily cover layers. This study highlights the importance of considering the heterogeneity of waste layers in safety factor analysis, and the use of multi-layered nonhomogeneous calculation method, which provides more flexibility in design parameters. This research presents a significant step forward in constructing safe and cost-effective landfills. The use of a new probabilistic calculation method in designing landfills leads to more accurate and reliable results while maintaining safety standards. This research has important implications for the design and management of landfills and can be used as a guide for future studies in this field. [ABSTRACT FROM AUTHOR]

The controlling microplastics (MPs) at source is a management method that can effectively reduce the amount of contamination in the environment. The main source of MPs was landfills that the decomposition of solid waste, MPs has an impact on environmental quality especially the health of humans. This research was investigated of MPs contamination at landfill site in the Muangpak municipality for analysis of MPs quantitative and source apportionment of MPs. The results of the composition of municipal solid waste by quartering method found that biodegradable solid waste was as high as 36.27% followed by general solid waste of 35.97% which was mostly plastic waste and effect the contamination of MPs in the environment. The distribution of MPs in environmental found that highest abundance was 66.44% of leachate sludge pond 1 followed by leachate sludge pond 2 (26.30%), sediment of surface water (3.32%), leachate pond 1 (1.04%), leachate pond 2 (0.80%), groundwater point 3 (0.62%), groundwater point 1 (0.58%), surface water (0.53%) and groundwater point 2 (0.37%). The contamination of polymer types of MPs at higher densities of low density polyethylene (LDPE) and high density polyethylene (HDPE) than polypropylene (PP) was found in samples closest to landfill area especially leachate pond more than 90%. The source apportionment of MPs using statistical analysis found that plastic waste has correlated to occurrence of LDPE and plastic bottle waste has correlated to occurrence of HDPE that both types of plastic waste are related to the amount of general solid waste and recycle solid waste increases every year. [ABSTRACT FROM AUTHOR]

Cadmium (Cd) is a mobile heavy metal that is highly toxic to almost all lifeforms. Urban eco-systems are susceptible to Cd contamination due to certain anthropogenic activities. Despite being recognised as an acutely toxic element, its biogeochemical behaviour is still poorly studied and understood, especially in urban ecosystems of tropical countries. Therefore, this study was undertaken to address this knowledge gap. This study was conducted at Air Hitam Sanitary Landfill (AHSL) in Puchong, Malaysia. Samples were collected from various abiotic and biotic factors representing the biogeochemical cycle, including soil, flora, arthropods, atmospheric deposition, leachates, and river water samples. Acid digestion using aqua regia was conducted to determine the total Cd concentration in all samples collected. Cd concentrations at AHSL were relatively high in all biotic and abiotic factors with the concentrations showing a range of 0.019 ppm to 1.568 ppm. The bulk of Cd contamination in the ecosystem was found to eventually end up in rivers. The average Cd concentration in the river samples exceeded several environmental guidelines. There was also evidence of Cd entering food chains via soil arthropods and plants. Thus, Cd poses a credible threat to inhabitants of tropical urban ecosystems. [ABSTRACT FROM AUTHOR]

Municipal solid waste (MSW) management practices that lack scientific rigor and use impromptu methods have produced massive leachate in urban complexes. Nowadays, the management of leachate has become an utmost concern worldwide. The MSW landfill site was a low-lying, open dump that operated in a non-engineered way. In this context, the physicochemical characterization of leachate has been carried out. Leachate sampling was done at the Bhandewadi dumpsite, Nagpur, for three seasons (summer, rainy, and winter). During analysis, parameters such as COD, BOD5, pH, TKN, TSS, sulfates, and chlorides were analyzed, and the obtained data was compared with the standard EPA 2003 and CPHEEO 2016 methods. Values of COD, BOD5, TKN, sulfates, and chlorides were in the range of 2500–16,000 mg/L, 495–2500 mg/L, 167–1900 mg/L, 240–900 mg/L, and 1400–5900 mg/L with respect to all three seasons, respectively. In conjunction with physicochemical analysis, the landfill leachate's leachate pollutant index (LPI) was assessed. The highest LPI values were observed for summer (14.323) as compared to rainy (12.301) and winter (11.348) data. This index reflects the hazardous character of MSW leachate and the total potential for leachate contamination. The results of this study showed seasonal variations in the observed data. Age and seasonal fluctuations therefore substantially influence the composition of the leachate. [ABSTRACT FROM AUTHOR]

The only way to dispose of municipal solid waste (MSW) in Oman is in engineered landfills without pre-treatment. An effective waste management system requires a reliable database of solid waste composition, properties, and energy content. Although investigating waste in landfills in Muscat Governorate is challenging and complex, it is essential. In this study, MSW from Muscat Governorate landfills is examined. The MSW samples were collected et al. Amerat and Barka landfills in 2020 in order to determine some of the importance of their physiochemical properties and the ratio of materials (food, plastic, and paper). It was found that approximately 50% of the weight of the disposed waste was recyclable. There were high levels of biodegradable organic material in MSW. In terms of moisture content, MSW ranged from 21.5 to 43.3%. Both the volatility and loss of ignition of MSW were high. It was found that the total oxide ratios ranged from 12.4 to 44.06%. The elemental analysis of Muscat MSW resulted in six chemical formulas for MSW with and without sulfur. Silica is the most influential oxide, followed by calcium oxide. The findings of this study indicate that almost half of Muscat's municipal solid waste can be recycled. Solid waste can be recycled to create renewable materials that can replace oil as a by-product of the recycling industry. Additionally, Muscat MSW has a high moisture content, which enables it to be composted and biodegraded. Moreover, waste-to-energy technologies are feasible due to their high-energy content. [ABSTRACT FROM AUTHOR]

Use of sanitary landfill in waste management may involve complex processes but has proven to be sustainable and effective in mitigating environmental degradation when the site is properly located. Despite this innovation, waste mismanagement compounded by alarming population growth, increasing urbanization and industrialization had raised much environmental concern in Edo State, Nigeria. Therefore, the present study integrated ten most common and applicable selection criteria with a view to identifying suitable landfill sites with environmental and socio-economic benefits for proper waste management, rational land use and sustainable development planning in four Local Government Areas in the State. The selection criteria used are surface water bodies, land use, land slope, depth to groundwater, geology, lineament, soil media, built-up area, road network and airport location. The Analytic hierarchy process technique was used to compute pair-wise comparison matrix for determining criteria weights while the weighted linear combination method was employed in combining the criteria weights. ArcMap 10.2 overlaid the ten thematic maps to generate a landfill site suitability map. The results of the study showed significant land use dynamics and drastically increasing built-up areas. This rapid urbanization had overtaken all the existing dumpsites which failed to meet adopted standards in the metropolis thereby rendering their locations inappropriate in today's urban setting. Hence, the dumpsites constituted potential environmental menaces with socio-economic and health implications. This study has identified eight potential sites for sanitary landfill which could guide decision makers in formulating effective policies towards sustainable environment, urban planning and water resources development in the area. [ABSTRACT FROM AUTHOR]

Selecting appropriate locations for Municipal Solid Waste (MSW) management facilities, such as landfills, is an important issue in rapidly developing regions. Multiple alternatives and evaluation attributes need to be analyzed to finalize the locations of these facilities. The selection of a landfill site in an urban area is a critical issue due to the involvement of many parameters. The decisive parameters are environmental, economic, and social, some of them conflicting, making landfill site selection a tedious and complex process. Multi Attribute Decision Making (MADM) approaches are found to be very effective for ranking several potential locations and, hence, selecting the best among them based on the identified attributes. Therefore, this study presents a two-stage MADM model that also accounts for all possible combinations of locations. This study evaluates economic, environmental, social, and technical attributes based on realistic conditions. Based on the results, 15 attributes are first identified through a comprehensive literature review and with the help of municipal officials during field surveys. These attributes are categorized into four types, i.e., economic, technical, environmental, and social, based on their respective propensity. In the second step, a statistical analysis questionnaire was distributed among the study population, and Cronbach's alpha was explained for all four main factors of the study. Therefore, in the last step, the rank of all research variables was calculated using the Nonlinear analysis method. Based on the results of this study, the technical variable was ranked first, the economic variable was ranked second, and the environmental and social variable was ranked third. This article has three theoretical, practical, and technical contributions. Also, this article provides a clear explanation of the theoretical contribution related to the accumulated knowledge, both in the introduction and theoretical background sections of the article. Therefore, studying the past research describes a relatively complete background of the planned theoretical contributions of this article compared to the previous research. Therefore, the theoretical contribution of this article solves the scientific gap about effective indicators for determining the location of waste disposal. From the point of view of practical contribution, this article presents practical concepts related to managers and experts and has practical suggestions presented in the conclusion section. Also, the technical contribution of this article is presented by combining fuzzy logic and Nonlinear mathematical programming. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Engineering & Architectural Faculty of Eskisehir Osmangazi University / Eskişehir Osmangazi Üniversitesi Mühendislik ve Mimarlık Fakültesi Dergisi is the property of Eskisehir Osmangazi University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Solid waste management is an imperative aspect of a hygienic environment. Lack of attention towards solid waste management leads to environmental pollution which causes catastrophic health issues and reduces the quality of life. Therefore, it's required to develop environmentally safe and adequate protocols to manage solid waste for the fortification of human health and the environment. The study presents a master plan to facilitate the local municipal authorities in developing a better waste management framework. The main aim of the research is to predict municipal solid waste (MSW) collection by using the GRU model in Multan city, Pakistan. The GRU model has utilized a dataset collected through a weighbridge at Habiba Sial landfill site (HSLS) which is the most reliable source for the data. The dataset consists of monthly data for the past five years with a total of 180 records; 60 records for months 60 records for vehicle trip numbers and 60 for collected MSW. The number of months and monthly vehicle trip numbers have been used as the input data and monthly collected MSW has been used as output data. The window of time for collected data is June 2017 through June 2022. The dataset has been divided into 3 subparts where 70% of the data has been utilized for model training, 15% of the data has been used for model testing and 15% of the data has been utilized for validation purposes. The GRU model's performance has been evaluated by using the performance metrics; mean square error (MSE), and Regression values for training, testing, and validation data. According to the results, 2-5-2-1 topology with 5 hidden neurons gives the best results with the least value of MSE being 0.0388 and the maximum value of regression being 0.94. The study also proposed a master plan for waste management, considering options like landfilling, recycling, incineration, and composting. As the landfilling method is the most common practice to dispose of waste, therefore the study estimated the required landfill area based on the predicted solid waste generation rate and its collection rate by the year 2031 for Multan city, Pakistan. The master plan can be utilized alternatively, especially for the cities with the same type of demographics which may help the municipal authorities for the development of a better solid waste management framework. [ABSTRACT FROM AUTHOR]

This study aims to simulate the steam-enhanced co-gasification of hybrid blends (HB) composed of municipal solid waste (MSW) and urban forest waste (UFW), with torrefaction as pretreatment. Experimental (torrefaction), numerical (gasification thermodynamic equilibrium model), and optimization (response surface methodology) techniques evaluated the gasification process to produce (i) hydrogen-rich gas or (ii) enhanced calorific value gas. The torrefaction (225–275 °C), steam-to-biomass (0.4–1.2 S/B) ratio, and HB proportion (0–50% of MSW) influences were investigated to assess H 2 %, exergy efficiency of H 2 -production (η H 2 ), lower heating value (LHV), cold gas efficiency (CGE), and CO 2 %. The hybrid methodology defined the optimal conditions for 600 °C gasification as (i) 0.9 S/B and an HB comprising 31% MSW and 69% torrefied UFW at 275 °C, presenting an η H 2 of 49%; and (ii) 0.4 S/B and an HB containing 23% MSW and 77% torrefied UFW at 275 °C, showing an LHV of 6126 kJ.Nm−3. [Display omitted] • Urban solid waste valorization by torrefaction and gasification for H 2 production. • Co-gasification of torrefied wood and municipal waste blends for waste mitigation. • Steam-gasification improved the exergy efficiency of H 2 production from residues. • Severe torrefaction enhanced the producer gas' quality and reduced carbon emission. • Excellent correlation (R2 = 0.99) of response surface methodology prediction models. [ABSTRACT FROM AUTHOR]

The past few decades have been marked by a rapid acceleration in Municipal Solid Waste (MSW) generation because of industrialization, urbanization, and economic growth combined with a high population growth rate. Thus, the most economically effective alternative to developing new landfills is the construction of reinforced soil walls (RSW) in existing MSW landfills to allow for their vertical expansion. This paper presents a structure for the system reliability-based seismic design optimization (SRBSDO) approach for landfills by incorporating the variability associated with design parameters under seismic conditions. The formulation considers a three-part wedge mechanism based on the pseudo-static limit equilibrium method. The influence of the horizontal seismic acceleration coefficient (kh) on the stability against external and internal modes of failure is studied. A target reliability index of not less than 3.0 is adopted to obtain the optimum dimensions of RSW required to achieve stability against three modes of failure (bearing capacity, sliding, and eccentricity). The dimensions of RSW are presented with respect to vertically expanded heights in the form of design charts. The results of the internal stability analysis of an RSW are provided to obtain the optimum number of geosynthetic reinforcement layers required for the stability of RSW under seismic loading. It is reported that kh has a substantial influence on the reliability of RSW, and higher values of mean and coefficient of variations of kh may cause instability. It is observed that the total length of the reinforcement (B2) should not be less than 0.67 and 0.91 times the height of the RSW (H2) for kh = 0.1 and 0.2, respectively. The minimum required number of reinforcement layers to maintain overall stability are 13 for kh = 0.10 with minimum B2/H2 of 0.66 and 19 for kh = 0.20 with minimum B2/H2 of 0.83. [ABSTRACT FROM AUTHOR]

Leachate is one of the main sources of pollution from landfills, posing a greater threat to the quality of soil, surface water and groundwater, and bringing serious environmental and human health problems. The composition and properties of leachate are very complex, so studies on leachate yield prediction, leachate treatment technology and physicochemical properties are premised on understanding the mechanism of leachate generation. This paper starts from the physical and chemical characteristics of municipal solid waste to study the generation mechanism of leachate. The biggest difference in the composition of municipal solid waste between developing and developed countries is the content of kitchen waste. The initial water content and field water holding capacity of municipal solid waste with high kitchen waste content are higher than those of municipal solid waste with low kitchen waste content, with better water holding performance and better liquid production capacity. The degradation characteristics of municipal solid waste with high kitchen waste content and low kitchen waste content are quite different. The content range of each compound in the two types of MSW is given, and their degradation rates are classified. The degradation process and transformation mechanism of different degradation stages were summarized, and the degradation rate of each stage and its influencing factors were analyzed. The characteristics of the different stages of leachate are also discussed. This study will provide insight into the research of physicochemical properties and treatment methods of leachate. [ABSTRACT FROM AUTHOR]

• Multi-species dynamic models based on balances of carbon and hydrogen are used. • Dynamics of δ13C-CO 2 and δ2H-H 2 O are used to evaluate the ongoing microbiological processes. • After a start of aeration, CO 2 becomes the product only causing a decrease in δ13C-CO 2. • Equations for two-compartment reactor with vertical water flow are suggested. • Water is enriched with 2H through reactions and then diluted with incoming water. The sequence of microbiological processes occurring during the decomposition of fresh and old organic wastes from landfills is analyzed using the developed dynamic models, which are verified on the basis of experimental data previously obtained in anaerobic and aerobic laboratory reactors. The models are based on the material balances of the heavy and light isotopes of carbon and hydrogen during the biodegradation of cellulosic waste as a relatively poorly degradable substrate. According to the models, under anaerobic conditions, dissolved carbon dioxide is a substrate for hydrogenotrophic methanogenesis, which leads to an increase in the isotope signature of carbon in carbon dioxide and its subsequent stabilization. After the introduction of aeration, methane production ceases, and from that time on, carbon dioxide remains only a product of cellulose and acetate oxidation, which causes a significant decrease in the isotopic signature of carbon in carbon dioxide. The dynamics of the deuterium content in the leachate water is described as a consequence of the rate of its entry into and exit from the two (upper and lower) compartments of the vertical reactors, as well as the rates of its consumption and formation during microbiological reactions. According to the models, in the anaerobic case, the water is first enriched with deuterium due to acidogenesis and syntrophic acetate oxidation and then diluted with deuterium-depleted water, which is continuously fed to the top of the reactors. In the aerobic case, a similar dynamic is simulated. [ABSTRACT FROM AUTHOR]

Copyright of Investigación e Innovación en Ingenierías is the property of Universidad Simon Bolivar and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study assesses the biomethane (CH4) generation and greenhouse gas (GHG) emissions resulting from municipal solid waste landfilling in Phnom Penh, Cambodia, with a focus on the impact of fugitive CH4 emissions and operation processes in four landfilling scenarios: simple dumping (S1), improved management with leachate treatment (S2), engineered landfill with flaring (S3), and engineered landfill with energy recovery (S4). The study also considered the environmental benefits of carbon sequestration and landfill gas utilization. The LandGEM and IPCC FOD models were used to calculate CH4 generation over the period of 2009–2022, and it was found that approximately 18 and 21 M kg/year of CH4 were released, respectively. The energy potential from CH4 recovery was 51–61 GWh/year. Overall, GHG emissions in S2 were the highest, amounting to 409–509 M kg CO2-eq/year, while S1 had lower emissions at 397–496 M kg CO2-eq/year. Flaring-captured CH4 in S3 could reduce GHG emissions by at least 55%, and using captured CH4 for electricity production in S4 could mitigate at least 83% of GHG emissions. Electricity recovery (S4) could avoid significant amounts of GHG emissions (−52 to −63 kg CO2-eq/tMSW). The study suggests that landfill gas-to-energy could significantly reduce GHG emissions. [ABSTRACT FROM AUTHOR]

This research aimed at evaluating the effects of capping on the mitigation of impacts generated by a closed unlined landfill in São Carlos, SP, Brazil. Physicochemical and microbiological analyses (16S rRNA sequencing) of buried solid waste samples were performed, in capped and uncapped areas. Even though leachate pockets could still be encountered in capped areas, the capping construction reduced oxygen availability and created more reducing conditions, propitiating the development of sulfate-reducing bacteria and possibly contributing to the precipitation of the metals Pb, Cd, Ni, Co, As, and Zn as metal sulfides, causing their immobilization. The microbial populations adapted to the anaerobic conditions created under capped zones belonged to the phyla Firmicutes, Chloroflexi, and Euryarchaeota and the genera Methanosaeta, Hydrogenispora, Smithella, and Gelria. Differently, the phyla Acidobacteria, Proteobacteria, Bacteroidetes, and Actinobacteria were more abundant in samples from the uncapped zones, in which the abundance of different genera varied homogeneously. Methanogenic activity was not impaired by the intervention measure, as assessed by the specific methanogenic activity (SMA). Capping of old unlined landfills brings benefits to the immobilization of metals and does not impair microbial degradation, being effective for the mitigation of impacts on soils and water resources. [ABSTRACT FROM AUTHOR]

Municipal solid waste (MSW) landfills using leachate recirculation optimize the waste stabilization process by providing nutrition and moisture for biological activity. However, the leachate recirculation creates an environment with complex processes due to accelerated biodegradation and generated heat. Additionally, different timing in waste placement and the heterogeneous nature of MSW cause significant variations in properties throughout the intercalated layers. In this study, a settlement framework model employing Thermal–Hydraulic–Mechanical–Biochemical processes is proposed, which considers multiple MSW properties including temperature, pH, and saturation. The framework model includes a modified Cam-clay model to simulate short-term settlement and adopts mechanical and biological creep models for long-term settlement estimation. A long-term biological creep model that uses a single decay rate constant is revised to account for environmental factors such as temperature, pH, and saturation in estimating MSW decay rates. The framework model was calibrated using the data of large-scale column experiments, which were conducted at different temperatures and saturation conditions considering biodegradation rates. Also, an MSW placement strategy was developed to consider the effect of different waste layer placement timing in the progression of MSW landfill total settlement. The modeling framework was validated using settlement data from a landfill in Canada. The results showed that temperature and saturation have a significant influence on MSW settlement and therefore should be considered in MSW landfill settlement prediction models. In municipal solid waste (MSW) landfills, leachate recirculation increases biological activity and heat and therefore results in further breakdown of waste material and, subsequently, large settlements. Also, different climates and waste placement seasons, in addition to the nonhomogenous nature of MSW, create variations in landfill layers that need to be addressed. This study investigated a settlement model that was verified with an experiment where different temperature and saturation was applied to MSW. The settlement was divided into short-term settlement (from the compression of material) and long-term settlement from the breakdown of material with time. Additionally, since the whole MSW is not placed in a landfill at once, a strategy was developed to consider the different stages of waste placement in the developed model. The developed framework was verified using the data collected from a landfill in Canada. The results show that when we consider temperature and the amount of saturation in MSW, we can have a better prediction of MSW settlement and prevent unwanted consequences of landfill failure. [ABSTRACT FROM AUTHOR]

The estimation of leachate quantities produced in landfills is necessary to dimension the treatment plants allowing to reduce the polluting load of these effluents and consequently avoid their negative impacts on the environment. Different leachate quantification methods were used in this study to assess the leachate volume produced at the Oum Azza landfill. The water balance method give comparable estimations of leachate production to the Ouled Berjal landfill ratio. The first method showed average values between 487 and 495 m3/day for 2015, 2018, and 2019, and at the same time, the second method gave values between 470 and 477 m3/day for the same years. In contrast, the World Bank ratio showed high values that vary between 2260 and 2295 m3/day for 2015, 2018, and 2019. The on‐site data and the statistical analysis showed us that the World Bank ratio is not adapted for the estimation of the leachates produced in Oum Azza landfill, while the water balance and the ratio of Ouled Berjal landfill allowed to give comparable results to reality. [ABSTRACT FROM AUTHOR]

• Monitor settlement of landfill cells with different ages using GNSS. • Settlement of a single waste lift is monitored by settlement profilers. • Effects of biodegradation on geotechnical properties of MSWs are considered. • Predicted settlement well fits that from experimental bioreactors and landfills. This paper presents the development of a new settlement model to predict the long-term settlement of municipal solid wastes (MSWs). The total settlement of the MSWs results from the direct loss of solids due to decomposition and compression due to stress variation induced by loss of solids, flow of gas and liquid and mechanical creep. The geotechnical properties of MSWs are considered as functions of degrees of biodegradation (DOB). To validate the model, two settlement profilers (2.5 years) and three geodetic monitoring networks (2 years) were installed at Mugga Lane Landfill, ACT, Australia to monitor the settlement of an MSW lift and three closed landfill cells, respectively. The settlement rates of the landfill cells with the ages of 7, 8, 14, and 8, 9 and 15 years are 0.53, 0.35, 0.06 and 0.46, 0.36, 0.05 mm/day, respectively. In addition, 5 large scale and 3 small scale bioreactors were set up in the field and laboratory to address the long-term physical, mechanical and biochemical behaviours of the MSWs under different stress levels. The predicted settlement is compared to the test results from the bioreactors, in-situ monitoring data and the settlement predicted using an existing model, which has been improved by coupling the geotechnical properties of MSWs with DOBs. The predicted settlement using the proposed model well fits the test results and monitoring data. The settlement strain is predicted to be 28.2 % during the filling stage of the landfill and 5.9 % in 5 years after the closure. [ABSTRACT FROM AUTHOR]

Globally, there is growing concern about the problem of plastic waste. The majority of plastic waste is dumped into landfills, where it occupies space, reducing landfill capacity and causing a variety of environmental issues. Plastic waste pyrolysis has gained popularity because it can reduce the volume of plastic waste while also producing alternative fuels. This study assessed the feasibility of producing fuel oil from plastic waste using the catalytic pyrolysis process. Polyethylene (PE), polypropylene (PP), and polystyrene (PS) waste samples were collected from municipal solid waste (MSW) landfills on Samui Island, Surat Thani Province, Thailand. Pyrolysis was carried out in a 3-L bench-scale reactor at 450°C using a 3% spent FCC catalyst. PE, PP, PS, and mixed plastic waste were used as feedstocks. The results showed that the pyrolysis of PS produced the most liquid product (91.44 wt%), whereas the pyrolysis of PE produced the highest percentage of diesel range product (36.60 wt%). Furthermore, the results of the analysis revealed that the characteristics of diesel from improved PE pyrolysis oil by naphtha removal were similar to those of commercial diesel B7. According to the cost-benefit analysis, the operating costs of pyrolysis oil and improved diesel were 0.37 and 0.65 USD/L, respectively, which were lower than the current market price of diesel B7. The findings of the study demonstrated the feasibility of converting plastic waste from MSW on Samui Island into alternative energy using eco-friendly and cost-effective technology. [ABSTRACT FROM AUTHOR]

Landfilling is the main method to manage municipal solid waste (MSW) in Latin America due to the economic, technological and political characteristics of the region. The disposal of MSW in landfill sites may affect the quality of the environment and compromise a considerable share of the municipal budgets. The selection of suitable sites reduces the environmental and economic impact of landfills. In the present study the sustainable location index (SLI) is proposed as a methodology to assess environmentally, and economically, sanitary landfill site selection in the Metropolitan Area of Monterrey, a representative large-size city of Latin America. EVIAVE methodology was modified to include administrative and economic dimensions, which are assessed as a sustainable approach using together the SLI integrated with geospatial and multicriteria analysis tools. The assessment showed that the zones with the lowest SLI changes drastically when the importance of the economic or environmental factor varies. This result suggest that the inclusion of sustainability in landfill site selection decision-making is complex and it may requires the inclusion of local particularities such as municipal budgets, policies of MSW management and public perception about environmental deterioration. [ABSTRACT FROM AUTHOR]