Landfill Operation Research Articles

Experimental and modeled analysis of contaminant mobility in coal fly ash landfills under continuous rainfall regimes

In China, a significant amount of coal fly ash is stored or used for landfill reclamation. The contaminants in coal fly ash (CFA) leachate can cause regional soil and groundwater contamination during long-term storage. This paper focuses on a coal gangue comprehensive utilisation power plant in Fenyang City, Shanxi Province, China, where the leaching characteristics of CFA were investigated by leaching tests. Laboratory-scale long-term soil column leaching tests and long-term ash column leaching tests were conducted using compacted soil and compacted CFA, respectively, to simulate contaminant migration patterns from CFA during the early and later stages of landfill operation. Hydrus-1D simulation software was used to calculate contaminant transport from the CFA landfill. The test results indicate that the concentrations of six representative elements or compounds in the CFA leachate exceeded the Groundwater Standard Class III. Among these contaminants, Pb contamination was the worst, with concentrations 26.67 times above the standard. The flow rate of the leachate is lower when the degree of compaction of the Ma’lan loess and the CFA is higher, and it takes longer for the leachate to start flowing. The greatest release of the ions occurred at a Ma’lan loess compaction coefficient of 0.943 and a hydraulic conductivity of 6.031 × 10− 7. Under extreme rainfall conditions, the contaminants and heavy metals in the fly ash leachate migrate to a maximum depth of 56 cm in the compacted soil layer, with Pb reaching a depth of 28 cm, nickel 23 cm, cadmium 9 cm and hexavalent chromium 5 cm to meet Class III groundwater quality standards. These results indicate a potential risk of groundwater contamination in the vicinity of CFA deposits or land reclamation projects in long-term storage. To mitigate this risk, the Guofeng Power Plant may consider utilizing locally compacted Malan loess in combination with geosynthetic materials or implementing a liner much thicker than 1.5 m to enhance the impermeability of the fly ash landfill.

Mechanical Strength and Mechanism Analysis of Silt Soil Cured by Straw Ash-Calcium Carbide Slag.

Large-scale engineering projects frequently involve pit excavation and wetland landfill operations, resulting in significant silt accumulation that occupies land and adversely affects the environment. Curing technology offers a solution for reusing this waste silt. In this study, straw ash and calcium carbide slag are proposed as effective curing agents for silt soil. Various indoor tests were conducted to evaluate the mechanical properties of the cured silt soil, while X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to analyze its mineral composition and micro-morphology. The results showed that increasing the curing agent dosage significantly improved soil strength. Specifically, at a 10% dosage, the California bearing ratio (CBR) value increased to 18.7%, which is 13.4 times higher than untreated silt soil and exceeds road specifications by 8%. At a 20% dosage, the unconfined compressive strength (UCS) value reached 1.38 MPa, meeting the ≥0.8 MPa requirement for roadbeds. Based on economic considerations, a 20% dosage of straw ash-calcium carbide slag was selected as optimal. Microscopic analysis revealed that the addition of these agents promoted the formation of hydrated calcium silicate, filling pores and enhancing the mechanical properties of the cured soil, resulting in a more dense and stable structure.

The perils of open landfill: a study on environmental risk assessment in Dharamshala, Himachal Pradesh, India.

Improper and unscientific management of municipal solid waste (MSW) landfill sites has increasingly become a pressing environmental issue especially in the mountainous regions worldwide. In view of this, an attempt was made to assess the detrimental effects of MSW landfill on the natural water sources at Dharamshala, Himachal Pradesh. Further, the suitability of potential landfill site and dispersion of pollutant air masses were stipulated using Arc GIS and HYSPLIT model. The findings show a discernible increase in electrical conductivity (323-858 μS/cm) and total dissolved solids (1086-1144mg/kg levels) during sampling period. The results exhibited a notable increasing trend in the mean concentrations of heavy metals viz. As (0.13mg/kg and 0.10mg/kg), Hg (0.52mg/kg and 0.65mg/kg), Pb (0.10mg/kg and 0.06mg/kg), Zn (30.40mg/kg and 0.22mg/kg), Cd (0.46mg/kg and 0.04mg/kg), Cr (0.10mg/kg and 0.05mg/kg), Ni (0.28mg/kg and 0.10mg/kg), Mn (24.40mg/kg and 0.35mg/kg) and Fe (1.81mg/kg and 0.96mg/kg) during monsoon and post monsoon. High HPI values were observed at the sampling location near to landfill drain (9060), followed by spring site (7338). However, most of sampling points consistently exceeding the critical HPI value, across all seasons, indicated a severe level of heavy metal pollution, where sampling sites near to landfill drain pose significant environmental health risks of 63%. An overwhelming 93% population in vicinity of MSW site expressed their concern that the current landfill site poses substantial threat to their health and livestock. Furthermore, the obtained forward trajectories showed the downhill dispersion of polluted air arising from solid waste burning. A continuous monitoring of landfill leachate dynamics, atmospheric pollutants due to burning of waste and their potential impact on regional climate followed by appropriate adaptation strategies will be a promising step towards a sustainable future for the Indian Himalayan Region (IHR).

Heavy Metal Accumulation (Cd, As, Zn, Cu, Cr) in Hair and Bones of Small Mammal Prey of the Sentinel Species Common Genet (Genetta genetta) in an Anthropogenic Environment of Edough Mountain Forest, Northeastern Algeria.

Heavy metal pollution has complex impacts on terrestrial ecosystems, affecting biodiversity, trophic relationships, species health, and the quality of natural resources. This study aims to validate a non-invasive method for detecting heavy metals (Cd, As, Zn, Cu, Cr) in micromammalian prey, which constitute the primary diet of the common genet (Genetta genetta), a mesocarnivore sensitive to habitat degradation. By focusing on prey remains (hair and bones) rather than entire fecal samples, this approach leverages the genet's selective feeding habits to assess the bioaccumulation of contaminants in its preferred prey. Conducted in the Edough forest massif during the winter of 2021, the study analyzed 39 fecal samples, collected from the following two contrasting environments: a natural habitat and an area impacted by an open landfill. Results revealed significant levels of heavy metals, with higher concentrations in bones compared to hair, and increased accumulation in prey from the anthropized environment. Monitoring these contaminants in selective predators, such as the genet, offers a promising approach to better understanding environmental contamination and implementing measures to protect ecosystems and the species that depend on them.

Study of the methanogenic potential of urban waste from the city of N’Djamena for recovery into biogas

The different types of urban waste as well as household waste are generally disposed of in open landfills affecting environmental sustainability. These wastes, by the release of contaminants such as leachates and greenhouse gases, increase the pollution potential of the sites. We recovered a quantity to carry out our experiments. The recovery of waste into biogas inevitably takes place in hermetically sealed enclosures called biodigesters. In this work we highlighted several types of waste at room temperature in a 0.75l can equipped with an empty inflatable balloon used for the recovery of biogas, which constituted our biodigester. Then a second experiment was carried out on the mesophilic temperature and the results were compared. The aim is to see the waste with the best biogas potential in terms of quality and quantity of production. The experiment consisted of working at an ambient temperature around 35°C±2 °C and up to 45 °C (mesophilic temperature). For this experiment we found that some bio-digesters started producing after two hours of time, the inflatable balloon increased in volume every hour up to 24 hours before and remained constant. We used the resources in terms of substrate and equipment of the Afric-Lab laboratory and that of the Physics-Chemistry department of the Higher Normal School of N'Djamena.

Operation of solid municipal waste landfills in northern climates

The author considers specific features of operation of solid municipal waste landfills at the post-operation stage in northern climate conditions. It is emphasized that safe operation of landfills requires efficient management of landfill gas and leachate formation. Increased precipitation leads to increased waste moisture content and, as a consequence, to methane generation during different seasons. The author presents the results of measuring methane concentrations and calculating leachate volumes at a landfill located in the north-west of Russia. The conclusion is made about the need to control and manage leachate formation, as well as to take measures for its treatment to prevent environmental and sanitary-hygienic problems associated with evaporation and accumulation of leachate.

Разработка критической технологии извлечения золота из гале-эфельных отвалов (стратегическое минеральное сырьё)

One of the ways to solve the problems of rational and integrated use of mineral raw materials, including canned man-made facilities, is the development of critical technologies for their processing in order to extract strategic metals, which include gold. The object of research is a preserved gold-bearing mineral resource object (landfills) with a conservation period of 10 years. The purpose of the study is to identify the technological and environmental problems facing the Russian gold mining industry, hindering scientific and technological development and ensuring the independence and competitiveness of the state; to develop a critical technology for extracting gold from landfills (strategic mineral raw materials). Research objectives are as follows: to conduct a systematic analysis of the level of development of gold mining equipment and technology in Russia; to identify the technological and environmental problems facing the gold mining industry; to study the material composition of a preserved mineral resource facility (landfills); to develop a critical technology for extracting gold from landfills and conduct laboratory studies. Research methods are presented by the study of the material composition of the mineral raw materials samples, which has been carried out using modern tools: optical and electron microscopy, assay and atomic adsorption analysis methods. Based on a systematic analysis of the level of gold mining equipment and technology development in Russia, the main disadvantages of using non-stationary processing plants have been identified and technological and environmental problems arising during the operation of landfills for heap leaching of gold have been identified. The following flowcharts are presented: environmental assessment of the consequences of open-pit mining; the impact of methods, processes, elements, relationships, structures on environmental components during the processing of gold-containing mineral raw materials; the main components of the negative impact of gold-containing raw materials processing enterprises on the environment. A critical technology for deep processing of strategic mineral raw materials from landfills has been developed, and its technological scheme is given. Experimental studies have been conducted and the results are presented. This technology makes it possible to comprehensively use mineral raw materials, improve the environmental situation and increase the efficiency of gold extraction.

Innovative biogas energy system: Enhancing efficiency and sustainability through multigeneration integration

This research suggests using landfill gas, derived from landfilling operations, as a feasible alternative to fossil fuels. This study introduces a novel and all-encompassing method for utilizing landfill biogas. The proposed system utilizes a supercritical Brayton cycle with carbon dioxide as the working fluid, a transcritical CO2 cycle, two ammonia Rankine cycles, a single-effect desalination cycle, a proton exchange membrane electrolyzer, and an improved Kalina cycle. The system underwent evaluation using Aspen HYSYS software, enabling assessments in terms of energy, exergy, thermo-economic, and environmental variables. The examination of the findings indicates that the suggested solution has much higher energy efficiency compared to similar studies. The assessments determined the energy efficiency of the process in power generation, combined heat and power, combined cooling, heat and power, and multigeneration modes to be 23.62 %, 80.89%, 81.19%, and 82.72%, respectively. Furthermore, environmental research has revealed that the new process emits a total of 1743 kg/h of carbon dioxide and has an emission rate of 0.23 kg/kWh. The exergy analysis indicated that the fuel burner exhibited the greatest degree of irreversibility, accounting for 40%. Furthermore, a sensitivity analysis was performed on crucial parameters, including the temperature of the heat source in the single-effect desalination section and the rate at which water flows into the electrolyzer. The objective was to evaluate the influence of changes in these parameters on energy efficiency, exergy efficiency, carbon dioxide emission intensity, product production rate, and levelized energy cost. The economic analysis determined that the proposed scheme would have a total annual cost of 8,667,124 $ with a levelized energy cost of 0.17 $/kWh.

Investigating Major Sources of Methane Emissions at US Landfills.

Airborne remote sensing observations were collected at 217 landfills across 17 states in the US in 2023. We used these observations to attribute emissions to major sources, including the landfill work face, where new waste is placed at the landfill and gas-control infrastructure. Methane emissions from the work face appeared to be more prevalent than gas-control infrastructure emissions, with 52 landfills exhibiting work face emissions out of the 115 observed landfills shown to be emitting in 2023. Landfills with work face emissions were often the highest emitters, especially sites with associated renewable natural gas facilities, and the total average site emissions from these landfills accounted for 79% of the observed emissions, indicating inefficient gas capture at these sites. Landfills with work face emissions also displayed the greatest disparity between observed emission rates and hourly emission rates that we estimated using annual emissions reported to the US EPA's Greenhouse Gas Reporting Program. Work face emissions present a major opportunity for methane mitigation: Observed emissions from work face emitting-landfills in this study were equivalent to 15% of US methane emissions from municipal solid waste landfills in 2022, as reported in the 2024 Greenhouse Gas Inventory, though these landfills accounted for only 4% of open sites in the US. As the 217 landfills in this study cover only 17% of open landfills in the US, the total mitigation potential is likely greater. Using remote sensing, we find that the largest contributor to observed methane emissions at US landfills is the landfill work face, an area of the landfill often left out of the required monitoring and traditional emissions accounting methods.

Biocomposites Based on Polyethylene/Ethylene–Vinyl Acetate Copolymer/Cellulosic Fillers

This work studied biocomposites based on a blend of low-density polyethylene (LDPE) and the ethylene–vinyl acetate copolymer (EVA), filled with 30 wt.% of cellulosic components (microcrystalline cellulose or wood flour). The LDPE/EVA ratio varied from 0 to 100%. It was shown that the addition of EVA to LDPE increased the elasticity of biocomposites. The elongation at break for filled biocomposites increased from 9% to 317% for microcrystalline cellulose and from 9% to 120% for wood flour (with an increase in the EVA content in the matrix from 0 to 50%). The biodegradability of biocomposites was assessed both in laboratory conditions and in open landfill conditions. The EVA content in the matrix also affects the rate of the biodegradation of biocomposites, with an increase in the proportion of the copolymer in the polymer matrix corresponding to increased rates of biodegradation. Biodegradation was confirmed gravimetrically by weight loss, an X-ray diffraction analysis, and the change in color of the samples after exposition in soil media. The prepared biocomposites have a high potential for implementation due to the optimal combination of consumer properties.

AI-Powered waste management: Predictive modeling for sustainable landfill operations

AI-Powered waste management: Predictive modeling for sustainable landfill operations

Biotechnological Approaches for Metal Recovery from Electronic Wastes.

The disposal of electronic waste (EW) in open landfills has caused several toxic environmental effects. The harmful metallic components released in the environment due to deposition of EW act as hazards for living systems. EW management has been widely studied in recent days across the world. Though, several processes are implemented in extraction, recycling and recovery of heavy metals from the EW, most of them are not effective in recovering the precious metals. Various chemical processes are executed for efficient extraction of precious metals from e-wastes. Though the techniques are easy to process and rapid, however, the chemical leaching also has detrimental environmental consequences. Biological approaches, on the other hand, solves the purpose for efficient and environmentally friendly recovery of precious metals. Thus, both resource recovery as well as remediation can be targeted simultaneously. Biotechnological methods offer sustainable and efficient solutions for metal recovery from electronic wastes, presenting a viable alternative to traditional methods. Continued advancements in this field hold significant promise for addressing the growing e-waste challenge.

Influencing factors of bentonite for the directional electric repair of landfill HDPE membrane leakage in calcium ion solution

The timely repair of high-density polyethylene (HDPE) membrane leakage in landfills is an important means of environmental risk control, which is critical for preventing leachate from polluting groundwater and soil. Electric repair technology is expected to become a hot spot in the leakage repair of HDPE films, because it can solve the issues of complex operation, high costs, and security risks during the operation and closure of landfills. To explore the influence law of various technical factors on the electric repair process, we carried out single factor experiments on the main influencing factors such as the operation time, bentonite concentration and dispersant/bentonite dosage ratio, leakage size, and calcium concentration. We then explored the best technological conditions. The results showed that accumulation at the leakage site possessed a good repair effect with a permeability coefficient of 4.22 × 10−6 cm/s. Furthermore, we observed that the Zeta potential played an important role in the electric repair technology, where the higher the absolute value of the Zeta potential, the faster the electrophoretic migration rate of the bentonite particles, and the lower the permeability coefficient of accumulation. This study may serve as a theoretical basis and offer scientific guidance for the directional electric repair of HDPE membrane leakage during the operating period and after the closure of landfills.

Detecting and sourcing GHGs and atmospheric trace gases in a municipal waste treatment plant using coupled chemistry and isotope compositions

Landfill operations and waste processing facilities are important and highly heterogeneous sources of both greenhouse gases (GHGs) and non-GHG air pollutants in the atmosphere. This arises the need for detailed apportionment of waste sources in order to locate and subsequently reduce emissions from landfills. Here, a time series of in situ measurements of atmospheric trace gases and spatial allocation of specific emission source types under different processing phases and environmental conditions were conducted in and in the surroundings of a Municipal Solid Waste Treatment Plant (MSWTP) in south-western Poland. Results revealed that several individual GHG sources dominated across the waste processing facility and that GHGs concentrations displayed spatial seasonality. An increase in the ground-level CH4 concentrations, from ∼ 30.3 to 56.3 ppmv, was observed close (∼5 – 10 m) to the major emission sources within the MSWTP. While hotspot areas generally yielded elevated CH4 concentrations near the soil surface, these were relatively low (2.4 to 8.9 ppmv) along the facility’s fence line. The study of the corresponding δ13C delineated the extent of dispersion plumes downwind emission hotspots, characterized by a 13C depletion (around 4.0 ‰) in the atmospheric CH4 and CO2. For CH4, emissions were isotopically discriminated between the extraction wells at active quarters/cells (δ13C = –58.3 ± 1.1 ‰) and biogas produced in the biological waste treatment installation (δ13C = –62.7 ± 0.7 ‰). Most of the trace compounds (non-methane hydrocarbons, halocarbons, oxygen-bearing organic gases, ketones, nitrogenous and sulphurous gases, and other admixture compounds) detected at the ground surface were linked to the CH4- and CO2-rich spots. Despite the relatively high variability in the concentrations of organic and inorganic compounds observed at the MSWTP active zones, our results suggest that they do not have a meaningful impact on the surrounding air quality.

Alteration and progressive degradation of plastic waste in a polish operational landfill analysed over 60 years

Polyethylene (PE) plastic waste poses an environmental challenge. To explore degradation processes over an extended period, a 60-year study was conducted at an operational landfill in Poland. This landfill, in use since 1960, offers a unique chronological representation of degradation potential due to distinct layering of waste without mixing. Employing analytical techniques, such as Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimeter (DSC), Scanning Electron Microscopy (SEM), and fluorescence microscopy, plastic waste samples were examined over decades. FTIR identified and characterized the samples, revealing traces of degradation. DSC indicated reduced crystallinity, implying diminished chemical stability. SEM showcased plastic fragment liberation, confirming degradation. Fluorescence microscopy and SEM confirmed microorganisms’ involvement, forming colonies around areas of strong delamination. The study provides insights into plastic waste dynamics, emphasizing microorganisms and hydrolytic processes in landfills. This contributes to understanding over 60 years period and underscores the need for waste management to handle plastic pollution effectively.

Assessment of slope stability of municipal solid waste landfill slope at partial water saturation

One of the problems in operation and recultivation of municipal solid waste landfills is the danger of slope stability loss. This danger may be estimated by the methods used for designing embankment structures. The complexity oflandfill slope stability analysis is in uncertainty of properties of the material composing it. The studies described in foreign publications were analyzed for assigning physical-mechanical properties of solid waste. By the results of analysis there were assigned design values of strength properties of the landfill: angle of internal friction 26, cohesion 20 kPа. Design assessment slope stability was made on the example of the existing landfill, where wastes were stored for the height of 77 m. The specific feature of the landfill is the fact that it is located downhill in rock canyon, where inflow of surface and ground water is probable. Slope stability analyses were carried out with the aid of the software package PLAXIS 2D based on solving the problem of stress-strain state. Analyses are conducted for a wide range of solid waste density and several design cases of depression curve position. Analyses showed that the slopes of the considered landfill have sufficient stability factor due to the flat slope (1:3.28). The greatest effect on the slope stability is caused by the groundwater level in the structure; minimum stability factor is observed at the highest possible ground water level. Density of wastes does not greatly affect stability, which is related to presence in the structure of the retaining dike built of crushed stone with loam fill.

Application of selected indicators to assess contamination of municipal landfill leachate and its impact on groundwater

Leachate formation is one of the most important factors taken into account during the operation and long-term management of municipal waste landfills. Systematic assessment of groundwater and leachate contamination may be useful in selecting the appropriate method of leachate management or treatment processes. The use of indicators to quantify the contamination potential of leachate and groundwater in the vicinity of MSW could help landfill managers assess their quality. Therefore, the aim of the study was to assess the representativeness of selected indicator methods for analyzing the temporal variability of leachate and groundwater properties in the vicinity of two municipal waste landfills in a Central European country (Poland). The leachate pollution index (LPI), sub-LPI and adjusted leachate pollution index (r-LPI) were used to assess the quality of leachate water, while the landfill water pollution index (LWPI) was used to assess the variability of groundwater quality. The results confirmed that LWPI is an effective method for assessing the quality of groundwater in the vicinity of municipal waste landfills. The obtained results confirm the negative impact of landfills, despite the insulation used. LWPI showed poor quality of groundwater and visible impact of the landfill (landfill W, average LWPI - 2.34) and moderately polluted waters and minor impact of the landfill (landfill S, average LWPI - 1.37). In most cases, it was observed that two parameters, EC and TOC, are the main factors contributing to the deterioration of groundwater quality. The sub-LPI analysis showed that leachates from both landfills have a very low content of heavy metals, so they should not have a negative impact on the biological treatment process. The obtained r-LPI values were in all cases higher than the calculated LPI values. For landfill S, the average r-LPI was 26.3 (Z-1) and 25.7 (Z-2). However, the average LPI was 13.5 (Z-1) and 13.2 (Z-2). For landfill W, the average r-LPI was 14.6 and the average LPI was 11.4. Analysis conducted on multi-year leachate and groundwater data using specific indicators can help managers better understand the impact of MSW on surrounding areas and help avoid potential operational problems in the future.

Comparing roles of multiple contamination indicators in tracing groundwater pollution nearby a typical municipal solid waste (MSW) landfill

Groundwater pollution resulting from leachate leakage at landfill sites has garnered significant attention. Investigating the migration of pollutants from these landfills to adjacent groundwater is crucial for understanding the diffusion patterns and extent of contamination. It is imperative to develop cost-effective yet highly efficient tracer techniques to aid landfill operators in monitoring groundwater contamination stemming from their operations. The primary objective of this research was to compare the roles of conservative tracers sodium (Na+) and chloride (Cl−), and conventional pollutants permanganate oxidation (CODMn), ammonium nitrogen (NH4+-N), lead (Pb), and zinc (Zn) in assessing pollution levels from municipal solid waste landfills to groundwater. For this purpose, a typical municipal solid landfill was selected to investigate the origin of Cl−, groundwater quality, and spatiotemporal variations of multiple contaminations. Geochemistry analyses revealed that Na–Cl and Ca–HCO3 were the dominant groundwater type in this study and landfill was the primary source of Cl− in groundwater, with an average contribution of 78 %. Groundwater in proximity to the landfill (5#, 2#, 22#, 23#) exhibited elevated concentrations of Na+ (15.6–914.0 mg/L), Cl− (8.9–1352.0 mg/L), CODMn (0.54–95.9 mg/L), and NH4+-N (0.33–49.0 mg/L), yet demonstrated reduced levels of Pb (0.2–391.0 μg/L) and Zn (2.0–112.8 μg/L). In contrast, groundwater located at a considerable distance from the landfill (13#, 18#, 15#, 26#) displayed the inverse trend, with relatively low concentration of Na+ (3.2–8.5 mg/L), Cl− (0.1–0.7 mg/L), CODMn (0.28–4.78 mg/L), and NH4+-N (0.03–0.52 mg/L), but increased levels of Pb (1.2–483.0 μg/L) and Zn (1.6–357.0 μg/L). The primary determinant of groundwater quality near the landfill was NH4+-N, with the highest pollution index (Pi) of 492.85, whereas Pb was the predominant factor affecting water quality in areas distant from the landfill, with the highest pollution index (Pi) of 10.9. While no discernible seasonal variation was detected for all pollutants, spatial variation can be observed that pollution levels decreased progressively with increasing distance from the landfill, a trend particularly corroborated by the conservative Cl− and Na+ measurements. This research suggests that conservative ions, such as Cl− and Na+, exhibit superior efficacy in tracing the pollution range from municipal solid landfills to groundwater. Therefore, monitoring these conservative ions in groundwater can yield a more precise understanding of the extent of groundwater contamination originated from landfills.

Supply Chain Analysis of Municipal Solid Waste Released in Hetauda Sub-Metropolitan City of Nepal

In Nepal, solid waste management is one of the major environmental issues, especially in the urban areas. While solid waste management (SWM) has become a major concern for municipalities and the country as a whole, the status of SWM is not fully understood due to the lack of SWM baseline data, which are also essential for effective planning. Such a back drop, this research attempts to assess the plastic waste released, management and recycling in supply chain in Hetauda Sub-Metropolitan City. This study revealed that about 83.8% households segregate their waste. None of the surveyed households have had public waste collection bin nearby their home whereas all households have had knowledge on solid waste management. About 63% HHs heard of importance of plastic waste recycling and all express their readiness to segregate the plastic solid waste if recycling program is set up in municipal area. Per capita waste generation per day is 141 gm out of which about 15% is plastic waste. On an average daily waste released at household level are 0.8 kg/HH which is 28.1 kg per institution. Total wastes release per day from Hetauda city is 27.4 MT and 10006.8 MT per year. About 931 MT plastic per year are gone in dumping sites in the Hetauda Sub-Metropolitan City. This study suggests that municipal office needs to develop an appropriate policy and strategy framework together with technical guidelines on key issues such as organic composting, recycling and landfill operation from dumping sites. Int. J. Soc. Sc. Manage. Vol. 11, Issue-3: 34-42.

A Review of Grease Trap Waste Management in the US and the Upcycle as Feedstocks for Alternative Diesel Fuels

As byproducts generated by commercial and domestic food-related processes, FOGs (fats, oils, and grease) are the leading cause of sewer pipe blockages in the US and around the world. Grease trap waste (GTW) is a subcategory of FOG currently disposed of as waste, resulting in an economic burden for GTW generators and handlers. This presents a global need for both resource conservation and carbon footprint reduction, particularly through increased waste upcycling. Therefore, it is critical to better understand current GTW handling practices in the context of the urban food–energy–water cycle. This can be accomplished with firsthand data collection, such as onsite visits, phone discussions, and targeted questionnaires. GTW disposal methods were found to be regional and correspond to key geographical locations, with landfill operations mostly practiced in the Midwest regions, incineration mainly in the Northeast and Mid-Atlantic regions, and digestion mainly in the West of the US. Select GTW samples were analyzed to evaluate their potential reuse as low-cost feedstocks for biodiesel or renewable diesel, which are alternatives to petroleum diesel fuels. Various GTW lipid extraction technologies have been reviewed, and more studies were found on converting GTW into biodiesel rather than renewable diesel. The challenges for these two pathways are the high sulfur content in biodiesel and the metal contents in renewable diesel, respectively. GTW lipid extraction technologies should overcome these issues while producing minimum-viable products with higher market values.