Leachate Pollution Research Articles

Characteristics and pollution indices of leachates from municipal solid waste landfills in Iranian metropolises and their implications for MSW management

Leachate from municipal solid waste landfills poses a significant threat to aquatic ecosystems due to poor management practices. This study evaluated thirty leachate samples from Iranian metropolises using the Leachate Pollution Index (LPI). Various parameters, including BOD₅, COD, TDS, pH, EC, heavy metals, turbidity, PAHs, phthalates, and humic acid, were analysed. The BOD₅ levels ranged from 350 to 20,000 mg/L, and the COD levels ranged from 2,000 to 90,000 mg/L. The TDS content varied between 14.7 and 67 g/L, while the turbidity ranged from 15 to 186 NTU. Heavy metals were present but within standard limits. The phthalate concentrations ranged from 6 to 150.8 mg/L, and the humic acid concentrations ranged from 135 to 2,200 mg/L. Naphthalene was the most frequent hydrocarbon detected. The LPIs were less than 30 for all the samples, with the highest in Ahvaz and the lowest in the treated samples from Tehran. This study highlights the presence of persistent organic and hazardous contaminants in Iran’s municipal landfills, emphasizing the need for effective leachate treatment and improved waste management practices. Enhanced final disposal methods, increased waste recovery, and improved solid residue separation are crucial for preventing further leachate production and environmental contamination.

Physicochemical and toxicological characteristics of leachates and water quality around dumpsites in Lagos Nigeria

Improper waste management leading to contamination of groundwater resources is a global environmental issue. This study examined the physicochemical and toxicological characteristics of leachates and their effect on water quality around the dumpsite in Alimosho Lagos, Nigeria. Samples of water and leachates were collected from boreholes around the dumpsite. Physiochemical and toxicological characterization of water around the dumpsite was based on American Public Health Association standards. Seventeen physiochemical and heavy metals of leachate and borehole water samples were analysed. The result of the study shows that the temperature, odour, appearance and turbidity of the water in the study area were within the limits set by WHO. However, the pH was below the WHO limits indicative of the acidity of the groundwater. The presence of Pb, Cr, and Cd confirmed leachate pollution. The contemporary effects confirmed the insignificant effect of the dumpsite operations at the groundwater source. Without a properly designed leachate series system, uncontrolled accumulation of leachates at the bottom of the dumpsite poses capacity infection dangers to groundwater resources. It is recommended that proper disposal of waste, in addition to implementing a higher sustainable environmental sanitation practice, is needed to ensure the safety of groundwater within the locality.

Impact of Landfill Leachate on Groundwater Quality and Health Risk Assessment in Mohammedia Prefecture, Morocco

Several studies have been conducted to identify the potential impact of landfills on groundwater resources. This study evaluates the impact of landfills on groundwater resources in Mohammedia prefecture, Morocco. The groundwater was analysed from 2015 to 2022. The groundwater quality was evaluated based on electrical conductivity, pH, biological oxygen demand, chemical oxygen demand, total Kjeldahl nitrogen, phosphate, suspended solids, dissolved oxygen, ammonia, and total hydrocarbon, aluminium, iron, cadmium, chromium, copper, iron-nickel, zing, and mercury. The assessment was based on the water quality index, leachate pollution index, non-carcinogenic risk assessment, and carcinogenic risk assessment. A leachate pollution index <5 indicates that it poses a severe risk to groundwater resources. The non-carcinogenic risk HQ was determined to be <1, which infers no potential risk. The carcinogenic risk index value of 10-4 indicated that it is within the threshold of acceptable limit. The current study concludes that leachate from the analysed landfills does not infiltrate the groundwater resources of Mohammedia prefecture. However, the leachate pollution, even though it varies, is increasing over time. This is validated by the fact that the landfill is protected with a membrane covering the ground, which inhibits any possible infiltration of soil or water resources. Hence, this study calls for continuous monitoring of groundwater resources in the region. Future studies are required to investigate the groundwater in Mohammedia prefecture in terms of emerging pollutants to identify any potential risk.

An overview on analytical methods and the occurrence of organic pollutants in cigarette litter

Cigarette litter, such as cigarette ash, cigarette butts, and cigarette butt leachates, can contain organic pollutants similar to those in cigarette smoke, but studies on these waste types are still relatively limited. This review article compiles information from studies published over the past four decades on organic pollutants in cigarette ash, cigarette butts, and leachates from cigarette butts, to provide insights into quantitatively analytical methods and the presence of these toxicants in cigarette litter. The main organic pollutants found in cigarette litter include: volatile organic compounds (VOCs), semi-volatile organic compounds (SVOCs), polycyclic aromatic hydrocarbons (PAHs), nicotine, and aromatic amines. Gas chromatography or liquid chromatography coupled with mass spectrometry detection have been the most frequently used methods to characterize organic pollutants in cigarette litter. Toxic substances in improperly disposed cigarette waste can pollute the environment through evaporation into the air or leakage through leachates into the water environment, seepage into soil, accumulate in sediment, and cause negative effects on organisms. Further studies on analytical method development, pollution monitoring, and risk assessment related to organic pollutants in cigarette waste are needed.

Taxonomic variation, plastic degradation, and antibiotic resistance traits of plastisphere communities in the maturation pond of a wastewater treatment plant.

Wastewater treatment facilities can filter out some plastics before they reach the open environment, yet microplastics often persist throughout these systems. As they age, microplastics in wastewater may both leach and sorb pollutants and fragment to provide an increased surface area for bacterial attachment and conjugation, possibly impacting antimicrobial resistance (AMR) traits. Despite this, little is known about the effects of persistent plastic pollution on microbial functioning. To address this knowledge gap, we deployed five different artificially weathered plastic types and a glass control into the final maturation pond of a municipal wastewater treatment plant in Ōtautahi-Christchurch, Aotearoa/New Zealand. We sampled the plastic-associated biofilms (plastisphere) at 2, 6, 26, and 52 weeks, along with the ambient pond water, at three different depths (20, 40, and 60 cm from the pond water surface). We investigated the changes in plastisphere microbial diversity and functional potential through metagenomic sequencing. Bacterial 16S ribosomal RNA genes composition did not vary among plastic types and glass controls (P = 0.997) but varied among sampling times [permutational multivariate analysis of variance (PERMANOVA), P = 0.001] and depths (PERMANOVA, P = 0.011). Overall, there was no polymer-substrate specificity evident in the total composition of genes (PERMANOVA, P = 0.67), but sampling time (PERMANOVA, P = 0.002) and depth were significant factors (PERMANOVA, P = 0.001). The plastisphere housed diverse AMR gene families, potentially influenced by biofilm-meditated conjugation. The plastisphere also harbored an increased abundance of genes associated with the biodegradation of nylon, or nylon-associated substances, including nylon oligomer-degrading enzymes and hydrolases.IMPORTANCEPlastic pollution is pervasive and ubiquitous. Occurrences of plastics causing entanglement or ingestion, the leaching of toxic additives and persistent organic pollutants from environmental plastics, and their consequences for marine macrofauna are widely reported. However, little is known about the effects of persistent plastic pollution on microbial functioning. Shotgun metagenomics sequencing provides us with the necessary tools to examine broad-scale community functioning to further investigate how plastics influence microbial communities. This study provides insight into the functional consequence of continued exposure to waste plastic by comparing the prokaryotic functional potential of biofilms on five types of plastic [linear low-density polyethylene (LLDPE), nylon-6, polyethylene terephthalate, polylactic acid, and oxygen-degradable LLDPE], glass, and ambient pond water over 12 months and at different depths (20, 40, and 60 cm) within a tertiary maturation pond of a municipal wastewater treatment plant.

Enhanced reducing leachate pollution index through electrocoagulation using response surface methodology

Addressing the urgent need to effectively manage landfill leachate as a harmful flow for human health and the environment, this research investigates how electrocoagulation (EC) processes could alleviate the pollution potential of leachate. So far, no experimental study has been carried out on reducing the leachate pollution index (LPI) under the EC process. For this purpose, in this novel research, the LPI was utilized as a key metric to evaluate the efficiency of the treatment process. Central Composite Design (CCD) as a subset of Response Surface Methodology (RSM) was applied to enhance the LPI parameters decreasing percentage. The data were analyzed by analysis of variance and multivariate regression and 3D plots assessed variable interactions. Under optimal conditions, it showed removal of 97.48 % for COD, 91.42 % for BOD5, 98.52 % for N-NH3, and 91.6 % for TDS. Significant reductions were observed in 94.81 % TKN, 87.20 %, 82.80 %, 96.66 %, and 99.28 %, 99.18 %, and 96.56 % for TKN, Cl−, CN−, As, Cr, Zn, and Ni, respectively. Moreover, the kinetics of COD removal indicated that it follows a first-order model. Thus, based on experimental results, the LPI of raw leachate decreased from 38.06 to 7.22 (81 % decrease) under the EC treatment method. The study indicated that the EC treatment method successfully reduced leachate pollution and met the leachate discharge standard.

Migration and natural attenuation of leachate pollutants in bedrock fissure aquifer at a valley landfill site

Groundwater pollution from valley type landfills is concerning, and natural attenuation by contaminants is increasingly relied upon. However, the reliability of natural attenuation in such complex sites has been called into question due to incomplete understanding of their attenuation mechanisms. Therefore, we conducted field investigations, monitoring analyses, mathematical statistics, and machine learning techniques to elucidate the natural attenuation mechanisms of pollutants within bedrock fissures at a prototypical valley type landfill located in the east Yanshan Mountains, China. Our results indicate that 50% of the monitored indicators showed extreme pollution in bedrock fissure aquifers, due to seepage from the valley type landfill site. Ammonia nitrogen, arsenic, cadmium, lead, iron, manganese, and mercury were among the contaminants that could pose serious risks to human health. Pollutant concentrations in bedrock fissure aquifers were lower during the rainy season compared to the dry season as the aquifer was rapidly recharged by strong rainfall runoff. The initial concentration of bedrock fissure water generally increased during the flow through the landfill. However, significant natural attenuation of total dissolved solids, oxygen consumption, ammonia, cadmium, and lead occurred after passing through the landfill (p<0.05), with attenuation coefficients of 0.0041 m-1, 2.56×E-5m-2, 4.18×E-5m-2、0.0015 m-0.99, and 6.83×E-33m-12.49, respectively. The driving mechanisms for natural attenuation include physical migration, leaching, microbiological degradation, and adsorption, primarily occurring within 600-650 m downstream of the landfill boundary. This study makes fundamental contribution to the understanding of the migration and natural attenuation process of leachate pollutants in bedrock fissure aquifer, which will provide a scientific basis for implementation of natural attenuation strategies in complex site remediation. Future research should examine more precise evidence of natural attenuation feasibility in complex sites in conjunction with monitoring networks.

Uncertainty and sensitivity analysis of revised leachate pollution index.

Composite indicators (CIs) are being utilized more frequently to assess and monitor environmental systems. The revised leachate pollution index (r-LPI) is one such composite indicator used to quantify the pollution potential of landfill leachate on a scale of 5-100. The development of CIs involves several steps, and each of these steps has various methodological choices, each of which could lead to different results. Thereby, the reliability of the quantified pollution potential of leachate may be questioned. This study investigated the techniques for developing the r-LPI, examining decisions related to parameter selection, normalization technique, weighting approach, sub-indicator weights, and their aggregation. As the index developer made the decisions, each of these stages was fraught with uncertainty. The uncertainty in the various stages of the development of r-LPI was quantified using the Monte Carlo-based uncertainty analysis and the sensitivity analysis approach. Uncertainty analysis is a helpful but seldom-used step of index development that identifies the model's most dependable sections. Sensitivity analysis was carried out to ascertain the degree of impact the input parameters have on the r-LPI values. The combined use of sensitivity and uncertainty analysis in this study for the formulation of r-LPI affirmed the transparency, credibility, and accuracy of the index.

Assessment of leachate potential contamination of municipal landfill using leachate pollution index and multivariate statistical analysis based on seasonal variations

Sanitary landfills offer a convenient and cost-effective way to dispose of MSW waste. The breakdown of waste in landfills generates highly poisonous leachate. This liquid can disperse and percolate through the soil, potentially polluting the surrounding water bodies; minimizing the environmental damage caused by leachate lies in thoroughly understanding its unique characteristics at each landfill site. The present study evaluates the leachate's physio-chemical characteristics from municipal landfills and adjacent groundwater sources. To evaluate the impact of temporal seasonal fluctuation, leachate and water samples were collected in three distinct seasons such as pre-monsoon (Pre-M), monsoon (In-M), and post-monsoon (Post-M). The analysis revealed a seasonal variation in pollution levels in the leachate sample, as evidenced by the high Leachate Pollution Index (LPI) spanning 27.121–17.396. Water samples collected across three seasons yielded Water Quality Index (WQI) values ranging from 55.59 to 279.64, with the Pre-M season exhibiting the highest level of water quality. Scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) analysis were employed to understand the elemental composition further. The presence of heavy metals Zn, Cr, Cu, Ni, Fe, Si, and Hg was determined combined through the Inductive Coupled Plasma Atomic Emission Spectroscopy technique and EDX. The correlation matrix heat map helped to reveal the interconnection between different leachate parameters, and dendrogram clusters revealed the relation between the six sampling points. At the same time, Principal component analysis was performed to simplify the complex data set and determine the predominance of pollutants over the sample points. As explored in this study, understanding the contamination potential of landfill leachate is crucial for developing strategies before its disposal to mitigate its impact.

Two Birds with One Stone: High-Quality Utilization of COVID-19 Waste Masks into Bio-Oil, Pyrolytic Gas, and Eco-Friendly Biochar with Adsorption Applications

As a common necessity, masks have been used a lot in recent years, and the comprehensive utilization of waste masks has become a research priority in the post-COVID-19 pandemic era. However, traditional disposal methods suffer from a range of problems, including poor utilization and insecurity. To explore new solution ideas and efficiently utilize waste resources, waste masks and biomass wastes were used as raw materials to prepare mask-based biochar (WMB), bio-oil, and pyrolytic gas via oxygen-limited co-pyrolysis in this study. The obtained solid–liquid–gas product was systematically characterized to analyze the physicochemical properties, and the adsorption properties and mechanisms of WMB on the environmental endocrine bisphenol A (BPA) were investigated. The co-pyrolysis mechanisms were also studied in depth. Furthermore, the strengths and weaknesses of products prepared by co-pyrolysis and co-hydrothermal synthesis were discussed in comparison. The results indicated that the waste masks could shape the microsphere structure, leading to richer surface functional groups and stable mesoporous of WMB. Here, the risk of leaching of secondary pollutants was not detected. The theoretical maximum adsorption of BPA by WMB was 28.73 mg·g−1. The Langmuir and Pseudo-second-order models optimally simulated the isothermal and kinetic adsorption processes, which are a composite of physicochemical adsorption. Simultaneous pyrolysis of mask polymers with biomass polymers produces bio-oil and pyrolytic gas, which is rich in high-quality aliphatic and aromatic compounds. This could have potential as an energy source or chemical feedstock. The co-pyrolysis mechanisms may involve the depolymerization of waste masks to produce hydrocarbons and H radicals, which in turn undergo multi-step cleavage and oligomerization reactions with biomass derivatives. It is recommended to use the co-pyrolysis method to dispose of waste masks, as the products obtained are significantly better than those obtained by the co-hydrothermal method. This work provides a new contribution to the resourcing of waste masks into high-quality products.

Bioremediation of Nitrate and Nitrite on the Rehabilitation of Contaminated Jatibarang Landfill and the Application of Calla Lily

Currently, waste processing is a problem because it is not yet optimal. The high content of nitrates and nitrites results in environmental pollution which can cause losses because it affects health and biodiversity. One effort to control environmental pollution is phytoremediation using calla lily (Zantedeschia aethiopica) to remediate nitrate and nitrite levels that do not comply with quality standards so that pollution can be minimized. This research aims to determine the effectiveness of calla lily as a phytoremediation agent for landfill leachate nitrate and nitrite. This experimental research method uses a Completely Randomized Design (CRD) which consists of three treatment levels, namely variations in calla lily biomass of 0 grams, 200 grams, and 400 grams with 3 repetitions, and measurements of nitrate and nitrite levels are carried out on day 1, day 2. 3, and 7. The results showed that the most optimal percentage reduction in leachate nitrate levels occurred in the P1 on the day 7, namely 45%, while the most optimal percentage reduction in leachate nitrite levels occurred in the P1 on the day 7, it was 53%. The final nitrate content after the research was in accordance with the quality standards of PP RI No.22 of 2021, while the leachate nitrite content after treatment still exceeded the quality standards of PP RI No.22 of 2021. Calla lily has the potential to reduce nitrate and nitrite levels due to landfill leachate pollution.

Drivers of change behind the spatial distribution and fate of typical trace organic pollutants in fresh waste leachate across China

There have been growing concerns regarding the health and environmental impacts of trace organic pollutants (TOPs). However, fresh leachate from municipal solid waste (MSW) has been overlooked as a potential reservoir of TOPs. Therefore, we investigated 90 legacy and emerging TOPs in fresh leachate from 14 provinces and municipalities in China. Additionally, the fate and final discharge impacts of TOPs in 14 leachate treatment systems were analyzed. The results revealed that the detection rate of 90 TOPs was over 50 % in all samples. Notably, polychlorinated biphenyls, banned for 40 years, were frequently detected in fresh leachate. The concentration of pseudo-persistent TOPs (105–107 ng/L) is significantly higher than that of persistent TOPs (102–104 ng/L). Spatial distribution patterns of TOPs in fresh leachate suggest that economy, population, climate, and policies impact TOPs discharge from MSW. For example, economically developed and densely populated areas displayed higher TOPs concentrations, whereas warmer climates facilitate TOPs leaching from MSW. We confirmed that waste classification policies were a key driver of the decline in multiple TOPs in leachate. Mass balance analysis shows that the final effluent and sludge from current dominant leachate treatment systems contain refractory TOPs, especially perfluoroalkyl acids, which must be prioritized for control. This paper was the first comprehensive investigation of multiple TOPs in fresh leachate at a large geographic scale. The factors affecting the occurrence, spatial distribution, and fate of TOPs in fresh leachate were revealed. It provides a valuable reference for the establishment of policies for the management of TOPs in MSW and the associated leachate.

Developmental and heritable genetic defects induced in mice by municipal landfill leachate

Environmental pollution by solid waste leachate is a serious environmental and public health concern. Leachate contamination and pollution of environmental matrices have been reported, but no report of embryotoxic and developmental defects, and heritable transfer of leachate-induced toxicity in mice. We investigated the ability of Aba-Eku landfill leachate to induce embryonic malformations, developmental toxicity, and germline and somatic DNA damage in the F1 of exposed pregnant mice. Pregnant mice (n = 100) were randomly distributed into 5 experimental groups of 20 animals/group and exposed to 0.2 mL of 5–75% concentrations of the leachate (v/v; Aba-Eku landfill leachate: distilled water) by daily gavage from gestational day (GD) zero to postnatal day (PND) 21. A similar treatment was given to pregnant female mice administered with distilled water (negative control). At GD 18, ten dams from the treatment and control groups were sacrificed by cervical dislocation after which the embryos were collected from the uterus for analyses of fetal morphometric and skeletal metamers respectively. We then monitored the developmental conditions of F1 mice from the remaining ten dams until they were weaned at PND 21 and sacrificed at PND 56 and PND 98 for bone marrow micronucleus and spermiogram analyses respectively. We also analyzed the leachate for inorganic and organic pollutants and calculated the Leachate Pollution Index (LPI). The leachate reduced maternal and fetal birth weight and increased fetal mortality and postnatal appearance of physiological markers in the F1 mice. There was a significant increase (p < 0.05) in the frequency of fetal skeletal malformations, micronucleated polychromatic erythrocytes, and apparent decline of epididymal sperm parameters. The concentrations of the inorganic and organic pollutants, and the LPI exceeded standard limits. Exposure of pregnant female mice to Aba-Eku landfill leachate caused embryonic defects and heritable DNA damage in subsequent generations.

Vadose-zone characteristic pollutants distribution, microbial community structure and functionality changes in response to long-term leachate pollution of an informal landfill site

The study embarked on a comprehensive examination of the evolution and diversity of microorganisms within long-term leachate pollution environments, with a focus on varying depths and levels of contamination, and its linkage to soil characteristics and the presence of heavy metals. It was observed that microbial diversity presented distinct cross-depth trend, where archaeal communities were found to be particularly sensitive to alterations in soil depth. Noteworthily, Euryarchaeota increased by 4.82 %, 7.64 % and 9.87 % compared with topsoil. The abundance of Tahumarchaeota was successively reduced by 5.79 %, 9.58 %, and 12.66 %. The bacterial community became more sensitive to leachate pollution, and the abundance of Protebacteria in contaminated soil decreased by 10.27 %, while the abundance of Firmicutes increased by 7.46 %. The bacterial genus Gemmobacter, Chitinophaga and Rheinheimera; the archaeal genus Methanomassiliicoccus and Nitrosopumilus; along with the fungal genus Goffeauzyma, Gibberella, and Setophaeosphaeria emerged as pivotal biological markers for their respective domains, underpinning the biogeochemical dynamics of these environments. Furthermore, the study highlighted that geochemical factors, specifically nitrate (NO₃−-N) levels and humic acid (HA) fractions, played crucial roles in modulating the composition and metabolic potential of these communities. Predictive analyses of functional potentials suggested that the N functional change of archaea was more pronounced, with anaerobic ammonia oxidation and nitrification decreased by 15.78 % and 14.62 %, respectively. Overall, soil characteristics alone explained 57.9 % of the total variation in the bacterial community structure. For fungal communities within contaminated soil, HMs were the primary contributors, explaining 46.9 % of the variability, while soil depth accounting for 6.4 % of the archaeal variation. This research enriches the understanding of the complex interrelations between heavy metal pollution, soil attributes, and microbial communities, paving the way for informed strategies in managing informal landfill sites effectively.

Study on the microscopic characteristics and hydration mechanism of thermo-alkali activated electrolytic manganese residue geopolymers

As a form of solid waste, electrolytic manganese residue (EMR) exhibits low reactivity, high sulfate content, and exceeds the standards for heavy metals. To address these drawbacks, a high-temperature thermal activation method was employed to enhance its reactivity and remove pollutants. The study investigated the physicochemical properties and leaching toxicity of EMR under different thermal activation conditions. Additionally, the thermally activated EMR was utilized in the preparation of geopolymer material, and the influence of EMR activation temperature, EMR content, sodium silicate content, and molar ratio on the mechanical properties, hydration mechanism, microstructure, and leaching toxicity of the EMR geopolymers was analyzed. The results indicated that after activation in the temperature range of 0–1200°C, the active content of silica-alumina in EMR increased, sulfate decomposition occurred, and the leaching of Mn2+ and NH4+-N decreased to 21.24 and 0.576 mg/L, respectively. When the activation temperature reached 1200°C, the compressive strength of the geopolymer, prepared with 50 % EMR, 50 % granulated blast furnace slag (GBFS), 30 % sodium silicate, and a molar ratio of 1.2, could reach 53.2 MPa at 28-day. Under activation in the range of 0–800°C, ettringite was abundant in the geopolymers, providing strength support. With activation in the range of 800–1200°C, the geopolymers became denser, exhibiting flaky and agglomerate gels. A diffraction peak appeared at 20°-40°(2θ) corresponding to C-(A)-S-H and N-S-A-H gels. Due to the slow depolymerization-polymerization kinetics of the EMR geopolymer and high sulfate content, the heat release rate and cumulative heat were significantly lower than ordinary portland cement (OPC). In the structure of EMR geopolymer, Mn2+ replaced Na+ and Ca2+ in the silicoaluminate structure or chemically bonded with anionic groups to the geopolymer. Simultaneously, Mn2+ participated in the formation of the EMR geopolymer gel, encapsulating within the gel. Therefore, the leaching of pollutants from EMR geopolymers met the standards of GB8978–1996.

Characterization and spatiotemporal variations of fluorescent dissolved organic matter in leachate from old landfill-derived incineration residues and incombustible waste.

Dissolved organic matter (DOM) influences the bioavailability and behavior of trace metals and other pollutants in landfill leachate. This research characterized fluorescent dissolved organic matter (FDOM) in leachate from an old landfill in Japan during a 13-month investigation. We employed excitation-emission matrix (EEM) fluorescence spectroscopy with parallel factor analysis (PARAFAC) to deconvolute the FDOM complex mixture into three fluorophores: microbial humic-like (C1), terrestrial humic-like (C2), and tryptophan-like fluorophores (C3). These FDOM components were compared with findings from other studies of leachate in landfills with different waste compositions. The correlations among EEM-PARAFAC components, dissolved organic carbon (DOC) concentration, and ultraviolet-visible and fluorescence indices were evaluated. The FDOM in leachate varied spatially among old and extended leachate collected in the landfill and leachate treatment facility. The FDOM changed temporally and decreased markedly in August 2019, November 2019, and April 2020. The strong positive correlation between HIX and %C2 (r = 0.87, ρ = 0.91, p < 0.001)) implies that HIX may indicate the relative contribution of terrestrial humic-like components in landfill leachate. The Fmax of C1, C2, and C3 and the DOC concentration showed strong correlations among each other (r > 0.72, ρ > 0.78, p < 0.001) and positive correlations with leachate level (r > 0.41, p < 0.001), suggesting the importance of hydrological effects and leachate pump operation on FDOM.

Investigation of the impact of municipal solid waste disposal site leachate on surface water resources in Hosanna Town, Ethiopia.

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

Ecotoxicological risk of asphalt pavements to aquatic animals associated with pollutant leaching

Contaminants such as heavy metals and polycyclic aromatic hydrocarbons (PAHs) can be released from asphalt pavement and transported through stormwater runoff to nearby water bodies, leading to water pollution and potential harm to living aquatic animals. This study characterizes the heavy metal and PAH leaching from various asphalt paving materials and their potential ecotoxicological effects on zebrafish Danio rerio. Artificial runoffs were prepared in the laboratory concerning the effects of water, temperature, and traffic. The concentrations of heavy metals and PAHs in the leachates were quantified, while the toxicity assessment encompassed mortality, metal stress, PAH toxicity, inflammation, carcinogenicity, and oxidative damage. Gene expressions of related proteins or transcription factors were assessed, including metallothionines, aryl hydrocarbon receptors, interleukin-1β, interleukin-10, nuclear factor-κB, tumor necrosis factor-α, tumor suppressor p53, heat shock protein 70, and reactive oxygen species (ROS). The findings demonstrate that leachates from asphalt pavements containing waste bottom ash, crumb rubber, or specific chemicals could induce notable stress and inflammation responses in zebrafish. In addition, potential carcinogenic effects and the elevation of ROS were identified within certain treatment groups. This study represents the first attempt to assess the ecotoxicity of pavement leachates employing a live fish model, thereby improving the current understanding of the environmental impact of asphalt pavements.

A Descriptive Study on Performance Evaluation of Sewage Treatment System

Abstract: As The rapid expansion of modern housing and industrialization around the cities has polluted environment. This trend was observed in many developed countries in the beginning of nineteenth century which resulted in the contamination of air, water, soil etc. with pollutants. If the pollutants are released in the environment and left untreated they would cause serious diseases in both humans and animals. Large scale pollution of water bodies around the globe became a major problem due to release of industrial and domestic waste directly in water streams. To prevent the leaching of pollutants in the ground water scientist developed various methods of wastewater treatment based on the hazardous chemicals and microorganisms, which were present in the untreated water. Modern sewage treatment plants were installed in big cities to treat the water released from households. Most STPs were designed based on the stringent criteria to check the pollutants levels in the treated water so that when it is released or recycled it is safe to the environment. Modern day STP plants have a high cost of operation due to huge power consumption. In order to reduce the pollutant levels in the wastewater this study was conducted using a Eco Bio Block (EBB) techniques with aeration and without aeration. A comparison of EBB was also carried out with MBBR technique. Our results show that when EBB technique was applied with aeration it is effective in reducing pollutant levels in the wastewater akin to MBBR. In addition, we tested the EBB without aeration and found that the treated waste water has relatively low levels of BOD, COD and turbidity, suggesting that the treated water can be utilized for landscaping and horticulture activities. Overall, the outcomes from this study are encouraging to adopt EBB in smaller towns and in small housing societies to treat the wastewater prior to release. The paper focuses on reviewing the various sewage treatment methods and their results.

Assessment of dumpsites leachate, geotechnical properties of the soil, and their impacts on surface and groundwater quality of Sunyani, Ghana

Leachate from sanitary landfill and dumpsites have potential to cause soil and groundwater contamination, and disrupt ecosystems. However, there is little information about dumpsite leachates and geotechnical properties and their impacts on surface and groundwater in Bono region, Ghana. This study assessed dumpsites leachate, geotechnical properties of the soil, and their impacts on surface and groundwater quality in Sunyani. Six triplicate leachates, eleven triplicate groundwater and three triplicate surface water samples were taken at (up-stream, mid-stream and down-stream) urban dumpsite, and eight triplicate groundwater samples taken around peri-urban dumpsite. Water samples were stored (<4°C) in polyethylene bottle for laboratory analysis. Physicochemical properties of leachate and water samples were analyzed using standard methods. Heavy metals (Cd, Hg, Pb, Zn, Cr, Fe, Cu, and Ni) were determined using atomic absorption spectroscopy. Water quality index (WQI) and leachate pollution loads (LPL) were investigated, while plasticity index (Ip) and liquid index (Il) were determined using Atterberg limit test. The results showed that all leachate samples were heavily polluted with mean concentrations of chlorides ranged between (2830±220 and 63810±340), biochemical oxygen demand (358±36 to 820±80), ammonium ions (82.8±2.2 to 267.6±62), and cadmium (0.49±0.02 to 5.32±1.0); with their leachate pollution index (LPI) and LPL exceeding their leachate disposal standards (LDS>100). WQI ranged from 6.51 to 289, indicating excellent to heavily polluted groundwater sources. Surface water was heavily polluted with WQI between 0.84 and 776.75, with majority having WQI>100. The heavily polluted samples were located 75-155 m away from urban dumpsite. Moderate significant negative association was established between (WQI-P and WQI-H) and distance with multiple R2=0.4709, p=0.0191 and R2= 0.4482, p=0.02425 respectively. Statistically, strong significant negative association between (WQI-P & WQI-H) and Ip (p < 0.05). This implies that when plasticity index and distance from groundwater sources to dumpsite increased, WQI values decreased, and groundwater quality improved.