Arsenic and heavy metals in reclaimed soils of sulfide-containing waste dumps: contamination levels, spatial distribution, bioavailability, and health risk assessment.

First environmental surveillance, source-sink fate modelling, and risk assessment of polybrominated diphenyl ethers in the Tapi and Daman Ganga riverine catchments draining into the Arabian Sea.

Spatial heterogeneity of microplastic pollution and associated emerging contaminants in tropical estuarine environments: Novel insights into distribution, bioavailability, and ecological risk.

Effects of inoculum sources from different depths and oxygen concentration on bioleaching and microbial community assembly in mine waste dump.

Open dumping of municipal solid waste (MSW) remains a widespread and meagrely regulated waste management practice in many developing nations, resulting in sizeable environmental degradation and increased health risks. This study evaluates the extent of contamination of eight heavy metals silver (Ag), arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), lead (Pb), and zinc (Zn) in soils at depths of 0.5m, 1.0m, and 1.5m at the Second Seventh Municipal Solid Waste Dumpsite (SSMSWD) in Lae City, Papua New Guinea. Soil samples were digested using reverse aqua regia and analyzed with Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES). The findings showed that the maximum observed concentrations as µg/g were significantly higher than the recommended values as per World Health Organization (WHO) with Pb-450, Zn-173, Cd-120, Ag-44, As-38, Cu-18, Fe-1.34 and Cr-1.4 respectively. Pollution indices, which classify contamination severity relative to the background concentrations, indicated that Pb, Cd, Zn, As, Ag and Cu fall within the pollution category (PI > 5), while Pollution Load Index (PLI > 1) values reveal the overall deterioration of soil quality. Cumulative Pollution Index (PIsum) was between 93 and 714, meaning very high overall contamination (PIsum > 4n), and the average Pollution Index (PIavg > 1) was between 12 and 89 and this proved that the vertical concentration profiles specify that metal enrichment extending to 1.5m depth, reflecting downward redistribution inferred from concentration patterns. Findings signify severe multi-metal contamination that degrades soil quality and creates a considerable risk of escape to shallow groundwater, with possible potential repercussions for ecosystem integrity and human health.

The present work aims to achieve degradation of UV treated Polypropylene (PP) by utilizing the capabilities of two bacterial strains designated as KRS102 and KRS236. Both strains were isolated from a waste dump site in Rishikesh (India), identified through 16S rDNA sequencing and compared for PP degradation ability. Detection of biosurfactant production and hydrophobicity assessment validated biodegradation potential of the isolated strains while 16S rDNA secondary structure prediction using RNAfold confirmed their thermodynamic stability. The biodegradation of PP films in terms of percent weight loss by Bacillus cereus KRS102 and Bacillus tropicus KRS236 was found to be 3.4 ± 0.20% and 2.9 ± 0.18%, respectively following 90days of incubation period. Strain KRS102 exhibited faster depolymerization dynamics than KRS236, as indicated by its higher biomass (protein content: 9.64 ± 3.3µgmL⁻1), greater degradation rate constant (0.000384day⁻1), and shorter half-life (1805days) as determined by kinetic modeling. EDX analysis indicated oxidative cleavage of the polymer chains. The KRS102-treated film showed a marked increase in oxygen content (27.74%) and a corresponding decrease in carbon (72.26%), reflecting extensive oxidative modification. In contrast, the control PP film exhibited minimal oxygen (0.94%) and was predominantly composed of carbon (99.10%). The FTIR study revealed changed functional group intensities and an increase in the carbonyl index. These alterations show that the biofilm matrix promotes substrate enzymatic interactions and biochemical transformations, indicating increased metabolic activity in the microbial biofilm. GC-MS and SEM analysis corroborated these findings through degradation intermediates and visible surface alterations respectively. Overall, Bacillus cereus KRS102 exhibited higher biodegradation efficiency than Bacillus tropicus KRS236, highlighting its potential as environment friendly PP degrader.

The development of mines creates substantial amounts of soil-rock mixture (S-RM) waste that is accumulated as waste dumps. These dumps pose significant safety hazards that require management. In this study, S-RM was sampled from a waste dump at a copper mine in Jiangxi Province, China. Consolidated-undrained triaxial tests were conducted on four gradations of S-RM specimens. Numerical simulations of dump slope stability were performed by considering factors such as groundwater level, rainfall intensity, and root reinforcement depth. The findings are as follows: (1) cohesion and friction angle are sensitive to rock content; (2) the power-law model outperforms the Duncan-Chang model in fitting triaxial data; (3) the stability of the dump deteriorates as the groundwater level gets shallower; (4) the factors of safety decrease with increasing rainfall duration and intensity with an approximately exponential decay pattern; (5) vegetation root reinforcement improves slope stability; however, extreme rainfall can trigger perched water accumulation, which can compromise stability. These findings provide valuable indicators that can assist in managing the safety hazard posed by such waste dumps.

Satellite-Based Forensic Mapping of Illegal Construction and Demolition Waste Dumping Sites for Urban Environmental Governance Assessment in China

ABSTRACT Heavy metal contamination has become a critical environmental concern in rapidly industrializing regions, particularly in areas dominated by mining and thermal power activities. This review identifies the prospect of green algae (Chlorophyta) as credible bioindicators and sustainable bioremediation tools to detect the presence of heavy metal pollution, particularly in the Korba industrial region of Chhattisgarh in India. The emission produced by industries, mining, and improper dumping of waste has resulted in high levels of harmful toxic metals in the environment, which have caused serious ecological and health hazards to both the aquatic life and human beings. Green algae have special biological traits such as rapid growth, high surface‐area/volume ratio, and high metal‐binding capacity, which allow them to be used in biosorption and bioaccumulation of heavy metals. The further development of analytical, spectroscopic, and omics‐based imaging methods has made the approaches of algal biomonitoring more precise and advanced knowledge of the mechanisms of metal uptake. Algae‐based approaches are cost‐effective, eco‐friendly, and scalable in comparison to traditional physicochemical remediation approaches to pollution evaluation and remediation. Future studies ought to focus on the real‐time biosensing systems and built‐in biomonitoring systems to enhance the sensitivity of detection and remediation of highly industrialized landscapes.

Open dumps as a critical source of per- and polyfluoroalkyl substances in agricultural soils of Pakistan: evidence of trifluoroacetic acid dominance.

Solid waste dumping differentially impacts soil prokaryotic, fungal, and viral communities: Insights from metagenomics.

Comprehensive assessment of the geoecological state of areas adjacent to mining waste dumps using the electromagnetic geophysics method

The nearby study analyses the solid waste management in Tamil Nadu. Solid waste comprised all the wastes arising from human and animal activities that are normally solid and that are discarded useless or unwanted. The increasing difficulty in managing wastes in different states in Tamil Nadu. On the basis of the results, it was recommended to increase public awareness through enlightenment campaign against danger of indiscriminate dumping of wastes as they affect human health.

The indiscriminate dumping of municipal solid waste in Malawi, particularly at Lunzu dumpsite in Blantyre, has raised significant environmental concerns due to the potential contamination of surrounding soils and water sources by heavy metals (HMs). This study assessed the concentrations, spatial distribution, and ecological risks of selected heavy metals, cadmium (Cd), lead (Pb), copper (Cu), zinc (Zn), iron (Fe), manganese (Mn), and cobalt (Co) in soil and groundwater around the dumpsite. Samples were collected at varying distances (0-250 m radius from the dumpsite) during both dry and wet seasons and analyzed using Flame Atomic Absorption Spectrophotometry (AAS). In soil, the highest concentrations were recorded at the dumpsite center during the dry season: Cd at 3.08 mg/kg, Cu at 316.18 mg/kg, and Pb at 80.00 mg/kg, exceeding the WHO and EU permissible limits. In the wet season, metal concentrations were lower but still elevated, with Cd at 2.77 mg/kg, Zn at 635.22 mg/kg, and Pb at 72.00 mg/kg. In water samples, the maximum concentrations during the dry season were Cd at 0.02 mg/L, Pb at 0.14 mg/L, and Fe at 1.56 mg/L, which exceeded WHO drinking water standards, particularly for cadmium and lead. Correlation analysis revealed strong positive relationships among most metals and soil organic carbon (SOC), suggesting common pollution sources and the role of organic matter in metal retention. Water samples also revealed elevated concentrations of cadmium and lead, with levels surpassing WHO, EU, and Malawi Bureau of Standards (MBS) guidelines, posing serious health risks to nearby communities. Contamination assessment indices like the contamination factor (CF), geo-accumulation index (Igeo), enrichment factor (EF), and potential ecological risk index (PERI) consistently identified cadmium and mercury as the most ecologically hazardous metals. The spatial trend showed a decline in metal concentrations with increasing distance from the dumpsite, confirming the dumpsite as the primary contamination source.

The study aimed to deconstruct urban flooding in Peshawar (one of Pakistan's rapidly urbanizing cities) from the perspective of flood vulnerable communities. The research was conducted using a mixed-methods approach, synthesizing qualitative data with quantitative geospatial analyses of Land-Use/Land-Cover change and flood exposure. Qualitative data were collected through the Focus Group Discussion and In-depth Interviews checklist with a total sample size of 89 participants. The quantitative aspect (geospatial) was used to triangulate community-identified patterns (e.g., encroachment, land cover change). Study results reveal that the fast-increasing urban flooding phenomenon within Peshawar's rapidly urbanizing Bhudni Nullah Basin (BNB) is the outcome of a multifaceted and interrelated human-natural systems failures, driven by the merging of hydro-climatic conditions, anthropogenic modification and governance deficits. The basin's intensifying flood risk is fundamentally linked to impaired hydrological response resulting from rapid and unplanned urbanization. Erratic, high-intensity precipitation and an elevated water table critically diminish the basin's natural water retention and conveyance capacity. Geospatial analysis documented an increase in the artificial surface (impervious), surging from 39.60% in 2017 to 46.01% 2020 and eventually reached 59.96% in 2025. The transformation significantly accelerates surface runoff volume and velocity, overwhelming the existing drainage infrastructure. Unregulated riparian zone infringement and the persistent solid waste dumping severely reduce the effective cross-sectional area of the Bhudni Nullah. Concurrently, the Height Above Nearest Drainage model-based flood exposure assessment quantifies a critical vulnerability, with 11.57 km 2 (22.14%) classified as “Very High” and “High” flood exposure, concentrated within the built environment. The study provides socio-physical, environmental, and economic indicators for future urban flood modeling and research studies.

ABSTRACT The water quality of urban rivers is reported to be polluted due to the discharge of untreated wastewater and the dumping of solid waste, resulting in critical damage to the river ecosystem. This study focuses on the Mula-Mutha River in Pune, Maharashtra, India, which has been severely affected by urban development. The primary aim of this study is to develop a model of Mula-Mutha river for simulating river hydraulics and water quality parameters, such as DO and BOD. The work involves integrated water quality modeling, calibration and validation of 123 km river stretch from Khadakwasla reservoir to Daund. Close agreement was observed between simulated and observed values for DO and BOD at five representative locations of the study area. Process constants, including manning’s n, first-order decay rate and half-saturation oxygen concentration, were tuned for the development of the model. Model efficiency of greater than 90% and a correlation factor of about 0.900 are achieved. Simulations conclude that a release of fresh water of 3 cumec can improve water quality for propagation of fish in an initial urban river stretch. The model can be used for evaluating and predicting water quality dynamics of urban rivers and studying strategies for urban river rejuvenation.

Mine waste dumps represent significant sources of toxic and hazardous elements, posing long-term environmental risks such as acid rock drainage and heavy metal migration, particularly over extended periods. The inherent uncertainty in the chemical composition of waste rocks, particularly for less-studied elements such as arsenic, complicates long-term waste dump management. This study investigates the uncertainty in waste rock characteristics, with a focus on arsenic, to enhance waste dump design and provide recommendations for managing the dispersion of this toxic element. Initially, the uncertainty in arsenic grade is quantified using the Sequential Gaussian Simulation method. Subsequently, a waste dump optimization model, building upon our previously developed deterministic model, is adapted to incorporate arsenic content into the design and construction of the waste dump. This approach is implemented at a gold mine. The results indicate that, while the mathematical model achieves a more homogeneous arsenic distribution within the waste dump, some cells still contain elevated concentrations due to the overall high arsenic content. The uncertainty analysis reveals that, in an optimistic scenario, approximately 557,197 tons of arsenic would be deposited, whereas, in a pessimistic scenario, this amount could reach 747,254 tons. Finally, several strategies are proposed and discussed to reduce arsenic levels in waste dumps, aiding decision-makers.

• Pre- and post-failure deformation is compared in surface mining complexes. • InSAR observations reveal precursory deformation months to years before failures. • Post-failure deformation hotspots persist or even exceed pre-failure velocities. • Ongoing post-failure deformation may indicate residual instability. Operations in surface mining complexes are frequently associated with geotechnical engineering instability, which can have serious consequences for mining operations, nearby communities and the environment. Monitoring surface deformation is therefore a critical component of safe mining practices, and satellite-based Interferometric Synthetic Aperture Radar (InSAR) has become a widely used tool for this purpose. While most studies have focused on the conditions leading up to failures, post-failure deformation processes remain poorly investigated, even after events involving fatalities. In this study, we analysed ten cases in surface mining complexes worldwide, involving slope failures in open pits, tailings dams, heap leaches and waste dumps, six of which involved fatalities. Using InSAR, we examined surface deformation during both the pre- and post-failure periods, not only in the area specifically affected by the failure but also across the entire mining site, aiming to determine whether surface deformation anomalies diminish following such failures within the mining complex as a whole. Our results show that all failure sites exhibited precursory movements months to years before the events. Furthermore, we identified post-failure deformation hotspots across several mining areas, with some exhibiting velocities exceeding those prior to failure at the initial failure sites. These findings highlight the persistence and spatial redistribution of deformation within mining complexes following failure events, underscoring the importance of continued deformation monitoring beyond the immediate failure zones.

Hidden acidification beneath soil-covered mine waste dumps: links to oxygen-limited sulfur oxidation.

Phthalate esters, a plasticizer widely used in various plastic-based consumer products, readily leach into the environment and later on, significantly threaten human health and ecosystems. Among them, benzyl butyl phthalate (BBP), a significant environmental contaminant, is classified as a hazardous chemical due to its toxic effects on aquatic and terrestrial life forms. In this study, we evaluated the biodegradation of BBP in batch culture and in soil microcosms using a Gram-positive bacterium, Paenarthrobacter sp. strain M76, isolated from a plastic waste dump yard in Puducherry, India. HPLC analysis confirmed that BBP (0.5g/L) was completely degraded by M76 within 13days at 28°C, under shake culture conditions. To evaluate its applicability in real soil samples, a soil microcosm experiment was conducted using BBP and M76, which showed significant degradation of 60.00% and 64.21% of BBP within 20days in sterilized and unsterilized soil, respectively. An intracellular esterase enzyme was responsible for initiating BBP biodegradation. Pathway metabolites were identified using different chromatographic and spectrophotometric assays, and degradation mechanisms were established. To the best of our knowledge, this is the first report of BBP biodegradation by a single Paenarthrobacter strain in soil microcosms and in liquid media. The outcomes underscore the adaptability and capacity of strain M76 to efficiently eradicate BBP from contaminated soils, positioning it as a promising candidate for BBP degradation in terrestrial environments.