Groundwater pollution: Occurrence, detection, and remediation of organic and inorganic pollutants

Water Environment Research, Journal Year: 2020, Volume and Issue: 92(10), P. 1659 - 1668

Published: July 24, 2020

Groundwater pollution is a result of natural and anthropogenic activities. While the elevated levels various inorganic constituents could be attributed to processes, such as geological weathering aquifer characteristics, many times, activities also substantially pollute groundwater. On contrary, occurrence organic pollutants primarily due Extensive groundwater mining, hydraulic connection between other surface water bodies, leaking underground buried infrastructure contribute pollution. Water resources are scarce commodities, preserving quality critical concern. This paper documents instances impact during year 2019 both throughout world. PRACTITIONER POINTS: problems reported reviewed documented. Occurrence organic, inorganic, microbial in reported. Remediation technologies for selected

Language: Английский

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Machine-Learning Predictions of High Arsenic and High Manganese at Drinking Water Depths of the Glacial Aquifer System, Northern Continental United States

Environmental Science & Technology, Journal Year: 2021, Volume and Issue: 55(9), P. 5791 - 5805

Published: April 6, 2021

Globally, over 200 million people are chronically exposed to arsenic (As) and/or manganese (Mn) from drinking water. We used machine-learning (ML) boosted regression tree (BRT) models predict high As (>10 μg/L) and Mn (>300 in groundwater the glacial aquifer system (GLAC), which spans 25 states northern United States provides water 30 people. Our BRT models' predictor variables (PVs) included recently developed three-dimensional estimates of a suite age metrics, redox condition, pH. also demonstrated successful approach significantly improve ML prediction sensitivity for imbalanced data sets (small percentage values). present predictions probability concentrations groundwater, uncertainty, at two nonuniform depth surfaces that represent moving median depths GLAC domestic public supply wells within model domain. Predicted likelihood anoxic condition (high iron or low dissolved oxygen), predicted pH, relative well depth, several modeled hydrologic position were all PVs retained both models; however, PV importance influence differed between models. High-As high-Mn was with large portions central part GLAC.

Language: Английский

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Spatial and temporal evolution of groundwater arsenic contamination in the Red River delta, Vietnam: Interplay of mobilisation and retardation processes

The Science of The Total Environment, Journal Year: 2020, Volume and Issue: 717, P. 137143 - 137143

Published: Feb. 5, 2020

Geogenic arsenic (As) contamination of groundwater poses a major threat to global health, particularly in Asia. To mitigate this exposure, is increasingly extracted from low-As Pleistocene aquifers. This, however, disturbs flow and potentially draws high-As into Here we report detailed characterisation the Van Phuc aquifer Red River Delta region, Vietnam, where Holocene being drawn aquifer. This study includes data eight years (2010-2017) observations develop an understanding spatial temporal evolution redox status hydrochemistry. Arsenic concentrations were highly variable (0.5-510 μg/L) over scales <200 m. Five hydro(geo)chemical zones (indicated as A E) identified aquifer, each associated with specific As mobilisation retardation processes. At riverbank (zone A), mobilised freshly deposited sediments Fe(III)-reducing conditions occur. then transported across B), vertical intrusion evaporative water, likely enriched dissolved organic matter, promotes methanogenic further release C). In transition zone at boundary two aquifers D), decrease by sorption incorporations onto Fe(II) carbonates Fe(II)/Fe(III) (oxyhydr)oxides under reducing conditions. The sorption/incorporation Fe(III) minerals Mn(IV)-reducing has consistently kept below 10 μg/L for studied period 2010-2017, location does not appear have propagated significantly. Yet, largest hydrochemical changes found caused advection critical calls investigations.

Language: Английский

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Dissolved Organic Matter Sources in High Arsenic Groundwater From a Sand‐Gravel Confined Aquifer

Journal of Geophysical Research Biogeosciences, Journal Year: 2023, Volume and Issue: 128(2)

Published: Feb. 1, 2023

Abstract Sources of dissolved organic matter (DOM) triggering arsenic enrichment in deep confined groundwater is a highly debated issue. Along these lines, the spectroscopic and molecular characteristics DOM were monitored both shallow unconfined from Songnen Basin, China. Results demonstrated that with higher concentrations was characterized by more abundant labile compounds than groundwater. The three‐end‐member mixing model estimated had fraction surface water, while primarily recharged lateral flow. Groundwater sources fluorescence index (FI) values, which suggests sourced water stronger terrestrial signatures. However, mainly situ sedimentary release or by‐products microbial activity Higher values degradation (I_deg) indicate undergone greater extents one. anoxic environments occurred via pathway where saturated low‐molecular‐mass preferentially degraded to produce mid‐molecular‐mass unsaturated, aromatic, This explained significant positive correlations between FI I_deg values. A state conducive work successfully identified distinct DOM, proposed paradigm processing pathways during under environments.

Language: Английский

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Key drivers regulating arsenic enrichment in shallow groundwater of the Pearl River Delta: Comprehensive analyses of iron, competitive anions, and dissolved organic matter

Applied Geochemistry, Journal Year: 2023, Volume and Issue: 151, P. 105602 - 105602

Published: Feb. 16, 2023

Language: Английский

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Exogenous-organic-matter-driven mobilization of groundwater arsenic

Environmental Science and Ecotechnology, Journal Year: 2023, Volume and Issue: 15, P. 100243 - 100243

Published: Feb. 3, 2023

The potential release capacity of arsenic (As) from sediment was evaluated under a high level exogenous organic matter (EOM) with both bioreactive and chemically reactive matters (OMs). OMs were characterized by FI, HIX, BIX, SUVA254 fluorescence indices showing the biological activities kept at during experimental period. At genus level, Fe/Mn/As-reducing bacteria (Geobacter, Pseudomonas, Bacillus, Clostridium) (Paenibacillus, Acidovorax, Delftia, Sphingomonas) that can participate in metabolic transformation using EOM identified. reducing condition occurs which promoted As, Fe, Mn releases very concentrations OM. However, As increased first 15-20 days, followed decline contributed secondary iron precipitation. degree may be limited reactivity Fe (hydro)oxides. infiltration enhances aqueous conditions causing risk groundwater pollution, could occur specific sites such as landfills, petrochemical sites, managed aquifer recharge projects.

Language: Английский

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Iron mineral transformations and their impact on As (im)mobilization at redox interfaces in As-contaminated aquifers

Geochimica et Cosmochimica Acta, Journal Year: 2021, Volume and Issue: 296, P. 189 - 209

Published: Jan. 13, 2021

Language: Английский

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Surface Flooding as a Key Driver of Groundwater Arsenic Contamination in Southeast Asia

Environmental Science & Technology, Journal Year: 2021, Volume and Issue: 56(2), P. 928 - 937

Published: Dec. 24, 2021

Chronic exposure to groundwater contaminated with geogenic arsenic (As) poses a significant threat human health worldwide, especially for those living on floodplains in South and Southeast (S–SE) Asia. In the alluvial deltaic aquifers of S–SE Asia, aqueous As concentrations vary sharply over small spatial scales (10–100 m), making it challenging identify where contamination is present mitigate exposure. Improved mechanistic understanding factors that control levels essential develop models accurately predict spatially variable concentrations. Here we demonstrate surface flooding duration interannual frequency are master variables integrate key hydrologic biogeochemical processes affect A machine-learning model based high-resolution, satellite-derived, long-term measures effectively predicts heterogeneous at fine Cambodia, Vietnam, Bangladesh. Our approach can be reliably applied locations safe unsafe sources sufficient accuracy management decisions by solely using remotely sensed information. This work important evaluate exposure, impacts public health, shed light underlying hydrogeochemical drive mobilization into groundwater.

Language: Английский

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Shift in groundwater recharge of the Bengal Basin from rainfall to surface water

Communications Earth & Environment, Journal Year: 2023, Volume and Issue: 4(1)

Published: Jan. 9, 2023

Abstract Groundwater supports agriculture and provides domestic water for over 250 million people in the Bengal Basin. Here we investigate source of groundwater recharge using 2500 stable isotope measurements from region. We employ a Monte Carlo statistical analysis to find distributions possible components by accounting variability ratios each sources. that sources have shifted last decades with ~50% increase stagnant surface bodies (mostly during latter part dry season) relative decrease contribution direct infiltration precipitation (which occurs mostly early monsoon). attribute this shift an standing irrigated rice fields ponds, downward hydraulic gradient season driven pumping.

Language: Английский

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Arsenic in the Tibetan Plateau’s geothermal systems: a detailed analysis of forms, sources, and geochemical behaviors

Deleted Journal, Journal Year: 2024, Volume and Issue: 6(4)

Published: April 8, 2024

Abstract In high-altitude tectonic regions, significant geothermal activity influences groundwater arsenic levels, presenting crucial resource and environmental challenges. The present study examines the Gonghe-Guide Basin located in northeastern region of Qinghai-Tibet Plateau. employs a comprehensive approach encompassing field sampling, hydrochemical analysis, thermodynamic modeling, statistical analysis to ascertain composition origins groundwater. research data indicates that area displays weak alkalinity medium high mineralization, with principal types being SO 4− Cl·Na Cl·Na. concentration has notable inverse relationship Cl − positive correlation water temperature DO. According calculations, most common kind is As 5+ . properties are shaped by rock weathering, evaporative concentration, ion-exchange adsorption working together. These factors contribute favorable circumstances for formation migration throughout environment. Notably, between sodium ions calcium magnesium significantly impacts concentration. This marks first discovery unique contamination pattern within Tibetan Plateau, revealing temperature, dissolved oxygen content. provides new perspective on understanding pollution regions.

Language: Английский

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