Microplastics in groundwater: Environmental fate and possible interactions with coexisting contaminants.

Microplastics (MPs) are emerging environmental pollutants which represent a serious threat to ecosystems and human health and have received significant attention from the global community. Currently, a growing number of studies have found the presence of MPs in groundwater. This study exhaustively reviewed varying degrees of recent publications in Web of Science database and investigated the characteristics of MPs (concentration, types, sizes and shapes) in groundwater ecosystems, their migration characteristics, and interactions with co-occurring contaminants.

Impact of microbial activity on fluoride release from sediments in areas with high fluoride groundwater: Mechanisms, sources and the lithology diversity.

This study explores the interplay between microbial activity and sediment lithology in influencing fluoride release from sediments. Sediment samples, collected from Yuncheng Basin: a region known for significant groundwater fluoride contamination, exhibit fluoride concentrations well above the global average, ranging from 206.2 mg/kg to 780.

Sulfate-reducing bacteria (SRB) mediated carbonate dissolution and arsenic release: Behavior and mechanisms.

Carbonate bound arsenic act as an important reservoir for arsenic (As) in nature aquifers. Sulfate-reducing bacteria (SRB), one of the dominant bacterial species in reductive groundwater, profoundly affects the biogeochemical cycling of As. However, whether and how SRB act on the migration and transformation of carbonate bound arsenic remains to be elucidated.

Hydrogeochemical characteristics, stable isotopes, positive matrix factorization, source apportionment, and health risk of high fluoride groundwater in semiarid region.

Chronic exposure to high fluoride (F) levels in groundwater causes community fluorosis and non-carcinogenic health concerns in local people. This study described occurrence, dental fluorosis, and origin of high F-groundwater using δH and δO isotopes at semiarid Gilgit, Pakistan. Therefore, groundwater (n = 85) was collected and analyzed for F concentrations using ion-chromatography.

Mechanisms and health implications of toxicity increment from arsenate-containing iron minerals through gastrointestinal digestion.

Inadvertent oral ingestion is an important exposure pathway of arsenic (As) containing soil and dust. Previous researches evidenced health risk of bioaccessible As from soil and dust, but it is unclear about As mobilization mechanisms in health implications from As exposure. In this study, we investigated As release behaviors and the solid-liquid interface reactions toward As(V)-containing iron minerals in simulated gastrointestinal bio-fluids.

Geochemical control, water quality indexing, source distribution, and potential health risk of fluoride and arsenic in groundwater: Occurrence, sources apportionment, and positive matrix factorization model.

Fluoride (F), and arsenic (As) in the groundwater cause health problems in developing countries, including Pakistan. We evaluated the occurrence, distribution, sources apportionment, and health hazards of F, and As in the groundwater of Mardan, Pakistan. Therefore, groundwater samples (n = 130) were collected and then analyzed for F, and As by ion-chromatography (IC) and Inductively-coupled plasma mass-spectrometry (ICP-MS).

Groundwater Quality, Health Risk Assessment, and Source Distribution of Heavy Metals Contamination around Chromite Mines: Application of GIS, Sustainable Groundwater Management, Geostatistics, PCAMLR, and PMF Receptor Model.

Groundwater contamination by heavy metals (HMs) released by weathering and mineral dissolution of granite, gneisses, ultramafic, and basaltic rock composition causes human health concerns worldwide. This paper evaluated the heavy metals (HMs) concentrations and physicochemical variables of groundwater around enriched chromite mines of Malakand, Pakistan, with particular emphasis on water quality, hydro-geochemistry, spatial distribution, geochemical speciation, and human health impacts. To better understand the groundwater hydrogeochemical profile and HMs enrichment, groundwater samples were collected from the mining region (n = 35), non-mining region (n = 20), and chromite mines water (n = 5) and then analyzed using ICPMS (Agilent 7500 ICPMS).

Comparative study on effects of pH, electrolytes, and humic acid on the stability of acetic and polyacrylic acid coated magnetite nanoparticles.

The poor colloidal stability of magnetite nanoparticles (MNPs) limits their mobility and application, so various organic coatings (OCs) were applied to MNPs. Here, a comparative study on the colloidal stability of MNPs coated with acetic (HAc) and polyacrylic acids (PAA) was conducted under varied pH (5.0-9.

Mobilization of arsenic from As-containing iron minerals under irrigation: Effects of exogenous substances, redox condition, and intermittent flow.

Irrigation activities can cause strong geochemical and hydrological fluctuations in the unsaturated zone, and affect arsenic (As) migration and transformation. The As geochemical cycle in the unsaturated zone is coupled with that of iron minerals through sorption-desorption, coprecipitation and redox processes. Dynamic batch experiments and wetting-drying cycling column experiments were conducted to evaluate As mobilization behaviors under the effects of exogenous substances, redox condition and intermittent flow.

Geochemical Modeling Source Provenance, Public Health Exposure, and Evaluating Potentially Harmful Elements in Groundwater: Statistical and Human Health Risk Assessment (HHRA).

Groundwater contamination by potentially harmful elements (PHEs) originating from the weathering of granitic and gneissic rock dissolution poses a public health concern worldwide. This study investigated physicochemical variables and PHEs in the groundwater system and mine water of the Adenzai flood plain region, in Pakistan, emphasizing the fate distribution, source provenance, chemical speciation, and health hazard using the human health risk assessment HHRA-model. The average concentrations of the PHEs, viz.

Hydrogeochemical assessment of carcinogenic and non-carcinogenic health risks of potentially toxic elements in aquifers of the Hindukush ranges, Pakistan: insights from groundwater pollution indexing, GIS-based, and multivariate statistical approaches.

Globally, potentially toxic elements (PTEs) and bacterial contamination pose health hazards, persistency, and genotoxicity in the groundwater aquifer. This study evaluates PTE concentration, carcinogenic and noncarcinogenic health hazards, groundwater quality indexing (GWQI-model), source provenance, and fate distribution in the groundwater of Hindukush ranges, Pakistan. The new estimates of USEPA equations record new research dimensions for carcinogenic and noncarcinogenic hazards.

Aggregation of varied organic coated magnetite nanoparticles: Adsorbed mass and thickness of coatings and interactions with natural organic matter.

Magnetite nanoparticles (MNPs) with varied organic coatings (OCs) which improved their stability have broad environmental applications. However, the adsorbed amounts and layer thickness of varied OCs onto MNPs during the synthesis were generally not or poorly characterized, and their interactions with natural organic matter (NOM) were still in progress. In this study, acetic (HAc), citric (CA), and polyacrylic acid (PAA) were selected as model OCs, the adsorption behaviors of OCs on MNPs were characterized under varied aqueous C/Fe ratios, and the aggregation behaviors of MNPs with varied OCs (OC-MNPs) at neutral pH (7.

The occurrence of geogenic fluoride in shallow aquifers of Kenya Rift Valley and its implications in groundwater management.

Widespread concerns about high-fluoride groundwater and their health risks have been raised worldwide. Weathering of volcanic minerals is regarded as a principal source of groundwater fluoride in regions with volcanic bedrocks. However, how does the volcanic minerals control fluoride occurrence, if it induces other hydrogeochemical processes participating in and how this relates to human health still remain unclear.

Assessment of shallow aquifer vulnerability to fluoride contamination using modified AHP-DRASTICH model as a tool for effective groundwater management, a case study in Yuncheng Basin, China.

Vulnerability assessment is an effective tool for the precaution of groundwater quality to specific pollutants. Groundwater fluoride pollution is severe and universal in the world, however, the method of groundwater risk assessment to fluorine is never built. The objective of this study was to establish an effective method to assess the potential level of groundwater vulnerability to fluoride by a modification of the typical DRASTIC model.

Sources and pollution path identification of PAHs in karst aquifers: an example from Liulin karst water system, northern China.

Karst water, with constituting major sources for water supply worldwide, is vulnerable and prone to be polluted. In this study, it is reported that karst water polycylic aromatic hydrocarbons (PAHs) pollution is caused by the infiltration of surface runoff in the bared carbonate areas, which is of universal significance for the protection of groundwater resources in karst region. Hydro-geochemistry, stable isotopes (δD, δO and Sr/Sr) and characteristic ratio method were conducted together to illustrate the concentration, distribution, sources and pollution path of polycyclic aromatic hydrocarbons in groundwater in the Liulin karst water system of northern China.

A review of the distribution, sources, genesis, and environmental concerns of salinity in groundwater.

Awareness concerning the degradation of groundwater quality and their exacerbating adverse effects due to salinization processes is gaining traction, raising for adequate understanding of the distribution, sources, genesis, and environmental concerns of salinity in groundwater. Saline groundwater is widely distributed all over the world, with an area of 24 million km (16% of the total land area on earth) and 1.1 billion people living in the affected areas, especially the arid/semi-arid areas in developing countries.

Human Activity and Hydrogeochemical Processes Relating to Groundwater Quality Degradation in the Yuncheng Basin, Northern China.

Groundwater quality degradation has raised widespread concerns about water supplies and ecological crises in China. In this study, hydrogeochemistry, environmental stable isotopes (δO, δD), and principal component analysis were conducted together to reveal the mechanism's response to the hydrogeochemical and quality degradation of groundwater in Yuncheng Basin, Northern China, so that reasonable water resource management strategies can be developed. The study reveals that groundwater faces a tremendous risk of quality decrease during the past decade: (1) the hydrochemical facies of groundwater shows that the bicarbonate and chloride type water was replaced with sulfate type water and the occupying area of SO·Cl-Na, SO·HCO-Na type water expanded dramatically in shallow and intermediate-deep aquifers.

Temporal Network Pattern Identification by Community Modelling.

Temporal network mining tasks are usually hard problems. This is because we need to face not only a large amount of data but also its non-stationary nature. In this paper, we propose a method for temporal network pattern representation and pattern change detection following the reductionist approach.

Geochemical modeling, source apportionment, health risk exposure and control of higher fluoride in groundwater of sub-district Dargai, Pakistan.

The present study examined the hydrogeochemical profile of higher fluoride (F) in groundwater of mixed industrial and mining areas of Dargai, northern Pakistan. Groundwater samples (n = 75) were collected from three hydrogeochemical environments. The mean concentrations of pH, EC, TDS, Depth and Temperature were (7.

Fluoride contributes to the shaping of microbial community in high fluoride groundwater in Qiji County, Yuncheng City, China.

As a toxic element, excessive amounts of fluoride in environment can be harmful because of its antimicrobial activity, however little is known about the relationship between fluoride and the bacterial community in groundwater systems. Here, we use samples from a typical fluorosis area to test the hypothesis that fluoride concentration is a fundamental structuring factor for bacterial communities in groundwater. Thirteen groundwater samples were collected; high-throughput 16S rRNA gene sequencing and statistical analysis were conducted to compare the bacterial community composition in individual wells.

Indigenous microbes induced fluoride release from aquifer sediments.

Release of fluoride from Quaternary sediments produces F-contaminated groundwater which threatens the health of millions of people worldwide. Despite the mechanisms of fluoride release from sediments are documented by numerous studies, it remains poorly understood that whether indigenous microbes participate in or not for the formation of F-rich groundwater by releasing fluoride from aquifer sediments. A microcosm-based approach, geochemistry and techniques of microbiology and molecular ecology were conducted together to investigate these mechanisms.

The Potential Environmental Impact of PAHs on Soil and Water Resources in Air Deposited Coal Refuse Sites in Niangziguan Karst Catchment, Northern China.

Long-term deposition of coal spoil piles may lead to serious pollution of soil and water resources in the dumping sites and surrounding areas. Karst aquifers are highly sensitive to environmental pollution. In this study, the occurrence and release/mobilization of polycyclic aromatic hydrocarbons (PAHs) in coal waste and coal spoils fire gas mineral (CSFGM) were evaluated by field and indoor investigations at Yangquan city, one of the major coal mining districts in the karst areas of northern China.

Assessment of Groundwater Quality at Yuncheng Basin: Denotation for the Water Management in China.

Dramatic decreases in groundwater quality have raised widespread concerns about water supplies and ecological crises in China. In this study, hydrochemistry, stable isotopes, and graphical and multivariate statistical methods are integrated to identify hydrogeochemical processes controlling groundwater quality in the Yuncheng Basin, China. Our results show that groundwater with 21 variables (pH, temperature-T, total dissolved solid, major-trace elements, and stable isotopes) is chemically classified into three distinct clusters: fresh water [C1], brackish-saline water [C2], and saline water [C3].