[Pollution Characteristics, Source Analysis, and Health Risk Assessment of Heavy Metals of Soil in a Certain Coal Mining Area of Western Jiangxi Province].

To explore the pollution characteristics, sources, and possible human health risks of soil heavy metals in a coal mine concentration area near western Jiangxi. The Nemerow index method was used to evaluate the characteristics of soil heavy metal pollution in the study area, the correlation of soil heavy metal pollution characteristics was described based on a self-organizing neural network （SOM）, the PMF model was used to trace the soil heavy metal pollution, and the exposure risk model established by EPA was used for health risk assessment. The results showed that the average content of heavy metals in the six soils ranged from 0.

Comparison and prediction of shallow groundwater nitrate in Shaying River basin based on urban distribution using multiple machine learning approaches.

Groundwater, a pivotal water resource in numerous regions worldwide, confronts formidable challenges posed by severe nitrate pollution. Traditional research methodologies aimed at addressing groundwater nitrate contamination frequently struggle to accurately depict the intricate conditions of the groundwater environment, particularly when dealing with high variability and nonlinear data. However, the advent of machine learning (ML) has heralded an innovative approach to simulating groundwater dynamics.

Process-based quantitative description of carbon biogeochemical cycle in a reclaimed water intake area.

Reclaimed water plays a pivotal role in addressing water scarcity and pollution. The carbon (C) cycle significantly impacts aquatic ecosystems and water quality, yet the C biogeochemical cycle in nutrient-rich reclaimed water remains enigmatic. This study focuses on reclaimed water, developing a conceptual biogeochemical mass balance model to examine C cycling and assess the C budget in the highly eutrophic Jian and Chaobai rivers.

A new approach combining principal component factor analysis and K-means for identifying natural background levels of NO-N in shallow groundwater of the Huaihe River Basin.

Establishing natural background levels (NBLs) of nitrate‑nitrogen (NO-N) is crucial for groundwater resource management and pollution prevention. Traditional statistical methods for evaluating NO-N NBLs generally overlook the hydrogeochemical processes associated with NO-N pollution. We propose using a method that combines principal component factor analysis and K-means clustering (PCFA-KM) to identify NO-N anomalies in three typical areas of the Huaihe River Basin and evaluate the effectiveness of this method in comparison with the hydrochemical graphic method (Hydro) and the Gaussian mixture model (GMM).

Comparative study of the quick action effect of multiple enzyme-based nano-emulsified oils in enhancing nitrate contamination remediation in groundwater.

Emulsified vegetable oil (EVO), as a novel green slow-releasing substrate, has performed great potential in subsurface bioremediation due to its slow release and longevity. Nevertheless, the long time it takes to initiate this process still exposed some limitations. Herein, multiple enzyme-based EVOs (EN-EVOs) were developed to enhance the quick-acting effect in nitrate-contaminated bioremediation.

Revealing the drivers and genesis of NO-N pollution classification in shallow groundwater of the Shaying River Basin by explainable machine learning and pathway analysis method.

Nitrate (NO-N), as one of the ubiquitous contaminants in groundwater worldwide, has posed a serious threat to public health and the ecological environment. Despite extensive research on its genesis, little is known about the differences in the genesis of NO-N pollution across different concentrations. Herein, a study of NO-N pollution concentration classification was conducted using the Shaying River Basin as a typical area, followed by examining the genesis differences across different pollution classifications.

Effect and genesis of soil nitrogen loading and hydrogeological conditions on the distribution of shallow groundwater nitrogen pollution in the North China Plain.

The North China Plain (NCP) has experienced increasingly severe groundwater nitrogen (TN) pollution. However, the factors influencing TN distribution are still poorly understood. Previous studies have identified surface soil nitrogen (TSN) loading and intrinsic groundwater vulnerability (Inv) as the main factors controlling groundwater TN pollution.

Hydrochemical evolution characteristics and genesis of groundwater under long-term infiltration (2007-2018) of reclaimed water in Chaobai River, Beijing.

The reuse of reclaimed water (RW) for river ecological restoration in global water-shortage regions has inevitably brought some potential risks for groundwater. However, little is known about the effects of reclaimed water on the hydrochemical evolution of groundwater especially under long-term infiltration conditions. Herein, 11-years monitoring data (2007-2018) of reclaimed water and groundwater were adopted to analyze the characteristics and genesis of groundwater hydrochemical evolution under long-term infiltration of reclaimed water from Jian River to Chaobai River in Beijing.

Transport and retention of nano emulsified vegetable oil in porous media: Effect of pore straining, roughness wedging, and interfacial effects.

Emulsified vegetable oil (EVO), as one of the novel green substrates, has been widely used in subsurface remediation. In these applications, the retention behavior of EVO presents a challenge to remediation efficiency as mechanism insights into the retention of EVO is limited. Herein, Brinell funnels experiments with X-ray microtomography (XMT) were conducted to examine the drainage and retention of nanoscale EVO in porous media, with a specific focus on investigating the impact of pore straining, grain surface roughness, and interfacial effects on Nano-EVO (NEVO) retention.

Coupling of multi-hydrochemical and statistical methods for identifying apparent background levels of major components and anthropogenic anomalous activities in shallow groundwater of the Liujiang Basin, China.

Natural background levels (NBLs) is a prerequisite for distinguishing anthropogenic groundwater pollution and judging the evolution of groundwater quality. However, due to regional differences of hydrogeochemitry and water-rock interaction, coupled with long-term anthropogenic activities, it is no longer accurate to assess NBLs with only statistical methods or without considering human impact. Herein, multi-hydrochemical and statistical methods were examined to identify apparent background levels and anthropogenic anomalous activities of shallow groundwater by selecting Liujiang Basin as a study area.

Pore-scale identification of residual morphology and genetic mechanisms of nano emulsified vegetable oil in porous media using 3D X-ray microtomography.

The application of emulsified vegetable oil (EVO) has attracted widespread attention in environmental remediation. Residual morphology is an important factor affecting its migration and mass transfer. However, proper identification of the EVO residual morphology at pore-scale has still remained a challenging task.

Assessment, formation mechanism, and different source contributions of dissolved salt pollution in the shallow groundwater of Hutuo River alluvial-pluvial fan in the North China Plain.

With rapid urbanization and industrialization processes, the problem of groundwater pollution under the influence of various human activities has become increasingly severe in most developed areas of China. However, the problem of dissolved salt pollution caused by increasing concentrations of conventional ions is often overlooked and easier to be seen as a high background of natural formation rather than pollution. The Hutuo River alluvial fan in North China was selected as the study area; dissolved salt pollution is evaluated based on the factor analysis method (FA); groundwater exploitation, pollutant input, and the attenuation of the vadose zone were discussed to explain the salt pollution; the formation mechanism and different source contributions were also explored.

Sensitivity assessment of denitrifying bacteria against typical antibiotics in groundwater.

The effects of antibiotics on nitrate denitrification in groundwater have acquired growing concern. Denitrification is a microbially mediated process. The effects of antibiotics on denitrification were mainly reflected in denitrifying bacteria.

Effect of hydrogeological conditions and surface loads on shallow groundwater nitrate pollution in the Shaying River Basin: Based on least squares surface fitting model.

Nitrate pollution in groundwater has become a widespread problem worldwide, but understanding of the factors influencing groundwater nitrate pollution remains limited. Numerous studies have attributed nitrate pollution mostly to surface conditions and have neglected the role of hydrogeology. Therefore, this study used the Shaying River Basin as the study area and developed a least squares surface fitting (LSSF) model to systematically analyze the effect of hydrogeological conditions and surface pollution loads on groundwater nitrate pollution.

Formation process and mechanism of humic acid-kaolin complex determined by carbamazepine sorption experiments and various characterization methods.

To explore the formation process and mechanism of organic matter and organic-mineral complex under humification and mineralization conditions, a series of samples including humic acid, kaolin, and humic acid-kaolin complex were prepared using a subcritical water treatment method (SWT) under specific temperature, pressure and reaction time conditions. HA was used as a surrogate for natural organic matter because it has a similar abundant pore structure, variety of carbon types, and chemical components. These samples were used in carbamazepine (CBZ) sorption experiments and characterized by a variety of techniques.

Abnormal pH elevation in the Chaobai River, a reclaimed water intake area.

The pH is a primary index reflecting water quality in rivers. The Jian River and Chaobai River are two reclaimed water intake areas which have elevated pH. This elevated pH has a marked effect on both the phytoplankton, species in water and vegetation on the shore.