Thiolated non-conjugated nano polymer network for advanced mercury removal from water.

Developing advanced adsorbents for selectively deducing mercury (Hg) in water to one billionth level is of great significance for public health and ecological security, but achieving the balance among efficiency, cost and environmental friendliness of adsorbents still faces enormous challenges. Herein, we present a high thiol content non-conjugated nano polymer network (PVB-SH) through simple microemulsion polymerization for efficient Hg ion (Hg(II)) removal. The PVB-SH is prepared by conventional commercial reagents and does not consume toxic organic solutions.

Mercury methylation and bioaccumulation in purple paddy soil systems with different acid-base properties.

Paddy soil is recognized as a hotspot for mercury (Hg) transformation. Soil acid-base property (expressed as pH) plays a crucial role in Hg methylation and accumulation in paddy systems. However, it is challenging to study this process in soils with varying pH values due to the rarity of a single soil type spanning a wide pH range.

Mercury reduction by agricultural organic waste-derived dissolved organic matter: Kinetic analysis and the role of light-induced free radicals.

Agricultural organic wastes can leach dissolved organic matter (DOM) into surrounding water bodies, establishing them as significant sources of aquatic DOM. Given the importance of DOM in biogeochemical cycling of mercury (Hg), this DOM may mediate divalent Hg (Hg(II)) reduction, a process that remains poorly understood. This study investigated Hg(II) reduction using DOM derived from six representative agricultural wastes, categorized into livestock manure (chicken, pig, cow) and crop straw (rice, corn, rapeseed), with systematic considerations of the kinetics of reduction processes and the involvement of key free radicals.

Identifying heavy metal sources and health risks in soil-vegetable systems of fragmented vegetable fields based on machine learning, positive matrix factorization model and Monte Carlo simulation.

Urban fragmented vegetable fields offer fresh produce but pose a potential risk of heavy metal (HM) exposure. Thus, this study investigated HM sources and health risks in the soil-vegetable systems of Chongqing's central urban area. Results indicated that Cd was the primary pollutant, with 28.

The different effects of molybdate on Hg(II) bio-methylation in aerobic and anaerobic bacteria.

In nature, methylmercury (MeHg) is primarily generated through microbial metabolism, and the ability of bacteria to methylate Hg(II) depends on both bacterial properties and environmental factors. It is widely known that, as a metabolic analog, molybdate can inhibit the sulfate reduction process and affect the growth and methylation of sulfate-reducing bacteria (SRB). However, after it enters the cell, molybdate can be involved in various intracellular metabolic pathways as a molybdenum cofactor; whether fluctuations in its concentration affect the growth and methylation of aerobic mercury methylating strains remains unknown.

Efficient and selective capture of various mercury species from water using an exfoliated thiocellulose.

The primary challenge in mercury (Hg) adsorbents for large-scale practical applications is to achieve the balance between performance and economy. This work attempts to address this issue by synthesizing an exfoliated thiocellulose (CU-SH) with high thiol density and hierarchical porosity using in-situ ligands grafting combined with chemical stripping. The prepared CU-SH shows remarkable physical stability and chemical resistance, and the micron sized fiber is conducive to separation from water.

Heavy metal pollution in agricultural soils from surrounding industries with low emissions: Assessing contamination levels and sources.

The potential for heavy metal (HM) pollution in agricultural soils adjacent to industries with elevated HM emissions has long been recognized. However, industries with relatively lower levels of HM emissions, such as alumina smelting and glass production, may still contribute to the pollution of surrounding agricultural soils through continuous, albeit low-level, emissions. Despite this, this issue has not garnered adequate attention thus far.

Anthropogenic activities enhance mercury methylation in sediments of a multifunctional lake: Evidence from dissolved organic matter and mercury-methylating microorganisms.

Multifunctional lakes are highly susceptible to anthropogenic influences, potentially introducing exogenous pollutants or nutrients into aquatic sediments. This, in turn, affects the mercury (Hg) methylation in the sediments. This study was conducted in the Changshou Lake, a representative multifunctional lake in southwestern China, with a specific focus on investigating the Hg variations, the potential of Hg methylation, and the influential factors affecting the methylation process within sediments across different functional areas.

Modified Lignin-Based Cement Solidifying Material for Improving Engineering Residual Soil.

Although lignin improves the strength and modulus of soil, it is less active when unmodified, and it exhibits more limited effects on soils in combination with traditional Ca-based curing agents. Lignin-solidified soil also exhibits deficiencies, such as poor durability under dry-wet cycling conditions, and thus, the amelioration effect is limited. This study investigated the enhancement of cement-solidified soil using hydroxylated lignin with sodium silicate and quicklime used as activators to improve the engineering performance and durability of the treated soil.

Causes of low mercury levels in fish from the Three Gorges Reservoir, China.

Previous studies have suggested that growth dilution may be an important factor contributing to the low fish Hg levels in China. To evaluate the impact of growth rate to MeHg bioaccumulation in fish in the Three Gorges Reservoir (TGR), this study used two fish species, Aristichthys nobilis (A. nobilis) and Coilia nasus (C.

Hg bioaccumulation in the aquatic food web from tributaries of the Three Gorges Reservoir, China and potential consumption advisories.

The Three Gorges Reservoir (TGR) holds the distinction of being China's largest reservoir, and the presence of pollutants in the fish from the reservoir have a direct impact on the health of local residents. Thus, 349 fish specimens of 21 species and 1 benthos (Bellamya aeruginosas) were collected from four typical tributaries of the TGR from 2019 to 2020. These specimens were analyzed for the concentrations of total mercury (THg) and methylmercury (MeHg), and some representative samples were tested for δC and δN values to reveal the characteristics of bioaccumulation and biomagnification.

Tracing and quantifying the source of heavy metals in agricultural soils in a coal gangue stacking area: Insights from isotope fingerprints and receptor models.

Historic coal gangue stacking probably brings heavy metals (HMs) into the surrounding agricultural soil, posing potential harm to human and environmental health. For better controlling and preventing agricultural soil HMs pollution, the screening of priority pollutants and identification of their pollution pathways are urgent in coal gangue stacking areas. Thus, this study selected a coal gangue stacking area in Chongqing, China as the research object and conducted the pollution evaluation, spatial distribution and source apportionment of the HMs (Cd, Cr, Ni, Cu, Zn, As, Pb and Hg) in surrounding agricultural soil.

Distribution of Mercury and Methylmercury in Farmland Soils Affected by Manganese Mining and Smelting Activities.

Manganese (Mn)-related activities would affect the mercury (Hg) cycling in farmlands, whereas this was not well understood. Here, one of the largest Mn ores in China was selected to study the effects of Mn-related activities on the accumulation and distribution of total Hg (THg) and methylmercury (MeHg) in farmland soils. The soil THg concentrations in the mining area were 0.

Occurrence of methylmercury in aerobic environments: Evidence of mercury bacterial methylation based on simulation experiments.

Methylmercury (MeHg) is mainly produced by anaerobic δ-proteobacteria such as sulfate-reducing bacteria (SRB). However, mercury bio-methylation has also been found to occur in the aerobic soil of the Three Gorges Reservoir (TGR). Using γ-proteobacterial TGR bacteria (TGRB) and δ-proteobacterial Desulfomicrobium escambiense strains, the efficiency of mercury methylation and demethylation was evaluated using an isotope tracer technique.

Role of the rhizosphere of a flooding-tolerant herb in promoting mercury methylation in water-level fluctuation zones.

The water-level fluctuation zone (WLFZ) has been considered as a hotspot for mercury (Hg) methylation. Flooding-tolerant herbs are gradually acclimated to this water-land ecotone, tending to form substantial root systems for improving erosion resistance. Accompanying rhizosphere microzone plays crucial but unclear roles in methylmercury (MeHg) formation in the WLFZ.

Distribution of mercury and methylmercury in river water and sediment of typical manganese mining area.

Manganese (Mn) ores contain substantial concentrations of mercury (Hg), and mining and smelting of Mn ores can bring Hg into the surrounding aquatic environment through atmospheric deposition, leaching of electrolytic Mn residue and Mn gangue dump. However, limited is known that how these processes influence the environmental behaviors of Hg in waterbody. Therefore, the seasonal distribution and existing form of Hg in water and sediment in one Mn ore area in Xiushan County, Chongqing were investigated.

Exposure of the residents around the Three Gorges Reservoir, China to chromium, lead and arsenic and their health risk via food consumption.

Hydrological management of the Three Gorges Dam has resulted in the interception of heavy metals in the Three Gorges Reservoir (TGR). However, the exposure to heavy metals and health risks among local residents remained poorly understood. Here we collected 208 biomarker samples (hair) and 20 food species from typical regions in the TGR to assess the exposure levels of three toxic metals (Cr, Pb and As) in residents of the TGR, and subsequently investigated their health risk via dietary intake.

Use smaller size of straw to alleviate mercury methylation and accumulation induced by straw incorporation in paddy field.

Straw sizes were found to affect the methylmercury (MeHg) accumulation in rice grains induced by straw incorporation. The mechanism behind, however, still remains unclear. Here, we incorporated rice straw in different sizes (powder, 2 cm and 5 cm) into a Hg-contaminated paddy soil.

[Structural Characteristics of Zooplankton and Phytoplankton Communities and Its Relationship with Environmental Factors in a Typical Tributary Reservoir in the Three Gorges Reservoir Region].

Based on the data of zooplankton, phytoplankton, and water environmental factors in different seasons in a typical tributary reservoir in the Three Gorges Reservoir Region (Changshou Lake), this study explored the relationships between the structures of the zooplankton and phytoplankton communities and environmental factors using Pearson correlation analysis. The results showed that there were a total of 107 species of 8 phyla of phytoplankton, and cyanobacteria was the most critical constituent with a relative abundance of 61%. The dominant populations included , , and .

Total mercury and methylmercury in human hair and food: Implications for the exposure and health risk to residents in the Three Gorges Reservoir Region, China.

Three Gorges Dam (TGD) is the largest hydroelectric construction in the world, and its potential impacts on the ecological environment and human health risks have invoked considerable global concern. However, as a mercury (Hg) sensitive system, limited work was conducted on the Hg exposure level of local residents around the Three Gorges Reservoir (TGR). Thus, 540 human hair samples and 22 species of local food samples were collected to assess the Hg exposure and human health risk to the residents located in the Three Gorges Reservoir Region (TGRR) and to investigate their dietary exposure to Hg.

The efficiencies of inorganic mercury bio-methylation by aerobic bacteria under different oxygen concentrations.

Limited information is available about the bio-methylation of inorganic mercury (iHg) under aerobic conditions. In this study, two γ-proteobacteria strains (P. fluorescens TGR-B2 and P.

Potential Ecological Risk of Heavy Metals in a Typical Tributary of the Three Gorges Reservoir.

Water and sediment samples were collected from a tributary (Ruxi River) of the Three Gorges Reservoir (TGR) to analyze the concentrations of seven heavy metals (HMs) and their fractions for better understanding the migration, bioavailability and potential environmental risk of HMs. The results indicated that the concentrations of HMs in water were lower than the Environmental Quality Standards for Surface Water Class I standards, except for Ni. Cd in sediment was found to be more sensitive to environmental changes, as the acid-soluble fraction of Cd accounted for about 40% of total Cd, and the sediment-water partition coefficient of Cd was the smallest among all the HMs.

A Study on Hair Mercury Levels of University Students.

Total mercury (THg) and methylmercury (MeHg) concentrations were measured in hair of 98 Chinese university students to study their levels of Hg exposure and influencing factors. The results showed that Hg exposure for university students was at a low level with concentrations lower than the USEPA recommended reference level (1 µg/g) across all hair samples. The percentage of MeHg to THg (%MeHg) in hair was about 50%, lower than the previously reported value of 70-100%, probably associated with the low %MeHg in the diet of university students.