Novel insight into deriving remediation goals of arsenic contaminated sites with multi-media-equivalent dose and local exposure parameters.

The remediation goal (RG) for arsenic (As) calculated by the traditional method is approximately 0.45 mg·kg, significantly lower than the background values. This poses significant challenges for the management of As-contaminated sites.

Water-fertilizer regulation drives microorganisms to promote iron, nitrogen and manganese cycling: A solution for arsenic and cadmium pollution in paddy soils.

The co-contamination of arsenic (As) and cadmium (Cd) in rice fields presents a global imperative for resolution. However, understanding the complex microbially driven geochemical processes and network connectivity crucial for As and Cd bioavailability under the frequent redox transitions in rice fields remains limited. Here, we conducted a series of microcosm experiments, using flooding and drainage, alongside fertilization treatments to emulate different redox environment in paddy soils.

A review of amendments for simultaneously reducing Cd and As availability in paddy soils and rice grain based on meta-analysis.

Arsenic (As) and cadmium (Cd) accumulation in rice grains is a global food safety issue, and various methods and materials have been used to remove or reduce As and Cd in agricultural soils and rice grains. Despite the availability of synthesized materials capable of simultaneous As and Cd reduction from soil and rice grains, the contributions, efficiency, and main ingredients of the materials for As and Cd immobilization remain unclear. The present study first summarized the biogeochemistry of As and Cd in paddy soils and their transfer in the soil-food-human continuum.

Metal-Binding Protein TaGlo1 Improves Fungal Resistance to Arsenite (As) and Methylarsenite (MAs) in Paddy Soil.

Trivalent arsenicals such as arsenite (As) and methylarsenite (MAs) are thought to be ubiquitous in flooded paddy soils and have higher toxicity than pentavalent forms. Fungi are widely prevalent in the rice rhizosphere, and the latter is considered a hotspot for As uptake. However, few studies have focused on alleviating As toxicity in paddy soils using fungi.

Evidence for the transportation of aggregated microplastics in the symplast pathway of oilseed rape roots and their impact on plant growth.

As an emerging contaminant, microplastics are absorbed by crops, causing diverse impacts on plants. Plants may have different physiological responses to different uptake modes of microplastics various stage of growth. In this study, the distribution of polystyrene (PS) microspheres in the roots of oilseed rape and the physiological responses at different growth stages were investigated by confocal laser scanning microscope, scanning electron microscopy, and biochemical analysis.

Thermodynamics, Kinetics, and Mechanisms of the Co-Removal of Arsenate and Arsenite by Sepiolite-Supported Nanoscale Zero-Valent Iron in Aqueous Solution.

In this study, a newly synthesized sepiolite-supported nanoscale zero-valent iron (S-nZVI) adsorbent was tested for the efficient removal of As(III) and As(V) in aqueous solution. Compared with ZVI nanoparticles, the As(III) and As(V) adsorption abilities of S-nZVI were substantially enhanced to 165.86 mg/g and 95.

[Arsenic Methylation Efficiency Changes During Paddy Soil Drying and Its Key Influencing Factors Analysis].

The straight head disease of rice is one of the main problems limiting rice production. Arsenic (As) methylation in paddy soils is considered to be highly related to the occurrence of the straight head disease. As a typical field practice, rice fields are usually drained during the late tillering stage and the mid-late grain filling stage.

Manure application facilitated electrokinetic remediation of antibiotic-arsenic co-contaminated paddy soil.

The co-existence of antibiotics and heavy metals in soil with manure application poses high risk to both environment and human health, and thus effective remediation methods are in urgent need. This study investigated the synergistic effects of electrokinetic remediation (EKR) on antibiotic resistance and arsenic (As) in co-contaminated paddy soils. EKR treatments in soil amended with pig manure (EKR-PD) showed better remediation efficiency compared with that without pig manure.

Enrichment characteristics and dietary evaluation of selenium in navel orange fruit from the largest navel orange-producing area in China (southern Jiangxi).

Diet is the main intake source of selenium (Se) in the body. Southern Jiangxi is the largest navel orange-producing area in China, and 25.98% of its arable land is Se-rich.

Synergistic removal of As(III) and Cd(II) by sepiolite-modified nanoscale zero-valent iron and a related mechanistic study.

Arsenic (As) and cadmium (Cd) are two highly toxic elements. In recent years, many newly synthesized chemical materials have been used widely for treatments of As- and Cd-contaminated effluents. However, most materials do not exhibit high efficiencies for simultaneous removal of As and Cd from water systems.

Influence of straw-derived humic acid-like substance on the availability of Cd/As in paddy soil and their accumulation in rice grain.

Humic acid amendments have been widely advocated for the remediation of heavy metal-contaminated soil. However, the impacts of straw-derived humic acid-like substances on the remediation of cadmium (Cd) and arsenic (As) co-contaminated paddy soil remain unclear and the potential mechanism required clarification. In this study, we employed a pot experiment and chose a straw-derived humic acid-like substance (BFA) as the amendment with four doses to investigate how BFA affects the availability of Cd and As in soil and their accumulation in rice.

The performance and mechanism of cadmium availability mitigation by biochars differ among soils with different pH: Hints for the reasonable choice of passivators.

The performances of passivation materials mitigating Cadmium (Cd) bioavailability considerably vary with the pH condition of Cd-contaminated soils. However, less information was available for the method of improving Cd passivation efficiency taking into account the pH of the targeted soil. Furthermore, the underlying mechanism of Cd availability mitigation in soils with different pH has not been clearly explored.

Soil ridge cultivation maintains grain As and Cd at low levels and inhibits As methylation by changing arsM-harboring bacterial communities in paddy soils.

The simultaneous mitigation of toxic arsenic (As) and cadmium (Cd) in rice grain remains a global challenge. The over-accumulation of husk dimethylarsinic acid (DMAs) induces the rice straight-head disease, which threatens rice production worldwide. In this study, we investigated various soil ridge height treatments with Eh ranging from - 225-87 mV and pH ranging from 6.

Simultaneous mitigation of Cd and As availability in soil-rice continuum via the addition of an Fe-based desulfurization material.

The simultaneous mitigation of toxic arsenic (As) and cadmium (Cd) in rice grain remains a global challenge. Passivation with natural or artificially modified materials has shown great potential to simultaneously reduce the bioavailability of As and Cd in paddy soils. To date, however, limited materials have are available, with unclear underling mechanisms.

Cadmium and arsenic availability in soil under submerged incubation: The influence of humic substances on iron speciation.

Humic substances (HSs), as electron shuttles, are associated with iron oxide transformation, yet the manner by which HSs affect Cd/As availabilities during this process under anaerobic conditions remains unclear. Two HSs (humic sodium, HA-Na, and biochemical fulvic acid, BFA) were applied at 0, 1, 2, and 4 gCkg in a submerged incubation experiment. The dissolved, extractable and fractions of Cd/As and different iron oxides in soils were monitored.

Exogenous fulvic acid enhances stability of mineral-associated soil organic matter better than manure.

Mineral-associated soil organic matter (MAOM) is seen as the key to soil carbon sequestration, but its stability often varies with types of exogenous organic materials. Fulvic acid and manure are ones of the exogenous organic materials used for the improvement of degraded soil. However, little is known about if and how fulvic acid and manure affect the stability of MAOM.

[Comparison in cadmium accumulation capacities of different leafy vegetables through cadmium-rich substrate cultivation].

To acquire a feasible method for a rapid comparison of the cadmium (Cd) accumulation capacities of different leafy vegetables, using substrate cultivation with different contents of Cd and cultivation time, we compared the observed Cd accumulation capacity with these obtained in the field. The results showed that the Cd content and bio-concentration factors (BCFs) value in the aboveground tissue of leafy vegetable varied significantly with Cd content and cultivation time. Multi-factor analysis of variance showed that vegetable variety, cultivation time, Cd content in substrate and their interaction had significant effects on BCFs of Cd in leafy vegetable.

Contradictory tendency of As(V) releasing from Fe-As complexes: Influence of organic and inorganic anions.

The strong ability of ferrihydrite and its aged minerals for fixing arsenate is a key factor in remediating arsenate-polluted environments. It is therefore crucial to clarify the stability of Fe-As complexes and the release conditions for As(V). The As(V) release amount was evaluated and compared in the presence of six representative anions, namely, phosphate, silicate, sulfate, inositol hexaphosphate, citrate, and oxalate.

Seeking for an optimal strategy to avoid arsenic and cadmium over-accumulation in crops: Soil management vs cultivar selection in a case study with maize.

Soil management and cultivar selection are two strategies to reduce the accumulation risk of heavy metals in crops. However, it is still an open question which of these two strategies is more efficient for the safe utilization of contaminated soil. In this study, the available bio-concentration factors (aBCF) of arsenic (As) and cadmium (Cd) among 39 maize cultivars were determined through a field experiment.

Long-Term Manure Application Changes Bacterial Communities in Rice Rhizosphere and Arsenic Speciation in Rice Grains.

Bioavailability and speciation of arsenic (As) are impacted by fertilization and bacteria in the rice rhizosphere. In this study, we investigated the effects of long-term manure application on As bioavailability, microbial community structure, and functional genes in a rice paddy field. The results showed that manure application did not affect total As in the soil but increased soluble As forms by 19%, increasing arsenite (As(III)) accumulation in rice grains and roots by 34 and 64% compared to a control.

Stability of Fe-As composites formed with As(V) and aged ferrihydrite.

During the aging process, ferrihydrite was transformed into mineral mixtures composed of different proportions of ferrihydrite, goethite, lepidocrocite and hematite. Such a transformation may affect the fixed ability of arsenic. In this study, the stability of Fe-As composites formed with As(V) and the minerals aged for 0, 1, 4, 10 and 30 days of ferrihydrite were systematically examined, and the effects of molar of ratios Fe/As were also clarified using kinetic methods combined with multiple spectroscopic techniques.