Predicting bioavailable barium transfer in soil-bok choy systems: A study induced by shale gas extraction in Chongqing, China.

Barium (Ba) is a significant contaminant from shale gas extraction and is also used in various other industries. However, there has been very limited attention paid to Ba. Elucidating the Ba in soil-crop system are of great significance for both human health risk assessment and pollution control.

[Microbial Mechanisms of Removal of Phthalic Acid Esters in Purple Soils Revealed Using Metagenomic Analysis].

The removal mechanisms of phthalic acid esters (PAEs) have attracted much attention because of their endocrine-disrupting properties and persistence in environmental media. In order to reveal the removal mechanism of PAEs and involved keystone taxa and functional genes, purple soils were polluted by di--butyl phthalate (DBP) and di-2-ethylhexyl phthalate (DEHP), respectively, along a gradient of 0, 5, 10, and 20 mg·kg and cultured for 90 days in the dark. The results showed that the degradation dynamics of DBP and DEHP were well-fitted by the first-order kinetic model, and the half-life of DBP and DEHP ranged from 17.

Effect of environmental factors on accumulation of trace metals in a typical shale gas exploitation area: A comprehensive investigation by machine learning and geodetector models.

Whether a certain relationship is exist between shale gas exploitation and accumulation of trace metals in soil is a controversial issue in recent years. To date, few study clearly reveal the intrinsic contributions of natural and anthropogenic factors to accumulation of trace metals in soil. In this study, machine learning and geodetector models were integrated to investigate to contribution of environmental factors to variations of trace metals concentration.

An integrated approach to identify the source apportionment of potentially toxic metals in shale gas exploitation area soil, and the associated ecological and human health risks.

Public awareness of the potential environmental risks of shale gas extraction has increased in recent years. However, the status and environmental risks of potentially toxic metals (PTMs) in shale gas field soil remain unclear. A total of 96 topsoil samples were collected from the first shale gas exploitation area in China.

Prediction of phthalate acid esters degradation in soil using QSAR model: A combined consideration of soil properties and quantum chemical parameters.

Phthalic acid esters (PAEs) are predominant hazardous substances and endocrine-disrupting compounds to be controlled in soil. The degradation behaviors of PAEs in soil had been long term concerned. Thus, the degradation rate (K) is important for assessing theexposure risk and is of great significance in evaluating the ecological risk of PAEs in soil environment.

Temporal changes of microbial community structure and nitrogen cycling processes during the aerobic degradation of phenanthrene.

Phenanthrene (PHE) is frequently detected in worldwide soils. But it is still not clear that how the microbial community succession happens and the nitrogen-cycling processes alter during PHE degradation. In this study, the temporal changes of soil microbial community composition and nitrogen-cycling processes during the biodegradation of PHE (12 μg g) were explored.

The vital function of humic acid with different molecular weight in controlling Cd and Pb bioavailability and toxicity to earthworm (Eisenia fetida) in soil.

Humic acid (HA) plays vital roles in regulating the environmental behaviors of metals and thus their toxicity to biota. However, the inner relation between metal bioavailability to soil organisms and the presence of HA with different molecular weight (Mw) is not well documented. In this study, we separated HAs into four fractions with Mw range of 5-30k Da, and discussed their ability to alleviating the toxicity of Cd and Pb to earthworm.

Pb (II) bioavailability to algae (Chlorella pyrenoidosa) in relation to its complexation with humic acids of different molecular weight.

Humic acid (HA) has a major influence on the environmental fate of metal ions due to its heterogeneity in chemical compositions, structure and functional groups. In this study, we investigated the effect of humic acid (HA) with different molecular weight (Mw) on the bioavailability of Pb for a representative algae-Chlorella pyrenoidosa. The results showed that HA with larger Mw had stronger inhibitory effects on the bioavailability of Pb to algae, and the biosorption capacity of Pb decreased with increasing Mw, which is in accordance with the variations of complexation capacities of Pb for HA fraction.

Relating Cd binding by humic acids to molecular weight: A modeling and spectroscopic study.

Molecular weight (Mw) is a fundamental property of humic acids (HAs), which considerably affect the mobility and speciation of heavy metals in the environment. In this study, soil humic acid (HA) extracted from Jinyun Mountain, Chongqing was ultra-filtered into four fractions according to the molecular weight, and their properties were characterized. Complexation of cadmium was investigated by titration experiments.