Fractions Transformation and Dissipation Mechanism of Dechlorane Plus in the Rhizosphere of the Soil–Plant System

Published on 2020-04-10T10:43:27Z (GMT) by
The fractions transformation and dissipation mechanism of Dechlorane Plus (DP) in the rhizosphere of soil–plant system were investigated and characterized by a 150-day experiment using a rhizobox system. The depuration, accumulation, and translocation of DP in rice plants were observed. The contributions of plant uptake, microbial degradation, and bound-residue formation to DP dissipation under the rhizosphere effect were modeled and quantified. The gradients of DP concentrations correlated well with microbial biomass in the rhizosphere (<i>R</i><sup>2</sup> = 0.898). The rhizosphere facilitated the bioavailability of DP (excitation) and modified the bound-residue formation of DP (aging). DP concentrations in roots were positively correlated with the labile fraction of DP in soil (<i>R</i><sup>2</sup> = 0.852–0.961). There were spatiotemporal variations in the DP fractions. Dissolved and soil organic carbon were important influences on fraction transformation. Contributions to total DP dissipation were in the following ranges: microbial degradation (8.33–54.14%), bound-residue formation (3.64–16.43%), and plant uptake (0.54–3.85%). With all of these processes operating, the half-life of DP in the rhizosphere was 105 days. The stereoselectivity of DP isomers in both rice and DP fractions in soil were observed, suggesting a link between stereoselective bioaccumulation of DP in terrestrial organisms and dissipation pathways in soil.

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Cheng, Yu; Ding, Jue; Liang, Xiuyu; Ji, Xiaowen; Xu, Ling; Xie, Xianchuan; et al. (2020): Fractions

Transformation and Dissipation Mechanism

of Dechlorane Plus in the Rhizosphere of the Soil–Plant System. ACS Publications. Collection. https://doi.org/10.1021/acs.est.9b06748