Effects of aging and reduction processes on Cr toxicity to wheat root elongation in Cr(VI) spiked soils. (1st March 2022)

• Record Type: Journal Article
• Authors: Yang, Yang; Peng, Yemian; Ma, Yibing; Chen, Guojun; Li, Fangbai; Liu, Tongxu
• Is Part Of: Environmental pollution. Volume 296(2022)
• Publication Date: 2022-03-01
• Subjects: Chromium -- Toxicity -- Soil -- Bioavailability -- Kinetics; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2021.118784
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: The bioavailability of chromium (Cr) in soils is highly dependent on Cr fractions and soil physicochemical properties, but it is still unclear how the Cr fractions change in different soils. In this study, phytotoxicity to wheat root elongation was evaluated in different soils across China, and the kinetics of the biogeochemical processes of the added Cr(VI) were examined. After 105 days of soil Cr(VI) spiking, the added Cr(VI) causing 10% inhibition (EC10 ) of wheat root elongation varied greatly in soils (0.92–151.12 mg kg −1 ). The results of correlation analysis between EC10 and soil properties showed that the toxicity of Cr was affected by pH, organic matter (OM), clay, cation exchange capacity (CEC), and amorphous Fe oxides. Moreover, the correlation analysis showed that wheat root elongation was more sensitive to extracted Cr(VI) than Cr(III) after 105 days of incubation. A kinetic model was established to evaluate the redox and aging-activating reactions of Cr(VI)/(III) over 105 days. The correlation analysis between the soil properties and rate constants of the model showed that the pH, clay, and amorphous Fe/Al oxides might be the key factors controlling the aging and reduction processes of Cr(VI), and the OM and CEC might greatly affect the aging process of Cr(III). This modeling study is helpful in understanding which soil properties control the transformation and toxicity of Cr in soils. Graphical abstract: Image 1 Highlights: The wheat phytotoxicity was examined by fitting the curves of root elongation. The exogenous Cr(VI) in soils experienced aging and reduction processes. Kinetics of Cr transformation in 21 soils were assessed with a simplified model. Aging and reduction of Cr determined soil Cr bioavailability. Abstract : Exogenous Cr(VI) to wheat toxicity was mainly determined by the transformation of Cr(VI) in different soils.