Effect of sterilization on cadmium immobilization and bacterial community in alkaline soil remediated by mercapto-palygorskite

Yale Wang; Yingming Xu; Qingqing Huang; Xuefeng Liang; Yuebing Sun; Xu Qin; Lijie Zhao

doi:10.1016/j.envpol.2021.116446

Effect of sterilization on cadmium immobilization and bacterial community in alkaline soil remediated by mercapto-palygorskite

Environ Pollut. 2021 Jan 13:273:116446. doi: 10.1016/j.envpol.2021.116446. Online ahead of print.

Authors

Yale Wang¹, Yingming Xu², Qingqing Huang¹, Xuefeng Liang¹, Yuebing Sun¹, Xu Qin¹, Lijie Zhao¹

Affiliations

¹ Key Laboratory of Original Environmental Pollution Control, Agro-Environmental Protection Institute, Ministry of Agriculture and Rural Affairs, Tianjin, 300191, PR China.
² Key Laboratory of Original Environmental Pollution Control, Agro-Environmental Protection Institute, Ministry of Agriculture and Rural Affairs, Tianjin, 300191, PR China. Electronic address: ymxu1999@126.com.

PMID: 33486245
DOI: 10.1016/j.envpol.2021.116446

Abstract

Cadmium (Cd) pollution in alkaline soil in some areas of northern China has seriously threatened wheat production and human health. However, there are still few effective amendments for alkaline soil, and the mechanism of amendments with a good immobilization effect remains unclear. In this study, soil sterilization experiments were conducted to investigate the effects of soil microorganisms on the immobilization of a novel amendment-mercapto palygorskite (MPAL) in Cd-contaminated alkaline soils. The results showed that the mercapto on the MPAL surface was not affected by autoclaving. Compared with the control, the available Cd concentration in 0.025% MPAL treatments decreased by 18.80-29.23% after 1 d of aging and stabled after 10 d of aging. Importantly, the immobilization of MPAL on Cd in sterilized soil was significantly better than that in natural soil due to the changes in Cd fractions. Compared with MPAL-treated natural soil, exchangeable Cd fraction and carbonate-bound Cd fraction in MPAL-treated sterilized soil decreased by 20.79-27.09% and 20.05-26.45%, while Fe/Mn oxide-bound Cd fraction and organic matter-bound Cd fraction increased by 17.77-22.68% and 18.85-27.32%. Phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt) analysis found that the potential functions of the microbial community in normal and sterilized soil were different significantly. Soil sterilization increased the soil pH and decreased the arylsulfatase activity, but did not change the soil zeta potential and available sulfur. The changes in Cd fractions in MPAL-treated sterilized soil may be related to the reduction in the bacterial community and the changes in function microbial, but not to the soil properties. In addition, MPAL application had little effects on the bacterial community, soil pH value, zeta potential, available sulfur, and arylsulfatase. These results showed that the immobilization of MPAL on Cd in alkaline soil was stable and effective, and was not affected by soil sterilization and soil microorganism reduction.

Keywords: Alkaline soil; Bacterial community; Cadmium immobilization; Mercapto-palygorskite; Soil sterilization.