Using organo-mineral complex material to prevent the migration of soil Cd and As into crops: An agricultural practice and chemical mechanism study

Xuehao Zheng; Miaomiao Zhao; Lina Sun; Luge Rong; Bin Zhang; Fengjie Fan; Fangxi Zhang; Chengqiang Shu; Xiangyu Shi; Dan Zhao; Jianfeng Fu; Yuxin Zhang; Nan Dai; Dan Song; Hui Wang; Belay Tafa Oba; Hui Ding

doi:10.1016/j.scitotenv.2023.163662

Using organo-mineral complex material to prevent the migration of soil Cd and As into crops: An agricultural practice and chemical mechanism study

Sci Total Environ. 2023 Jul 20:883:163662. doi: 10.1016/j.scitotenv.2023.163662. Epub 2023 Apr 24.

Authors

Xuehao Zheng¹, Miaomiao Zhao², Lina Sun³, Luge Rong³, Bin Zhang⁴, Fengjie Fan⁴, Fangxi Zhang⁴, Chengqiang Shu⁴, Xiangyu Shi⁵, Dan Zhao², Jianfeng Fu², Yuxin Zhang⁶, Nan Dai⁶, Dan Song⁷, Hui Wang³, Belay Tafa Oba⁸, Hui Ding⁹

Affiliations

¹ Sichuan Provincial Engineering Laboratory of Monitoring and Control for Soil Erosion in Dry Valleys, China West Normal University, Nanchong 637009, China; Key Lab of Eco-restoration of Regional Contaminated Environment, Shenyang University, Ministry of Education, Wanghua Road, Shenyang 110044, China; School of Environmental Science and Engineering, Tianjin University, Weijin Road, Tianjin 300072, China.
² School of Environmental Science and Engineering, Tianjin University, Weijin Road, Tianjin 300072, China.
³ Key Lab of Eco-restoration of Regional Contaminated Environment, Shenyang University, Ministry of Education, Wanghua Road, Shenyang 110044, China.
⁴ Sichuan Provincial Engineering Laboratory of Monitoring and Control for Soil Erosion in Dry Valleys, China West Normal University, Nanchong 637009, China.
⁵ Ecological Environment Bureau of Leshan, Chunhua Road, Leshan 614001, China.
⁶ College of Materials Science and Engineering, Chongqing University, Chengnan Road, Chongqing 400044, China.
⁷ Chongqing Academy of Eco-Environmental Sciences, Qishan Road, Chongqing 401147, China.
⁸ College of Natural Science, Arba Minch University, Arba Minch 21, Ethiopia.
⁹ School of Environmental Science and Engineering, Tianjin University, Weijin Road, Tianjin 300072, China. Electronic address: dinghui@tju.edu.com.

PMID: 37100122
DOI: 10.1016/j.scitotenv.2023.163662

Abstract

The migration and transformations of Cd and As in soil are different, so it is difficult to simultaneously control them. In this study, an organo-mineral complex (OMC) material was prepared using modified palygorskite and chicken manure, the Cd and As adsorption capacities and mechanism of the OMC were explored, and the response of the crop to the OMC was clarified. The results show that the maximum Cd and As adsorption capacities of the OMC under pH values of 6-8 are 12.19 mg·g^-1 and 5.07 mg·g^-1, respectively. In the OMC system, the modified palygorskite contributed more to the adsorption of the heavy metals than the organic matter. Cd²⁺ may form CdCO₃ and CdFe₂O₄, and AsO₂^- may form FeAsO₄, As₂O₃, and As₂O₅ on the surfaces of the modified palygorskite. Organic functional groups such as hydroxyl, imino, and benzaldehyde groups can participate in the adsorption of Cd and As. The Fe species and carbon vacancy in the OMC system promote the conversion of As³⁺ into As⁵⁺. A laboratory experiment was conducted to compare five commercial remediation agents with OMC. Planting Brassica campestris in the OMC remediated soil with excessive contamination increased the crop biomass and decreased the Cd and As accumulation sufficiently to meet the current national food safety standards. This study emphasizes the effectiveness of OMC in preventing the migration of Cd and As into crops while promoting crop growth, which can provide a feasible soil management strategy for CdAs co-contaminated farmland soil.

Keywords: Adsorption; Cadmium–arsenic co-contamination; Food security; Soil remediation; Transformation.