Removal of Heavy Metal Cd Element from Paddy Soil by Geo-Electrochemical Technology

Abstract

A Cd-contaminated paddy field at the Quanzhou County Institute of Agricultural Science in Guilin was selected as the research object, and geo-electrochemical technology (GT) was used to treat the Cd-contaminated paddy field in situ. The technology’s effectiveness in removing the heavy metal Cd element from paddy soil and the change rule of Cd accumulation and transport in various parts of rice plants under the action of an electric field were studied. That was to provide a theoretical basis and a new technical choice for remediating paddy soil polluted by Cd. The results showed that the GT effectively removed the heavy metal Cd element from the paddy soil. When the level of soil Cd in the paddy field was 0.58 mg/kg, after in situ treatment with the GT, the soil Cd decreased to 0.39 mg/kg, which met the requirements of soil contamination risk control for agricultural land. Geo-electrochemical technology effectively reduced the content of the Cd element in various tissues and organs of rice plants, made the Cd content in brown rice lower than the requirement of the national food pollutant limit standard of 0.2 mg/kg, and achieved the production of safe rice. Geo-electrochemical technology reduced the enrichment of Cd in the tissues and organs of the rice plants, including roots, stems, leaves, and grains, and at the same time affected the process of rice roots transporting Cd.