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.

Arsenic pollution in paddy soil is a major environmental issue, and its remediation has become a subject of broad interest. Geo-electrochemical technology has been shown to have significant potential for remediating heavy metal-contaminated soils in recent years. Taking contaminated paddy soil from northern Guangxi as the research subject, this study aims to assess the effectiveness of geo-electrochemical technology for arsenic remediation. An orthogonal experimental design was used to identify the optimal combination of parameters, including power supply duration, voltage gradient, power supply mode, and electrolyte type. The arsenic removal efficiency was thoroughly assessed, and the underlying remediation mechanisms associated with geo-electrochemical technology combined with EDTA-2Na were extensively investigated. The findings revealed a substantial decrease in the residual arsenic fraction after treatment, accompanied by a substantial increase in the mobility and bioavailability of arsenic. The maximum removal rate of arsenic from the soil was determined to be 19.59%. Among the analyzed factors, electrolyte type exerted the most significant influence on the arsenic removal efficiency, followed by power supply duration and voltage gradient, while the impact of the power supply mode was less significant. The optimal remediation effect was achieved under the following conditions: a power supply duration of 108 h, a voltage gradient of 0.6 V/cm, continuous power supply mode, and the use of EDTA-2Na as the electrolyte. The multiple strong coordinating atoms in EDTA-2Na can form stable chelates with Fe³⁺ and Al³⁺ bound to arsenic in the soil, thereby causing the desorption of arsenic. The integration of geo-electrochemical technology with EDTA-2Na forms a synergistic multiphase electrochemical reaction mechanism, significantly improving the overall remediation efficiency in arsenic-contaminated soils.