Research Advances in Barrier Technology of Paddy Soil Co-contaminated with As and Cd

Abstract

Arsenic (As) and cadmium (Cd) are the most common toxic and harmful heavy metal elements in paddy soils and are easily transferred from the soil to grains. At present, As and Cd and their co-contamination in paddy soils in China are widespread, posing a serious threat to food security and human health. As and Cd have opposite environmental behaviors in soil, and the simultaneous remediation of co-contamination with As and Cd is a current technical difficulty for safe rice production. This review focuses on several practical techniques for simultaneous mitigation of As and Cd uptake and transport in rice in recent years, including water management, passivation, drenching techniques, electrokinetic remediation, phytoremediation, selection of low-accumulation rice varieties, and foliar spraying application. The treatment effects, mechanisms of action, and constraints of various technologies are summarized and analyzed; the development direction of the main barrier control technologies is proposed and the importance of constructing a comprehensive technology model with high regional adaptability is emphasized to provide a reference for the remediation of co-contamination with As and Cd in paddy and safe rice production.