[Research Progress of In-situ Passivation Remediation Materials for Cadmium-contaminated Soil（Farmland）].

Abstract

The proportion of soil pollution points exceeding the standard in China has reached 19.4%， and the proportion of cadmium exceeding the standard was the highest， reaching 7.0%. Once Cd was absorbed by crops and entered the human body， it could cause damage to the kidneys， bones， digestive system， etc. As the half-life of cadmium is 15 to 30a in humans， it severely jeopardize human health. The in-situ passivation remediation materials for cadmium-contaminated soil can effectively reduce the migration and bioavailability of cadmium and reduce the damage to crops caused by cadmium accumulation. It also has the advantages of simple operation， good stability， and fast passivation rate and does not affect agricultural production. For in-situ passivation remediation of Cd-contaminated soil， the mechanism and effect of different types of passivation materials were studied， the influencing factors and applicable conditions of passivation materials were analyzed， and five directions for the future development of passivation materials were put forward， as follows： ① conduct a stability study of the passivating agent and Cd after passivating； ② monitor and evaluate the effects of soil physicochemical properties， texture， and environmental quality and the growth， yield， and quality of crops after soil restoration by passivating agent application； ③ develop the corresponding passivating agent and formulate the corresponding standard according to the specific application environment； ④ research and apply the technology of reducing the total Cd in soil； and ⑤ accelerate the research of new materials in reducing costs and improving efficiency and accelerate the application of new materials. Through comprehensive analysis of cadmium-contaminated soil， the development direction and effective solution of cadmium-contaminated soil passivation materials were provided.