Research Advances on the Immobilization Remediation of Farmland Soil Cadmium Pollution

The farmland soil cadmium pollution is one of the major environmental problems in the world. Due to the advantages of being economical and practical, easy to operate and effective, the immobilization remediation was used widely in the control and remediation of the farmland soil cadmium pollution. There were many advances on the remediation materials, mechanisms and application effects in the recent years. In the present article, the organic, inorganic and composite materials for immobilization remediation were introduced firstly. The chemical mechanisms for the reduce of available cadmium concentration and bioavailability of in soils induced the immobilization remediation materials were expounded on the change of soil pH value, formation of deposition, adsorption and ion exchange, formation of organic complex, and ion competition, respectively. Then, the application effects of different types of immobilization materials on farmland soil cadmium pollution remediation were summarized under indoor and field conditions. Finally, the prospects were discussed on the persistence and stability of immobilization remediation, immobilization mechanisms, remediation materials innovation, and combination of immobilization with phytoremediation on farmland soil cadmium pollution.