Study on the remediation effect and mechanism of Cd-contaminated soil by nano-magnesium hydroxide

With the rapid development of agriculture and industry, the continuous exploitation of mines, the reckless discharge of cadmium-containing wastewater and the abuse of pesticides and fertilizers, cadmium pollution has spread all over the world. Soil cadmium pollution in China has become an environmental problem that cannot be ignored, and it is urgent to seek economical and effective treatment and remediation technologies that do not produce secondary pollution. In situ chemical immobilization remediation technology is one of the important ways to control heavy metal pollution in soil. By applying passivators to the soil, we can regulate and change the distribution of heavy metals in the soil, reduce the exchangeable components and their mobility in the soil, and thus reduce the biological effectiveness of cadmium.

Nano magnesium hydroxide is a new inorganic material with small particle size and large specific surface area, which has the characteristics of non-toxic, harmless and strong adsorption capacity, etc. It has been widely used in the treatment of heavy metals in wastewater and is known as a green and safe water treatment agent. Although nano-magnesium hydroxide has been reported in the field of environmental protection and fertilizer, there are few reports on the application of nano-magnesium hydroxide in the remediation of soil heavy metal pollution at home and abroad. Therefore, in this experiment, we investigated the remediation effect and mechanism of Cd-contaminated soil by using nano-magnesium hydroxide and common magnesium hydroxide as passivating agents and clarified the suitable application amount of nano-magnesium hydroxide for the remediation of Cd-contaminated soil and the safe production of vegetables.