Rapid Immobilization of Transferable Ni in Soil by Fe78Si9B13 Amorphous Zero-Valent Iron

Fe-Si-B amorphous zero-valent iron has attracted wide attention because of its efficient remediation of heavy metals and dye wastewater.In this paper,the remediation effect of amorphous zero-valent iron powder(Fe78Si9-B13^(AP))on Ni contaminated soil was investigated.Results show that the immobilization efficiency of nickel in soil by Fe_(78)Si_(9)B_(13)^(AP)with low iron content is higher than that by ZVI.The apparent activation energies of the reactions of Fe_(78)Si_(9)B_(13)^(AP)with Ni^(2+)ions is 25.31 kJ/mol.After continuing the reaction for 7 days,Ni^(2+)ions is mainly transformed into monoplasmatic nickel(Ni0)and nickel combined with iron(hydroxide)oxides.Microstructure investigations show that the product layer with nano-pore structure is beneficial to improve the reaction activity of Fe_(78)Si_(9)B_(13)^(AP).After that,a magnetic separation process is introduced,in which part of the immobilized Ni are removed to reduce the total Ni content in soil by 58.21%.The results of simulated acid rain leaching experiment showed that the release of Ni in the soil after Fe_(78)Si_(9)B_(13)^(AP)remediation is 62.89%lower than that before remediation.