针铁矿对含铀废水中U(VI)的固定机理及进展

Research Advances of the Mechanism of Aqueous U(VI)Immobilization by Goethite

放射性污染水体中U(VI)的净化一直是研究的热点。针铁矿是自然界中最为稳定的羟基氧化铁,在处理污染水体中的铜、铬、铅、钴、砷和铀等有毒有害重金属离子方面展现出巨大的潜能与优势。本文综述了近些年来针铁矿对含铀废水中U(VI)的固定机理研究进展,包括:1)针铁矿颗粒与铀酰离子发生表面络合作用,形成双齿-共边配位或双齿-共顶点配位复合物;2)U(VI)在针铁矿结构中的晶格嵌入作用,主要是通过Fe(II)诱导水铁矿形态转变过程或Fe(II)与U(VI)共沉淀过程实现。并总结了碳酸盐和磷酸盐对针铁矿固定U(VI)的影响,展望了通过针铁矿来固定含铀水体中U(VI)的研究方向。

The purification of U(VI)in radioactive contaminated water has always been a hot research issue.The goethite is the most stable hydroxyl iron oxide in nature,with abundant surface sites and high affinity for many anions,cations and radioactive elements.The immobilization mechanisms of aqueous U(VI)by goethite are reviewed,including the surface complexation between goethite particles and uranyl with the formation of the bidentate corner-sharingand bidentate edge-sharingsurface complexes,as well as the lattice embedding of uranium into goethite structure during the Fe(II)induced morphology transformation of the ferrihydrite or the coprecipitation process of Fe(II)and U(VI).The effects of carbonate and phosphate on the retention of U(VI)by goethite are discussed.The further research directions of uranium immobilization by the goethite are prospected.