Analysis of soil cadmium immobilization by hydroxyapatite prepared from cattle bones

Abstract

We expected that hydroxyapatite prepared from cattle bones (cattle-derived HAp) would immobilize soil cadmium and reduce its long-term availability to crops, because insoluble cadmium is stable in weakly acidic regions. To evaluate this expectation, we added cattle-derived HAp to soil and performed x-ray absorption fine structure analyses. We found that insoluble cadmium differed from plant-available cadmium: cadmium was fixed at calcium sites of cattle-derived HAp.