Effect of phosphate-induced immobilization of lead on its mobility and bioavailability.

Lead (Pb) can be immobilized using insoluble phosphate compounds in the presence of phosphate solubilizing bacteria (PSB) which facilitate phosphorus (P) solubilization from insoluble P sources. The mobility and bioavailability of Pb as affected by P-induced immobilization was examined using leaching and plant growth experiments. Phosphate solubilizing bacteria promoted the solubilization of rock phosphate, thereby leading to the immobilization of Pb without causing any significant leaching of P in soils. Phosphate solubilizing bacteria reduced Pb in pore water, and rock phosphate and soluble P amendments significantly reduced Pb accumulation by sunflower.