Alteration of Heavy Metal Fractions in Soil of Guiyu, South China by Native<i> Bacillus cereus</i> under the Effect of BDE209

Abstract

Microbiologic experiments together with Tessier sequential extraction and ICP-OES determination showed that distributions of Pb, Cu, Cd and Cr in soil of Guiyu, an e-waste dismantling region in South China, have changed after activities of native combined Bacillus cereus. Exchangeable fractions of these heavy metals were 1.52, 12.32, 3.98 and 34.50-fold those of original ones after 8 h interaction, here the organic phases were supposed to be the main alteration origin. The changing interaction time brought different impacts on concentration variation of heavy metals. Decabromodiphenyl ether (BDE209) influenced combined Bacillus cereus to redistribute the shares of heavy metals. BDE209 of 1 mg/L favored the alteration to make heavy metals become more bioavailable, while 5 mg/L and 10 mg/L of BDE209 baffled this alteration. However, influences of these strains on heavy metal speciation could be generally enhanced at the presence of BDE209, particularly for Cu and Pb Therefore, non-residual fractions were easier to be transferred into bioavailable ones after interaction with biomass, thus favoring the subsequent bioremediation of soil.