Abstract :

Biochar is a prospective absorbent for the remediation of heavy metal pollution in mine soils.However,the amendment of biochar will cause the change of microbial communities and their biochemical processes. Dissimilatory metal reducing-microorganism (DMRB) can lead to the mobilization and redistribution of Fe/Mn ion and the associated heavy metal ions through the reductive dissolution of soil minerals, so the change of the growth and the performance of DMRB in biochar amended soils has profound influence for the remediation of heavy metal pollution, which is the overall object of this research. At the first stage of this research,a microcosm study is firstly conducted to investigate the mechanism of the influence of biochar amendment on the typical DMRBs and their performance of Fe(Ⅲ)-reduction.At the second stage based on a flow-cell equipment, the object is to reveal the influence of the dynamical change of biogeochemical factors on the microbial community structure particularly the dynamics of DMRB, and to investigate the response of biological mineral reductive dissolution process to the interaction between biochar and soils.At the third stage,the column experiment is conducted to study the distribution of DMRBs and their performance on the metal reductive mobilization in the mine soils with biochar amendment under in-situ environmental condition, and to explore the effect of biological reductive dissolution of soil minerals on the retention of heavy metal ions by biochar amendment.This study will provide useful information for the application of biochar amendment for the remediation of heavy metal contamination in mining zones.