Perchlorate removal by the beads with immobilized nanoscale Fe0 and microbes

A strain with capability of reducing perchlorate was isolated from activated sludge. In addition to general morphological and biochemical characteristics, the strain was identified by 16S rDNA sequence and systematic analysis. The results show that its 16S rDNA sequence of strain has similarity of 99% with the Thauera Phenylacetica strain. The beads of immobilized NZVI combined with microbes were prepared with calcium alginate as encapsulated carrier. Scanning electron microscopy was used to study the bead microstructure, and its perchlorate degradation performance was further studied. The batch experiments were carried out to examine the perchlorate removal rate under different temperatures and pHs. Results show that the beads with diameter of 3~5 mm have many holes which allow the materials to enter availably, and the perchlorate reduction process is based on the adsorption and chemical reduction combined with biodegradation. And, the latter two processes are in accord with the process of one-order kinetics. In addition, it shows that the better removal efficiency could occur under moderate temperature and neutral pH value. Based on its good adaption of the temperature and pH, the beads with immobilized nanoscale Fe0 and microbes are favorable for in-situ remediation.