Influence of Fe elements on sulfate reduction process and the response of microbial community

The influence of different valence state Fe element on sulfate reduction process and the dynamic response of corresponding microbial community were explored by conventional chemical analyses and microbial community denatured gradient gel electrophoresis (DGGE) technique. Only 5d after the starting of reactor, the sulfate-removal rate reached 80%, in this process, the community bands decreased gradually, but the already departed corresponding band of the sulfate-reducing bacteria (SRB) did not appear. The addition of Fe²⁺ altered remarkably the structure of original high efficient community. The sulfate-removal rate reduced to 20% and oxygen reduction potential (ORP) had a little increase; but the addition of Fe²⁺ and Fe⁰ did not alter the structure model of the extreme community. Already formed sulfate-removal rate also did not reduce markedly and only the concentration change of sulfide had short response on the addition of Fe²⁺.