Search

Continuous-flow experiment was conducted in an acidogenic sulfate-reducing reactor supplied with molasses as sole carbon resource and sulfate sodium as electron acceptor. The composition of Volatile fat acid(VFA) in terminal liquid products, the distribution of acetic acid, the existence of microbial populations and the interspecific relationship between sulfate-reducing bacteria (SRB) and acidogenic bacteria (AB) were investigated in different experimental stages when sulfate removal rate and gas production maintained at a relatively stable status. The experimental results showed that an acetic-acid type microbial metabolism pathway was formed based on the fact that the proportion of acetic acid in terminal liquid products was as high as 50% to 82%. It was also explained the formation of acetic-acid type microbial metabolism pathway was resulted from acetic acid accumulation in the terminal liquid products, which was subjected to the bio-chain cooperation relationship between populations of SRB and AB, and the incomplete-oxidation of organic substance in acidogenic-phase reactor of two-phase anaerobic treatment process. It was also presented that the formation of acetic-acid type microbial metabolism pathway depended on the capability of acetic-acid utilized-SRB (ASRB) population competing against other populations and its ability of acetic acid consumption. Furthermore, this kind of metabolism pathway could offer suitable carbon resource for methane producing reactor in the two-phase anaerobic treatment process, and has significant effect on the sulfate removal rate of the whole treatment system and its running stability.