Treatment characteristics of high strength fermentation wastewater consisting of high sulfate and ammonia by UAHB process

In this study, the formation process of granules and treatment characteristics were discussed for an Upflow Anaerobic Hybrid Blanket (UAHB) reactor, adding water absorbing polymer particles (WAP) for treating a fermentation process wastewater consisting of high sulfate and ammonia. Sulfide toxicity to methanogenic bacteria and the TOC/SO42− ratio that was usually used as an index of inhibition to methanogenesis were also examined. The results indicated that the granules could be developed in an UAHB process, in which a filter was installed in the upper part of reactor and WAP were also added into inoculum, for treating sulfide- and ammonia-rich wastewater, and inhibition caused by sulfide did not occurred when free hydrogen sulfide concentration was less than 200 mgl−1. Therefore, the UAHB process in the presence of adding WAP was shown to have a better stability for treating the refractory wastewater. The results also showed that total dissolved sulfide concentration had to be considered for inhibition assessment as well as the TOC/SO42− ratio.