Assessment of microbial diversity profile in activated sludge using biochemical reaction method

Abstract

Activated sludge process is a secondary treatment that used to reduce biological and chemical contaminants in the municipal wastewater. Activated sludge contains abundance of microorganisms that oxidize organic matter to CO2 and H2O, metabolically and hence, remove most of the dissolved solids remaining during the sewage treatment. It also transforms dissolved organic matter to microbial biomass and perform decomposition by most aerobic microorganisms. This study was carried to determine the distribution of dominating microorganisms in activated sludge. The microbial screening and isolation technique and bacteria l staining were performed in the preliminary study. Biochemical reaction method was used to identify the isolated pure colony of the bacteria. The bacteria were identified via the APIweb for closest Genus classification. In the results, Bifidombacterium, Actinomyces Israelii and Clostridium Beijerinckii were found to be dominant in the activated sludge culture. Bifidombacterium is common in the activated sludge system. While, Actinomyces Israelii is known for their contribution in improving to settleability of the sludge flocs in the succeeding sedimentation tanks in which the biomass is easily separated from the treated sewage. For Clostridium Beijerinckii, is the minority group in activated sludge that commonly causes sludgefoaming.