Analysis of Microbial Community Structure for Effective Removal of Mixed Wastewater in Biological Wastewater Treatment

Abstract: Depending on season, mixed wastewater can show great deviations in terms of the influent ratios of tannery and seafood-wastewater. Increases in the ratio of tannery waste-water in influent water also result in increases in the concen-tration of chromium, which decreases the ratio of BOD/T-N so that the removal efficiency of organic and nitrogen pollut-ants in biological wastewater treatment deteriorates. No sub-stantial differences occur in the ratios of Eubacteria/total bacteria as the ratio between tannery wastewater and seafood wastewater changes in the influent water. In contrast, the cell numbers and activities of Eubacteria and total bacteria signifi-cantly decline with increasing ratios of tannery wastewater in the influent water. Stable removal of organic and nitrogen pol-lutants by biological wastewater treatments leads to domi-nance of Proteobacteria groups in all biological treatmen