Study on Oily Wastewater Treatment with High-Effective Acclimated Bacteria

Twelve bacteria strains were isolated from four kinds of activated sludge. The preliminary experiment showed that the oil removal rate of all bacteria strains can reach 80% or above in the condition of high concentration of oil (COD Cr 10 g/L). The oil removal rates of bacteria strain GSH 1, GSH 2 and GSH 3 are 94.2%, 92.9% and 92.5%, respectively. Strain GSH 1 was used in further static experiments to estimate the impact of some conditions: Surfactant did not restrain the activity of GSH 1 strain, but improve the oil removal rate. Changes of oil concentration affected treating time and process of biodegradation. The optimum pH was between 6 and 7, the optimum temperature was between 32～45 ℃, and oil concentration is less than 2 g/L. In practical process of treating restaurant wastewater, the COD Cr removal rate reaches the level higher than 86% in 30hrs. This high effective acclimated bacterium has excellent ability of removing oil pollutants in conditions of high concentration of oil and surfactant.