Bioremediation Of Micro-polluted Raw Water By Microbial Agents

In recent years, the drinking water eutrophication problem has been the focus of the researchers’ study. In micro-polluted raw water treatment process, the bacteria-throwing technology is widely used because of low price、efficiency and energy cost. The research is mainly about the denitrification characteristics of the high efficient nitrification-denitrification aerobic strain has been isolated from sediment in water reservoir and the source recombination effects on pollutants removal between the water and sediment. It’s investigated the feasibility that the strain can used to treat micro-polluted water. The main results of this study are as follows:First, it’s explored the optimal condition of the high efficiency strain A14(Acinetobacter pittii) by different environmental factor and orthogonal test. The efficient nitrogen removal can be 78.89% when nitrogen as the nitrogen source and the strain’s partial napA functional gene was cloned. When ammonia as the nitrogen source, ammonia removal rate can be 95.25%. The optimal conditions of the strain can be concluded that proves that the strain can adapt to the environment with low temperature and low C/N.Second, we choose a method that cultivate and acclimate rapidly to make the strains adapt to the denitrification condition and make effects on nitrogen removal. In this method, the strain’s TN removal can be 38.12%-51.67% and nitrogen removal can be 62.3%-87.58%. By source recombination(A13+A14+A16+A17), TN removal can be 31.48%, the nitrogen removal can be 39.72%. TOC removal can be 31.93% when the strain is dosed in reservoir raw water. It demonstrated that the strains exhibited excellent biological activity and high efficiency on nitrogen removal.Third, it’s under the different conditions of DO that the microbial agent can also remove the pollutant efficientively in the simulated reservoir environment contained micro-polluted water and sediment.The results prove the microbial inoculants’ efficiency that the microbial inoculants’ TN removal can be 44.74% and nitrogen removal can be 45.25% in the simulated environment when DO=7-9mg/L. Also, the microbial inoculants can be used in raw water. The research also shows that the function of aeration can promote the nitrification-aerobic strains’ growth and enhance the water micro-organisms carbon source consumption and the diversity of microbial community structure, which all prove a theoretical basis for the practical application of bacteria-throwing technology in the future.