Application Of Microorganism Stregthened In Situ Bioremediation In Polluted Urban River

The Pingyang urban river is one branch of Feiyun River system which is one of the eight major river systems in Zhejiang province. With the acceleration of urbanization and the development of modern agriculture, the county’s urban river pollution is getting worse. In this thesis, microbiological remediation methods were applied in3rivers water treatment, which is Beimen River, Suidong River and Daizhuang River. Rresearch results are as follows:1. Photosynthetic bacteria, Rhodopseudomonas palustris and Bacillus subtilis BSW were applied in Beimen River first watercourse restoration in October2011. After treatment, water NH4+-N concentration decreased of about18.9%, and CODMn decreased of about55.1%;2. During Beimen River second watercourse, Suidong River and Daizhuang River first watercourse rehabilitation, the additional microorganisms significantly improved the water quality in several days. Within10days, the average removal rate of NH4+-N in Beimen River, Suidong River and Daizhuang River were about25.2%,23.3%,42.0%, respectively; TN removal efficiencies were about27.1%,22.5%,39.9%, respectively;3. Bacterial community structure in the water body of Beimen River was characterized using PCR-DGGE analysis. In the early stages of treatment, there were2or3obviously superiority strains in the Beimen River water body; and in the later stage of treatment, the bands amount in DGGE map increased significantly. These results indicated that through the enhanced microbial remediation, water bacterial diversity in Beimen River water body increased significantly and the water ecology got certain degree of recovery.4. Sodium acetate as organic carbon source, Suidong River water as test sample, simulating treatment experiment was conducted. The result showed that NH4+-N removal rate of water up to50%within3days. Then sodium acetate was added in Suidong River upstream, the experimental water NH4+-N removal rate increased by more than25%and TN removal rate increased by more than16%after second carbon source addition. These results indicated that additional organic carbon source could significantly speed up the nitrogen-rich water nitrogen removal.5. The impact of sediment on the river water treatment was tested under laboratory conditions. Beimen River water and sediment were mixed thoroughly and settled for1day, NH4+-N and TN content increased about1times, then decreased slowly. After bacteria was added in the mix and aeration processing was carried on, NH4+-N removal efficiency reached38.3%, TN removal rate reached32.0%within10days; CODMn content in water gradually increased with the sediment increase, and accumulated to1-3times to10days. This result indicated that the sediment continuously released pollutants into water. Compared with control, the CODMn content in experimental group was lower, which indicated that bacteria cast and aeration processing had positive effect on degradation of organic pollution and water quality improvement.