Research On Immobilized Microbial In-Situ Remediation Technology Applied In Lake Water Contamination

Eutrophication continual development would fundamentally change the healthy functioning of the lake ecosystem primary productivity structure, leading the lake ecosystem structure, function and ecological balance to destroy, seriously affecting the water quality. This paper focus on the typical eutrophic lake water in-situ remediation problem, designed a type of device used in enclosed shallow eutrophic town water body restored, because a high concentration of biological, environmental adaptability and stability characteristics in repairing process. Obtained a process parameters through the release of sediment simulation experiments, repairing water simulation experiments and pilot test, Last successfully using in the rural water environment governance and urban landscape water body repair. The results are as follow:(1) In the neutral pH conditions, the less impact of sediment COD, NH3-N and TP release. When the pH was 7, after simulation sediment contamination releasing experiment, the concentration of NH3-N and TP were 1.86mg/L,0.09mg/L, which was the lowest of all.(2) The carrier storage column settings depth and water pH had a significant impact on the treatment. When it set at half of the depth, COD and NH3-N removal rate were 46.6%,60.4% better than laying in the bottom of the water; when the pH of water was 7.0 to 8.0, the best treatment effect on COD and NH3-N were 47% and 80%; added the amount of filler might improve the removal rate and finally degrade affect of COD, NH3-N, TP in the water.(3) The shallow enclosed lake water remediation pilot test has proved than this immobilized microorganisms in-situ remediation devices can removal the COD, NH3-N and TP from water. After restored, COD NH3-N and TP dropped obviously. The concentration of COD and TP were 20.1mg/L,0.1mg/L nearly meet the Water Environment Quality Standard (GB3838-2002) water quality requirements of type Ⅲ and achieve the research goal.(4) The immobilized microorganisms in-situ remediation system worked stability in the rural water environment governance(one month) and urban landscape water body repair(five month). After remediation, the concentration of COD NH3-N and TP were 18mg/L,1.7mg/L,0.2mg/L in the rural stabilization pond and 2.5mg/L,1.3mg/L,0.11mg/L in the urban landscape lake. Both of them nearly meet the Water Environment Quality Standard (GB3838-2002) water quality requirements of type Ⅳ.