The Research On Eutrophic Water Repairing Technology Of Part Of East Lake In Wuhan

Much untreated city sewage containing large amount of N,P discharge into East Lake ofWuhan since last century sixty years, which caused East Lake’s serious eutrophication. Thepaper introduces kinds of engineering measures and water repairing technology, for the aim ofimproving water quality, reconstructing water ecosystem, restoring the ecological balance andself-purification ability of water, and promoting parts of the lake environment quality, whatprovide technical support for the East Lake ecological water network-“six lakes connected”project and the East Lake comprehensive management.On the base of the pre-project of the East Lake regional water environmentcomprehensive treatment, which contained interception, dredging and the peripheral surfacesource manage, the study researched the East Lake regional water body from2aspects,including water purification of the part of the lake and the control of non-point sourcepollution. In the research of water restoration, the paper mainly studied biological aeratedfilter and mobile water producing system. The result showed as follows:(1)In the process of the lake purification, both ceramic and zeolite biological aeratedfilter’s time of natural biofilm formation was21days. Comparing the two kinds ofbiological aerated filter, the former was better for removing of CODCr, the later wasbetter for ammonia nitrogen; based on the need of the engineering and theeconomical, the best choose is ceramic;(2)While ceramic biological aerated filter treating the water, HRT should on less than60min, and air/water ratio should be1:1. The best condition was follows: substrateconcentration(CODCr) of10.3mg/L, air/water ratio of1:1and HRT of60min;(3)In the process of restoration of lake water, one of the emergency treatment systemswas called ballasted flocculation magnetic separation, which was better than thetraditional water treatment technology,especially when removing Phosphorus, theremoval rate was91.18%, from0.67mg/L to0.06mg/L.(4)In the comprehensive treatment project of the retoration of lake, biological aetatedfilter and movable type water treatment system for small regional lake water hasobvious adantages, and for the restoration of lake water in large area, the ecologicalfloating island is more useful on the long-term performance and economy.