Physi-chemical Phenomenon And Study In Biological Treatment Of Leachate

Leachate is a kind of sewage containing high concentration organic compounds. Of all possible techniques biological treatment technique is the most prevalent one due to its low cost in operation.Leachate is typical of high CODcr , high ammonia, and low ratio of BODs/CODcr. In addition, it may contain more than seventies organic materials and heavy metals. It has been shown that leachate cannot be treated to the discharging standard by only biological method without any other assistant treatments.Based on existing researches and on the drawback of updated anaerobic and aerobic methods , a new treatment process, "nutrient adjustment→UASB→ blow out→ SBR", is put forward in this thesis and verified by laboratory test and theoretic analysis. The conventional design method depending on HRT is replaced by a new method depending on sludge age and data from laboratory experiments. This method improves the reliability of project design.The paper involves the following topics:the current state of leachate treatment technology; designing and verifying the treatment process of Chongqing leachate; major factors which influence leachate treatment results; establishing calculation protocol and working out related dynamic parameters.The following results have been obtained. (1) Leachate would not meet the standard of discharge if only through biological process. (2)UASB method is capable to treat the nutrient-adjusted leachate effectively, and the longer the sludge aging, the better the elimination efficiency. (3)Ammonia blow-out is a critical measure for the efficiency of SBR treatment. 甌he process, nutrient adjustment→ UASB→ blow out →SBR, can remove pollutants in leachate effectively if the sludge age is long enough and the discharge can meet the class I standard of integrated wastewater discharge standard.