| Sludge water from Urban sewage treatment plant has such characteristics with a high temperature (nearly 30℃), high concentration ammonia-nitrogen (nearly 1000mg/L). The amount of Sludge water is only 1% ~ 2% of inlet water to sewage treatment plant, but nitrogen load of it is accounted for the total load 15% ~ 25%. Most built and being built urban sewage treatment plants in China adopt reflux to intake & re-processing method, making the actual system nitrogen load is higher than design loads. Total nitrogen becomes an important indicator to measure that outlet from sewage treatment plant meet the standard or not because sewage treatment plants improve discharge standards. Therefore, the research about water quality characteristics of sludge and sludge water treatment will be one of hot topics in sewage treatment.This paper mainly discusses the topics of amount of sludge deposition, the material balance and the quality of activated sludge through the research of mechanism of nitrogen and phosphorus removal of sludge water, and comparison of BOD5, CODcr, SS, TN, TP and ammonia nitrogen, and applying activated sludge process in large-scale municipal wastewater treatment plant.The results show that high concentration and dehydration of the six indicators make the water quality in grille improve to a certain extent, which means BOD5, SS, and TP increase at a higher level, but ammonia-nitrogen increase at minimal level. Moreover, through the analysis of standard deviation, the water quality of grille has much more volatile and has influence on the amount of sludge deposition in catch pit, the material balance and the activity of activated sludge. This paper has significance meaning for the stable operation of municipal wastewater treatment plant with the recommendations according to above issues. |
