On Experimental Study Of Biologiacal Nutrient Removal With Disintegrated Sludge As Carbon Source By Ultrasonic Treatment

With the types and concentrations of pollutants in water increasing, the wastewater techniques developed gradually from the period of pure chemical oxygen demand(COD)removal to the period of simultaneous COD,nitrogen and phosphorus removal. Today, the nitrogen and phosphorus removal technology aimed for eutropMcation control has been the focused study in the wastewater treatment area. Because of specific technical and economic advantages, the biological N removal technology has been widespread concerned.At present, in most sewage treatment plant, carbon content in sewage is observed to be low and become the main factor influencing biological denitrification efficiency. Herein extra carbon source supplement should be considered to provide electron donors needed in biological denitrification process. Ultrasonic sludge is the economy and technology carbon source.On this paper, based on sewage treatment plant of Wuxi Taihu Newcity for the experiment field, the technology of ultrasonic sludge to carbon source was studied. The research included changes on ultrasonically sewage sludge, the intermittent denitrification experiment, ultrasonic sludge recycle to carbon source on reversed A~2/O process and ultrasonic sludge recycle to reduce sludge production .The major achievements in the paper are as follows:(1)When the ultrasound waves propagate through the sludge medium, the phenomenon of cavitation bubbles will occur, and the characters of sludge will be affected. As the ultrasonic time extended, the sludge temperature promoted, the sludge flocs were destructed constantly, and the solubility of sludge was increased. (2)Through the intermittent denitrification experiment, I investigated the change of nitrogen and the carbon source as the ultrasonic sludge to be the carbon source. It is observed that degradation of nitrate underwent stepwise process.(3)Based on 1 and 2 two groups of sewage treatment plant of Wuxi Taihu Newcity, I studied the influences on the effluent quality and the production of excess sludge, after 40%, 50% and 60% excess sludge treated by ultrasound was reflew into the 2 hypoxia reactor. Compared to the control, the removal of TN was tallest, the removal of NH3-N,C0D had a small increase, and It did not affect settlement of sludge, when proportion is 50%, It is the best Dosage. Ultrasonic disintegration on sludge can enhance the sludge cryptic growth, the total amount of sludge reduced.