Study On The Effect Of Ultrasound On The Hydrolysis Of Sludge

With increasing eutrophication, wastewater treatment technology has gradually shifted from a single stage of conventional treatment removal of organic matter into the simultaneous removal of organic matter and nitrogen and phosphorus in the depth of processing stages, the nitrogen and phosphorus removal wastewater treatment process aimed for eutrophication control has become the hot research field.As we all known, The C/N ratio of the municipal wastewater in our country is low, it’s the reason why the nitrogen and phosphorus can’t be removed effective by the biological treatment process.The low carbon content in sewage has become the main factor influencing biological denitrification efficiency. In order to enhance the remove ratio of nitrogen and phosphorus, it needs to add other carbon source. sludge,after Ultrasonic pretreatment and hydrolyzed, can be used as economical and practical source of carbon.on this paper,base on sewage treatment plant of Wuxi Taihu Newcity for the experiment fielding, sludge hydrolysis was studied under different ultrasonic treatment conditions.the reserch conclude:the influence of ultrasound on sludge under different conditions; the influence of ultrasound on sludge hydrolysis under different conditions sludge; denitrification rate test.the major achievement in the paper are as follows:(1) the influence of ultrasound on sludge under different conditions:the greater the value of these four factors,which contain retention time, amplitude, sound energy density, pressure, the stronger the broken effect on sludge.(2) the influence of ultrasound on sludge hydrolysis under different conditions sludge:the value of sound energy density has little influence on the size of the SCOD in sludge hydrolysis process, and the sludge hydrolysis with low-density has higher SCOD peaks. The value of TN, TP, VFA increased with the increase of sound energy density; The value of amplitude has little effect on the size of SCOD in sludge hydrolysis process, but sludge can give out more P with the small amplitude; stirring can accelerated the process of sludge hydrolysis markedly, and within a certain range, the faster the stirring speed (the speed is appropriate when the surface of the sludge does not produce a large spiral vortex), the more promotion to the hydrolysis of sludge; the percentage of organic has large effect on hydrolysis, the greater the percentage, the higher the size of SCOD.the organic matter decreased a percentage point each, the average increase in SCOD of sludge will be reduced8.3mg/(L-d).(3) the denitrification rate tests show that the hydrolysis by the sludge is feasible as denitrification carbon source, and better than the CH3COONa. the denitrification rate of sludge hydrolysis is1.94mg NO3-N/(g MLVSS-h), and the denitrification rate of CH3COONa is1.53mg NO3-N/(g MLVSS-h), so the hydrolysis of sludge is more efficient. And as it has higher N, P concentration, before backing to the anoxic zone,we should remove N, P element with the MAP method, so as not to increase the N, P load of system.