Study On Denitrification Efficiency In ANDA Process

The wasterwater can not be ran well in winter and be short of carbon source in denitrification of the wastewater tretment plant. In order to solve the problem, the piolt-scale study on new wasterwater treatment process—ANDA process in the dissertation is carried on.In the ANDA process, different micro-organisms are intensified in different reactors, so the conflicts between them caused by different metabolism conditions are reduced, thereby the nitrogen can be removed effectively and steadily.The wastewater of Wuxi Chengbei Wastewater Treatment Plant is used and the capability of the pilot-scale ANDA process is 10 stere per day in the study. The main content of the study is: establish the operation index of separate nitrification unit(MLSS,HRT,SRT,temperature etc.),the nitrification rate and function of the unit to improve the ANDA's removal effect; study the various influencing factors to denitrification and establish the denitrification rate.Experiment indicates, Main investigation was operated to the factors, which affected the nitrification effect, results showed that when MLSS was 3.5~5g/L, HRT was 4.8 hours and SRT was 25 days, the nitrification efficiency was the best. when MLSS was 4~6g/L, HRT was 3.6 hours and SRT was 10 days, the denitrification efficiency was the best. And its nitrification and denitrification efficiencies under the best operational conditions were analyzed. when nitrification unit under the best operational conditions, removal rates of ammonia, COD, SS, TN and TP were 98.3%,63.4%,76.2%,23.3% and 71.0%, respectively; when denitrification unit under the best operational conditions, the average concentration of nitrate and TN of effluent are 9mg/L and 10.2mg/L, removal rates of nitrate and TN were 60% and 56%, respectively.Study also indicates, nitrification is enhanced due to the separate zone. Ammonia can be removed effectively and steadily in winter. The feasibility of using the excess sludge hydrolysis-acidification liquor as a carbon source for nitrogen removal is investigated by batch experiment. The denitrification efficiency of hydrolysis-acidification liquor is closed to methanol.So the problem of short of carbon source in denitrification of the wastewater tretment plant is sloved and the denitrification efficiency is enhanced in denitrification unit.