The Study Of Denitrogen And Dephosphorus Of A Industrial Sewage With Lower C/N By A Submerged A-BAF Process

It is more serious that the eutrophication due to the large input of nitrogen and phosphorus by increasingly human activity.China is a country with many lakes. At present, the nitrogen and phosphorus pollution in China’s lakes and reservoirs has become increasingly serious. The massive growth algae is longstanding in water with wide coverage and multiple outbreaks, which has caused serious harm to aquatic organisms and human health. At the same time, with the development of industrial production, the improvement of people’s living standards and the increase of water consumption, low carbon source in the city sewage is becoming worse.According to "The Emission Standard for Urban Sewage Treatment Plant " GB18919~2002, the nitrogen and phosphorus emissions target was added. It is extremely important to explore the new technology of nitrogen and phosphorus removal. Aiming at the wastewater in an industrial park with lower C/N,"a submerged A-BAF process" and "the synergistic effect of Magnesium Ammonium Phosphate Precipitation and the submerged A-BAF process" was researched. It aims to make the effluent’s TN, TP and SS achieve the first class of A standard of "The Emission Standard for Urban Sewage Treatment Plant " GB18919-2002by secondary biological treatment on the basis of the existing secondary treatment structures at the same time.This research is based on a sewage treatment plant in an industrial park. The experiment takes the effluent of the sewage treatment plant’s primary settling tank as the object. The research result shows that:1. When the mass concentration of COD,NH3-N, TN,TP and SS in raw water is89mg/L~137mg/L,27.4mg/L~42.3mg/L,38.9mg/L~57.7mg/L2.61mg/L~4.06mg/L and72mg/L~153mg/L respectively, the average removal rate of COD, NH3-N, TN, TP and SS by using the submerged A-BAF process was89.75%,96.47%,58.00%,79.00%and92.47%respectively, and the mass concentration of COD, NH3-N and SS in the effluent achieved the first class of A standard.2. Na2HPO4-12H2O and MgCl2-6H2O was the optimum chemical to be used in Magnesium Ammonium Phosphate Precipitation. The optimum operating conditions in Magnesium Ammonium Phosphate Precipitation was found as:pH was9.5, the reaction time was30min, Mg/N was1.3and P/N was1.06.3. When the mass concentration of COD,NH3-N, TN,TP and SS in raw water was100mg/L~133mg/L,29.1mg/L~41.4mg/L,39.5mg/L-54.8mg/L 3.92mg/L~2.69mg/L and75mg/L~146mg/L respectively, the average removal rate of COD, NH3-N, TN, TP and SS by the synergistic effect of Magnesium Ammonium Phosphate Precipitation and the Submerged A-BAF process, the mass concentration of COD, NH3-N,TN, TP and SS in the effluent can meet the first class of A standard simultaneouslyThe mass concentration of TN, TP and SS in the effluent can meet the first class of A standard of "The Emission Standard for Urban Sewage Treatment Plant " GB18919~2002by using "a submerged A-BAF process" and "the synergistic effect of Magnesium Ammonium Phosphate Precipitation and the Submerged A-BAF process" to treat the the wastewater with lower C/N in the industrial park simultaneously. The experimental results achieved the desired goal.The above process is a sustainable wastewater treatment process, and there is a good application prospect for it...