A Comparative Study On The Two Kinds Of Wastewater Treatment System Of Dongguan Wastewater Treatment Plant

In China biological method is the most popular treatment used in wastewater treatment plants at present. Common biological treatments include Anaerobic Oxic, Anoxic Anaerobic Oxic, Oxidation Ditch, Adsorption biodegradation, Sequencing Batch Reactor, Biomembrane and so on. Most of the comparative studies are focus on between Anoxic Anaerobic Oxic and Sequencing Batch Reactor or Oxidation Ditch system. The comparative studies between Anaerobic Oxic and Anoxic Anaerobic Oxic are much lesser. This article analyzed these two kinds of system in terms of economy and treatment result.This research did the analytical estimating of Anaerobic Oxic and Anoxic Anaerobic Oxic's construction investment. Total treatment result has been analyzed though the water quality parameter of the effluent. This paper also studied the changing rule of NO₃-N, NO₂-N, TP, DO and pH in water and discussed the biological characteristics of the polyphosphoric, nitrobacteria and denitrifying bacteria in the activated sludge.The following conclusions can be drawn according to economic and result analysis of Anaerobic Oxic system and Anoxic Anaerobic Oxic system of Dongguan Wastewater Treatment Plant:(1) The construction investment of Anoxic Anaerobic Oxic system is 2.119million RMB higher than the one of Anaerobic Oxic system.(2) The electrical energy consumption of the two kind of system are almost the same. But the consumption of Anaerobic Oxic system is a little higher than the Anoxic Anaerobic Oxic system.(3) Both of the two systems' BOD removal are pretty well. The effluent's BOD can conform to the National primary standard. But compared to Anaerobic Oxic system, the removal rate of BOD of Anoxic Anaerobic Oxic system is lower.(4) The effluent's COD of the two systems both can conform to the Nationalprimary standard. But compared to Anoxic Anaerobic Oxic system, the removal rate of COD of Anaerobic Oxic system is better.(5) Neither of the two systems' TN removal rate are good enough. But both of the effluent's TN can conform to the National primary standard. And the removal rate of TN of Anaerobic Oxic system is better the the one of Anoxic Anaerobic Oxic system.(6) The TP removal is the worst one compared to the three one above, no matter which system the sewage get through. The average TP of Anaerobic Oxic system's effluent even fail to meet the National primary standard. Anoxic Anaerobic Oxic system is a little better than Anaerobic Oxic system at this point.In summary, in terms of organic substance and TN removal, Anaerobic Oxic system is superior to Anoxic Anaerobic Oxic system. Anoxic Anaerobic Oxic system only can do better on the removal of TP. But the construction investment of Anoxic Anaerobic Oxic system is much higher than Anaerobic Oxic system. Relatively, the result is not so reasonable.