Study On The Treatment Effect Of Carrousel Oxidation Ditch Process Before And After Improvement

Oxidation ditch technology is the new wastewater treatment technology developed in the middle of the20century,and because of its own advantages, this technology has gradually become the mainstream of the wastewater treatment technology. Through decades’ of development and improvement, the Carrousel type, Orbal type, integrated oxidation ditch, T type and DE type oxidation ditch are relatively mature and have the good effect n sewage treatment project in China.Carrousel oxidation ditch technology has attracted more and more attention in sewage treatment throughout the world because of its advantages in technology and economy.With the show of its advantages, increasing wastewater treatment plant use this method. The characters of domestic and foreign Carrousel oxidation ditch and the problems exsiting in their application are well explained in previous literatures, besides, the importance of adding primary settling tank before oxidation ditch, is also demonstrated that Carrousel oxidation ditch can remove inorganic mineral from wastewater and ensure the running stabilize of further oxidation ditch. Therefore, this paper takes the industrial wastewater and domestic wastewater which discharge by a certain mining area in Tai’an as object. According to characters of water quality, adding primary settling tank before oxidation ditch of the sewage treatment facilities in this area is to study the removal effects of pollutants before and after adding primary settling tank, and it analyzed the changes of COD, ammonia nitrogen and SS before and after reformation which providing the scientific basis for domestic wastewater treatment. We can draw the conclusions:(1)After using the improved water treatment process in a certain wastewater treatment plant in Tai’an,the Carrousel oxidation ditch runs stabily and the average removal rate of COD SS changed from44.89%82.6%to69.11%80%. The average removal rate of ammonia nitrogen changed from negative to59.96%. The average removal rate of COD improved and SS’s improved remarkably.(2)Though the average removal rate of ammonia nitrogen improved remarkably,it is unsteady.Suggestion is made in the light of existed problem:According to the problem about the unsteady removal rate of ammonia nitrogen, some concrete measures can be taken,such as in high pH media,long sludge retention time, large aeration rate in in aerobic stage and long aeration time.