Study Of Wastewater Treatment Technique Of Triple Oxidation Ditch

Triple oxidation ditch treatment process have imported to our country from nineteen eighties. It has the advantages of simple processes; continous treatment without secondary sedimentation tank; less building; simply management, adaptable for effluent wastewater; less ground demand and satisfactory nitrogen removal result. After Handan sewage treatment plant have adopted triple oxidation ditch treatment process, Xinyi sewage treatment plant, Zhangjiagang sewage treatment plant, Changshu north city sewage treatment plant and so on sewage treatment plant have adopted this treatment process. It's used widely in wastewater treatment engineering.This subject statistic the triple oxidation ditch data of Guicheng sewage treatment plant. Find out the effect of CODcr, SS, NH3-N removal rate in certain temperature, pH, MLSS, dissolved oxygen. The statistic results shows that:1. The wastewater CODcr, SS and NH3-N meets GB18918-2002 <City sewage treatment plant pollutant discharge standard> secondary standard after treated by triple oxidation ditch. Triple oxidation ditch meets basic needs of city wastewater treatment.2. Except the CODcr influent concentration lower than 500mL, the removal rate suffer bigger effect from influent concentration than other enviroments and items. System stability is good.3. The removal rate of CODcr and SS rise with increased of influent concentration, but it is without linear change relatives. NH3-N removal rate didn't influence by influent concentration.4. CODcr, SS and NH3-N nearly no influence by temperature between 11-30℃.5. The chance of low removal rate in pH between 7.50-7.62 is lower than other range.6. NH3-N removal rate achieve better results when dissolved oxygen between 1.1mg/L to 4.7mg/L.7. CODcr removal rate goes down when MLSS increses.8. Triple oxidation ditch CODcr, SS and NH3-N removal rate is better than traditional oxidation ditch.To sum up, triple oxidation ditch will obtain a good performance of CODcr, SS and NH3-N in pH range between 7.50-7.62, dissolved oxygen between 1.1mg/L-4.7mg/L and low MLSS level.