Study On The Factors Of Pre-denitrification Dealing With The Wastewater From Alcohol Ketone Device

It becomes one of the key problems that whether the discharge of wastewater from chemical industries can meet standards.The wastewater from chemical industries contains a lot of organic pollutants.Different from inorganic wastewater treatment,biochemical treatment is the used to deal with this organic wastewater.It is difficult to control due to many factors influencing the treatment,so that the discharge of wastewater is poor.In this study,adipic acid wastewater treatment of Shandong HuaLu-HengSheng chemical co.,LTD.was studied,and the existing problem and factors of pre-denitrification of adipic acid wastewater treatment were anlyized.The result is favors to improve the existing wastewater treatment effect.At present,there are some problems in the pre-denitrification of adipic acid wastewater treatment:The denitrification time is short and the denitrification is not complete,due to the short reaction time;the removal rate is low,due to different between Nitrifying bacteria and denitrifying bacteria on the factors and pH indexes.For high COD and total nitrogen content,and instabile pH value,pH value could increase and go beyond the suitable index of denitrifying bacteria in the denitrification reaction,which decreased denitrifying bacteria activity,and even death.Nitrification and denitrification occurred simultaneously in the pre-denitrification tank,and the optimal values of dissolved oxygen were not consistent.Therefore,it is poor of the removal efficiency of total nitrogen.In view of the present operation situation of the wastewater treatment system that is compatible with the alcohol ketone unit in Shandong Hualu-Hengsheng Chemical Co.,Ltd.,the pre-denitrification treatment was studied in this paper.The effects of COD,ammonia nitrogen,and total nitrogen were analyzed by adjusting the indexes(pH value,the concentration of dissolved oxygen,temperature,and the reflux ratio of waste water)in the pre-denitrification reactor and changing the kind and dosage of carbon source under the vested environment.The pH value,dissolved oxygen,reflux ratio,the kind and dosage of carbon source of the pre-denitrification were studied in this article.The wastewater treatment of the pre-denitrification was the best when the optimum range of pH value was 7.1-7.3,the optimum control range of dissolved oxygen was 1.4-1.6 mg/L,the optimum control range of temperature was 24?26 ?,the reflux ratio was 1.5,the kind of the carbon source was ethanol,and the dosage of ethanol was 500 kg d-1.Under this treatments,the removal rate of TN in wastewater can reach the optimum 50.88%.