| Phosphorus and organic matter are two indicators that are difficult to meet the stable standard of secondary effluent in municipal sewage treatment plants.Conventional coagulation method has good treatment effect on phosphorus and certain removal effect on organic matter in wastewater.However,it is difficult to make phosphorus and organic matter meet the emission standards at the same time.Ozone oxidation has good removal effect on organic matter because of its efficient oxidation,but the cost is high.In this paper,ozone-coagulation combined process is used to simultaneously remove phosphorus and organic matter in wastewater,and explores the best combination of ozone-coagulation combined synchronous removal of phosphorus and organic matter.The main conclusions of this paper are as follows.This paper investigates coagulant dosage,p H,initial concentration of wastewater and hydraulic condition on the removal of phosphorus and organic matter in wastewater by separate coagulation.When the p H value of wastewater is 7,0.5 g/L PAC is the best for 2 mg/L phosphorus containing wastewater,and the removal rate of total phosphorus(TP)can reach 76.54%;Adding 1.0 g/L PAC has the best removal effect on 5 mg/L phosphorus containing wastewater,and the TP removal rate can reach 91.57%,which meets the first class a standard TP discharge standard.When the p H value of wastewater is 5,0.5 g/L PAC is the best,and the removal rate of organic matter can reach 52.07%.When the p H value of wastewater is 9 and 0.5g/lpac is added,the removal efficiency of TP and organic matter is 72.799% and 77.24% respectively.This paper investigates ozone flow rate and p H on the removal effect of phosphorus and organic matter in wastewater.The experimental results show that the effect of ozone oxidation on phosphorus removal is not obvious and is not affected by conditional changes.The removal efficiency of organic matter in wastewater by ozone oxidation is obvious.The larger the ozone flow rate is,the better the removal effect of organic matter is.After 30 minutes of ozone treatment,the removal rate of organic matter can reach more than 99%,and the removal rate of TOC to wastewater can reach32.69%.Within 20 minutes before treatment,the p H,initial concentration and ozone flow rate of wastewater have great influence on the removal efficiency of organic matter,p H=9,low initial concentration and high ozone flow rate can shorten the treatment time.When ozone removes both phosphorus and organic matter in wastewater,treatment can only complete the effective removal of organic matter without removing phosphorus from wastewater;when both phosphorus and organic matter exist in wastewater,the optimal conditions for ozone removal of organic matter change.Separate coagulation and separate ozone have a good removal effect on phosphorus and organic matter in wastewater,but it does not achieve the ideal effect of removing phosphorus and organic matter from wastewater at the same time.Therefore,the effect of coagulation and ozone combination processes on the removal of phosphorus and organic matter from wastewater at the same time was investigated.The effects of ozone-coagulation combination,p H,coagulant addition,ozone flow rate and water conservancy conditions on the simultaneous removal of phosphorus and organic matter from ozone-coagulation wastewater were investigated.The results show that the ozone-coagulation combined process is the best effect of phosphorus and organic matter in wastewater,p H=9,with the removal rates of phosphorus and organic matter of77.63% and 95.48%,respectively.This paper investigates the simultaneous removal of phosphorus and organic matter from the wastewater by ozone-coagulation.The experimental results show that this process is feasible,but when treating different p H and initial concentrations wastewater,it is also necessary through a small trial to determine the specific combination method and optimal treatment conditions. |
