Study On Process Optimization Of Desulfurization Wastewater Physicochemical Treatment Process In Coal-fired Power Plants

Based on the previous site investigation and water quality detection,single factor and orthogonal experiments of magnetic loading coagulation,electroflocculation and magnetic coagulation-electroflocculation combined process were carried out to solve the low water quality problems of high suspended matter,high fluorine and high COD in the existing wastewater treatment process of Tianjin Power Plant.According to the removal effect of various pollutants in the desulfurization wastewater,it can be known that:1.When studying the effect of suspended solids removal in the coagulation test,the order of significant effects of various factors on the treatment effect of suspended solids is:sedimentation time>pH>coagulating agent type>coagulant aid;when researching the removal effect of COD,the order is:pH>coagulant aid>sedimentation time>coagulating agent type.The most outstanding contribution of the coagulation test was the removal of most suspended solids,with a maximum removal rate of 86.33%.For the magnetic coagulation test,the removal efficiency of pollutants is the best when the magnetic powder dosage is 0.2g/L.The removal rate of suspended solids and COD is99.91%and 45.48%,respectively.2.When the electroflocculation test was used to treat the desulfurization wastewater,the influence of four factors on the removal rate of suspended solids was ranked from large to small in order of current intensity,plate spacing,reaction temperature and time;when studying the effect of fluoride removal,the influence of each factor is significantly sorted from large to small in order of reaction time,reaction temperature,current intensity and plate spacing.The removal rate of suspended matter and fluoride from desulfurization wastewater by electroflocculation is 99.10%and95.00%,respectively.Especially in the treatment of fluoride,the content of effluent fluoride is much less than the discharge standard value of 30mg/L.3.The magnetic coagulation-electrocoagulation treatment has a good effect on the removal of suspended matter and fluoride in desulfurization wastewater.The removal rates are up to 97.20%and 98.20%,respectively.The concentration of suspended solids after treatment was all below 70 mg/L by orthogonal test.It also contributes to the removal of other indicators such as COD,heavy metals,hardness,chloride ions,etc.,and its removal efficiency is not as obvious as that of suspended solids and fluorides.4.According to the removal efficiency of suspended solids,fluoride and COD in wastewater and,it was concluded that the optimal process level for the treatment of desulfurization wastewater by magnetic coagulation-electric flocculation method was pH 8.5,coagulant the PFC concentration was 40 mg/L,the coagulant was 2 mg/L PAM plus 0.2 g 300-500 mesh Fe₃O₄,the current intensity was 2.4 A,the plate spacing was 6cm,the electrocoagulation temperature was 40°C,the electrolysis time of 50 min and standing time of 50 min.Compared with traditional coagulation,the removal efficiency of suspended solids,fluoride and COD was obviously improved,and the highest removal efficiency were 99.97%,98.07%and 48.24%,respectively.Figure[37]Table[22]Reference[88]...