Study On Preparation And Application Of High Performance Polyferric Chloride Coagulant

The iron-based water purification agent can cope with various complicated water quality in the water treatment industry with its excellent coagulation and sedimentation performance,In particular,polyferric chloride（PFC）polymer coagulant has a tendency to replace polyaluminumchloride（PAC）.Especiallyinthe environmentally-friendly situation where the production of raw materials for PAC is rapidly shortageing,the treatment of by-products is difficult,and the problem of biological toxicity is receiving increasing attention,the market is in urgent need of alternatives.PFC,as a late-developing iron-based inorganic polymer coagulant,can be produced by using steel pickling waste liquid as raw material,which not only opens up new ways for the utilization of hazardous waste resources,but also greatly reduces the production cost of the medicament,thereby reducing the cost of water treatment.This experiment focuses on stable,high-concentration PFC performance（stability and performance）research and industrial production applications,while comparing the cost performance of PFC and PAC through coagulation e xperiments,and its impact on the residual iron content in treated water.By optimizing the preparation conditions and introducing different anions,a PFC with stable storage and an iron content of more than 10%and a salt basis of more than 15%is obtaine d.The optimum experimental conditions are as follows:1)gas-liquid mixing using jet pump;2)preparation temperature not exceeding 60°C;3)raw material iron content critical value 14%,H/Fe molar ratio 0.75;4)catalyst dosage is chlorination The total amount of the ferrous solution is 0.25%;5)the amount of stabilizer added AH₂P and HP（P/Fe molar ratio）is0.06,and the HS（S/Fe molar ratio）is 0.05 to 0.06.PFC exhibits optimal coagulation performance in the range of 12%²0%salt base and pH value of 6⁹.In order to verify that PFC has superior coagulation performance and high cost performance,the kaolin simulated wastewater was treated with PFC,PAC and PFS coagulant,and the turbidity removal rate and residual iron content in the coagulation proc ess were determined.The results show that under the same coagulation process conditions,the coagulation performance PFC>PAC>PFS;pH application range PFC>PFS>PAC.Under different coagulation conditions,the residual iron content of PFC can be kept below 0.5 mg/L,which will not affect the advanced treatment of wastewater.To realize the industrial production and application of PFC.The reaction system is designed with automatic control system,high degree of automation,strict control of reaction conditi ons,accurate indication of reaction process,high production efficiency and high safety,and product quality meets national standards.The industrial grade PFC is practically applied in coal chemical wastewater,and the control experiment is set with the enterprise special agent GH-A.The experimental results show that the PFC has a COD removal rate of more than 60%and a turbidity removal rate of over 95%.The removal efficiency of GH-A COD was slightly higher under the same dosing amount,but the turbidity removal effect was more excellent,and the effect of residual iron ions was not significantly different.Through cost accounting,it is found that PFC has a higher cost performance ratio and can save 37.5%of pharmaceutical cost per year compared with G H-A.