Research On Removal Of Cu²⁺, CODcr, Ammonia Nitrogen And Total Phosphorus From Sewage By Potassium Ferrate Assisted PAC

With the social and economic development,urbanization accelerated,water pollution and water scarcity become the common problems in the face of the environmental.Our country’s heavy metal pollution is very pressing,heavy metal pollution is difficult to control,threat to human health,so need to take some measures to control and prevent heavy metal pollution.Now more commonly used inorganic aluminum salt coagulant PAC,Al3+is the by-product of PAC soluble in water have large harm on human body,used PAC alone would have large dosage,the effect is not obvious.So to enhance the effect of PAC and reduce the second pollution must to cooperate with other agents,so that we can get the efficient and economic effect.Potassium ferrate(K2Fe04) is the development of new multi-function water treatment agent,can enhance the coagulation effect of the PAC effectively.In the field of water treatment,because of its superior oxidation resistance and green features are attracted attention increasingly,have good prospects for development.In this paper,mainly use of the strong oxidation characteristics of potassium ferrate in water treatment process,via potassium ferrate assisted PAC oxidation-coagulation experiments,simulation study of potassium ferrate in the secondary wastewater treatment auxiliary PAC coagulation removal of heavy metals Cu(II),at the same time examines several typical pollutants(CODcr,ammonia nitrogen,total phosphorus) removal efficiency,analysis on the main factors of removing,the best remove conditions.And further explore the high iron potassium and polymerization mechanism and effect of the removal process each material influence to each other.This paper based on discharge standard of pollutants for municipal wastewater treatment plant level1type A standard,preparation of simulated wastewater In the laboratory,for the following experiment:(1)Configuration of Cu2+0.8mg/L,CODcr is50mg/L,ammonia nitrogen is5mg/L,total phosphorus is0.5mg/L mixed solution as the liquid.Test removal efficiency of each materials when individual dosing inorganic flocculant PAC.(2)Configure the same liquid,increasing the height of a single cast iron potassium when the material removal efficiency.Test removal efficiency of each materials when individual dosing potassium ferrate. (3)Configure the same liquid,by potassium ferrate assisted PAC coagulation treatment.Examine the dosage of potassium ferrate,the dosage of PAC,the oxidation section of pH,oxidation time,flocculation segment pH,flocculation time six factors for the removal effect,and preliminary explore the mechanism of removal,analysis of potassium ferrate assisted removal effect and in the process of removing influence each other.(4)Configuration Cu2+is0.8mg/L,CODcr is50mg/L,ammonia nitrogen is5mg/L of liquid.Examine the dosage of potassium ferrate,the dosage of PAC,the oxidation section of pH,oxidation time,flocculation segment pH,flocculation time six factors for the removal effect,and preliminary explore the mechanism of removal,analysis of potassium ferrate assisted removal effect and In the process of removing influence each other.(5)Configuration Cu2+is0.8mg/L,CODcr is50mg/L,total phosphorus is0.5mg/L of liquid.Examine the dosage of potassium ferrate,the dosage of PAC,the oxidation section of pH,oxidation time,flocculation segment pH,flocculation time six factors for the removal effect,and preliminary explore the mechanism of removal,analysis of potassium ferrate assisted removal effect and In the process of removing influence each other.The main conclusions include: (1)Potassium ferrate assisted PAC enhanced coagulation and the removal of Cu2+,CODcr,ammonia nitrogen and total phosphorus from sewage,the optimum conditions is K2FeO4dosage10mg/L,PAC dosage of30mg/L,the oxidation of section pH is7.0,flocculation pH is7.0,oxidation time is15min,flocculation time is30min.(2)Potassium ferrate auxiliary PAC and removal of Cu2+,CODcr,ammonia nitrogen and total phosphorus in sewage together than the removal rate of single removal is decreased,CODcr removal rate is not very different.(3)The use of joint dosing method for the city of sewage Cu2+,ammonia nitrogen and phosphorus removal is more effective,potassium ferrate assists to deal with2nd standard of sewage treatment plant not only can strengthen the removal of heavy metals and organic from a certain extent,and also be able to effectively improve the removal efficiency of total phosphorus and ammonia nitrogen in water.Ammonia nitrogen and organic matter enhance the role of the removal of heavy metals,total phosphorus there is no obvious impact.(4)Effluent can reach the requirement of<Discharge standard of pollutants for municipal wastewater treatment plant>(GB/T18920-2002)(heavy metal Cu (Ⅱ)0.5mg/L) level1type A standard.