Study On The Removal Effect Of Humic Acid By Coagulation Filtration And Its Combination Process

Humic acid is a kind of natural organic matter w idely existed in water environment.The existence of humic acid has a lot of influence on drinking water quality and treatment process.For example: humic acid in the water showing a dark brown,seriously affecting the color of water;humic acid chlorinate d chlorine will generate chlorinated hydrocarbons,chlorinated disinfection by-products are the main precursor.In this paper,humic acid was chosen as the research object.Four kinds of coagulants such as polyaluminum chloride,aluminum sulfate,polyferric sulfate and ferric chloride,quartz sand and activated carbon were selected respectively.Method to study the process of conventional water treatment processes and their combination of humic acid removal effect,the results show that:Coagulation sedimentation is the most effective way to remove humic acid in water.By selecting the right coagulant,control dosage and p H and other factors,most of the humus can be removed from water.Experiments show that when the control p H 6.0-8.0,the use of four conventional inorganic coagulant,in their respective best dosage,HA removal rate of up to 82%-87%.The mechanism of removing HA by four kinds of conventional inorganic coagulants is mainly that of compressive double layer and electric neutralization.The four coagulants dissolved in water have a positive charge,but the Zeta potential difference is large,so the electric coagulation and water coagulant HA optimal dosage is different.The filter has a certain effect on the removal of humic acid,the main factor s that affect the filter removal effect is the filter type and filtration rate.Sand filtration on the removal of humic acid is not good,and carbon filters can remove 30%-40% of humic acid in water.Therefore,the carbon filter is connected with the coag ulation and sedimentation,further removal of HA,reduce the by-product,to ensure the safety of water supply the last effective barrier.Coagulation and sedimentation → sand filtration → carbon filter combination process can basically remove humic acid in water,the HA removal rate of up to 98.2%.Among them,coagulation and sedimentation are the main steps to remove humic acid in water.Filtration,especially carbon filter,can further improve HA removal.Combined process can handle the water color,turbidity to drinking water quality standards to protect the chemical safety of drinking water caused by humic acid.The result of pilot test is consistent with that of lab test,and the removal rate of humic acid in pilot test is higher,which indicates that the results are reliable and can provide a reliable reference for the removal of humic acid in practical production.