Effect And Mechanism Of Iron And Manganese Preoxidation On The Improvement Of Alga-Containing Water Ultrafiltration Treatment

Algal blooms serious in recent years in natural water,the lake water and reservoir water are the main water source of water,so the water containing algae processing problem is necessary to consider water plant operations.Recently,the regular algea-water treatment include oxidation and ultrafiltration.In this paper,starting from the conventional oxidant potassium permanganate,combined with ferric and manganese,to study the efficiency of its combined system in the treatment of alga-containing water.At the same time,the efficiency of ferrate combined with ferric and manganese was studied.In addition,the process and ultrafiltration process were combined to study the treatment efficiency of algae water.Through experiments,it was proved that KMn O₄/Fe SO₄,KMn O₄/Mn SO₄,KMn O₄,K₂Fe O₄/Fe SO₄,K₂Fe O_/Mn SO₄,K₂Fe O₄can reduce the humic acid and fulvic acid in the prophyalgal solution,and release a lot of organic matter and increase DOC by oxidation.At the same time,the system releases more proteins.By the function of Mn SO₄ and Fe SO₄,the protein content decreases,which is due to the flocculation which removes part of the protein.Combined with the ultrafiltration process shows the same characteristics.All systems can increase Zeta potential and strengthen flocculation.KMn O₄/Fe SO₄,KMn O₄/Mn SO₄,KMn O₄,K₂Fe O₄/Fe SO₄,K₂Fe O₄/Mn SO₄ and K₂Fe O₄ systems will form a concentrated and stable bimodal structure with the increase of concentration.Observe the reaction samples.Significant flocs can be observed and the flocculation effect is promising.MnSO₄ and FeSO₄ have little damage to cells.At low concentrations,KMn O₄/Fe SO₄,KMn O₄/Mn SO₄and KMn O₄ damage algal cells slightly.With the increase of concentration,the damage degree increases.K₂Fe O₄/Fe SO₄,K₂Fe O₄/Mn SO₄ and K₂Fe O₄systems damage cells,and the degree of damage increases with the increase of concentration.MnSO₄ and FeSO₄ can reduce disinfection by-products,but the effect is limited.KMn O₄/Fe SO₄,KMn O₄/Mn SO₄and KMn O₄,K₂Fe O₄/Fe SO₄,K₂Fe O₄/Mn SO₄ and K₂Fe O₄ system can effectively reduce the contents of trihalomethane,haloacetic acid,halogenated ketone,halogenated aldehyde,halogenated acetonitrile,halogenated nitromethane.However,some other disinfection by-product precursors are generated due to oxidation and decomposition in system,so new haloacetic acid and haloacetonitrile disinfection by-products will be generated.Combined with the ultrafiltration process shows the same characteristics.Compared to the pure flocculation,combination systems show better performance,but because of the combination system generates a loose filter cake layer,the resistance of the formation of filter cake resistance is reversible,therefore combination system can effectively extend the service life of membrane to reduce the cost,actually.Choose one membrane of each system as the representative of the samples were characterized,potassium permanganate system formed in the membrane surface,we found that the filter cake layer more rough,Fe SO₄ and Mn SO₄ formed a relatively smooth filter cake layer,high-speed rail system formed set of filter cake layer is smooth,this is because compared with manganese oxide,iron oxide particle size smaller,The resulting filter cake layer is denser,so the surface is smoother,but it has more internal pores,and the performance of the filter cake layer is also better.