Reseach On Mine Water Treatment By Coagulation-Ultrafiltration Process

Mine water is produced by coal mining, mine area is also arid region, where has the phenomenon of water shortage. How to use the mine water efficiently is very significant. As a traditional treatment technology, coagulation has a good treatment effect. Ultrafiltration, a deep treatment, will optimize the index of enflluent. It is worth studing that coupling coagulation and ultrafiltration to treat the mine water. Uncontrollable factor of coagulation conditions and membrane fouling also need deep study.This research used mine water in northwest region of china. those that Analizing best condition of coagulation, the removal efficient of the coagulation-ultrafiltration coupling, the membrane flux decline, the influence of the dosage of coagulation to membrane fouling, molecule weight distribution of water and membrane fouling structure, are used to investigate the mechanism of the coagulation-ultrafiltration coupling. The results of my study are as follow:(1)In coagulation experiment, by comparing four different coagulation react with mine water in different dosage、PH、coagulation time, it can be seen that: PFS which can improve water quality is the best coagulation. The removal rates of the suspended solid and COD are 92%,70%.COD’removal rate is low, which need remove by deep treatment. According to analize the coagulation mechanism of Zeta potential, floe form and size turns out: PFS has a better treatment efficiency. Its Zeta potential close to 0,it has bigger flocculation size and branching structure(2)In coagulation-ultrafiltration experiment, analizing transmembrane pre SSure, coupling mode, dosage of coagulant, it turns out that:30mg/L of PFC was used to treat the mine water for 1 hour, then the dead-end ultrafiltration was carried out under the pressure of 0.1MPa.this process had a better effect, the COD’s removal rate reached more than 93%,more than 99% suspended solid was removed. It also shows:Zeta potential play a decisive role in coagulation reaction, floe with more brunches can prevent membrane fouling and optimize water quality.(3)In the coagulation-ultrafiltration experiment, the study of membrane fouling and principle of membrane separation shows: cake layer resistance which is easy to be removed is the reversible resistance. The irreversible resistance which is caused by particles in the film hole is hard to be removed, this is the reason for membrane flux decline. Coagulant is in the cake layer. Hydrophilic substance which is hard to be removed influence the water quality.