Effects of electroflocculation/oxidation pretreatment on the fouling characteristics of ultrafiltration membranes

Abstract

In order to reduce the membrane pollution of ultrafiltration caused by natural organic matter and improve the treatment efficiency, electro-flocculation/oxidation is used as the pre-membrane treatment method. The membrane specific flux attenuation characteristics was compared and analyzed under the conditions of direct ultrafiltration and electro-flocculation/oxidation-ultrafiltration. Combined with the analysis of the reversibility of membrane fouling, the mechanism of electro-flocculation/oxidation pretreatment to alleviate ultrafiltration membrane fouling was evaluated, and the membrane pore clogging model was used to fit the fouling law. The results show that, in the continuously fed filtration experiment, the electro-flocculation/oxidation process involved in the pretreatment and the direct ultrafiltration membrane filtration decreased the ultrafiltration membrane flux to 79.1% and 28.5%, respectively. The reversible resistance generated by ultrafiltration and electro-flocculation/oxidation-ultrafiltration processes accounted for 37.70% and 62.26% of their total pollution resistance, whereas the irreversible resistance generated accounted for 47.30% and 12.40% respectively. Meanwhile, the direct correlation between the the flux dropped and complete clogging became less than that of ultrafiltration process. The pretreatment significantly strengthened irreversible fouling resistance of the membrane pores. The membrane permeation flux was significantly increased after the electro-flocculation/oxidation pretreatment.

Existing Filtration Treatment on Drinking Water Process and Concerns Issues

“…Unlike coagulation, the oxidation process produces a lesser amount of sludge formation. The process is useful for the removal of dissolved organic contaminants such as arsenic and humic acid [ 133 ], the same as the ozonation process [ 60 , 134 ]. The main advantage of ozonation treatment is that it does not produce any sludge, but it can cause the degradation of biopolymers and high energy consumption.…”