Influence of bulk solution concentration on the operation of submerged ultrafiltration system
To study the effect of solution concentration on the operating characteristics of im-mersion ultrafiltration systems and optimize the recovery rate,this study utilized a 3 m3/h pilot-scale submerged hollow fiber membrane system to investigate the decontaminate efficiency and membrane fouling during the continuous increase in bulk solution concentration.The experimental results showed that as filtration progressed,the turbidity of the bulk solution increased approxi-mately linearly over time,but the concentration of soluble organic matter did not change signifi-cantly.The bulk solution concentration had no significant impact on the turbidity and CODMn of the ultrafiltrate permeate.When the bulk solution concentration was low(recovery＜92％),mem-brane fouling was relatively low.When the bulk solution concentration was high(92％＜recovery rate＜97％),membrane fouling increased significantly due to the increase in foulants concentra-tion.When the bulk solution concentration was further increased(recovery＞97％),a cake layer rapidly formed at the beginning of filtration,which acted as a secondary membrane.Moreover,the flocs present can also adsorb pollutants.Under the combined action of the two,although reversible pollution is greater,irreversible pollution is lighter.During long-term operation,ultrafiltration ex-hibited lower membrane fouling at a 97.5％recovery compared to a 95.0％recovery.Therefore,controlling ultrafiltration processes to operate at a high recovery may help control membrane foul-ing.
万方数据
维普
