Effect Of Dosing Coal Fines On Removal Efficiency And Membrane Fouling In MBR

Membrane bioreactor (MBR) technology is a combined process of biological treatment with membrane separation. As an efficient and feasible technology of water-reusing, it has gained consanguineous attention among scholars in the world. Using the MBR, into which coal fines was dosed, pilot scale tests were carried on to treat simulate domestic wastewater. Compared with the MBR without coal fines, the results showed that the MBR with coal fines could not only reduce the filtration resistance and keep good membrane flux, but also improve the effluent quality. Experimental results show:In the whole running of MBR, COD and NH₄⁺-N are always under 30mg/L and 5mg/L. Coal fines can not adsorb any pollutant, but it changes the character of active sludge, so the it can improve the effluent quality.When DO was 0.8¹.2mg/L, simultaneous nitrification and denitrification had removal TN efficiencies keep with more than 80% basically. When DO is conformable, the effect denitration of the MBR with coal fines is better than the MBR without coal fines.When fitful effluent changed for continuous effluent, there were not difference in membrane flux attenuation, but coal fines can reduce the filtration resistance and keep good membrane flux. No-effluent aerating were good for the comeback of membrane flux, but it is halfway. Leave unused was a little better than no-effluent aerating for the comeback of membrane flux. When the intensity of air backwash was 0.75m³/m² · h, membrane flux declined linear after air backwash if without coal fines, and membrane flux declined linear in two phase after air backwash if with coal fines. In the first phase, membrane flux declined was more slowly than in the second phase.Water wash, NaOH marinating, HCl marinating and NaClO marinating were good for the comeback of membrane flux. The effect of comeback of membrane fluxwith NaCIO was equivalent to the sum of anther there. NaCIO can remove from the organically and mineral sediment which adhere to membrane effectually, so it is a effective way for membrane cleaning.