A new microfiltration system with two sets of dead-end membrane cells and driven by a piston force system was designed in this study. In this system, suction of the filtrate was through the membrane in the reverse direction with a piston to backwash and reduce membrane fouling. In addition, after a few forward-reverse filtration cycles, the concentrated suspension of particles or solute on the retentate side was discharged into the stock tank under the cross flow condition. For maximizing the filtrate volume, it was found that the optimum times for forward and reverse filtration were 90 s and 3 s respectively, and the discharge frequency of retentate was 1 time per cycle. Moreover, it was also found that the filtrate volume increased with an increase in particle size and membrane pore size but decreased with an increase in feed concentration. Furthermore, an optimal filtrate volume existed on effecting the pressure drop. Finally, it could be used efficiently to treat and recycle the backwash wastewater from a rapid sand filter by a membrane with pore size of 0.1 and 0.22 μm.

This content is only available as a PDF.
You do not currently have access to this content.