A study on submerged rotating MBR for wastewater treatment and membrane cleaning

摘要

A submerged rotating membrane bioreactor (SRMBR), with a rotatable, rounded, flat-sheet Poly(vinyldiene fluoride) (PVDF) membrane module fixed on hollow axes and moved by an electromotor, was used for wastewater reclamation. It was found that the effluent COD became stable and lower than 20 mg/L after one day running. The equilibrium permeate flux increased from 42.5 to 47.5 L/m2·h with the rotation speed increasing from 15 r/min to 25 r/min. Prolonging relaxation time could alleviate membrane fouling and enhance the flux. Finally, membrane cleaning was studied. The results showed that flushing the membrane surface with water, water/NaOH and water/NaOH/HCl recovered permeate flux to 48.4%, 83.5% and 90.2% of that of the initial operation, respectively.