[Effects of soluble microbial product on the performance of submerged membrane bioreactor].

The behaviors of soluble microbial products (SMP) and SMP effects on an operational process of submerged membrane bioreactor (SMBR) were studied. Within 90 days performance period, total organic carbon (TOC), molecular weight distributions (MWDs), specific oxygen uptake rate (SOUR)were periodically monitored. The dead-end filtration tests were used to indicate the SMP effect on membrane fouling. Experiment results showed that the concentration of SMP in SMBR supernatant obviously accumulated. As the operation time was prolonged, the concentrations of SMP with MW > 10,000 remarkably increased in SMBR supernatant. Compared with the SMP of MW < 1,000, the SMP with MW > 10,000 obviously affected sludge activity and membrane fouling, but did not significantly influence the SMBR effluent.