Treatment of effluent from wastewater treatment plant with PAC-MBR process

A submerged-flat membrane bioreactor with powdered activated carbon(PAC) addition was used in secondary effluent treatment.The performance of this hybrid system,the effect of PAC on removal efficiency of pollutants,fouling of membrane and sludge characteristics were investigated.It is found that more than 60% TOC,95% NH+4-N and 98% turbidity in influent are removed under condition of a low TOC loading 0.014 kg/(kg·d).Parallel experiments show PAC increases organic removals significantly however has no visible influence on NH+4-N and turbidity removals.Meanwhile,at constant flux,the TMP(trans-membrane pressure) increasing rate of the membrane bioreactor system can be delayed by powdered activated carbon addition.Quantitative calculations show the polarization layer resistance and the total resistance of membrane are decreased about 40.5% and 17.4% respectively.Analyses were then made from various aspects such as sludge conformation,sludge viscosity and specific oxygen uptake rate to elucidate the major factors giving rise to performance of system.