Thesis (M.Sc.)--Chulalongkorn University, 2002

The objectives of this research were to investigate COD, color, TKN, and TP removal from landfill leachate by using MBR and BPAC-MBR varying at intermittent aeration time of 120-120 and 150-150 minutes. In the experimental runs, the BPAC-MBR at an intermittent aeration time of 150-150 minutes gave the best removal efficiency in terms of COD at 83%, color at 85%, TKN at 97%, and TP at 68%. The activated carbon in BPAC-MBR system also helped adsorb slowly biodegradable organic matters, increased exposure time, and reduced inhibition, which resulted in hihger substrates removal than single MBR systems. The substrates removal efficiency at an intermittent aeration time of 150-150 minutes was more than at an intermittent aeration time of 120-120 minutes. The reason might be that the microorganisms had a longer time for both aerobic and anaerobic period to treat readily biodegradable influent COD and to reduce soluble inert COD from microbial activities. The degradation mechanisms needed consecutive aerobic and anaerobic periods. Therefore, a longer intermittent aeration time could increase the efficiency for removal of substances in landfill leachate.