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Batch experiments were done to assess the removal of 17α-Ethinylestradiol (EE2) using sludge acclimated from a lab-scale submerged membrane bioreactor (SMBR). Though activated sludge (AS) was found to effectively remove EE2 from wastewater, membrane bioreactor showed a faster rate of removal. Results obtained revealed that EE2 was removed completely within 18 h in SMBR while it took 96 h in AS. The removal of EE2 fits first-order rate reactions with a kinetic rate constant, k, of 0.96 d-1 and 6.96 d-1 for AS and SMBR, respectively. This showed that EE2 rate of removal using SMBR sludge is 7X faster than using AS. The role of nitrification in enhancing the removal of EE2 was investigated in terms of the effect of different initial ammonium concentration on both sorption and biodegradation. As the initial ammonium concentration is increased, biodegradation of EE2 is enhanced whereas sorption of EE2 onto the SMBR biomass is decreased. Sorption studies revealed that competition for sorption sites happened between ammonium ions and EE2. The partitioning coefficients, K D were 0.31 L (g MLSS)-1 and 0.09 L (g MLSS)-1 for SMBR and AS, respectively. These results showed that EE2 adsorbed more to SMBR sludge than to AS. Results of this study suggest that MBR improves the biological removal of EE2.

Treatment of wastewater alone using submerged MBR and without energy requirement in permeate withdrawal was investigated. The effect of organic loading rate (OLR) was determined by monitoring organic matter removal, characteristics of organic matter, nitrogen and phosphorus, and permeate flux decline. Four lab-scale subMBR were operated at HRT of 4.5, 7, 12, and 24 hours giving a corresponding OLR of 6.9, 4.5, 2.6, and 1.3 kg COD /m 3 -day, respectively. The wastewater supplied was obtained at the university's cafeteria with a COD range of 770-2050 mg/L. Regardless of high COD variations relatively stable permeates were obtained at OLR of 4.5, 2.6, and 1.3 kg COD /m 3 -day with COD Ͻ40 mg/L. HRT of 4.5 hours was too short to degrade the high organic loading supplied to the system. This resulted to accumulation of organic matter inside the reactor and relatively high COD of permeate ranging from 40-70 mg/L. Furthermore, the accumulated organic matter inside each reactor was characterized. Increase in larger molecules (0.1-0.45 m) was observed at OLR of 6.9 and 1.3 kg COD /m 3 -day, but COD and biodegradability were high at OLR of 6.9 kg COD /m 3 -day and low at OLR of 1.3 kg/m 3 day. This indicated that the accumulated organic matter in a high OLR system was due to the undecomposed matter from the influent, while the ones accumulated in low OLR system was due to the microbial by-products. Nitrates and phosphates were low at high OLR due to frequent sludge withdrawal and high at low OLR since these are released during the decay of microorganisms. Severe fouling was observed in reactor at OLR of 6.9 kg COD /m 3 -day, followed by the reactors at OLR of 4.5, 2.6, and 1.3 kg COD /m 3 -day, respectively.