A real trial of an innovative membrane bioreactor for saline sewage treatment

We have recently developed non-woven membrane modules to be immersed in activated sludge bioreactor for treating saline sewage. To evaluate the feasibility and energy consumption of this technology, a pilot trial of up to 7 m3/day was conducted over 270 days at the Hong Kong University of Science and Technology (HKUST). This paper reports part of the data obtained from this pilot trial. The pilot plant produced steady and good quality effl uent. The average effluent total nitrogen (TN) was 7.7 mg N/L, total chemical oxygen demand (TCOD) 27 mg/L and total suspended solids (TSS) 15 mg/L, respectively. The maximum effective permeate flux was found to be up to 6 m/d, while the air-to-water volumetric ratio could be as low as 15. The transmembrane pressure (TMP) was maintained at 0.1 bars after each backwash with around 1% of the effluent. The backwash was conducted once in 48 hrs. The membrane modules worked well without clogging for 270 days until an accidental failure of power source, which lasted for 30 hr...