Potential of aerobic membrane bioreactor for recycling and reuse of domestic wastewater for irrigation

This paper explored the positive attributes of aerobic membrane bioreactor for recycling and reuse of domestic wastewater for irrigation. For this purpose, performances of two different full-scale treatment plants, one designed as aerobic membrane bioreactor (AMBR) equipped with a hollow fiber membrane with a nominal pore size of 0.03 μm, and the other, as a conventional nitrogen removal activated sludge plant with pre-denitrification (A2O) were evaluated and compared. The effluent of the A2O system included an average of 109 mg L−1 chemical oxygen demand (COD), 32 mg L−1 total suspended solids (TSS) and 17 mg L−1 of total nitrogen. The AMBR system was able to reduce the effluent COD level to 24 mg L−1, obviously with lower TSS and turbidity. The effluent quality of the AMBR was in compliance with irrigation water standards; its nitrogen content should be evaluated as an added nutritional value for most plants. Considering the additional profit of the recovered water, the investment and operational costs of A2O and AMBR processes were compatible. The results underlined the merit of AMBR process, especially in low populated areas also requiring resources for irrigation.