Nitrification in a hollow-fibre membrane bioreactor Original Research Article

Partial nitrification is required before transporting secondary treated wastewater by pipe, which is common in most schemes of wastewater reclamation for irrigation. Sulfide, generated in the anaerobic conditions of the pipe, induces toxicity, corrosion and unpleasant odours. However, a low nitrate concentration (5 mg/l) enables inhibiting sulfide production. A pilot-scale hollow-fibre membrane bioreactor was tested for partial or total nitrification. Aeration in the membrane module appeared to be very important to avoid fouling of the micro-ultrafiltration membrane. This study enabled the identification of hydraulic conditions required to achieve partial or total nitrification of a real effluent. Moreover, the permeate did not contain TSS, while its organic content was very low. The results obtained can be used for implementing nitrification membrane reactors at full scale.