| The combined MBR-RO pilot system, using A２/O-MBR technology as a pre-treatment process, has been set up for the direct municipal wastewater treatment and recovery. The objective of this pilot study was to further investigate the feasibility of MBR system as a pretreatment process for RO permeation, estimate the MBR-RO process to produce high grade effluent, and evaluate the different pre-conditions affecting the RO permeability and bio-fouling. The results showed that the average RO permeate qualities were as TOC<1.3 mg/Ｌ, NH＋４-N<0.03 mg/Ｌ, TN<0.1 mg/Ｌ and not detectable for TP, in terms of conductivity<30 μS/cm and turbidity<0.12 NTU, and complete inorganic irons rejection could be achieved with the lowest concentration, thus the grade of RO effluent could meet the drinking water standard. MBR technology was suitable as a pre-treatment process for RO in the MBR-RO process and thus no severe RO bio-fouling occurred during the whole study period of 6 months. |
