Treatment of Municipal Wastewater by Membrane Processes

Industrialization, population growth, and urbanization are the main causes for the generation of increasing quantities of municipal wastewater (MWW) which, untreated, pose a serious threat to natural aquifers. In order to protect the environment and natural resources, it is necessary to use high-efficiency and environmentally friendly technologies for the treatment of MWW. The goal of this work was treatment of MWW with advanced membrane processes; membrane bioreactor (MBR) and nanofiltration (NF) and reverse osmosis (RO). Laboratory and pilot treatment of MWW with MBR resulted in a reduction of more than 92 % in chemical oxygen demand (COD), biochemical oxygen demand (BOD5), turbidity and suspended matter. The number of microbiological parameters decreased by 4.12 log(10) to 4.88 log(10). Subsequent treatment of MBR effluent with RO/NF membranes (XLE and NF270) further reduced all measured parameters.