It is proposed to use Membrane Bio-Reactor (MBR) system working on the principle of filtration of activated sludge through the concept of using flat sheet type or hollow fibre type submerged membrane modules in bioreactors. The membranes in a MBR system are made from polymeric organics (PVDF, PE or PES) and assembled into units (modules, cassettes, stacks) with high packing density. Raw wastewater pre-treatment is important to sustain stable MBR performance and fine screening is essential operation.