Sewage from the sump enters bioreactor. Here, sewage encounters microbes in suspension with higher surface area-to-volume ratio, which oxidises the contaminants effectively. The membrane barrier separates treated water from sludge, retaining microbes in the bioreactor. This prevents washing out the microbial population and hence enhances the performance of biological process. Permeate from membrane is infused with ozone for effective disinfection. Due to the high concentration of microbes in bioreactor and precise membrane separation, BioGene System produces treated water that is significantly better than a traditional biological system and meets reuse standards consistently.