Technologies for urban water recycling

This paper presents a comparative analysis of 5 systems for the treatment of greywater for reuse. The systems investigated were a biological system: a membrane bioreactor (MBR), a chemical system: a membrane chemical reactor (MCR) and three constructed wetlands: vertical (VFRB) and horizontal (HFRB) flow reed beds and a green roof (GROW). The results revealed that the GROW and the HFRB achieved a limited treatment of the greywater. Alternatively, the MBR, the MCR and the VFRB achieved a good general treatment of the greywater. However, the MBR and MCR alter more significantly the solids and microbial fractions. Overall, the MBR was found to be the most suitable technology for greywater recycling due to its robustness. Indeed, the MBR constantly achieved an excellent treatment of the high strength greywater.