An assessment of technological development and applications of decentralized water reuse: a critical review and conceptual framework

Rapid development, urbanisation and population growth have contributed to water stress in many parts of the world. As freshwater sources are finite, it is essential to source for alternatives to ensure water security. Reclamation of non-conventional water sources (i.e.: rainwater and greywater) can be a viable alternative to alleviate water stress. In this work, various laboratory, pre-commercialisation scale and commercialised products for rainwater harvesting and greywater treatment and reuse were reviewed. As a result, a conceptual framework is proposed to provide an overview on the applicability of technologies under various settings, which were mapped against the intended use of treated water and the potential for water supply expansion. This conceptual framework could aid decision makers in deciding on a suitable decentralised solution for water reclamation depending on limiting criteria. Decentralised systems of rainwater harvesting and greywater treatment for reuse are going to be crucial in reducing the dependence on the centralised water supply