ABSTRACT
The past few decades have witnessed greywater (GW) as a growing water source for sustainable water management. Existing GW treatment and reuse systems in developing countries are designed in a decentralized fashion with direct access to household occupants. Different reuse standards for potable and nonpotable use have been identified by other countries based on the treatment scheme available. Every individual technology has its pros and cons in treating GW, and hence the hybrid treatment scheme has been proposed recently to meet the GW reuse standards. The selection of an optimum technology for GW treatment and reuse depends on multiple factors like the type of GW, scalability, availability of land, operational cost, and so on. To implement this technology at an industrial scale, it needs to be both energetically and economically feasible. Thus, this chapter initially focuses on the transition from centralized to decentralized water management systems in treating GW. The first section of the chapter describes the characteristics of GW, followed by the reuse standards and conventional treatment technologies. Finally, state-of-the-art sustainable technologies for treating and recycling GW are highlighted.
