Recycling/reusing grey water and yellow water (human urine): motivations, perspectives and reflections into the future

Baykal A. B.

DESALINATION AND WATER TREATMENT, vol.172, pp.212-223, 2019 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 172
  • Publication Date: 2019
  • Doi Number: 10.5004/dwt.2019.24667
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.212-223
  • Istanbul Technical University Affiliated: Yes


Stream segregation is a recent domestic wastewater management approach which while providing pollution control offers a new approach to valorization of domestic wastewater as a source. Grey water (wash water from household use which excludes toilet wastes) and yellow water (human urine) are two of the streams which result from segregation of domestic wastewater at their points of generation. After proper treatment, grey water may be returned to almost any point in the water cycle to be recycled for a number of purposes, while human urine may be used as an alternative source of fertilizers for recycling nutrients. Only through recycling grey water for flushing, 25% of daily water use will be speared; while recycling nutrients in urine can provide about 30% of the fertilizer demand. Application of this technically and environmentally promising approach also requires economic and social acceptance to be claimed as a sustainable practice. Work undertaken so far reveals that this is a promising option also from the perspective economic and social acceptability. Recycling and reuse of grey water and yellow water may indeed contribute to more efficient use of water resources/pristine water, food security and sustainability for the current and future welfare of mankind.