An Appraisal of Domestic Wastewater Segregation from the Perspective of Recovery, Recycling, and Reuse

One recent sustainable alternative for domestic wastewater management is stream segregation at the source to recover, recycle, and reuse valuable materials embedded in each stream. Gray water may be treated to remove organic matter and pathogens to return the reclaimed water to almost any point in the water cycle as an alternative source of water including toilet flushing and irrigation. Yellow water may be used as a significant source of nitrogen, phosphorus, and potassium as plant nutrients to be recycled as fertilizers through direct or indirect routes. Finally, organic matter in brown and black water may be used as a source of energy or as a soil conditioner after composting. Regardless of the form of segregation, each stream presents a new concept/route in terms of recycling and reuse to enable revaluation of this “waste” stream, i.e., domestic wastewater, as a beneficial source.