Meeting growing demand for fresh water requires that every drop count
Increasing human population, industrialization, and expanding agriculture are all putting strains on fresh water resources. Populations have expanded into water stressed areas, while even water rich regions are finding the demands on water resources are increasing to the point of strain.
Responsible water stewardship requires all users of water to make every drop count. Industries are looking for ways to use water several times before discharge, to reduce their water footprint to a minimum. Municipalities, particularly in water strained areas, are also looking to process water for reuse, primarily for non-potable uses such as irrigation and agriculture that don’t require potable levels of treatment. Some areas are even exploring the idea of direct potable reuse, recognizing that wastewater treated to discharge levels is often more pure than the receiving stream, requiring less treatment than raw water pulled from downstream.
Reuse just makes sense. It reduces the demand for additional water resources and is often more cost effective than treating a raw water resource. After treating a waste stream to discharge level, it may require significantly less energy and additional treatment to bring it to a reuse level than to treat a raw water stream, making reuse not only environmentally responsible but cost effective. Reuse reduces carbon footprint as well as water footprint.
While the exact reuse treatment requirements depend upon the waste stream and the reuse purpose, to be cost effective, the treatment must be energy efficient and have a high water yield. Reuse generally requires advanced treatments such as membrane filtration or reverse osmosis, combined with disinfection or advanced oxidation.