"Chris Morrow, a third-year doctoral student at the University of Southern California, is studying low-energy potable reuse through osmotic membrane bioreactors coupled to membrane distillation. His work couples two waste products, waste heat and wastewater, to produce a drinking water quality product with minimal external energy supply.
'We are seeing increased water stress all over the world, particularly in urban areas, and wastewater reuse has the potential to fill the gap,' Morrow said. 'This research is important because it provides a low-energy alternative to conventional wastewater reuse that is energy intensive. This technology has the potential to not only increases domestic water supply, but also to protect the environment by decreasing water withdrawals.' "
See full text here: https://www.wateronline.com/doc/changing-membranes-and-the-future-of-water-0001