Enhancing industries exploitation: Integrated and hybrid membrane separation processes applied to industrial effluents beyond the treatment for disposal

Facilities intended for industrial effluents treatment for only disposal are no longer interesting from an environmental and economical perspective. Rather than that, they started to be designed for by-products recovery as well. Stand-alone treatment units are often ineffective for that purpose, which led to researches that investigate integrated and hybrid treatments. It has been reviewed integrated membrane-based technologies intended for by-products recovery from industrial effluents in bench and full-scale applications. Consolidated technologies as ultra-, micro-, nanofiltration and reverse osmosis membrane have been combined with different biological and physicochemical technologies that allow for by-products recovery. It has been summarized the merits and demerits of their integration, in addition to recommendations to improve their efficiency. Besides the conventional membrane separation processes, emerging technologies as electrodialysis and membrane contactors (membrane scrubbers, membrane distillation, and membrane crystallizers) were summarized. Although considered emerging, they have a great potential to be further scale-up and combined with different processes. Aside from their performance in effluent treatment and by-product recovery, their economic viability has been discussed as well. Up-coming membrane modules combining different processes, markedly known for their small area requirement and performance improvement, were also presented. The current literature points out integrated/hybrid systems and effluents valorization as one of the alternatives to overcome the scarcity of the raw materials to be faced in a near future. However, advancements in membranes of greater resistance, lower costs, antifouling characteristics, and lower propensity for wetting would be of paramount importance to extend the application of these systems for effluents beneficiation.