Clean water reclamation from tannery industrial wastewater in integrated treatment schemes: a substantial review toward a viable solution

Abstract Amid the current state of a highly competitive world market concerned with high turnover, the tannery industries are focusing on higher production strategies to cope up with growing demand. The huge volume of consumption of fresh water by these industries for the tanning and associated processes for leather processing and discharge of contaminated toxic waste water make these industries questionable in terms of ecofriendliness and environmental sensibilities. The extremely high concentrations of TSS, TDS, chemical oxygen demand, and ions like chromium, sulfate, and chloride causes tannery waste water to be extremely hazardous for any living species. Moreover, due to high industrial reluctance and profit-focusing attitudes, most of the tannery houses are not as bothered about effective treatment of wastewater maintaining environmental regulations. That is why research was directed toward the reduction and separation of pollutants from tannery industrial liquid waste discharge. With the evolution of hybrid technologies involving low operating pressure-driven membranes, an innovative regime of process integration and technology development has started. This has grasped the devotion of scientific experts, innovators, and industrial owners. Technology transfer from pilot to industrial scale is extremely crucial in the present scenario of environmentally sensible global economic forums developing new legislation on zero-discharge strategies and the circular economy. A substantial review on integrated processes finds that a forward osmosis nanofiltration membrane-integrated system hybridized with advanced oxidation of concentrated retentate has enormous potential in clean water reclamation from tannery industrial waste discharge. Possible options of recalcitrant sludge disposals have also been reviewed critically. Thus membrane-integrated photo-Fenton treatment process technologies with environmentally benign sludge disposal could be used as the strategies of sustainable solution in a highly flexible, cleaner, modular, and more efficient, less energy consuming, compact, and small plants while assuring intrinsic safety.