Tannery wastewater treatment: conventional and promising processes, an updated 20-year review

Abstract Mismanagement of various wastes especially waste water produced by tanning processes has caused serious environmental problems and ultimately impaired human health. Constant efforts have been making to alleviate the pollution tannery wastewater (TWW), yet terminal treatment still takes dominance. In this review, research on TWW from 2000 2021 was summarized, main methods such as coagulation flocculation, adsorption, biological treatment, membrane filtration, advanced oxidation process were briefly discussed. More detailed introduction given method electrochemical since it excellent performance friendliness high efficiency, hence attracting more attention in recent years. view harsh physi-chemical conditions TWW, integrated or combined are accordingly recommended with better multi-function, however comprehensive studies optimization combination cost-effectiveness needed. The certain issues that residue Cr sludge salinity effluent remain put forward work potential solutions provided. Moreover, review proposed perspective realizing recycling, intensification should be developing direction for future treatment. This is expected provide a general guide researchers who aspire ameliorate understand utilized field. Graphical abstract