Research recap of membrane technology for tannery wastewater treatment: a review

As a highly complex aqueous effluent, tannery wastewater from leather industry should be treated appropriately before discharging into the environment. Membrane technology has been shown to be a promising approach for tannery wastewater treatment as it may achieve “Zero Liquid Discharge (ZLD)”. This work, as the state-of-the-art, attempts to review the world-wide research trends of membrane technologies, the technical recapitulation and recent advances of such technology for tannery wastewater treatment. Generally, manufacture membrane, membrane-based integrated process, MBR, NF, UF and RO are the hotspots in this field. Details of different membrane technologies configured for tannery wastewater treatment, such as membrane materials, scale, membrane modules, operating conditions and removal efficiency of pollutants, are also summarized. It should be noted that membrane fouling is still a major challenge in the membrane technology during tannery wastewater treatment. Therefore, process coupling, either within diverse membrane technologies or between membrane and non-membrane technologies, is considered as a promising alternative to treat the leather tannery wastewater in the future. Graphical abstract