Membranes and integrated membrane operations as clean technologies in the leather industry

The leather industry is characterized by the production of a huge amount of wastewater with a high organic/inorganic charge, causing widespread water and soil pollution. Pressure-driven membrane operations and membrane bioreactors have long been proven to be a valid approach for the treatment of tanning wastewaters aimed at the recovery of raw materials as well as for the removal of toxic and environmentally harmful substances. Such processes, opportunely integrated among themselves and/or with conventional physical-chemical and biological treatments, also provide useful protocols for the treatment of global wastewaters with significant advantages in terms of environmental protection, decrease of disposal costs, simplification of cleaning-up processes and saving of water and chemicals. This paper, as the state of the art, attempts to revise the potential and perspectives of membrane-based technologies in the leather industry with related applications in beamhouse, tanning and post-tanning operations as well as in the treatment of global wastewaters.