Experimental study on integrated membrane processes in the treatment of solutions simulating textile effluents. Energy and exergy analysis

Abstract Membrane processes in the textile industry can minimize pollution phenomena contributing also to decrease energy consumption, to increase product quality and improve the overall process efficiency. In this study the energy consumption of simulated textile processes have been analyzed and compared with systems where membrane technologies have been introduced. The value of dye and salt concentration which might be reached have been tested in a reverse osmosis pilot plant. The hydrodynamic characteristics of the spiral wound modules used and evaluation of their efficiency in terms of rejection, fluxes and life time of the membranes are reported. The possibility of reaching higher concentration of chemicals by membrane distillation, using the concentrate of reverse osmosis as feed, has also been studied. Based on experimental results, an energy and exergy analysis was attempted. Substitution factors, related to the electrical energy consumption in reverse osmosis and in an integrated reverse osmosis — membrane distillation process have been calculated and compared to cycles with chemical recovery and without recovery.