آب و فاضلاب (Apr 2022)
Reverse Osmosis and Nano Filtration Membranes Performance's Comparison in Assaluyeh Industrial Wastewater Treatment
Abstract
Restriction of freshwater resources is one of the major challenges that humanity has always been faced with. The use of treatment membranes in effluent recovery is one of the basic solutions to deal with this global problem. Therefore, in the present study, the performance of nanofiltration and reverse osmosis membranes in Assaluyeh industrial wastewater treatment has been compared and evaluated. The membranes used in this system are of commercial type of spiral woven polyamide. The effect of flow pressure and flow rate on the membrane permeate flux, total dissolved solids, separation efficiency percentage and membrane flux reduction have been evaluated. In both membranes, with increasing pressure from 5 to 7 bar at a constant flow rate of 720 L/h, the flux enhanced and the TDS rate decreased. The separation efficiency percentage of industrial wastewater using NF and RO membranes at optimum pressure of 7 bar was obtained 92% and 98.4%, respectively, which indicates higher RO filtration performance than NF. Increasing the flow rate from 600 to 840 L/h at a constant pressure of 7 bar improved the permeate flux for the samples. The amount of TDS with rising flow rate in NF membrane showed a decreasing and then increasing trend while in RO membrane there were slight changes. Meanwhile, the flow rate had no effect on the separation efficiency percentage of RO membrane, but in NF membrane, first an increasing and then a decreasing trend was observed. The highest separation efficiency percentage with NF and RO membranes at 720 L/h flow rate was 92% and 98.5%, respectively. The study of the effect of increasing pressure and flow rate on the percentage of flux reduction showed that in RO membrane it increases while in NF membrane this parameter depends on the result of the effect of flow rate and pressure.
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