Membranes Selection for Effluent Treatment with Cadmium Sulfate

摘要

The membrane process that is unitary process has grown for effluent treatment due to reduce energy consumption and to be easy operation. Polymeric materials featuring high mechanical and thermal resistance have been widely employed in membranes preparation. The present work aims to investigate the performance of commercial membranes (polyamides and cellulose acetate) on the removal of cadmium sulfate, a highly toxic contaminant, largely found in industrial wastewater generated by steel industry, galvanization and other sources. Synthetic solutions of cadmium sulfate, at concentrations 150 and 500 mg L-1, were used for membrane treatment (reverse osmosis and nanofiltration) at lab scale, concentrations, simulating processes from metal mechanics industrial wastewater. Experimental results indicated that the rejection degree for all reverse osmosis membranes were over 96%. It is important to point out that the Low Energy Reverse Osmosis polyamide membrane presented the best performance: water permeate flux (48.44 L h-1 m-2) and heavy metal removal (98%). Besides it is biodegradable and features low chemical resistance to acid solutions, due to it has special morphology to treat brackish water at a low pressure.