Removal of Cd(II) ions from aqueous solution and industrial effluent using reverse osmosis and nanofiltration membranes.

Industrial effluents loaded with cadmium have contributed to the pollution of the environment and health troubles for humans. Therefore, these effluents need treatment to reduce cadmium concentration before releasing them to public sewage. The purpose of the research is to study the major role of reverse osmosis (RO) and nanofiltration (NF) processes, which can contribute to the removal of cadmium ions from model water and wastewater from the battery industry. For this reason, two RO and two nanofiltration membranes have been used. The effects of feed pressure, concentration, ionic strength, nature of anion associated with cadmium and pH on the retention of Cd(II) were studied with model solutions. Thereafter, NF and RO membranes were used to reduce cadmium ions and total salinity of battery industry effluent. Among these membranes, there are only three which eliminate more than 95% of cadmium. This was found to depend on operating conditions. It is worth noting that the Spiegler-Kedem model was applied to fit the experimental results.