Removal of chromium ions from waste waters using reverse osmosis AG and SWHR membranes

The aim of this work is to investigate removal of chromium from waste waters. The effect of pH and concentration of the feed water and operating pressure on the chromium rejection were also investigated. In the study; the reverse osmosis (RO) technique and the sea water high rejection (SWHR) and high rejection brackish water (AG) membrane were used for the separation process. Results of the study indicated that chromium rejection mostly depends on the membrane type, pH of the feed water and operating pressure. Also pH of the feed water was found to be 3 for the effective removal of chromium. Furthermore the rejection efficiency of the membranes was found to be in the order of AG > SWHR. For two membranes, chromium rejection increased with increasing operating pressure. Finally, waste water sample containing 7542 mg/L (with 100 mg/L) of chromium was treated by using RO technique with AG membrane. RO could be efficiently used (with >91% rejection) for the removal of chromium from waste water sample.