Continuous foam fractionation of chromium(VI) ions from aqueous and industrial effluents

Abstract

AbstractThe purpose of this study was to investigate the use of foam fractionation to recover Cr(VI) ions from simulation aqueous solution and tannery effluent. The effects of operation parameters, such as air flow rate, liquid pool height, feed concentration, surfactant concentration, pH of the feed, and feed flow rate on the separation characteristics were studied in the continuous operation. Enrichment ratios of 5.2 and 4.8 with percentage removal of 65% and 61% were achieved for the removal Cr6+ ions from simulation aqueous solution and tannery effluent on the basis of optimization of parameters, respectively. As the optimized results, the air flow rate and liquid pool height were 0.1 lpm and 30 cm, feed concentration and surfactant concentration were 10 ppm and 0.1 % (w/v), pH of the feed was 6 and feed flow rate was 4 lph. The Cr(VI) concentration in the effluent was around 0.5 ppm which could meet the Bureau of Indian standards (BIS2490) wastewater discharge standards. Box–Behnken model and Analysi...