Biosorption of Cd2+ using an admixture of Ulva lactuca and fly ash from coal-fired power plant

Abstract

This study investigated the adsorption of Cd2+ in a simulated wastewater using green macro alga, U. lactuca and fly ash from coal-fired power plant, individually and as an admixture (25:75, 50:50, and 75:25). The maximum adsorption capacities for 0:100, 25:75, 50:50, 75:25 and 100:0 ratios of U. lactuca and fly ash were 6.47, 6.28, 6.27, 6.19, and 6.39 mg/g adsorbent, respectively. The optimum adsorption was found to occur at an initial Cd2+ concentration of 70 mg/L at 293 K, pH 5, 120-minute contact time, 300 rpm agitation speed, and 10 g/L biosorbent dosage. The obtained results fitted well with Langmuir Isotherm, suggesting a monolayer adsorption with adsorption capacity of 6.852 mg/g adsorbent. The highest adsorption capacity was observed using fly ash while the lowest was observed using 75:25 U. lactuca to fly ash ratio.