화학공학소재연구정보센터
Chemical Engineering Journal, Vol.352, 828-836, 2018
Enhancing lead removal from water by complex-assisted filtration with acacia gum
In this work, for the first time, the use of AG as a natural, widely available and cheap material to enhance the removal of lead from contaminated water using polymer-enhanced membrane filtration (PEMF) has been carried out. In this technique, heavy metal ions are chelated with high molecular weight water-soluble polymers with following rejection of the formed polymer-metal complexes with the wide-porous and high flux polymer membranes. Acacia gum (AG) is a natural gum, which is collected from the hardened sap of some species of the acacia tree. The surface area particle sizes, zeta potential and elemental composition of AG were evaluated using BET, FE-SEM, zeta potential analyzer, EDS and XPS methods. The effect of AG dosage, lead concentration, feed pH, and contact time on lead-AG complex formation has been studied. The highest binding capacity of AG was about 12.2 mg/g when 1000 ppm AG was added to 35 ppm lead solution at pH 7. It was found that, with a dosage of 1000 mg/L of AG at pH 7, successful lead removal efficiencies of 97.5%, 98.3% and 99.9% were achieved using microfiltration polytetrafluoroethylene (PTFE), 30 kDa and 3 kDa molecular weight cut-off ultrafiltration cellulose membranes, respectively. The possible mechanism of lead removal with AG has been discussed. The obtained data have shown that AG can be used as a safe and cheap chelating agent for lead removal from water.