Removal of Lead From Aqueous Solutions by A Novel Gel Adsorbent Synthesized from Condensed Tannin

摘要

A novel gel adsorbent was synthesized from natural condensed tannin and lead removal from aqueous solutions was performed using this adsorbent.It was found that lead removal was strongly affected by pH.Within pH range of 2-6,when initial lead concentration was 100 mg/l,removal efficiency was more than 90% and distribution within 150 minuts.The adsorption isotherm was described with Langmuir Equation well and the gel adsorbent had the saturated adsorption uptake of 190 mg/g dry adsorbent.The process was exothermic and the adsorption heat was up to 38.4 kJ/mol.It was concluded that possible adsorption mechanisms were ion exchange,hydrolytic adsorption and surface precipitation.