Adsorbent Prepared From Waste Pomelo Peel and Its Adsorption of Pb~(2+) in Wastewater

A kind of adsorbent prepared from pomelo peels using the zinc chloride activating method was used in laboratory to test its capability of removing Pb2+ from wastewater and to study effects of pH of the wastewater,duration of exposure,dosage of the adsorbent,initial concentration of Pb2+ in wastewater,and temperature on the capability,and kinetics and laws of the adsorption as well.Results show that the effects of these factors enumerated above were significant.The optimal conditions for the adsorption were found to be 5.3-6.5 in initial pH of the wastewater,1.5 h in duration of exposure,10 g·L-1 in dosage of the adsorbent,100 mg·L-1 in initial Pb2+ concentration of the wastewater,and 30 ℃ in temperature.Under the circumstance,the adsorbent could remove more than 90% of the Pb2+ from the wastewater.Its Pb2+ adsorption kinetics tallied with the second-order reaction equation and its adsorption isotherm could well be described with the Langmuir,Freundlich and Temkin models.