Thermodynamic study of (pb2+) removal by adsorption onto modified magnetic Graphene Oxide with Chitosan and Cysteine

Abstract

A new modified magnetic Graphene Oxide with Chitosan and Cysteine wassynthesized for removing Pb2+ ions from aqueous solution. The properties of thisadsorbent were characterized by Field Emission Scanning Electron Microscopy (FESEM),Vibrating Sample Magnetometer (VSM) and Energy Dispersive Analysis Systemof X-ray (EDAX). Physicochemical parameters such as effect of pH, contact time,adsorbent dosage and initial concentration of Pb 2+ was also studied. The results showedthat the maximum capacity of absorbent in Lead ions adsorption (at Equilibriumconcentration of 120 ppm) occurred at pHOptimum= 5.75, tOptimum= 30 min andadsorbent 85.4 mg/g dosage=0.1 gr. Maximum empirical adsorption capacity (qmax) wascalculated 85.4 mg/g. The thermodynamic parameters (ΔHᵒ, ΔGᵒ and ΔSᵒ) showed thatthe adsorption process of Pb 2+ on modified magnetic Graphene Oxide with Chitosanand Cysteine was endothermic and spontaneous. Removal percentage was reduced to15% after five stages of Sorption/desorption studies. So, modified magnetic GrapheneOxide with Chitosan and Cysteine can be used as a complementary process for removalof Pb2+ ions from water and wastewater