Thermodynamic study of (pb۲+) removal by adsorption onto modified magnetic Graphene Oxide with Chitosan and Cysteine

A new modified magnetic Graphene Oxide with Chitosan and Cysteine wassynthesized for removing Pb۲+ 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 ۲+ was also studied. The results showedthat the maximum capacity of absorbent in Lead ions adsorption (at Equilibriumconcentration of ۱۲۰ ppm) occurred at pHOptimum= ۵.۷۵, tOptimum= ۳۰ min andadsorbent ۸۵.۴ mg/g dosage=۰.۱ gr. Maximum empirical adsorption capacity (qmax) wascalculated ۸۵.۴ mg/g. The thermodynamic parameters (ΔHᵒ, ΔGᵒ and ΔSᵒ) showed thatthe adsorption process of Pb ۲+ on modified magnetic Graphene Oxide with Chitosanand Cysteine was endothermic and spontaneous. Removal percentage was reduced to۱۵% after five stages of Sorption/desorption studies. So, modified magnetic GrapheneOxide with Chitosan and Cysteine can be used as a complementary process for removalof Pb۲+ ions from water and wastewater.

Keywords:

Magnetic Graphene Oxide , Surface modification , Nanoparticles , Removal of lead , Adsorption thermodynamics