heavy metal removal using sno2 nanoparticles prepared in a grape extract media

Sno2 nanoparticles were first synthesized using a grape extract media, then characterized by xrd, fe-sem, tem, bet, and dls techniques, and finally used as an efficient adsorbent for the removal of pb2+ and cd2+ ions from wastewater. the prepared sample had a tetragonal phase with an average crystallite size of 41 nm (xrd analysis), a specific surface area of 47.08 m2.g-1 (bet method)/46.25 m2.g-1 (bjh method), and a pore diameter of 6.49 nm (bjh method). the best conditions for adsorbing were a 30 ppm concentration of metal ions, ambient temperature, ph of 6, and 0.025 g of an adsorbent. the maximum adsorption for pb and cd ions was 97 and 93%, respectively. the elovich model was matched as the most suitable kinetic model, indicating that the adsorption mechanism is chemical adsorption. the negative values of δg (pb: -6.38 kj.mol-1; cd: -4.16 kj.mol-1) represent the spontaneousness of the adsorption process. the negative values of the parameters δh (pb: -63.0 kj.mol-1; cd: -42.95  kj.mol-1) and δs (pb: -188.8 j.mol-1; cd: -128.4 j.mol-1) represent the exothermic nature of the adsorption.