Application of adsorption process by activated carbon derived from scrap tires for Pb+2 removal from aqueous solutions

Background and Aim: Heavy metals have been recognized as very poisonous elements and their discharge into water sources can cause damaging effects on human and environmental health. The present study aimed at producing activated carbon from scrap tires and using it in removing Pb+2 from synthetic aqueous solutions. Materials and Methods: In this experimental study, activated carbon powder was derived from scrap tires under laboratory conditions. The effect of Pb (II) ions with the concentration 10-100mg/l, pH 2-8, contact time 3 hs , and the adsorbent dosage 0.1-0.6 g were investigated in batch adsorption system. Besides, the chemical composition and solid structure of the derived activated carbon were analyzed using Scanning Electron Microscopy (SEM) coupled with energy dispersive spectrometry (EDS). The surface area of derived activated carbon was calculated by Brunauer-Emmett-Teller (BET) and Barret-Joyner-Halenda (BJH) isotherms. The experimental data was analyzed using Langmuir and Freundlich isotherm models. Results: It was found that the main component of activated carbon was Carbon element (83.276%). BET and BJH Surface areas of activated carbon were approximately 185.046 and 146.443 m2/g, respectively. It was discovered that activated carbon dosage increasing leads to decreasing in qmax , while with increasing of pH of Pb+2 ions adsorption increased. The experimental adsorption isotherm complied with Freundlich equation model (R2=0.982) and the maximum amount of adsorption (qmax) was 8.695 mg/g. Conclusion: The present study showed that derived activated carbon from scrap tires is highly effective in Pb removal from aqueous solutions. In addition, producing activated carbon from scrap tire can provide a two-fold green and cost-effective advantage and it can be a suitable recycling method for scrap tires.