Facile synthesis of reduced graphene oxide/carbon/calcium alginate aerogel for the removal of pharmaceutical pollutants

Pharmaceuticals are the new emerging challenge pollutants to removal from the aquatic environments. In this study, a series of reduced graphene oxide/carbon/calcium alginate (rGO/C/CA) aerogel was fabricated using an environmentally friendly freeze-drying method. The surface properties including surface textures, elemental contents, crystal structures, and functional groups of rGO/C/CA aerogel were investigated. The aerogels were utilized for the adsorptive removal of oxytetracycline (OTC) and amitriptyline HCl (AMT) drugs in contaminated aquatic environments. Results showed that rGO/C/CA aerogel had much higher adsorption efficiency of OTC and AMT compared to other pristine and binary aerogels due to the enhanced surface properties and synergetic effect of functional groups. The equilibrium data were best fitted to the Toth isotherm model for both OTC and AMT and the mathematical interpretation of fitting data suggests a monolayer adsorption for both drugs. The results demonstrated that rGO/C/CA aerogel could be a reusable adsorbent for eliminating wastewater related pharmaceutical pollutants.