Potential elimination of diclofenac sodium (DCF) from aqueous solution by adsorption using orange peel waste-based activated carbon
摘要
In the environment, residual pharmaceuticals are a type of developing pollutants that damage human health. One of the famous widely produced and used anti-inflammatory drugs globally is diclofenac sodium (DCF), which is commonly found in water bodies. Among the water treatment processes, adsorption is an easy and efficient process. Recently, bio-based carbons obtained from eco-friendly biomass materials have received considerable attention. In the current work, a novel orange peels activated carbon (OPAC) was prepared and examined as an adsorbent to remove DCF from aqueous solution. Initially, OPAC was characterized by determining its physio-chemical properties. It clear that OPAC exhibited notable characteristics like high specific surface area of 779.05 m2 g−1, mesoporous structure and acidic properties. During adsorption procedure, the best operating conditions for DCF elimination by OPAC were pH 6, contact time of 25 min, temperature of 25 °C, biosorbent dose of 200 mg L−1 and initial concentration of 25 mg L−1. The Langmuir isotherm model fitted better the experimental data than Freundlich model. The adsorption capacity determined by Langmuir model was qe = 91.31 mg g−1. The DCF adsorption presented a pseudo-second order kinetics and the study of thermodynamic parameters showed that the adsorption of DCF on OPAC is endothermic and spontaneous.