Fast removal of diclofenac sodium from aqueous solution using sugar cane bagasse-derived activated carbon

The production of high quality activated carbon from inexpensive, abundant and sustainable feedstocks such as agro-waste materials with improved adsorption capacity towards pharmaceuticals and personal care products (PPCPs) in wastewater has lately become one of the principal focuses in the environmental research. Herein, porous activated carbon (SCB-AC) has been produced from sugar cane bagasse, one of the most prevalent agro-waste materials in Egypt, through a facile single-step ZnCl2 activation and then used for the adsorptive removal of diclofenac sodium (DFC), as a representative PPCP, out of aqueous solution. Techniques such as XRD, Raman spectroscopy, N-2 adsorption-desorption measurements, FTIR, SEM and HRTEM have been conducted to study the structural characteristics and the surface chemistry of the synthesized SCB-AC. SCB-AC not only exhibited fast adsorption rate and high binding capacity towards DFC but also remarkable recyclability via simple washing of the DFC-saturated adsorbent with acetone. The equilibrium and kinetics aspects of DFC adsorption onto SCB-AC were explored and implied the aptness of the Langmuir and the pseudo-second-order kinetic models for interpreting the adsorption of DFC onto SCB-AC. Additionally, the influence of pH on the adsorbent surface charge and DCF adsorption capacity was investigated to reveal the presumable mechanism underlying the current adsorption process. All the results demonstrated that SCB-AC is a brilliant adsorbent for the effectual removal of PPCPs from contaminated effluents. (C) 2019 Elsevier B.V. All rights reserved.