Adsorptive Removal of Ibuprofen, Ketoprofen and Naproxen from Aqueous Solution Using Coconut Shell Biomass

Abstract

The use of commercial activated carbon (AC) to remove organic micropollutants from aqueous solution is expensive and unsustainable. In this study, coconut shell activated carbon (CSAC) was synthesized and applied for the removal of ibuprofen, ketoprofen and naproxen from aqueous solutions. The effects of carbonization and acid activation on the CSAC were studied using Fourier-transform infrared spectroscopy, scanning electron microscope, proximate and ultimate analyses. The influence of initial concentration (200-1000 mg/L), contact time (10-200 min), and temperature (30-60°C) was also investigated. The adsorptive capacity of CSAC for various pollutants was found to increase with concentration up to 150 min. Ibuprofen, ketoprofen and naproxen removal obeyed Langmuir (R2 = 0.9978), Temkin (R2 = 0.9551) and Freundlich (R2 = 0.9879) isotherm, respectively. The kinetic data obtained for various pollutants are best described by the pseudo-first-order model with correlation coefficient values in the range 0.96-0.99. The free energy (G) values ranged between 1.0 and 9.0 kJ/ mol for all the pollutants investigated. The mechanism of adsorption is physical, endothermic, and non-spontaneous. This study shows that CSAC is an effective alternative adsorbent for sequestering mixture of organic pollutants from aqueous solution.