Removal of Sulfamethoxazole, Sulfapyridine and Carbamazepine, from Simulated Wastewater Using Conventional and Nonconventional Adsorbents

Abstract

The use of phosphate rock (PR), porcelanite (PC) and granite (GR) as natural locally abundant adsorbents compared with adsorption by granular activated carbon (GAC) for removing pharmaceuticals including sulfamethoxazole (SMX), sulfapyridine (SP) and carbamazepine (CBZ) from simulated wastewater was examined. The removal efficiency of the three pharmaceuticals was found to follow the consequences as: PC ˃ GAC ˃ PR ˃ GR. The uptake efficiency of sulfamethoxazole was 91.51, 86.69, 69.51 and 53.97% onto PC, GAC, PR and GR, respectively, at initial concentration, pH, dosage and temperature of 50 mg/L, 4, 0.5 g/100 mL and 30 °C, respectively. The removal efficiency of sulfapyridine was 84.71, 81.97, 63.25 and 49.71%, respectively. However, for carbamazepine it was 80.46, 79.61, 54.10 and 43.44%, respectively. Fourier transform Infrared (FTIR) was carried out for PC before and after adsorption to determine the type of functional groups. Carbonyl and hydroxyl functional groups on the surface of PC were the major groups responsible for adsorption process. The effect of pH (5, 7 and 9), agitation speed (50–300 rpm), dosage (0.1–1.4 g/100 mL), contact time (30–360 min), temperature (10–60 °C) and initial concentration (25–100 mg/L) are studied to find out the optimum conditions for removing the selected pharmaceuticals using PC. Adsorption isotherms and kinetic models had been used to fit the experimental data. From which Langmuir and pseudo-second order models were found to be more represented to the experiments with high correlation coefficient for the three pharmaceuticals.