Characterisation of Biochar Obtained from Organic Material and its Application for Removal of Ciprofloxacin

Abstract

Ciprofloxacin is the second generation of quinolone antibiotic used to treat infections in living beings. After using this antibiotic, some percentages of the compound are not metabolized in the body and is excreted along with the urine and excreta. This will reach the treatment plant and the conventional treatment methods are not designed to treat these micropollutants, so it is released into the environment. The presence of ciprofloxacin is detected in surface water samples collected from different areas of the world. This study is conducted to find an effective adsorbent that can remove the ciprofloxacin from wastewater. Biochar produced from agricultural waste can be used as an effective adsorbent. Biochar is prepared under a process called pyrolysis which is carried out under relatively higher temperatures and low oxygen content. In this study, biochar is prepared from rice husk at different temperatures ie, 2000C, 2500C and 3000C. The adsorption experiments were conducted at the varying contact time, varying the initial concentration of biochar and varying residence time in the muffle furnace. The biochar prepared at 3000C showed 96% removal in a contact time of 90 minutes. FTIR results showed that stretching vibration of -OH group, phenolic C-OH stretch, C-O in phenol, C-H stretching vibration and C=O stretching play a vital role in ciprofloxacin adsorption. The pseudo-second-order kinetic reaction and Freundlich isotherm agreed well with ciprofloxacin adsorption process. SEM images after adsorption showed a drastic change in the surface morphology of the rice husk biochar.