Removal of Pharmaceutical Residues from Wastewater using Activated Carbon from Rice Husks

Abstract

The presence of pharmaceutical residues in discharges that end up in rivers is a growing concern for the disruption of aquatic ecosystems and human health. The risk of exposure to these medical wastes becomes greater because they are not biodegradable even after sewage treatment. This study aimed to remove trimethoprim (antibiotic), paracetamol (painkiller), and nevirapine (anti-retroviral) from wastewater using activated carbon made from rice husks, an agricultural waste that was investigated as a potential adsorbent. The instrument used for analysis was a liquid chromatography-tandem mass spectrometer (LC-MS/MS). The powdered carbon of rice husks was carbonated at a temperature of 500oC and then activated by phosphoric acid to increase its porosity. After activation, it was successfully characterized by the use of Scanning electron microscopy which showed irregular cavities with open fine pores. Fourier transform infrared showed different functional groups which determined adsorbent- adsorbate interactions while X-ray diffraction revealed amorphous particle arrangement. The effects of the adsorbent dose, contact time, pH, and initial drug concentration were studied. Freundlich and Langmuir's isotherms were used in the evaluation of adsorption phenomena. Thus, obtained results showed that rice husks activated carbon is an effective adsorbent.