Techno-Economical Investigation of Rifampin Antibiotic Removal from Aqueous Solution Using Electrocoagulation Process

Antibiotics, which are extensively produced and used all over the world, are considered as emerging contaminants. These organic compounds cannot be efficiently removed by traditional methods applied in wastewater treatment plants. Continuous discharge of antibiotic-containing wastewaters into the aquatic environments can lead to long-term adverse effects on aquatic life and human health. Rifampin is the most widely used antibiotic for treatment of tuberculosis. For this reason, its removal from water and wastewater is of high importance. Electrocoagulation is an advanced treatment method which has been effectively applied for removal of complex organic compounds such as chemical drugs. The main aim of the present study is to investigate the techno-economic aspects of the EC process for removal of RIF antibiotic from aqueous solution. In this study, effects of different parameters including initial pH, voltage, stirring speed, initial RIF concentration, reaction time, inter-electrode distance (die), shape of electrodes and their arrangement inside the reactor were evaluated on RIF removal efficiency using the EC process and its operating costs. The EC process was induced in batch mode using a 1 L reactor and synthetic RIF containing solution. The experiments were designed by one-factor-at-a-time method and relative standard deviation was used to compare the grade of the effect of the parameters on removal efficiency and operating costs of the process. Based on the obtained results, under optimal conditions, i.e., initial pH of 5, die of 1 cm, voltage of 20 volt, stirring speed of 200 rpm, initial RIF concentration of 10 mg/l, reaction time of 30 min and hole-punched shape electrodes in horizontal arrangement, the removal efficiency and the operating costs of the process reached about 92.49% and 89 US$/kg RIF removed, respectively. According to RSD values, among all the parameters investigated, reaction time, initial RIF concentration, voltage and initial pH were distinguished as the most effective ones on both RIF removal efficiency and operating costs. Generally, results of the study showed that the EC process has a high ability for removal of RIF antibiotic from water.