Tetracycline Antibiotic Removal from Wastewater via Air-Cathode Microbial Fuel Cells

Tetracyclines are the second most used group of antibiotics in the world. This type of antibiotic has a weak attraction in the body and enters wastewater through urine and feces. This study investigated the effectiveness of tetracycline removal from wastewater by air-cathode microbial fuel cells. The current study was bench-scale experimental research as a batch mode. The anode was made of flat graphite and the air cathode was a carbon cloth with four PTFE diffusion layers with platinum cover (0.3 mg/cm2). Two similar reactors were used. The influent wastewater (500 mg/L) was injected into two reactors (one with tetracycline and the other without tetracycline). Both reactors were used in a batch mode with 1000 Ohm external impedance in 25±2 Cº via artificial wastewater. The results of the study showed that the voltage production time in the tetracycline reactor was considerably longer than the tetracycline-free reactor. The amount of COD reduction was almost similar in both reactors. Although the effectiveness of COD reduction was similar in both reactors, because the operation time for the tetracycline reactor was longer, the rate of COD removal was considerably higher in the tetracycline-free reactor. The air-cathode microbial fuel cell reactor could remove about 50% of tetracycline antibiotic from the wastewater.