Biodegradation of carbamazepine and production of bioenergy using a microbial fuel cell with bioelectrodes fabricated from devil fish bone chars

Abstract

This work focused on developing inexpensive materials with desirable characteristics as bioanodes in Microbial Fuel Cells (MFC) for bioenergy production from the biodegradation of carbamazepine. This pharmaceutical compound is an emerging pollutant in water due to its presence in wastewater, persistence in conventional treatment plants, and widespread occurrence in water bodies. The materials were fabricated from devil fish bone chars synthesized by calcination process using a nitrogen atmosphere (BCN) and an air atmosphere (BCA). Their performances were compared with carbon felt (CF). Three cylindrical-shaped single-chamber MFC were constructed with each material and were operated with 50 mg/L of carbamazepine. Biodegradation efficiencies were estimated from the removal percentage of the carbamazepine and the chemical oxygen demand (COD). MFC electrochemical properties were characterized by linear sweep voltammetry, electrochemical impedance spectroscopy, and chronoamperometry. Biofilm formation on the materials was analyzed by environmental scanning electron microscopy. Results showed that MFC with BCN and BCA had better performance than CF. COD removal and carbamazepine biodegradation efficiencies of 87.5% and 79.58%, 81.1% and 77.88%, and 75.5% and 74.78% were obtained for BCN, BCA, and CF, respectively. Both bioanodes showed a maximum power density of 5.4 mW/m2 and Coulombic efficiency of ~14%, 210%, and ~ 116% higher than CF, an electron transfer resistance up two times lower, and a stable behavior higher than it. Micrographs confirmed the biofilm formation. Hence, these findings provide low-cost alternative materials to be used as bioanode in the sustainable construction of MFC applied to produce bioenergy and biodegrade carbamazepine.