Environmental impacts estimation by life cycle assessment of bioanodes fabricated from devilfish bone chars and their application in microbial fuel cells to produce bioenergy

This study estimated the environmental impacts by life cycle assessment (LCA) of bioanodes fabricated from devilfish bone chars and their application in microbial fuel cells (MFC). Two types of devilfish bone chars were obtained by calcination using nitrogen (BCN) and air (BCA) as purge gases. Two bioanodes were fabricated with BCN and BCA and applied independently in MFC to produce bioenergy from ibuprofen and carbamazepine biodegradation. LCA was performed using the methodology ISO 14,040. 1 kg of fabricated bioanode and 1 kWh of produced bioenergy were the established functional units, integrating a detailed inventory of the materials’ fabrication and application in MFC. The impact assessment was made with SimaPro 9.2 software and the ReCiPe 2016 Midpoint (I) method, considering 18 impact categories. Results showed that the bioanode fabricated with BCN has less environmental impacts (1.09 times) than BCA, finding the highest impact in the categories of human carcinogenic toxicity (1.04 kg 1,4-DCB) and human non-carcinogenic toxicity (13.60 kg 1,4-DCB). The environmental impacts in MFC-Ibuprofen were 3.1 times higher than MFC-Carbamazepine in the same impact categories, with 12.76 kg 1,4-DCB and 168.34 kg 1,4-DCB, respectively. Therefore, it is recommended to use BCN to fabricate the bioanode and to apply it in MFC to produce bioenergy from carbamazepine biodegradation. Although the LCA was performed with data obtained at a laboratory level, the results provide information on the environmental impacts that could be generated if both processes are transferred on a large scale, identifying opportunities for improvement to reduce these impacts.