Long-term performance and acute toxicity assessment of scaled-up air–cathode microbial fuel cell fed by dairy wastewater

• Published in: Bioprocess and biosystems engineering 2020-09, Vol.43 (9), p.1561-1571
• Main Authors: Marassi, Rodrigo J., Queiroz, Lucas G., Silva, Daniel C. V. R., dos Santos, Fabiana S., Silva, Gilmar C., de Paiva, Teresa C. B.
• Format: Article
• Language: English
• Subjects: Acute toxicity; Biochemical fuel cells; Biochemical oxygen demand; Biotechnology; Cathodes; Chemical oxygen demand; Chemistry; Chemistry and Materials Science; Consortia; Continuous flow; Dairy industry wastewaters; Electric power generation; Energy recovery; Environmental Engineering/Biotechnology; Food Science; Fuel cells; Fuel technology; Hydraulic retention time; Industrial and Production Engineering; Industrial Chemistry/Chemical Engineering; Load distribution; Loading rate; Maximum power density; Microorganisms; Organic loading; Organic nitrogen; Organic phosphorus; Performance degradation; Phosphorus; Pollutants; Research Paper; Retention time; Substrates; Sulfates; Toxicity; Toxicity testing; Wastewater
• ISSN: 1615-7591; 1615-7605
• DOI: 10.1007/s00449-020-02348-y

Long-term performance of a scaled-up air–cathode microbial fuel cell (MFC) and toxicity removal were studied with dairy wastewater (DW) used as the substrate. The MFC in a semi-continuous flow was strategically inoculated with consortium of Shewanella oneidensis and Clostridium butyricum . The scaled-up approach delivered a maximum power density of 0.48 W/m 3 (internal resistance of 73 Ω) removing 93% of total chemical oxygen demand and 95% of total biochemical oxygen demand at organic loading rate (OLR) of 0.9 kg COD/m 3 /d and hydraulic retention time (HRT) of 21 days. It also achieved high removal efficiency of nitrate (100%), organic nitrogen (57%), sulfate (90%) and organic phosphorus (90%). The power generation and DW degradation performance decreased with OLR of 1.8 kg COD/m 3 /d and HRT of 10.5 days. Furthermore, testing of acute toxicity with the microcrustacean, Daphnia similis, revealed high toxic effect of the raw DW, but no toxic effects of the MFC effluent during 95 days of operation. These outcomes demonstrated that scaled-up MFC fed with high-strength DW should be an effective system for pollutants removal and simultaneously energy recovery.