Optimization bio-nest coupled microbial fuel cell performance using Taguchi and response surface method on purifying eutrophic water.

Abstract

The bio-nest coupled microbial fuel cell is designed to transform chemical energy into electricity serving to purify river water pollutants. In this study, we utilized the river water adjusted to 15 mg/l for TIN, 7.5 mg/l for NO3-N, 7.5 mg/l for NH4-N, and 150 mg/l for COD concentrations. Within the anode chamber, uniformly mixed poly3-hydroxybutyrate-co-3-hydroxy, activated carbon, pyrite, and sponge iron particles were used. Our study focuses on the optimization of parameters by employing Response Surface Methodology and the Taguchi methods. We examined the factors of pH, hydraulic retention time (HRT), and dissolved oxygen (DO) on the removal efficiency of the responses nitrate, nitrite, ammonium, total inorganic nitrogen (TIN), and COD. The selected desirability was 0.921 with removal efficiencies 71.2% for NO3-N, 100% for NO2-N, 95% for NH4-N, 99.6% for TIN, and 84.3% for COD while the factors were at 8 mg/l DO, at pH 8, and a 72-hour HRT. Furthermore, we achieved a maximum voltage output of 334 mV while the COD concentration was 225 mg/l. The model initiates nitrification and heterotrophic or autotrophic denitrification to mitigate the pollution. Notably, the developed system reduces construction, installation, and operational costs while enhancing both bioelectricity generation and pollutant removal efficiency.