Enhancing residue degradation and methane production from active sludge: the role of conductive nanoparticles in anaerobic digestion systems

Abstract

The effects of stepwise addition of conductive nanoparticles (n-C, n-Cu2O, n-ZnO and n-Al2O3) on anaerobic digestion (AD) performance, biogas and CH4 generation, and the removal efficiency of organic matter were thoroughly assessed. The addition of n-C and n-Al2O3 improved the removal efficiencies of total solid by 19.12% and 8.87%, volatile solid by 22.54% and 11.15%, total chemical oxygen demand by 13.6% and 6.27%, degradation efficacy by 4.87% and 2.3%, biogas yields by 20.62% and 8.27% and CH4 content by 11.49% and 8.63%, respectively. Contrarily, the addition of n-ZnO and n-Cu2O had a negative impact on AD performance and led to significant drops in the production of biogas of 34.3% and 57.3%, respectively.