Biogas and methane production efficiency of sewage sludge supplemented with conductive materials

Abstract

Biogas production is one of the methods used in the recycling of sewage sludge which is a major problem for wastewater treatment plants to dispose. Methane is the most valuable content of biogas obtained from an anaerobic digestion (AD) process for energy production and accounts its 60%-70% when the AD process is operated efficiently. Recently, researches have focused on accelerating this process and obtaining much more methane content from different wastes. For this purpose, various conductive materials are used in the AD process to accelerate electron transfer between bacteria populations. In this study, granular activated carbon (GAC) and magnetite (Fe3O4) nanoparticles coated with pectin were used to determine their effects on the biogas and methane production from sewage sludge. Laboratory-scale fermentation reactors were used, and the highest biogas production and its methane content (%) were determined in the sample containing of 2.0 g-PNC/gVSS as 554.3±5.5 mL/g-dw, and 43.5±0.3%, respectively.