Evaluation of nano zero valent iron effects on fermentation of municipal anaerobic sludge and inducing biogas production

The application of nano size materials on wastewater is going extensive because its high reactivity compared with other materials. As a result, numerous research studies investigated the effectiveness of dosing nano zero valent iron (nZVI) or micro zero valent iron (mZVI) on anaerobic digestion (AD) of sludge and production of biogas as promising renewable energy but inconsistent outcomes have appeared. In this paper, different dosing concentrations of nZVI were applied on anaerobic activated municipal sludge to examine the impact of nZVI on sludge fermentation, biogas generation, and methane (CH₄) content stimulation. The results showed that addition 250 mg/L nZVI nanoparticles could enhance 25.23% biogas production and the methane content reached 94.05% after one week of digestion compared with 62.67% without adding iron nanoparticles.