Investigation of the potential effect of encapsulated metal nanoparticles on enhancement of thermophilic anaerobic digestion

Abstract

Then, these 7 NPs were tested first in batch experiments with acetate as a carbon substrate for bio-methane production. Ni/SiO2 and Co/SiO2 showed the best enhancement of methane production from acetate. From this part, both NPs were tested for bio-methane production on two different substrates: starch and glucose. With the starch substrate, the improvements of methane production were equal to 47% and 22%, respectively, for Ni- and Co/SiO2 compared to control sample. In the last part of this work, the influences of NP concentration and thermal pre-treatment applied to the NPs on bio-methane production from glucose were investigated. The results showed that all forms of nickel and cobalt NPs enhance the methane production, and their effect increased with the increase of their concentrations. The best sample was the calcined nickel NPs at a concentration of 10–4 mol L–1, leading to a methane production rate of 72.5% compared to the control.

Keywords

• nanoparticles
• heavy metal
• anaerobic digestion
• methane production
• hydrogen
• sol-gel process