Programmed Iron Oxide Nanoparticles Disintegration in Anaerobic Digesters Boosts Biogas Production

Abstract

A novel concept of dosing iron ions using Fe3O4 engineered nanoparticles is used to improve biogas production in anaerobic digestion processes. Since small nanoparticles are unstable, they can be designed to provide ions in a controlled manner, and the highest ever reported improvement of biogas production is obtained. The nanoparticles evolution during operation is followed by an array of spectroscopic techniques.

Impact of nanotechnology on biogas production: A mini-review

“…However, excess iron generates toxic free radicals as reported by Ram et al [41] for the effect of Fe 2 þ ions on the AD of organic matter in which the methane production showed a significant increase for the first 2 days upon adding 5 mM Fe 2 þ and then was similar to the control sample [41]. Casals et al [42] utilized the unique properties of nanoparticles and used iron oxide NPs, which slowly dissolve to supply the living microorganisms with the required iron ions without causing toxicity to the bacteria. Fe 3 O 4 NPs (7 nm) were added with a concentration of 100 ppm to anaerobic waste digester at mesophilic temperature (37 1C) for 60 days and the results showed a 180% increase in biogas production (see Fig.…”

“…Fe 3 O 4 NPs (7 nm) were added with a concentration of 100 ppm to anaerobic waste digester at mesophilic temperature (37 1C) for 60 days and the results showed a 180% increase in biogas production (see Fig. 16) and 234% increase in methane production, which is considered by the authors the greatest improvement to biogas production using NPs [42].…”

High‐Energy Resolution Fluorescence Detected X‐Ray Absorption Spectroscopy: A Powerful New Structural Tool in Environmental Biogeochemistry Sciences

“…This possibility is of great interest in environmental biogeochemistry because (i) the differences between spectra are often subtle and (ii) the improved resolution gives a more precise discrimination of the local structure around the absorbing atom. This possibility was, for example, fully exploited at the Fe K‐edge probing the Fe K β1,3 fluorescence line to study biomineralization processes (Baumgartner et al, 2013), to study magnetite nanoparticle evolution during conversion of biomass (Casals et al, 2014), at the Ce L III edge to characterize the behavior of cerium oxide nanoparticles in aquatic mesocosms (see below; Tella et al, 2015), or at the Hg L III edge to determine which chemical forms of Hg are present in human hair (Manceau et al, 2016). To highlight in more detail this real step forward, XANES measurements in conventional methods (transmission or total fluorescence yield measurement) and in HERFD are presented below to ascertain the valence state of Ce, in the case of biotransformation of CeO 2 nanoparticles, and the speciation of Hg bound to sulfur.…”

Understanding bioenergy production and optimisation at the nanoscale – a review

“…Fe 3 O 4 NPs (7 mm) were added with a concentration of 100 ppm to anaerobic waste digester at mesophilic temperature (37 C) for 60 days and the results showed a 180% increase in biogas production and 234% increase in methane production, which could be considered the greatest improvement in biogas production using NPs. [30] The new delivery system based on Fe 3 O 4 (magnetite) nanoparticles leads to enhanced AD, and consequently to higher methane production and organic matter processing ( Figure 5). The improved performance is due to the presence of Fe C2 /Fe C3 ions, introduced into the reactor in the form of nanoparticles in a Figure 5 .…”