The Impact of the Bisubstituted Aromatics Functional Groups on the Inhibition of Methane Biosynthesis (Biogas)

Abstract

Inhibitory compounds are often found to be the leading cause of anaerobic reactor upset and failure since they are present in substantial concentration in wastewaters and organic solid wastes. Among these inhibitory compounds, organic compounds are mentioned and more especially aromatic compounds. The purpose of this work was to evaluate the effect of bisubstituted aromatics functional groups on the methanogenic inhibition. The toxicity to acetoclastic methanogenic bacteria has performed in serum flasks, utilizing digested pig manure as inoculums, by measuring cumulative methane production. The results obtained indicate that some general relationships exist between the bisubstituted aromatic structures and their inhibitory effects on methanogenic bacteria. This demonstrates sufficiently that the grafting of hydrophobic or hydrophilic substituent on the benzene or monofunctional aromatic compound, make the obtained compound more or less toxic as the case and that in the same order of toxicity. A significant correlation was obtained indicating that the partitioning of bisubstituted aromatics into lipophilic membranes in bacteria may have a role in the inhibition of methane biosynthesis.

Crosslink network and phenyl content on the optical, hardness, and thermal aging of PDMS LED encapsulant

“…The percentage of water absorption of cured polysiloxane versus soaking times is plotted as in Figure 2. 17 Sulfur Dioxide Gas Permeability. 12 Moreover, PS-6HP-6 showed the lowest water absorption, which was 0.48% after 120 h. The phenyl ring is composed of relatively nonpolar bonds, thus the incorporation of polydiphenyl with polydimethyl group covering the surface of polysiloxane increase hydrophobicity of the polymer chains.…”

Electron Withdrawing Groups and Steric Effects on the Methanogenic Toxicity

“…The mechanism of action of aromatic compounds on the MT had been explained by their absorption on the cellular membrane of methanogenic bacteria and the modification of cellular diffusion that can lead to superficial tension change [13,17]. However, recently [14,19], It has been reported that this mechanism of action could also be explained by the disturbance of interactions between Coenzyme M (within the methanogenic bacteria) and the acetate substrate (from the decomposition of organic matter).…”

“…However, the aromatic compounds founded in agricultural and industrial organic waste constitute a limiting process factor [11][12][13].…”

Semi-empirical Approach on the Methanogenic Toxicity of Aromatic Compounds on the Biogas Production

“…However, several parameters, namely : temperature, pH and potential of the environment, the tightness, cost and permanent monitoring of the digester, the nature of the substrate and the presence of inhibiting substances in the substrate to be biomethanized, limit the development of this technology, by blocking the biological activity of the archaeous plants [3][4][5]. Of all these parameters, the presence of inhibiting compounds, especially aromatic compounds, is currently one of the main causes of malfunction of this technology, as these compounds are naturally present in most organic waste and industrial effluents [6][7][8][9]10].…”