Competition between methanogens and sulfate reducers: effect of COD:sulfate ratio and acclimation

Abstract

A discussion of the current understanding of the competition between sulfate‐reducing bacteria and methanogens is presented. The effect of artificially elevated sulfate and sulfide levels on anaerobic utilization of lactate was investigated using acclimated and unacclimated inoculum. The lactate degradation pathway was observed to be dependent upon the degree of acclimation to various chemical oxygen demand (COD):sulfate ratios. A ratio of 3.7 g/g resulted in a nonsulfate reducing pathway producing propionate and acetate as products, while a ratio of 1.6 g/g resulted in a sulfate reducing pathway producing only acetate as an organic product. The change in metabolic pathways dramatically changed the relative sulfide sensitivity of the methanogens and the sulfate reducers.

Effect of Sulfide Inhibition and Organic Shock Loading on Anaerobic Biofilm Reactors Treating a Low‐Temperature, High‐Sulfate Wastewater

“…At ratios less than 1.7, acetotrophic SRB were predominant, while at ratios greater than 2.7, aMA prevailed. Similar results were found by McCartney and Oleszkiewicz (1993); a ratio of 3.7 did not result in significant sulfate reduction, while ratios less than 1.6 showed evidence of sulfate reduction.…”

“…However, for a given concentration of DS, as the pH decreases the hydrogen sulfide concentration will increase, making the lower pH more likely to cause inhibition for MA. Conversely, at higher pH levels, SRB reactions become less favorable (McCartney and Oleszkiewicz 1993).…”

“…Many studies have emphasized the COD/sulfate ratio as an important operational parameter for sulfate fed systems (Choi and Rim 1991;Maillacheruvu et al 1993;McCartney and Oleszkiewicz 1993;Mizuno et al 1994;Parkin et al 1991;Weijma et al 2002). This ratio gives an indication of the amount of sulfate available for SRB metabolism.…”

Methanogens, sulphate and heavy metals: a complex system

“…Hydrogen sulphide can diffuse across the cell membrane and is responsible for protein denaturation, enzyme inhibition, and interference with the sulphur uptake metabolism (Speece 1983;McCartney and Oleszkiewicz 1993;Chen et al 2008). From an operational point of view, hydrogen sulphide causes malodour and corrosion problems (Colleran et al 1995).…”

Produção de biogás a partir de glicerol oriundo de biodiesel

“…São elas: ácidos graxos de cadeia longa (AGCL) (SHIN et al, 2003;HWU et al, 1998;HWU et al, 1996;ANGELIDAKI & AHRING, 1992;KOSTER & CRAMER, 1987), cloretos (RIFFAT & KRONGTHAMCHAT, 2006;VIJAYARAGHAVAN & RAMANUJAM, 1999;KARGÌ & DINÇER, 1999), sulfatos e sulfetos (HULSHOFF POL et al, 1998;MAILLACHERUVU & PARKIN, 1996;McCARTNEY & OLESZKIEWICZ, 1993).…”