Anaerobic digestion of high-sulphate-content wastewater from the industrial production of citric acid

Abstract

The start-up and steady-state operation of a full-scale fixed bed digester treating citric acid production wastewater with an estimated COD/sulphate ratio of approximately 4 are described. Parallel studies at laboratory-scale with two reactors, one of which received the same high influent sulphate concentration as the full-scale plant, confirmed the finding that methanogenesis was not inhibited by the level of sulphate reduction shown to occur. After long-term operation on a high sulphate influent, the retained biomass in the laboratory and full-scale reactors displayed a very low specific methanogenic activity against propionate and butyrate. Since propionate and butyrate were barely detectable in the effluents at steady-state, their oxidation under high influent sulphate conditions may be completely or incompletely mediated by fatty-acid-utilising SRB.

Investigation of the diversity of homoacetogenic bacteria in mesophilic and thermophilic anaerobic sludges using the formyltetrahydrofolate synthetase gene

“…In-vial acetate and % biogas methane concentrations were determined by gas chromatography, as described previously (Colleran et al 1994). and aligned using CLUSTALX (Thompson et al 1997).…”

A mathematical model of a high sulphate wastewater anaerobic treatment system

“…While only a few full scale plants treating high sulphate streams exist (Colleran et al, 1994;Scheeren et al, 1992;Barnes et al, 1992), numerous laboratory and pilot plant studies have been done. have been shown to be suitable for sulphate reduction.…”

Nitrogen removal performance of a hybrid anammox reactor

“…The support matrix region retains the suspended sludge within the reactor and treats the wastewater through the activity of the biofilm developed on the packing mate- rial. Although the hybrid reactor design has been successfully applied to the treatment of several wastewaters (Colleran et al, 1994;Ozturk et al, 1993;Borja et al, 1995), there are no studies of its application to the anammox process.…”