Emer Colleran

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Sulphate-containing wastewaters from the paper and board industry, molasses-based fermentation industries and edible oil refineries present difficulties during anaerobic treatment, leading to problems of toxicity, reduction in methane yield, odour and corrosion. The microbiology and biochemistry of dissimilatory sulphate reduction are reviewed in order to(More)
A region of the IncHI2 plasmid R478, encoding the phenotypes of tellurite resistance (Ter), phage inhibition (Phi), and colicin resistance (PacB), was cloned and sequenced. Analysis indicated seven open reading frames (ORFs), whose genes were designated terZ, -A, -B, -C, -D, -E, and -F. Five of these predicted ORFs (A to E) had extensive amino acid homology(More)
This paper reviews some of the key wastewater composition parameters, which influence the biological removal of phosphate from wastewaters, such as COD content, volatile fatty acid (VFA) content, cation concentration, phosphorus load, pH and food to microorganism ratio. The discussion also focuses on operational parameters affecting successful nutrient(More)
The diversity, population dynamics, and activity profiles of methanogens in anaerobic granular sludges from two anaerobic hybrid reactors treating a molasses wastewater both mesophilically (37 degrees C) and thermophilically (55 degrees C) during a 1081 day trial were determined. The influent to one of the reactors was supplemented with sulphate, after an(More)
Three novel ruminant-specific PCR assays, an existing ruminant-specific PCR assay and five existing human-specific PCR assays, which target 16S rDNA from Bacteroidales or Bifidobacteria, were evaluated. The assays were tested on DNA extracted from ruminant (n=74), human (n=59) and non-ruminant animal (n=44) sewage/fecal samples collected in Ireland. The(More)
This paper reviews the operation of a full-scale, fixed-bed digester treating a citric acid production wastewater with a COD: sulphate ratio of 3–4 : 1. Support matrix pieces were removed from the digester at intervals during the first 5 years of operation in order to quantify the vertical distribution of biomass within the digester. Detailed analysis of(More)
The effect of sulphate at an influent chemical oxygen demand (COD):sulphate ratio of 4 on the operational performance of anaerobic hybrid reactors treating molasses wastewater was investigated under mesophilic and thermophilic conditions in a long-term laboratory-scale study over a 1,081 day period. The presence of sulphate reduced the COD removal(More)
The IncHI2 plasmid R478, like other arsenic resistance IncH plasmids, provides increased levels of resistance to sodium arsenate (up to 100mM) and sodium arsenite (up to 10mM) to the host cell. An arsenic resistance fragment of R478 was cloned and sequenced revealing four arsenic resistance associated gene homologues, arsR, arsB, arsC, and arsH. Two other(More)
Start-up of four laboratory-scale anaerobic filters, containing clay, coral, mussel shell and plastic pall ring support materials, was achieved at a hydraulic retention time of 6 days and a constant COD loading, ab initio, of 5 kg COD.m−3.d−1 using a pig slurry supernatant feed. Start-up was most rapid with the clay filter (c. 20 days) and was slowest with(More)
Homoacetogenic bacteria are strict anaerobes capable of autotrophic growth on H(2)/CO(2) or CO, and of heterotrophic growth on a wide range of sugars, alcohols, methoxylated aromatic compounds and one carbon compounds, yielding acetate as their sole metabolic end-product. Batch activity tests on anaerobic granular sludge, using H(2)/CO(2) as a substrate and(More)