Scott D.B.,University of Waterloo |
Scott D.B.,ADI Systems Inc. |
Van Dyke M.I.,University of Waterloo |
Anderson W.B.,University of Waterloo |
Huck P.M.,University of Waterloo
Canadian Journal of Microbiology | Year: 2015
The potential for regrowth of nitrifying microorganisms was monitored in 2 full-scale chloraminated drinking water distribution systems in Ontario, Canada, over a 9-month period. Quantitative PCR was used to measure amoA genes from ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA), and these values were compared with water quality parameters that can influence nitrifier survival and growth, including total chlorine, ammonia, temperature, pH, and organic carbon. Although there were no severe nitrification episodes, AOB and AOA were frequently detected at low concentrations in samples collected from both distribution systems. A culture-based presence–absence test confirmed the presence of viable nitrifiers. AOB were usually present in similar or greater numbers than AOA in both systems. As well, AOB showed higher regrowth potential compared with AOA in both systems. Statistically significant correlations were measured between several water quality parameters of relevance to nitrification. Total chlorine was negatively correlated with both nitrifiers and heterotrophic plate count (HPC) bacteria, and ammonia levels were positively correlated with nitrifiers. Of particular importance was the strong correlation between HPC and AOB, which reinforced the usefulness of HPC as an operational parameter to measure general microbiological conditions in distribution systems. © 2015, Canadian Journal of Microbiology. All rights reserved.
Allison M.,University of New Brunswick |
Singh K.,University of New Brunswick |
Bhattacharyya D.,National Institute of Technology Calicut |
Webb J.,University of New Brunswick |
Grant S.,ADI Systems Inc.
Proceedings, Annual Conference - Canadian Society for Civil Engineering | Year: 2011
The production of acrylic acid results in a toxic wastewater containing acrylic acid, formaldehyde, acetic acid and maleic acid. Acrylic acid wastewater is a product of the petrochemical industry. Treating this wastewater can be challenging. Under aerated conditions the volatile compounds are released into the atmosphere, therefore the wastewater is currently incinerated. This study aims to treat this toxic wastewater using an innovative anaerobic membrane bioreactor. The study shows the wastewater is treatable at organic loading rates up to 5 kg·COD/m 3·d. This is a high strength wastewater with an average influent COD of 85 g/L. The effluent COD was found to be below 600 mg/L. The results obtained demonstrate that 99% of COD was removed. The effluent contained no detectable acrylic acid, and formaldehyde was found typically below 1.5 mg/L. Trans-membrane pressure (TMP) is an important operating parameter when using submerged membrane bioreactors. TMP indicates fouling of the membrane, resulting in reduced flux. During four months of continuous operation at a flux of 0.2 m 3/m 2·d the TMP was found to be below 2 kPa. This indicates that the membrane bioreactor is capable of treating this wastewater at loadings studied without significant membrane fouling. The research is continuing and higher organic loading rates (7 and 8.5 kg·COD/m 3·d) are being studied. These results have concluded that the anaerobic membrane bioreactor (AnMBR) can treat wastewater from the production of acrylic acid up to a loading of 5 kg·COD/m 3·d, with COD removal of 99%.
Christian S.,ADI Systems Inc |
Grant S.,ADI Systems Inc |
McCarthy P.,ADI Systems Inc |
Wilson D.,ADI Systems Inc |
Mills D.,Kens Foods Inc
Water Practice and Technology | Year: 2011
The anaerobic membrane bioreactor (AnMBR) incorporates anaerobic digestion and membrane filtration in one process to form an innovative technology for treating high-strength industrial wastewater. The first AnMBR installation in North America, also known as the largest AnMBR installation in the world, was built at Ken's Foods in Massachusetts, USA. Ken's Foods existing anaerobic process was upgraded to AnMBR in July 2008 to treat raw wastewater from the production of salad dressings and barbeque sauces. The system was converted to AnMBR due to lack of space, positive economics, and the ability to provide additional capacity for flow and organic load beyond the original anaerobic system design parameters. This AnMBR system has a design influent flow rate of 475 m 3/d with 39,000 mg/l COD, 18,000 mg/l BOD, and 12,000 mg/l TSS. The AnMBR system consistently produces a high quality effluent with non-detectable TSS concentrations and average COD and BOD concentrations of 210 and 20 mg/l, with removals of 99.4 and 99.9 percent, respectively. The AnMBR system provides superior performance and a very low rate of membrane fouling with the aid of biogas scour across the membrane surface. The first 20 months of AnMBR operating expenses were reduced by 50 compared to the prior 12-month fiscal period due to increased system capacity, ability to treat wastewater with higher biomass, and elimination of the need to dewater and dispose of dewatered solids. © IWA Publishing 2011.