How Biological Phosphorous Removal is Inhibited by Collection System Corrosion and Odor Control Practices

Kobylinski, Ed; Durme, Gayle Van; Barnard, James; Massart, Neil; Koh, Sock-Hoon

doi:10.2175/193864708788733666

Cited by 5 publications

(2 citation statements)

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“…Until recently, it was accepted that phosphorus could only be removed in conventional EBPR plants when the wastewater characteristics were favorable with an rbCOD/TP ratio of more than 15 (Kobylinski, et al, 2008). Wentzel et al (2008) focused their discussion on Candidatus Accumulibacter, which was abundant in conventional plants that relied on an external source of VFA and showed no ability to grow and take up phosphorus under anoxic conditions.…”

Section: Enhanced Biological Phosphorus Removal With Return Activatedmentioning

confidence: 99%

Rethinking the Mechanisms of Biological Phosphorus Removal

Barnard¹,

Dunlap²,

Steichen³

2017

Water Environment Research

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Enhanced biological phosphorus removal (EBPR) was observed in high-rate, non-nitrifying plants in the United States that were operated in a plug-flow mode. In facilities designed for nitrification and denitrification, a first-stage anaerobic zone, free of nitrate and nitrite was needed to accomplish EBPR, and this is referred to as the Phoredox (a.k.a. the AO and A2O) process. When a biological mechanism responsible for EBPR was proposed, these treatment configurations were accepted as normal practice, but many later observations showed that more reliable phosphorus removal could be achieved with alternative configurations. This paper discusses the development of alternative configurations for EBPR and the likelihood that a host of phosphate accumulating organisms (PAOs) that react to different environmental conditions might play a much bigger role in reliable and sustainable biological phosphorus removal. The conclusion is that conventional designs might have inadvertently selected for less efficient PAOs, while alternative configurations allowed for the growth of multiple PAO species such as Tetrasphaera, which can ferment higher carbon forms and take up phosphorus under anoxic conditions.

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Section: Enhanced Biological Phosphorus Removal With Return Activatedmentioning

confidence: 99%

Rethinking the Mechanisms of Biological Phosphorus Removal

Barnard¹,

Dunlap²,

Steichen³

2017

Water Environment Research

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“…Using chlorine and other strong oxidants for odor control, as well as aeration, can destroy rbCOD and hinder biological nutrient removal. Kobylinski et al (2008) describe several plants that used nitrate salts, aeration or chlorine to control sulfide in the sewer and experienced nutrient removal problems as a result. They further note that while iron salts alone will not destroy rbCOD, adding hydrogen peroxide downstream to reactivate the iron can result in simultaneous oxidation of VFA.…”

Section: Influent Characterizationmentioning

confidence: 99%

Denitrification Rates: Sampling, Modeling and Design Considerations

Phillips¹,

Barnard²,

deBarbadillo³

et al. 2009

proc water environ fed

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Biological denitrification of wastewater has been a topic of interest for several decades; however, recent nutrient reduction initiatives and the need to achieve limit-of-technology (LOT) effluent quality have renewed interest in denitrification rate research. Since readily-biodegradable chemical oxygen demand (rbCOD) drives rapid denitrification, it is essential for design efforts to include raw influent and primary effluent sampling, for different seasons if possible. However, the influent rbCOD/TKN ratio is not the only factor to consider, since rbCOD can be easily destroyed by non-optimal design and operating conditions. Two case studies are presented, each having very similar influent rbCOD/TKN ratios but very different full-scale denitrification performance. Furthermore, bench-scale tests that were conducted for the two plants yielded similar denitrification rates, which raises the question: how can engineers apply denitrification rate research to full-scale designs? Activated sludge models provide some insight to the unknown (dissolved oxygen in the mixed liquor recycle) but cannot predict rbCOD destruction due to hydraulic conditions, or fermentation due to heterogeneous mixing. This paper discusses all of the factors that affect denitrification and poses questions for future research.

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