Stimulating accumulation of nitrifying bacteria in porous carrier by addition of inorganic carbon in a continuous-flow fluidized bed wastewater treatment reactor

Jun, Byong-Hee; Tanji, Yasunori; Unno, Hajime

doi:10.1016/s1389-1723(00)88955-0

Cited by 29 publications

(13 citation statements)

References 19 publications

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“…The average porosity of the carriers was 0.93, their wet density was nearly that of water, 1.04 g/cm 3 , and their average dry weight was 7.4 mg/carrier . Similar carriers have been used for various applications, including as wet-scrubbers in biotrickling filters (Gabriel et al, 2004), aerobic quinoline degradation (Buchtmann et al, 1997), and for enhanced accumulation of nitrifying organisms (Jun et al, 2000).…”

Section: Carriersmentioning

confidence: 99%

Intimate coupling of photocatalysis and biodegradation in a photocatalytic circulating‐bed biofilm reactor

Marsolek¹,

Torres²,

Hausner³

et al. 2008

Biotech & Bioengineering

119

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Coupling advanced oxidative pretreatment with subsequent biodegradation demonstrates potential for treating wastewaters containing biorecalcitrant and inhibitory organic constituents. However, advanced oxidation is indiscriminate, producing a range of products that can be too oxidized, unavailable for biodegradation, or toxic themselves. This problem could be overcome if advanced oxidation and biodegradation occurred together, an orientation called intimate coupling; then, biodegradable organics are removed as they are formed, focusing the chemical oxidant on the non-biodegradable fraction. Intimate coupling has seemed impossible because the conditions of advanced oxidation, for example, hydroxyl radicals and sometimes UV-light, are severely toxic to microorganisms. Here, we demonstrate that a novel photocatalytic circulating-bed biofilm reactor (PCBBR), which utilizes macro-porous carriers to protect biofilm from toxic reactants and UV light, achieves intimate coupling. We demonstrate the viability of the PCBBR system first with UV only and acetate, where the carriers grew biofilm and sustained acetate biodegradation despite continuous UV irradiation. Images obtained by scanning electron microscopy and confocal laser scanning microscopy show bacteria living behind the exposed surface of the cubes. Second, we used slurry-form Degussa P25 TiO2 to initiate photocatalysis of inhibitory 2,4,5-trichlorophenol (TCP) and acetate. With no bacterial carriers, photocatalysis and physical processes removed TCP and COD to 32% and 26% of their influent levels, but addition of biofilm carriers decreased residuals to 2% and 4%, respectively. Biodegradation alone could not remove TCP. Photomicrographs clearly show that biomass originally on the exterior of the carriers was oxidized (charred), but biofilm a short distance within the carriers was protected. Finally, we coated TiO2 directly onto the carrier surface, producing a hybrid photocatalytic-biological carrier. These carriers likewise demonstrated the concept of photocatalytic degradation of TCP coupled with biodegradation of acetate, but continued TCP degradation required augmentation with slurry-form TiO2.

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Section: Carriersmentioning

confidence: 99%

Intimate coupling of photocatalysis and biodegradation in a photocatalytic circulating‐bed biofilm reactor

Marsolek¹,

Torres²,

Hausner³

et al. 2008

Biotech & Bioengineering

119

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“…There was an increase in pH to 7.7 in the second aeration pond, however there was no apparent increase in either the oxidation of NH 4 + to NO 2 − , or the conversion of NO 2 − to NO 3 − , suggesting that the low pH was not the limiting factor for NH 4 + oxidation in the first aeration pond. To achieve efficient nitrification, a supply of inorganic carbon as bicarbonate (HCO 3 − ) is required as a carbon source for nitrifying bacteria growth, as shown in equation 3 (Jun et al, 2000;Szwerinski et al, 1986;Wett and Rauch, 2003):…”

Section: Nitrification In the First Aeration Pondmentioning

confidence: 99%

Inorganic nitrogen transformations in the treatment of landfill leachate with a high ammonium load: A case study

Parkes

Jolley

Wilson

2006

Environ Monit Assess

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The inorganic nitrogen transformations occurring at a municipal waste leachate treatment facility were investigated. The treatment facility consisted of a collection well and an artificial wetland between two aeration ponds. The first aeration pond showed a decrease in ammonium (from 3480 (+/- 120) to 630(+/- 90) mg x L(-1)), a reduction in inorganic nitrogen load (3480 to 1680 mg N x L(-1)), and an accumulation of nitrite (< 1.3 mg-N x L(-1) in the collection well, to 1030 mg-N x L(-1)). Incomplete ammonium oxidation was presumably the result of the low concentration of carbonate alkalinity (approximately 2 mg x L(-1)), which may cause a limitation in the ammonium oxidation rate of nitrifiers. Low carbonate alkalinity levels may have been the result of stripping of CO(2) from the first aeration pond at the high aeration rates and low pH. Various chemodenitrification mechanisms are discussed as the reason for the reduction in the inorganic nitrogen load, including; the reduction of nitrite by iron (II) (producing various forms of gaseous nitrogen); and reactions involving nitrous acid. It is suggested that the accumulation of nitrite may be the result of inhibition of nitrite oxidizers by nitrous acid and low temperatures. Relative to the first aeration pond, the speciation and concentration of inorganic nitrogen was stable in the wetlands and 2nd aeration pond. The limited denitrification in the wetlands most probably occurred due to low concentrations of organic carbon, and short retention times.

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“…A carrier from the reactor was set in a measurement vessel with 200 ml working volume as described previously [10]. The position of the electrode tip was adjusted by a three-dimensional micromanipulator (MMS-77; Shimadzu, Kyoto, Japan) under CCD camera (DXC-107S; Sony, Tokyo, Japan) observation.…”

Section: Measurement Of Intracarrier Oxygen and Glucose Concentrationmentioning

confidence: 99%

“…Based on the effect of inorganic carbon on stimulated denitrification by supplying electron donor as reported elsewhere for CS [10], the effect of alkalinity was also examined.…”

Section: Hybrid Systemmentioning

confidence: 99%

“…Inorganic carbon supplements accelerated the nitrifying reaction, while a higher concentration of organic substance suppressed it. Because the organic substances are dominantly utilized by heterotrophic bacteria as carbon source, there is a competition between nitrifiers and fast-growing heterotrophic bacteria for available dissolved oxygen (DO) in the surface region of the carrier [10]. Consequently, little organic substance can diffuse into the anaerobic intracarrier region, where it provides electrons for denitrification.…”

Section: Introductionmentioning

confidence: 99%

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Removal of nitrogenous and carbonaceous substances by a porous carrier–membrane hybrid process for wastewater treatment

Jun

Miyanaga

Tanji

et al. 2003

Biochemical Engineering Journal

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Stimulating accumulation of nitrifying bacteria in porous carrier by addition of inorganic carbon in a continuous-flow fluidized bed wastewater treatment reactor

Cited by 29 publications

References 19 publications

Intimate coupling of photocatalysis and biodegradation in a photocatalytic circulating‐bed biofilm reactor

Intimate coupling of photocatalysis and biodegradation in a photocatalytic circulating‐bed biofilm reactor

Inorganic nitrogen transformations in the treatment of landfill leachate with a high ammonium load: A case study

Removal of nitrogenous and carbonaceous substances by a porous carrier–membrane hybrid process for wastewater treatment

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