Empirical model of the pH dependence of the maximum specific nitrification rate

Park, Seongjun; Bae, Wookeun; Chung, Jinwook; Baek, Seungcheon

doi:10.1016/j.procbio.2007.09.010

Cited by 101 publications

(59 citation statements)

References 21 publications

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“…This bell shaped curve indicates that the optimal pH for AOB activity is 8.2 ± 0.3 and 7.9 ± 0.4 for NOB populations. The work by Park et al (2007) work also indicates that NOB populations are much more sensitive to pH changes than AOB populations, resulting in a narrower bell-shaped curve.…”

Section: Phmentioning

confidence: 91%

“…Overall, pH ranging between 7.2 and 9 has been demonstrated to be the best for nitrification (Chen et al 2002). Other evidence suggests that relationship between pH and nitrification can be described as a bell-shaped curve for both AOB and NOB populations (Park et al 2007). This bell shaped curve indicates that the optimal pH for AOB activity is 8.2 ± 0.3 and 7.9 ± 0.4 for NOB populations.…”

Section: Phmentioning

confidence: 96%

“…This can be explained by a rapid increase in the reactor pH to values as high as 8.3 in all of the mixed liquor that received the COD spike (pH controllers worked only with automatic addition of alkalinity, not acid). It is well known that increases in pH can be beneficial for AOB activity (Park et al 2007), and this change could have been responsible for the unexpected AOB data on December 2. However, in other experiments conducted, both AOB and NOB nitrification rates declined as a result of the addition of COD to the mixed liquor.…”

Section: Effect Of Cod Addition On Nitrification Ratesmentioning

confidence: 99%

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Evaluation of Nitrification Kinetics for a 2.0 MGD IFAS Process Demonstration

Thomas¹,

Bott²,

Regmi³

et al. 2009

proc water environ fed

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The James River Treatment Plant (JRTP) operated a 2 MGD Integrated Fixed Film Activated Sludge (IFAS) demonstration process from November 2007 to April 2009 to explore IFAS performance and investigate IFAS technology as an option for a full scale plant upgrade in response to stricter nutrient discharge limits in the James River Basin. During the study, nitrification kinetics for both ammonia and nitrite oxidizing bacteria and plastic biofilm carrier biomass content were monitored on a near-weekly basis comparing the IFAS media, the IFAS process mixed liquor, and mixed liquor from the full-scale activated sludge process. Carrier biomass content is variable with respect to temperature and process SRT and relates to the localization of nitrification activity in the IFAS basin. Similar to trends observed for carrier biomass content (Regmi, 2008), ammonia oxidizing bacteria (AOB) and nitrite oxidizing bacteria (NOB) activity also shifted from the fixed film to the suspended phase as water temperatures increased and vice versa as the temperature decreased. The data suggest that AOB activity occurs on the surface of the biofilm carriers, while NOB activity remains deeper in the biofilm. During the highest temperatures observed in the IFAS tank, AOB activity on the media contributed as little as 30% of the total nitrification activity in the basin, and after temperatures dropped below 20 °C, AOB activity in the fixed film phase made up 75% of the total activity in the IFAS basin. During the warmest period of the summer, the media still retained more than 60% of the total NOB activity, and more than 90% of the total NOB activity during the period of coldest water temperature. This trend also points out that some AOB and NOB activity remained in the mixed liquor, even during the coldest periods. The retention of nitrification activity in the iii mixed liquor indicates that the constant sloughing of biomass off of the carriers allowed for autotrophic activity, even during washout conditions. Carrier biomass content and nitrification rates on the IFAS media remained constant along the length of the basin, indicating that the IFAS tank is will mixed with respect to biomass growth, although there was a concentration gradient for soluble species (NH 4 -N, NO 2 -N, NO 3 -N). In addition to the weekly nitrification rate measurements, experiments were also conducted to determine how operational inputs such as dissolved oxygen (DO) and mixing affect the nitrification rates. Mixing intensity had a clear impact on nitrification rates by increasing the velocity gradient in the bulk liquid and decreasing the mass transfer boundary layer mass transfer resistance. At higher mixing intensities, advection through the mass transfer boundary layer increased making substrate more available to the biofilm. The affect of mixing was much more profound at low DO, whereas increased mixing had less effect on nitrification rates at higher bulk liquid DO. DO also affected nitrification rates, such that as DO increased it penetrated deeper in...

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Section: Phmentioning

confidence: 91%

Section: Phmentioning

confidence: 96%

Section: Effect Of Cod Addition On Nitrification Ratesmentioning

confidence: 99%

See 1 more Smart Citation

Evaluation of Nitrification Kinetics for a 2.0 MGD IFAS Process Demonstration

Thomas¹,

Bott²,

Regmi³

et al. 2009

proc water environ fed

View full text Add to dashboard Cite

show abstract

“…Accordingly, alkaline pH of 8.4-8.5, temperature of 28-36 • C, and organic loading in the range of 0.15-1.1 gCOD/gMLVSS.day [135] were reported with uninhibited nitrification. A study of Park et al [139] provided insights of the optimal pH values of 8.2 ± 0.3 for AOB and 7.9 ± 0.4 for NOB. Increasing HRTs from 12 to 20 and to 22 h exhibited a poor nitrification, a partial nitrification with peak nitrite accumulation, and a complete nitrification, respectively [138].…”

Section: The Role Of the Secondary Activated Sludge Processmentioning

confidence: 99%

Distribution and Removal of Nonylphenol Ethoxylates and Nonylphenol from Textile Wastewater—A Comparison of a Cotton and a Synthetic Fiber Factory in Vietnam

Watanabe

2017

Water

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Abstract:The textile industry is a significant source of nonyphenol and their ethoxylates, which are suggested to be responsible for endocrine disruption in wildlife and humans. This study is a comparison of two conventional wastewater treatment processes in a cotton and a synthetic fiber factory in Vietnam, with regard to the distribution and removal of nonyphenol ethoxylates and nonyphenol throughout each process. Diverse trends in the distribution of nonyphenol ethoxylates in wastewater from factories, distinguished by their raw materials, could be revealed. Primary coagulation might not perfectly facilitate nitrification in the secondary activated sludge process regarding pH. Nevertheless, satisfactory removals were achieved during coagulation and activated sludge processes in both systems. The roles of long hydraulic retention times (21 and 16 h, respectively), low organic loadings (0.1 and 0.2 gCOD/gMLVSS.day, respectively), extended solids retention times (61 and 66 days, respectively), and mixed liquor suspended solids of greater than 2000 mg/L have been demonstrated. The findings provide evidence and a better understanding of nonyphenol ethoxylate and nonyphenol removal efficacy as well as influencing factors in Vietnamese textile wastewater treatment. The results are beneficial for the textile industry in Vietnam regarding investment decisions for wastewater treatment.

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“…It is generally accepted that optimal pH range for AOB and NOB are 8.2-0.3 and 7.9-0.4 respectively [17]. In solutions containing ammonium and/or nitrite nitrogen also their ion forms are present as FA and/or FNA, depending on their initial concentrations, pH value and temperature [18].…”

Section: Ph Free Ammonia (Fa) and Free Nitrous Acid (Fna)mentioning

confidence: 99%

Shortcut nitrification/partial nitritation start-up for reject water treatment in a SBR

Muszyński-Huhajło

Miodoński

2017

E3S Web Conf.

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Abstract. For many wastewater treatment plants (WWTPs), side-stream treatment of reject water from digested sludge dewatering is a feasible opportunity to improve N-removal efficiency without costly plant expansion. Biological nitrogen removal over nitrite or combined partial nitritation (PN)-Anammox process has recently become a popular treatment method for such ammonium-rich streams. Shortcut nitrification and PN start-ups were successfully performed in a pilot-scale SBR treating real reject water. In all performed experiments, effective nitrate production inhibition occurred in less than 20 days due to operational conditions selection and without advanced control system. pH adjustment in the PN reactor allowed to achieve NO2-N /NH4-N ratio suitable for Anammox process (1.24±0.07).

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Empirical model of the pH dependence of the maximum specific nitrification rate

Cited by 101 publications

References 21 publications

Evaluation of Nitrification Kinetics for a 2.0 MGD IFAS Process Demonstration

Evaluation of Nitrification Kinetics for a 2.0 MGD IFAS Process Demonstration

Distribution and Removal of Nonylphenol Ethoxylates and Nonylphenol from Textile Wastewater—A Comparison of a Cotton and a Synthetic Fiber Factory in Vietnam

Shortcut nitrification/partial nitritation start-up for reject water treatment in a SBR

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