Modeling and Simulation of Pollutants Removal in the Modified Oxidation Ditch

The kinetic models of COD removal and phosphorus release in anaerobic zone, and phosphorus uptake, nitrification, denitrification and COD removal in circulating corridors were established in this work, in order to provide the guidance on design and running of the modified oxidation ditch. At the same time, the coefficients of reaction rates were calculated. Using the kinetic models already been established and the coefficients already been calculated to simulate the experimental results, the results showed that the models can well simulate the removal effect of pollutants in the modified oxidation ditch.

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Improving the predictions of ASM2d through modelling in practice

Water Science & Technology ◽

10.2166/wst.2002.0107 ◽

2002 ◽

Vol 45 (6) ◽

pp. 199-208 ◽

Cited By ~ 9

Author(s):

L. Larrea ◽

I. Irizar ◽

M.E. Hildago

Keyword(s):

Phosphorus Uptake ◽

Pilot Scale ◽

Phosphorus Release ◽

Reduction Factor ◽

Experimental Results ◽

High Rate ◽

Predictive Capacity ◽

Kinetic Coefficients ◽

Autotrophic Biomass ◽

Rate Processes

The paper presents the adjustments carried out on the structure and in some default values of the kinetic coefficients of the ASM2d model in order to get an improved prediction for the experimental results obtained in pilot scale plants studies with different activated sludge treatment processes for carbon, nitrogen and phosphorous removal. In order to predict the high effluent filtered COD experimentally observed in high rate processes for carbon removal, a new model structure has been proposed, incorporating into the carbon model a soluble fraction of the slowly biodegradable substrate. Studies with the step feed and the alternating processes showed simultaneous nitrification-denitrification in aerated reactors which was predicted with increased values in the oxygen saturation coefficients for heterotrophic and autotrophic biomass. Both processes also showed loss of the denitrification capacity under unfavourable conditions, such us rains and low anoxic fraction, which required a very large decrease in the value of the reduction factor for denitrification so as to improve the predictions for effluent nitrate experimental results. Regarding phosphorus removal, the ASM2d model showed a satisfactory predictive capacity. For improved predictions of phosphorus release in anaerobic conditions, high values of the rate constant for storage of XPHA and low values of the anaerobic hydrolysis reduction factor were used. For phosphorus uptake in aerobic and anoxic conditions satisfactory predictions were obtained using the default values.

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Research on the Influence Factors of the Biological Phosphorus Removal in Carrousel Oxidation Ditch Process

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.356-360.2169 ◽

2011 ◽

Vol 356-360 ◽

pp. 2169-2174

Author(s):

Zhou Fang Guo ◽

Hua Zhang ◽

Jin Hu ◽

Xiao Wu Huang ◽

Yang Luo

Keyword(s):

Phosphorus Removal ◽

Influence Factors ◽

Treatment Plant ◽

Phosphorus Release ◽

Engineering Practice ◽

Oxidation Ditch ◽

Biological Phosphorus Removal ◽

Important Indicator ◽

Anaerobic Zone ◽

Carrousel Oxidation Ditch

Abstract: The concentration of total phosphorus(P-tot) in effluent is an important indicator of the effect of wastewater treatment plant(WWTP), excessive discharge of phosphorus will result in the tender eutrophication of natural water and other ecological pollution problems. In this paper, Qilidian WWTP in Guilin for the study object, researched Carrousel oxidation ditch process of the plant DO, pH, nitrate, BOD5 and P-tot in influent, and P-tot in influent and in effluent of the final clarifier, systems analyzed the factors and reasons affecting phosphorus removal. The result of the research shows itself as follows: the dissolved oxygen (DO) in oxidation ditch anaerobic zone above 0.5mg/l and at the end of the aerobic zone up to 3.87mg/l are not suitable for phosphorus accumulating organisms (PAOs) to release phosphorus; in the influent, B0D5/P-tot<20, carbon source used for PAOs in the sewage is insufficient; the concentration of P-tot in the effluent is higher than that in the influent, there occurs an obvious phenomenon of phosphorus release in the final clarifier. In addition, the pH in oxidation ditch ranges from 6.82 to7.19 and the concentration of nitrate in anaerobic zone below 0.2mg/l are suitable for the phosphorus removal process. This research provide technical support for the similar oxidation ditch process of upgrading and transformation,and have a higher value in engineering practice.

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Pond Treatment of Rettery Wastewaters

Water Science & Technology ◽

10.2166/wst.1987.0130 ◽

1987 ◽

Vol 19 (12) ◽

pp. 79-83

Author(s):

K. Bartoszewski ◽

A. Bilyk

Keyword(s):

Activated Sludge ◽

Treatment Process ◽

New Technology ◽

Treatment Plant ◽

Anaerobic Treatment ◽

Cod Removal ◽

Experimental Results ◽

Aerobic Conditions ◽

Aerobic Stabilization ◽

In Series

Rettery wastewaters were treated in anaerobic and aerobic ponds. Anaerobic treatment yielded efficiencies of BOD5 and COD removal as low as 20%. The treatment process conducted under aerobic conditions in aerated and stabilizing ponds arranged in series took from 18 to 20 days and gave efficiencies of BOD5 and COD removal amounting to 90%. The experimental results were interpreted by virtue of the Eckenfelder equation. Excess activated sludge was subjected to aerobic stabilization in a separate tank. A new technology was suggested for the existing obsolete industrial treatment plant.

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Experimental Study on the Optimal Thickness of Infiltration Media of the CRI System

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.415-417.1703 ◽

2011 ◽

Vol 415-417 ◽

pp. 1703-1707

Author(s):

Jun Min Chen ◽

Xiao Lin Yao

Keyword(s):

Experimental Study ◽

Removal Efficiency ◽

Significant Influence ◽

Soil Column ◽

Experimental Results ◽

Artificial Soil ◽

Optimal Thickness ◽

Effluent Quality ◽

Anaerobic Zone

Abstract. In order to investigate the optimal thickness of infiltration media in the Constructed Rapid Infiltration System, the artificial soil column is used to simulate the Constructed Rapid Infiltration System, and the CODCr, NH3-N and TN concentrations of the effluent from all the sampling sites are monitored. The experimental results and analysis show that the thickness of infiltration media exerts a significant influence on the CODCr, NH3-N and TN concentration and removal efficiency of the effluent; the CODCr, NH3-N and TN are mainly removed in the 0-1800mm zone of the artificial soil column; the total CODCr removal efficiency increases, as the thickness of infiltration media increases, but the CODCr removal efficiency in the 1800-2200mm zone is very low; the NH3-N and TN removal efficiency reaches the maximum where the thickness of infiltration media is 1800mm; the NH3-N and TN concentration of the effluent from 1800-2200mm zone dose not decrease, but increase 5-8%, due to the assimilation denitrification and amemoniation reaction on the end of the anaerobic zone; in consideration of the effluent quality, efficient biodegradation zone, construction investment, etc. the optimal thickness of infiltration media in CRI system should be 1800mm.

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Start-Up of A2/O Humic Activated Sludge Systemphosphorus Removal Efficiency Analysis

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.113-116.2201 ◽

2010 ◽

Vol 113-116 ◽

pp. 2201-2207 ◽

Cited By ~ 2

Author(s):

Jun Yin ◽

Lei Wu ◽

Ke Zhao ◽

Yu Juan Yu

Keyword(s):

Activated Sludge ◽

Removal Efficiency ◽

Phosphorus Removal ◽

Removal Rate ◽

Phosphorus Uptake ◽

Phosphorus Release ◽

Activated Sludge System ◽

Start Up ◽

Article Analysis ◽

Sludge Activity

In this article, analysis the start-up of A2/O humic activated sludge system phosphorus removal efficiency and the characteristics of anaerobic phosphorus release, aerobic phosphorus uptake, sludge activity and their change in the Series Technologies process. The results show that A2/O humic activated sludge system phosphorus removal rate stabilized at 90.7% ~ 97.6%. Sludge activity except for anoxic zone 2 increased, along the process showed a gradual decrease trend.

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Simultaneous Removal of Nitrogen and Phosphorus in Intermittently Aerated 2-Tank Activated Sludge Process Using DO and ORP-Bending-Point Control

Water Science & Technology ◽

10.2166/wst.1993.0691 ◽

1993 ◽

Vol 28 (11-12) ◽

pp. 513-521 ◽

Cited By ~ 13

Author(s):

Kousei Sasaki ◽

Yasuji Yamamoto ◽

Kazushi Tsumura ◽

Shigeru Hatsumata ◽

Masahiro Tatewaki

Keyword(s):

Control System ◽

Activated Sludge ◽

Phosphorus Uptake ◽

Material Balance ◽

Phosphorus Release ◽

Test Plant ◽

Activated Sludge Process ◽

Time Sharing ◽

Nitrogen And Phosphorus ◽

Time Control

The 2-tank intermittent aeration method is an anaerobic-aerobic activated sludge process of time-sharing type in which 2 complete mixing reaction tanks are connected in series, and aeration and agitation are periodically repeated in each tank. We have developed a new control system for the process which can secure anaerobic, anoxic and aerobic conditions through a combination of DO and ORP-Bending-point (corresponding to termination of denitrification) emergence time control. In the 1st tank, nitrification and phosphorus uptake occur in the aeration period, followed by denitrification and phosphorus release in the agitation. The 2nd tank performs nitrification and phosphorus uptake in the aeration and denitrification in the agitation. One cycle of aeration and agitation is approximately 2 hours. This control system was applied to the test plant (influent flow rate: 225 I/day) for two months under the conditions of HRT 16 hours and temperature 20 ±2 °C. We achieved stable and high removal ratios: TOC 94.9 %, T-N 89.4 %, and T-P 95.5 %. We also investigated the mechanisms of nitrogen and phosphorus removal and their material balance.

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Experimental evidence for the need of thermodynamic considerations in modelling of anaerobic environmental bioprocesses

Water Science & Technology ◽

10.2166/wst.1997.0370 ◽

1997 ◽

Vol 36 (10) ◽

pp. 109-115 ◽

Cited By ~ 5

Author(s):

Choon-Yee Hoh ◽

Ralf Cord-Ruwisch

Keyword(s):

Free Energy ◽

Experimental Evidence ◽

Positive Reaction ◽

Rate Equation ◽

Dynamic Equilibrium ◽

Reaction Rates ◽

Product Inhibition ◽

Experimental Results ◽

Biological Processes ◽

Laws Of Thermodynamics

For modeling of biological processes that operate close to the dynamic equilibrium (eg. anaerobic processes), it is critical to prevent the prediction of positive reaction rates when the reaction has already reached dynamic equilibrium. Traditional Michaelis-Menten based models were found to violate the laws of thermodynamics as they predicted positive reaction rates for reactions that were endergonic due to high endproduct concentrations. The inclusion of empirical “product inhibition factors” as suggested by previous work could not prevent this problem. This paper compares the predictions of the Michaelis-Menten Model (with and without product inhibition factors) and the Equilibrium Based Model (which has a thermodynamic term introduced into its rate equation) with experimental results of reactions in anaerobic bacterial environments. In contrast to the Michaelis-Menten based models that used traditional inhibition factors, the Equilibrium Based Model correctly predicted the nature and the degree of inhibition due to endproduct accumulation. Moreover, this model also correctly predicted when reaction rates must be zero due to the free energy change of the conversion reaction being zero. With these added advantages, the Equilibrium Based Model thus seemed to provide a scientifically correct and more realistic basis for a variety of models that describe anaerobic biosystems.

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Application of Biofilm Kinetics to Anaerobic Fixed Bed Reactors

Water Science & Technology ◽

10.2166/wst.1991.0584 ◽

1991 ◽

Vol 23 (7-9) ◽

pp. 1319-1326 ◽

Cited By ~ 4

Author(s):

I. E. Gönenç ◽

D. Orhon ◽

B. Beler Baykal

Keyword(s):

Removal Rate ◽

Fixed Bed ◽

Experimental Studies ◽

Pilot Scale ◽

Cod Removal ◽

Experimental Results ◽

Fixed Bed Reactor ◽

Removal Mechanism ◽

Term Operation ◽

Fixed Bed Reactors

Two basic phenomena, reactor hydraulics and mass transport through biofilm coupled with kinetic expressions for substrate transformations were accounted for in order to describe the soluble COD removal mechanism in anaerobic fixed bed reactors. To provide necessary verification, experimental results from the long term operation of the pilot scale anaerobic reactor treating molasses wastewater were used. Theoretical evaluations verified by these experimental studies showed that a bulk zero-order removal rate expression modified by diffusional resistance leading to bulk half-order and first-order rates together with the particular hydraulic conditions could adequately define the overall soluble COD removal mechanism in an anaerobic fixed bed reactor. The experimental results were also used to determine the kinetic constants for practical application. In view of the complexity of the phenomena involved it is found remarkable that a simple simulation model based on biofilm kinetics is a powerful tool for design and operation of anaerobic fixed bed reactors.

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