Retrofitting conventional primary clarifiers to activated primary clarifiers to enhance nutrient removal and energy conservation in WWTPs in Beijing, China

2011 ◽  
Vol 63 (7) ◽  
pp. 1446-1452 ◽  
Author(s):  
Jia-wei Wang ◽  
Tian-zhu Zhang ◽  
Ji-ning Chen ◽  
Zhi-rong Hu
Keyword(s):  
Carbon Source ◽  
Energy Conservation ◽  
Nutrient Removal ◽  
Wastewater Treatment Plants ◽  
Test System ◽  
Biological Nutrient Removal ◽  
Aeration Tank ◽  
Secondary Effluent ◽  
Nitrogen And Phosphorus ◽  
Primary Sludge

Biological nutrient removal requires sufficient carbon source. Meanwhile, the removal of organic matter in wastewater requires energy consumption in the aeration tank. Carbon source for nutrient removal in most wastewater treatment plants with conventional primary clarifier (CPC) is generally insufficient in China. In order to increase carbon source and to save energy, a part of the CPC may be retrofitted as an activated primary clarifier (APC). In this paper, a pilot scale experiment was conducted to examine the performance of primary sludge fermentation and its effect on nitrogen and phosphorus removal. Results show that the primary sludge fermentation in APC has produced a similar VFA/TP ratio but a higher BOD5/TN ratio compared with those in the CPC effluent, and the TN concentrations in the secondary effluent are at 8.0, 10.8, and 17.4 mg/L, while TP is at 0.45, 1.10, and 2.28 mg/L when the pilot test system was fed with (1) the APC effluent, (2) 50% from the APC effluent and 50% from the CPC effluent, and (3) the CPC effluent, respectively. Results also indicate that the BOD5/TN ratio is a more sensitive factor than the VFA/TP ratio for nutrient removal and energy conservation for the APC fermentation.

Upgrading Wastewater Treatment Plants for Biological Nutrient Removal

1990 ◽  
Vol 22 (7-8) ◽  
pp. 53-60 ◽  
Author(s):  
B. Rabinowitz ◽  
T. D. Vassos ◽  
R. N. Dawson ◽  
W. K. Oldham
Keyword(s):  
Wastewater Treatment ◽  
Nutrient Removal ◽  
Wastewater Treatment Plants ◽  
Design Flow ◽  
Biological Nutrient Removal ◽  
Nitrogen And Phosphorus ◽  
Conventional Activated Sludge ◽  
Recent Developments ◽  
Removal Technology ◽  
Biological Nitrogen

A brief review of recent developments in biological nitrogen and phosphorus removal technology is presented. Guidelines are outlined of how current understanding of these two removal mechanisms can be applied in the upgrading of existing wastewater treatment plants for biological nutrient removal. A case history dealing with the upgrading of the conventional activated sludge process located at Penticton, British Columbia, to a biological nutrient removal facility with a design flow of 18,200 m3/day (4.0 IMGD) is presented as a design example. Process components requiring major modification were the headworks, bioreactors and sludge handling facilities.

Biological nutrient removal model No.1 (BNRM1)

2004 ◽  
Vol 50 (6) ◽  
pp. 69-70 ◽  
Author(s):  
A. Seco ◽  
J. Ribes ◽  
J. Serralta ◽  
J. Ferrer
Keyword(s):  
Nutrient Removal ◽  
Volatile Fatty Acids ◽  
Wastewater Treatment Plants ◽  
Biological Nutrient Removal ◽  
Model Parameters ◽  
Nitrogen And Phosphorus ◽  
Hindered Settling ◽  
Whole Plant ◽  
Bacterial Groups ◽  
Removal Model

This paper presents the results of the work carried out by the CALAGUA Group on Mathematical Modelling of Biological Treatment Processes: the Biological Nutrient Removal Model No.1. This model is based on a new concept for dynamic simulation of wastewater treatment plants: a unique model can be used to design, simulate and optimize the whole plant, as it includes most of the biological and physico-chemical processes taking place in all treatment operations. The physical processes included are: settling and clarification processes (flocculated settling, hindered settling and thickening), volatile fatty acids elutriation and gasÐliquid transfer. The chemical interactions included comprise acidÐbase processes, where equilibrium conditions are assumed. The biological processes included are: organic matter, nitrogen and phosphorus removal; acidogenesis, acetogenesis and methanogenesis. Environmental conditions in each operation unit (aerobic, anoxic or anaerobic) will determine which bacterial groups can grow. Thus, only the model parameters related to bacterial groups able to grow in any of the operation units of a specific WWTP will require calibration. One of the most important advantages of this model is that no additional analysis with respect to ASM2d is required for wastewater characterization. Some applications of this model have also been briefly explained in this paper.

Polishing of secondary effluent by an algal biofilm process

2002 ◽  
Vol 46 (8) ◽  
pp. 83-90 ◽  
Author(s):  
G. Schumacher ◽  
I. Sekoulov
Keyword(s):  
Carbon Dioxide ◽  
Nutrient Removal ◽  
Wastewater Treatment Plants ◽  
Low Cost ◽  
Secondary Effluent ◽  
Nitrogen And Phosphorus ◽  
Dissolved Carbon ◽  
Algal Biofilm ◽  
Faecal Bacteria ◽  
Biofilm Process

The potential in polishing secondary effluent by an algal biofilm composed of different green and bluegreen algae was investigated. During the photosynthesis process of algal biofilm oxygen was produced while dissolved carbon dioxide was consumed. This led to an increasing pH due to the change of the carbon dioxide equilibrium in water. The high pH caused precipitation of dissolved phosphates. The attached algae took up nitrogen and phosphorus during the growth of biomass. In addition to nutrient removal, an extensive removal of faecal bacteria was observed probably caused by adsorption of the algal biofilm and by photo-oxidation involving dissolved oxygen. The experimental results suggest that a low-cost, close to nature process especially for small wastewater treatment plants for nutrient removal and bacteria reduction can be developed with the aid of an algal biofilm.

Biological nutrient removal applied to weak sewage

1994 ◽  
Vol 29 (12) ◽  
pp. 41-48 ◽  
Author(s):  
J. Charlton
Keyword(s):  
Nutrient Removal ◽  
Treatment Process ◽  
Treatment Plant ◽  
Domestic Wastewater ◽  
Biological Nutrient Removal ◽  
Nitrogen And Phosphorus ◽  
Primary Sludge ◽  
University Of British Columbia ◽  
Biological Nitrogen ◽  
Influent Wastewater

The Melby Wastewater Treatment Plant is located in the municipality of Frederiksværk on the island of Sealand, Denmark. This may be the first full-scale plant in Europe purpose built for biological nutrient removal from diluted wastewater, i.e. weak domestic wastewater mixed with infiltration waters. The relatively strict effluent standards have required the existing treatment plant to be upgraded in capacity, including the design for biological Nitrogen and Phosphorus removal. Due to the weak nature of the influent wastewater, the treatment process that has been adopted includes the application of a primary sludge fermenter to alter the influent characteristics suitable for biological nutrient removal. The treatment process used is the Modified University of Cape Town process utilising a primary sludge fermenter developed at the University of British Columbia in Canada. The combination of these two processes has been successfully applied to meet the strict discharge licence requirements, without the addition of chemicals, despite the unsuitable characteristics of the influent wastewater for biological nutrient removal. The paper describes the operational results for the treatment plant.

Removal of ibuprofen from wastewater: comparing biodegradation in conventional, membrane bioreactor, and biological nutrient removal treatment systems

2008 ◽  
Vol 57 (1) ◽  
pp. 1-8 ◽  
Author(s):  
T.M. Smook ◽  
H. Zho ◽  
R.G. Zytner
Keyword(s):  
Nutrient Removal ◽  
Rate Constants ◽  
Membrane Bioreactor ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Aerobic Biodegradation ◽  
Biological Nutrient Removal ◽  
Aeration Tank ◽  
Municipal Wastewater Treatment ◽  
Pharmaceutical Removal

Pharmaceuticals are continually being introduced into the influent of municipal wastewater treatment plants (WWTPs). Developing a better understanding of pharmaceutical removal mechanisms within the different treatment processes is vital in preventing downstream contamination of our water resources. In this study, ibuprofen, a popular over-the-counter pain reliever, was monitored by taking wastewater samples throughout the City of Guelph municipal WWTP. Greater than 95% of ibuprofen was found to be removed in the aeration tank, with aerobic biodegradation being the dominant mechanism. For comparison, first-order kinetics were used to quantify ibuprofen biodegradation in a conventional WWTP aeration tank and in a membrane bioreactor (MBR) pilot plant. The rate constants, kbiol, for the conventional tank and the MBR were determined to be (−6.8±3.3) L/g SS*d and (−8.4±4.0) L/g SS*d, respectively. These two rate constants were found to be statistically similar. Preliminary study of a biological nutrient removal pilot system also suggests that ibuprofen can be anaerobically degraded.

scholarly journals Benchmarking biological nutrient removal in wastewater treatment plants: influence of mathematical model assumptions

2012 ◽  
Vol 65 (8) ◽  
pp. 1496-1505 ◽  
Author(s):  
Xavier Flores-Alsina ◽  
Krist V. Gernaey ◽  
Ulf Jeppsson
Keyword(s):  
Wastewater Treatment ◽  
Electron Acceptor ◽  
Nutrient Removal ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Critical Discussion ◽  
Decay Rates ◽  
Biological Nutrient Removal ◽  
Nitrogen And Phosphorus ◽  
Reference Case

This paper examines the effect of different model assumptions when describing biological nutrient removal (BNR) by the activated sludge models (ASM) 1, 2d & 3. The performance of a nitrogen removal (WWTP1) and a combined nitrogen and phosphorus removal (WWTP2) benchmark wastewater treatment plant was compared for a series of model assumptions. Three different model approaches describing BNR are considered. In the reference case, the original model implementations are used to simulate WWTP1 (ASM1 & 3) and WWTP2 (ASM2d). The second set of models includes a reactive settler, which extends the description of the non-reactive TSS sedimentation and transport in the reference case with the full set of ASM processes. Finally, the third set of models is based on including electron acceptor dependency of biomass decay rates for ASM1 (WWTP1) and ASM2d (WWTP2). The results show that incorporation of a reactive settler: (1) increases the hydrolysis of particulates; (2) increases the overall plant's denitrification efficiency by reducing the SNOx concentration at the bottom of the clarifier; (3) increases the oxidation of COD compounds; (4) increases XOHO and XANO decay; and, finally, (5) increases the growth of XPAO and formation of XPHA,Stor for ASM2d, which has a major impact on the whole P removal system. Introduction of electron acceptor dependent decay leads to a substantial increase of the concentration of XANO, XOHO and XPAO in the bottom of the clarifier. The paper ends with a critical discussion of the influence of the different model assumptions, and emphasizes the need for a model user to understand the significant differences in simulation results that are obtained when applying different combinations of ‘standard’ models.

Primary sludge hydrolysis for biological nutrient removal

1996 ◽  
Vol 34 (1-2) ◽  
pp. 417-423 ◽  
Author(s):  
G. J. Hatziconstantinou ◽  
P. Yannakopoulos ◽  
A. Andreadakis
Keyword(s):  
Carbon Source ◽  
Nutrient Removal ◽  
Continuous Flow ◽  
Hydraulic Retention Time ◽  
Pilot Scale ◽  
Biological Nutrient Removal ◽  
Primary Sludge ◽  
Carbon Production ◽  
Sludge Hydrolysis ◽  
Removal Processes

Primary sludge hydrolysis can enrich primary effluent with the soluble organics which in turn can be a valuable carbon source to subsequent nutrient removal processes. By controlling hydraulic retention time and temperature it is possible to confine the anaerobic digestion of the primary sludge to the acidogenic and acetogenic phase (hydrolysis/fermentation process), and take advantage of the soluble organics produced. This paper presents the results of a research involving bench and pilot scale experiments related to primary sludge hydrolysis. The pilot scale sedimentation tank (4.10 m in diameter, 3.20 m in depth) operated over an expended period of 21 months as a conventional clarifier and following this as a fermentor unit employing sludge recirculation. Parallel to the pilot scale experiments, several batch and continuous flow bench scale experiments were conducted in order to determine the factors controlling the production of soluble organics and the effect of the latter on the denitrification process. The conclusions drawn were that a) a soluble COD production of the order of 5-6% in terms of sludge TCOD can be expected in a batch fermentor operating with HRT≅2days at T≤ 20°C, b) in a continuous flow fermentor, combinations of T>20°C and SRT>2 should be applied in order to achieve a production of the order of 10%, c) significant soluble carbon production can be achieved in primary sedimentation tanks (over 30% in terms of influent SCOD) when relatively increased SRTs (4 to 5 days) in combination with sludge recirculation are employed, under T>22°C, and d) increased denitrification performance of the order of 9 mgNOx/g MLSS.hr, can be achieved with hydrolysate as a carbon source.

Integrated side-stream reactor for biological nutrient removal and minimization of sludge production

2015 ◽  
Vol 71 (7) ◽  
pp. 1056-1064 ◽  
Author(s):  
M. Coma ◽  
S. Rovira ◽  
J. Canals ◽  
J. Colprim
Keyword(s):  
Activated Sludge ◽  
Nutrient Removal ◽  
Wastewater Treatment Plants ◽  
Pilot Scale ◽  
Biological Nutrient Removal ◽  
Slight Reduction ◽  
Nitrogen And Phosphorus ◽  
Effluent Quality ◽  
Side Stream ◽  
Sludge Production

Integrated processes to reduce in situ the sludge production in wastewater treatment plants are gaining attention in order to facilitate excess sludge management. In contrast to post-treatments, such as anaerobic digestion which is placed between the activated sludge system and dewatering processes, integrated technologies are placed in the sludge return line. This study evaluates the application of an anoxic side-stream reactor (SSR) which creates a physiological shock and uncouples the biomass metabolism and diverts the activity from assimilation for biosynthesis to non-growth activities. The effect of this system in biological nutrient removal for both nitrogen and phosphorus was evaluated for the anaerobic, anoxic and aerobic reactors. The RedOx potential within the SSR was maintained at −150 mV while the sludge loading rate was modified by increasing the percentage of recycled activated sludge feed to the SSR (0 and 40% at laboratory scale and 0, 10, 50 and 100% at pilot scale). The use of the SSR presented a slight reduction of phosphorus removal but maintained the effluent quality to the required discharge values. Nitrogen removal efficiency increased from 75 to 86% while reducing the sludge production rate by 18.3%.

Experience with nutrient removal in a fixed-film system at full-scale wastewater treatment plants

1997 ◽  
Vol 36 (1) ◽  
pp. 129-137 ◽  
Author(s):  
Vibeke R. Borregaard
Keyword(s):  
Wastewater Treatment ◽  
Surface Area ◽  
Nutrient Removal ◽  
Wastewater Treatment Plants ◽  
High Specific Surface Area ◽  
Biological Nutrient Removal ◽  
Growth Processes ◽  
Total N ◽  
Attached Growth ◽  
On Line

In the upgrade of wastewater treatment plants to include biological nutrient removal the space available is often a limiting facor. It may be difficult to use conventional suspended growth processes (i.e. activated sludge) owing to the relatively large surface area required for these processes. Recent years have therefore seen a revived interest in treatment technologies using various types of attached growth processes. The “new” attached growth processes, like the Biostyr process, utilise various kinds of manufactured media, e.g. polystyrene granules, which offer a high specific surface area, and are therefore very compact. The Biostyr plants allow a combination of nitrification-denitrification and filtration in one and the same unit. The results obtained are 8 mg total N/l and an SS content normally below 10 mg/l. The plants in Denmark which have been extended with a Biostyr unit have various levels of PLC control and on-line instrumentation.

Sign in / Sign up

Export Citation Format

Share Document