Performance and model calibration of R-D-N processes in pilot plant

1994 ◽  
Vol 30 (6) ◽  
pp. 355-364 ◽  
Author(s):  
A. de la Sota ◽  
L. Larrea ◽  
L. Novak ◽  
P. Grau ◽  
M. Henze
Keyword(s):  
Nutrient Removal ◽  
Pilot Plant ◽  
Model Calibration ◽  
Domestic Wastewater ◽  
Biological Nutrient Removal ◽  
Quasi Steady State ◽  
Batch Tests ◽  
Filamentous Microorganisms ◽  
Inhibition Of Nitrification ◽  
Removal Processes

This paper deals with the first part of an experimental programme in a pilot plant configured for advanced biological nutrient removal processes treating domestic wastewater of Bilbao. The IAWPRC Model No. 1 was calibrated in order to optimize the design of the full-scale plant. In this first phase the R-D-N process, incorporating an anoxic selector, was tested for eight months at three temperatures of approximately 20°C, 15°C and 11°C. Under quasi-steady state conditions the ammonia effluent varied from 1 to 5 mg N/l. A partial inhibition of nitrification in some periods was detected. This was clearly shown by regular maximum AUR batch tests and by the model calibration. The influent COD/TKN ratio was rather low (8-9) and the effluent nitrate concentrations varied from 10 to 12 mg N/l. The DSVI increased from 50 to 115 ml/g as the temperature decreased from 20°C to 11°C. An appropriate balance between floc-forming and filamentous microorganisms was maintained as a consequence of the combined configuration of the anoxic selector and the regeneration zone.

Biological nutrient removal in a sequencing batch reactor treating domestic wastewater

1996 ◽  
Vol 33 (3) ◽  
pp. 29-38 ◽  
Author(s):  
R. S. Bernardes ◽  
A. Klapwijk
Keyword(s):  
Nutrient Removal ◽  
Phosphorus Removal ◽  
Pilot Plant ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Treatment Plant ◽  
Domestic Wastewater ◽  
Biological Nutrient Removal ◽  
Carbon Oxidation ◽  
Nitrogen And Phosphorus

This investigation aims to monitor a strategy for biological nutrient removal (nitrogen and phosphorus) in a Sequencing Batch Reactor (SBR) treating domestic wastewater. For this, the performance of an SBR with nitrification, denitrification, carbon oxidation and phosphorus removal is evaluated. During this study the influent used was pre-settled domestic wastewater from Bennekom-Municipal Treatment Plant (The Netherlands). The average influent COD, TKN and phosphate were 443 mg COD/1, 71 mg N/1 and 7 mg P/1, respectively. Acetic acid was added to this influent from a feed solution, to increase the COD by an extra 100 mg COD/1. In this study, a pilot plant SBR was operated during 5 months in order to have: i) a mixed culture able to perform carbon oxidation, nitrification, denitrification and biological phosphorus removal and ii) long term assessment of the biological nitrogen and phosphorus removal processes. Pilot plant SBR consists of two cylindric polystyrene vessels, the first with total volume of 0.35 m3 (Reactor 1) and the second with total volume of 1.3 m3 (Reactor 2). The effluent had, in average, phosphate concentration lower than 1 mg P/1 and nitrogen concentration lower than 12 mg N/1.

Survey of filamentous populations in nutrient removal plants in four European countries

1998 ◽  
Vol 37 (4-5) ◽  
pp. 281-289 ◽  
Author(s):  
Dick H. Eikelboom ◽  
Andreas Andreadakis ◽  
Kjaer Andreasen
Keyword(s):  
Nutrient Removal ◽  
Seasonal Pattern ◽  
Plug Flow ◽  
Phosphate Removal ◽  
Particulate Fraction ◽  
Biological Nutrient Removal ◽  
Process Conditions ◽  
Minor Importance ◽  
Filamentous Microorganisms ◽  
Short Period

A joint EU research project aimed at solving activated sludge bulking in nutrient removal plants was initiated in 1993. The project started with a survey of the size and composition of the filamentous population in nutrient removal plants in Denmark, Germany, Greece and the Netherlands. The results show that biological nutrient removal process conditions indeed favour filamentous microorganisms in their competition with floc forming organisms. An increase in the size of the filamentous population resulted in a deterioration of the settling properties of the biomass, except for plants with Bio-P removal conditions. It is assumed that in the latter case the dense clusters of Bio-P bacteria increase the weight of the flocs, and compensate for the effect of the larger number of filaments. Although exceptions frequently occur, the following sequence in decreasing filamentous organism population size was observed for the process conditions indicated: - completely mixed + simultaneous denitrification; - completely mixed + intermittent aeration/denitrification; - alternating anoxic/oxic process conditions, with an anaerobic tank for biological phosphate removal (Bio-Denipho); - alternating anoxic/oxic process conditions (Bio-Denitro); - predenitrification The surveys provided little information about the effect of nutrient removal in plants with plug flow aeration basins. Simultaneous precipitation with aluminium salts nearly always resulted in a low number of filaments and a good settling sludge. The size of the filamentous organism population showed a seasonal pattern with a maximum in winter/early spring and a minimum during summer (in Greece: during autumn). This seasonal variation is primarily caused by the effect of the season on the population sizes of M. parvicella, N. limicola and Type 0092. M. parvicella is by far the most important filamentous species in nutrient removal plants. In Denmark only, Type 0041 also frequently dominates the filamentous population, but seldom causes severe bulking. Considering their frequency of occurrence, approx. 10 other filamentous micro-organisms are of minor importance. Growth of some of these species, viz. those which use soluble substrate, can be prevented by the introduction of Bio-P process conditions. M. parvicella and Type 0041 (and probably also Actinomycetes and the Types 1851 and 0092) seem to compete for the same substrates i.e. the influent particulate fraction. Most of the differences in composition of the filamentous microorganism population can be explained by whether or not premixing of influent and recycled sludge is used. In general, premixing for a short period of time followed by anoxic conditions favours Type 0041. M. parvicella seems to proliferate if the particulate fraction is first hydrolysed or if it enters the plant via an oxic zone. It is concluded that bulking in nutrient removal plants is mainly caused by filamentous species requiring the particulate fraction for their growth.

scholarly journals Modeling quaternary ammonium compound inhibition of biological nutrient removal activated sludge

2018 ◽  
Vol 79 (1) ◽  
pp. 41-50 ◽  
Author(s):  
Daniela Conidi ◽  
Mehran Andalib ◽  
Christopher Andres ◽  
Christopher Bye ◽  
Art Umble ◽  
...  
Keyword(s):  
Nutrient Removal ◽  
Quaternary Ammonium ◽  
Wastewater Treatment Plants ◽  
Inhibitory Effect ◽  
Biological Nutrient Removal ◽  
Ammonium Compound ◽  
Selective Toxicity ◽  
Experimental Systems ◽  
Inhibition Of Nitrification ◽  
Surface Active

Abstract Quaternary ammonium compounds (QACs) are surface-active organic compounds common in industrial cleaner formulations widely used in various sanitation applications. While acting as effective pathogenic biocides, QACs lack selective toxicity and often have poor target specificity. As a result, adverse effects on biological processes and thus the performance of biological nutrient removal (BNR) systems may be encountered when QACs enter wastewater treatment plants (WWTPs). Because of these impacts, there is motivation to screen wastewater influents for QACs and for process engineers to consider the inhibition effects of QACs on process evaluation and design of BNR plants. This paper introduces a mathematical model to describe the fate of QACs in a WWTP via biodegradation and bio-adsorption, and the inhibitory effect of QACs on nitrifiers and ordinary heterotrophic organisms. The model was incorporated as an add-on model in BioWin 5.3 and simulations of experimental systems were used for comparison of model results to measured data reported in the literature. The model was found to accurately predict the bulk phase concentration of QAC and the inhibition of nitrification with QAC concentrations ≥2 mg/L. This work provides a preliminary framework for simulation of BNR plants receiving inhibitory substances in the influent.

Settling Characteristics of Activated Sludge in Danish Treatment Plants with Biological Nutrient Removal

1994 ◽  
Vol 29 (7) ◽  
pp. 157-165 ◽  
Author(s):  
Gert Holm Kristensen ◽  
Per Elberg Jørgensen ◽  
Per Halkjær Nielsen
Keyword(s):  
Activated Sludge ◽  
Nutrient Removal ◽  
Volume Index ◽  
Biological Nutrient Removal ◽  
Sludge Volume Index ◽  
Filamentous Microorganisms ◽  
Best Parameter ◽  
One Year ◽  
Sludge Settling ◽  
Settling Characteristics

In 1989-91, a study was performed to investigate the settling characteristics of activated sludge in Danish treatment plants with biological nutrient removal. The study included three screening series on 38 treatment plants. Furthermore, the study included investigations during one year on seasonal variations in sludge settling characteristics at three treatment plants. The screening investigations were performed in November 1989 and May and September, 1990. Results showed that in the May-screening, 35-45% of the plants had a filament index of 2-2.5 or above, corresponding to a sludge volume index above 150 ml/g. When comparing data for diluted and non-diluted sludge volume indices, a SVI value of 150 ml/g seemed parallel to a DSVI of 110 ml/g. In the November- and September-screenings, some 30% of the plants had activated sludge showing a filament index in or above the critical area. Dominating filamentous microorganisms were found to be (in decreasing order): Microthrix parvicella, Type 0041, Type 021N, Type 0092, Type 0914, and Type 1851. A distinct variation over the year in sludge settling characteristics was found for the three plants. Sludge settling characteristics improved during summer, and deteriorated during winter. For activated sludge with a high content of filamentous microorganisms, the best parameter to follow the variations in sludge settling properties was the filament number. If the activated sludge concentration, the MLSS, varied significantly, the specific filament number was to be applied.

Comparison of phosphorus removal characteristics between various biological nutrient removal processes

1997 ◽  
Vol 36 (12) ◽  
pp. 61-68 ◽  
Author(s):  
Eun Lee Sang ◽  
Soo Kim Kwang ◽  
Hwan Ahn Jae ◽  
Whoe Kim Chang
Keyword(s):  
Adverse Effect ◽  
Nutrient Removal ◽  
Phosphorus Removal ◽  
Phosphorus Release ◽  
Biological Nutrient Removal ◽  
Phosphorus Concentration ◽  
Bench Scale ◽  
Removal Processes

Bench scale experiments were carried out with four biological nutrient removal(BNR) units, A/O, A2/O, Phostrip and P/L units, to investigate the behavior of phosphorus in the system and to compare the characteristics of phosphorus removal in four experimental BNR units. The influent COD/T-P ratio was varied from 22 to 64 by changing COD concentration while maintaining phosphorus concentration constant. In general sidestream BNR units such as Phostrip and P/L units outperformed mainstream BNR units such as A/O and A2/O units in terms of phosphorus removal. While phosphorus release and uptake in A/O and A2/O units became less significant at low influent COD/T-P, the phosphorus release in A2/O unit was further influenced by nitrate in return sludge and thus A2/O unit required even higher influent COD/T-P ratio for luxury uptake of phosphorus. The luxury uptake of phosphorus in Phostrip and P/L units were not affected by influent COD/T-P ratio and the adverse effect of nitrate in return sludge on anaerobic phosphorus release in P/L process was not significant due to the sludge blanket in P-stripper.

Evaluation of influent prefermentation as a unit process upon biological nutrient removal

2003 ◽  
Vol 47 (11) ◽  
pp. 9-15 ◽  
Author(s):  
T. McCue ◽  
R. Shah ◽  
I. Vassiliev ◽  
Y.-H. Liu ◽  
F.G. Eremektar ◽  
...  
Keyword(s):  
Nutrient Removal ◽  
Domestic Wastewater ◽  
Pilot Scale ◽  
Biological Nutrient Removal ◽  
P Availability ◽  
Unit Process ◽  
Design Engineers ◽  
N Removal ◽  
Technical Basis ◽  
P Removal

The objective of this NSF sponsored research was to provide a controlled comparison of identical continuous flow biological nutrient removal (BNR) processes both with and without prefermentation in order to provide a stronger, more quantitative, technical basis for design engineers to determine the potential benefits of prefermentation to EBPR in treating domestic wastewater. Specifically, this paper focused upon the potential impacts of primary influent prefermentation upon BNR processes treating septic domestic wastewater. This study can be divided into two distinct phases - an initial bench-scale phase which treated septic P-limited (TCOD:TP>40) wastewater and a subsequent pilot-scale phase which treated septic COD-limited (TCOD:TP<40) wastewater. The following conclusions can be drawn from the results obtained to date.•Prefermentation increased both RBCOD, SBCOD and VFA content of septic domestic wastewater.•Prefermentation resulted in increased biological P removal for a highly septic, non-P limited (TCOD:TP<40:1) wastewater. However, in septic, P-limited (TCOD:TP>40:1) wastewater, changes in net P removal due to prefermentation were suppressed by limited P availability, even though P release and PHA content were affected.•Prefermentation increased specific anoxic denitrification rates for both COD and P-limited wastewaters, and in the pilot (COD-limited) study also coincided with greater system N removal.

Nutrient removal from wastewaters using high performance materials

2003 ◽  
Vol 47 (11) ◽  
pp. 101-107 ◽  
Author(s):  
I.D.R. Mackinnon ◽  
K. Barr ◽  
E. Miller ◽  
S. Hunter ◽  
T. Pinel
Keyword(s):  
Wastewater Treatment ◽  
Total Nitrogen ◽  
Nutrient Removal ◽  
Pilot Plant ◽  
High Performance ◽  
Wastewater Treatment Plants ◽  
Significant Proportion ◽  
Biological Nutrient Removal ◽  
Wastewater Stream ◽  
Rich Solution

Return side streams from anaerobic digesters and dewatering facilities at wastewater treatment plants (WWTPs) contribute a significant proportion of the total nitrogen load on a mainstream process. Similarly, significant phosphate loads are also recirculated in biological nutrient removal (BNR) wastewater treatment plants. Ion exchange using a new material, known by the name MesoLite, shows strong potential for the removal of ammonia from these side streams and an opportunity to concurrently reduce phosphate levels. A pilot plant was designed and operated for several months on an ammonia rich centrate from a dewatering centrifuge at the Oxley Creek WWTP, Brisbane, Australia. The system operated with a detention time in the order of one hour and was operated for between 12 and 24 hours prior to regeneration with a sodium rich solution. The same pilot plant was used to demonstrate removal of phosphate from an abattoir wastewater stream at similar flow rates. Using MesoLite materials, >90% reduction of ammonia was achieved in the centrate side stream. A full-scale process would reduce the total nitrogen load at the Oxley Creek WWTP by at least 18%. This reduction in nitrogen load consequently improves the TKN/COD ratio of the influent and enhances the nitrogen removal performance of the biological nutrient removal process.

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