An integrated sensor for the monitoring of aerobic and anoxic activated sludge activities in biological nitrogen removal plants

2003 ◽  
Vol 47 (2) ◽  
pp. 141-148 ◽  
Author(s):  
G. Sin ◽  
K. Malisse ◽  
P.A. Vanrolleghem

An integrated sensor is developed as a tool for monitoring the activated sludge activity on which the performance of the treatment plant depends. The sensor provides information-rich data of high frequency obtained from respirometric-titrimetric and nitrate measurements in one single set-up. The sensor is shown to successfully monitor and provide in-depth insight into nitrification, denitrification and carbon source degradation processes occurring in BNR plants. Based on the experimental results it is hypothesized that the ratio of NUR to OUR rather reflects the rate of carbon source uptake (storage) under anoxic and aerobic conditions than growth process.

1999 ◽  
Vol 39 (6) ◽  
pp. 61-68 ◽  
Author(s):  
Klangduen Pochana ◽  
Jürg Keller

Experiments have been performed to gain an understanding of the conditions and processes governing the occurrence of SND in activated sludge systems. Sequencing batch reactors (SBRs) have been operated under controlled conditions using the wastewater from the first anaerobic pond in an abattoir wastewater treatment plant. Under specific circumstances, up to 95% of total nitrogen removal through SND has been found in the system. Carbon source and oxygen concentrations were found to be important process parameters. The addition of acetate as an external carbon source resulted in a significant increase of SND activity in the system. Stepwise change of DO concentration has also been observed in this study. Experiments to determine the effect of the floc size on SND have been performed in order to test the hypothesis that SND is a physical phenomenon, governed by the diffusion of oxygen into the activated sludge flocs. Initial results support this hypothesis but further experimental confirmation is still required.


1999 ◽  
Vol 40 (1) ◽  
pp. 275-279 ◽  
Author(s):  
G. (Goktayoglu) Demirbas ◽  
C. F. Gokcay ◽  
F. B. Dilek

A model activated sludge (AS) plant was fed by pulping effluents from a straw and reed processing paper works. The model was initially operated to simulate a dedicated treatment plant by continuously receiving chlorinated effluents from the pulp bleachery. In this simulation cycle the model activated sludge was seeded only once during start-up and did not receive any domestic sewage after that. A carbon source was added in some of the experiments to bring up the organic content. In the second simulation cycle the pulping effluent was co-treated with municipal sewage. In this case the activated sludge unit was being continuously dosed by microorganisms and the organics present in the sewage. A higher organic chlorine (AOX) removal was obtained at shorter SRTs in the co-treatment AS. High AOX removal was achieved at longer SRTs in the dedicated, once-seeded AS. The AOX removal mechanism was mineralization in both cycles.


REAKTOR ◽  
2017 ◽  
Vol 7 (1) ◽  
pp. 33
Author(s):  
Yunardi Yunardi

A laboratory study was  conducted to determine the feasibility of activated sludge reactor for treating humic acid waste waterand examine the effect of the presence of glucose as the second carbon source on treatment performance. Activated sludge obtained from a waste water treatment plant treating domestic wastewater was used as a seed for reactors. Synthetic wastewater containing humid acid as the sole carbon source and glucose as the second carbon source were used as feeds for the reactors operated in a fill-and-draw mode. The result showed  tht the presence of glucose in the wastewater enhanced the production of higher MLSS (mixed liquor suspended solids) than that without of glucose. The TOC (Total Organic Carbon) concentration in both reactors fluctuated greatly until the end of the experiment due to inability of keeping the input TOC at desired level. However the decrease in TOC suggested that there are some microorganisms capable of degrading the humic acid. Addition of glucose to the simulated humic acid wastewater improved the capability of microbes in degrading the acids. Most ammonium nitrogen in the wastewater was converted to nitrate nitrogen. Although the performance was lower compared to that of conventional system, activated sludge process was capable of degrading wastewater containing humic acids.Keywords : activated sludge, ammonium nitrogen, fill and draw, glucose, humic acid, wastewater


1992 ◽  
Vol 26 (5-6) ◽  
pp. 1315-1323 ◽  
Author(s):  
H. Aspegren ◽  
B. Andersson ◽  
U. Nyberg ◽  
J. la C. Jansen

Optimization of wastewater treatment plants with extensive phosphorus and nitrogen removal is complicated. The Klagshamn wastewater treatment plant in Sweden is operated with pre-precipitation of phosphorus with ferric chloride and denitrification with methanol as carbon source. An activated sludge process, operated with pre-precipitation and denitrification with external carbon source in a compartmentalized plant, requires only small tank volumes but increases the need for proper operation and optimization. On-line nitrogen, ammonia, and TOC sensors are used for a day-to-day control and optimization while mathematical modelling is used for long term strategic planning. The on-line measurements are further used as the basis for the modelling. TOC and ammonia sensors at the influent clearly identify typical and extreme loading variations and nitrate measurements in the activated sludge tanks and the effluent shows the dynamics of the processes. These measurements provide a basis for model calibration. In combination low residuals of nitrogen, phosphorus and organic matter can be achieved.


2002 ◽  
Vol 45 (4-5) ◽  
pp. 335-343 ◽  
Author(s):  
H. Spanjers ◽  
G.G. Patry ◽  
K.J. Keesman

This paper describes part of a project to develop a systematic approach to knowledge extraction from on-line respirometric measurements in support of wastewater treatment plant control and operation. The paper deals with the following issues: (1) test of the implementation of an automatic set-up consisting of a continuous laboratory respirometer integrated in a mobile trailer with sampling and dosing equipment, and data-acquisition and communication system; (2) assessment of activated sludge/sewage characteristics from sludge respirograms by model parameter estimation; (3) comparison of the parameter estimates with regular plant data and information obtained from supplementary wastewater respirograms. The paper describes the equipment and some of its measuring results from a period of one week at a large-scale wastewater treatment plant. The measurements were evaluated in terms of the common activated sludge modelling practice. The automatic set-up allowed reliable measurements during at least one week. The data were used to calibrate two different version of the model, and independent parameter estimates were obtained.


2013 ◽  
Vol 8 (1) ◽  
pp. 18-26
Author(s):  
T. Weinpel ◽  
V. Bakos ◽  
A. Jobbágy

Part-time aeration is frequently applied in activated sludge systems in order to decrease treatment costs by achieving nitrification and denitrification in the same basin. However, measurements and mathematical simulations carried out at the North-Budapest Wastewater Treatment Plant (Budapest, Hungary), clearly show that especially in the increasingly characteristic shortage of readily biodegradable carbon-source, this technique may lead to high effluent nitrate and/or ammonia concentrations at decreased temperatures. This situation may be worsened when co-digestion of external wastes with high N-content increase the ammonia concentration of sludge processing return flows. In these cases, denitrification should rather be enhanced in pre-anoxic zones. Pronounced pre-denitrification leads to better usage of the influent carbon-source and to considerably less methanol demand when dosing external carbon-source proves to be necessary.


2013 ◽  
Vol 68 (4) ◽  
pp. 916-922 ◽  
Author(s):  
Yinguang Chen ◽  
Xiong Zheng ◽  
Leiyu Feng ◽  
Hong Yang

Carbon, nitrogen, and phosphorus need to be recovered to reduce the environmental impact of waste activated sludge (WAS). In this study the improved short-chain fatty acid (SCFA) production from WAS by the addition of kitchen waste to adjust the ratio of carbon to nitrogen (C/N), and the efficient recovery of nitrogen and phosphorus from the fermentation liquid were reported. Firstly, the optimum conditions for SCFA production were found to be pH 8, temperature 35 °C, C/N ratio 21 mg-C/1 mg-N, and fermentation time 6 d, using the response surface methodology. After alkaline fermentation, the struvite precipitation method was applied to efficiently and simultaneously recover the released ammonia and phosphorus from the fermentation liquid. Finally, the fermentation liquid was used as the additional carbon source for biological nitrogen and phosphorus removal. It was observed that, compared with acetic acid, the use of fermentation liquid as carbon source showed greater removal efficiencies of total nitrogen and total phosphorus.


2017 ◽  
Vol 8 (3) ◽  
pp. 393-403 ◽  
Author(s):  
Abdelsalam Elawwad

Abstract Wastewater containing high ammonium concentrations is produced from various industrial activities. In this study, the author used a complex activated sludge model, improved by utilizing BioWin© (EnviroSim, Hamilton, Canada) simulation software, to gain understanding of the problem of instability in biological nitrogen removal (BNR). Specifically, the study focused on BNR in an industrial wastewater treatment plant that receives high-strength ammonium wastewater. Using the data obtained from a nine-day sampling campaign and routinely measured data, the model was successfully calibrated and validated, with modifications to the sensitive stoichiometric and kinetic parameters. Subsequently, the calibrated model was employed to study various operating conditions in order to optimize the BNR. These operating conditions include alkalinity addition, sludge retention time, and the COD/N ratio. The addition of a stripping step and modifications to the configuration of the aerators are suggested by the author to increase the COD/N ratio and therefore enhance denitrification. It was found that the calibrated model could successfully represent and optimize the treatment of the high-strength ammonium wastewater.


2004 ◽  
Vol 50 (7) ◽  
pp. 87-96 ◽  
Author(s):  
S. Salem ◽  
D.H.J.G. Berends ◽  
H.F. van der Roest ◽  
R.J. van der Kuij ◽  
M.C.M. van Loosdrecht

Bio-augmentation can be used to obtain nitrification in activated sludge processes that operate at ub-optimal solid retention times. A side-stream process, the so-called BABE® process that incorporates Nremoval and augmentation of nitrifiers has been developed. The principle is to implement a nitrification reactor in the sludge return line, the so-called BABE reactor. This reactor can be fed with an internal N-rich flow (e.g. effluent from the sludge treatment). Hence the nitrification capacity of an activated sludge process can be augmented by the addition of nitrifiers cultivated in the BABE reactor. A full-scale test of the BABE technology has been at the treatment plant Garmerwolde in Groningen, the Netherlands. The set-up allowed comparing between three different lines: with the BABE reactor, without rejectwater and with untreated rejectwater. Based on this, the two important tasks (N-removal and inoculation) performed by the BABE reactor could be quantified. The results of the practical work in Garmerwolde showed a higher nitrification rate in the water line where the BABE reactor was implemented and also lower effluent ammonia. The experiments on a practical scale have demonstrated univocally the effective and stable operation of the BABE technology. In addition, sludge samples in different streams as well as from the BABE reactor were analysed with FISH technique. The FISH results illustrated the augmentation effect of the BABE reactor on the stream with the BABE reactor. A mathematical model, based on ASM1 model and implemented in AQUASIM was developed and used for simulating the treatment plant of Garmerwolde. The simulation results indicated that better effect of the BABE technology is expected at lower ambient temperatures and smaller volume of the BABE reactor. The BABE reactor could also allow for providing more space for de-nitrification in the main water line when nitrification is efficient enough.


1999 ◽  
Vol 39 (8) ◽  
pp. 93-98 ◽  
Author(s):  
Chia-Yau Cheng ◽  
Irina Ribarova

This paper describes the results from a study carried out to investigate the feasibility of upgrading Parada wastewater treatment plant (WWTP) for biological nitrogen removal. The biological treatment of Parada WWTP is a conventional activated sludge process. Since 1992 only one of the three available aeration tanks has been used. Activated Sludge Model No.1 was used as a base for modelling of the activated sludge system. To accomplish all the calculations, AQUASIM software was applied. The model was calibrated and verified with data from Parada WWTP operation. Very good correlations between measured data and simulation results were achieved using stoichiometric and kinetic parameter values proposed by the authors of IAWQ Model No. 1. However, characterisation of the actual wastewater was necessary. Computer simulations with a verified and extended model were done to study whether the capacity of the treatment plant is enough for biological nitrogen removal. Very high effluent quality can be achieved if the first tank volume is used for denitrification, the second and third tank volumes are used for BOD removal and nitrification, the recirculating effluent flow ratio is 1.5 and the sludge age is 15 days.


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