Modelling and test of aeration tank settling (ATS)

2000 ◽  
Vol 41 (9) ◽  
pp. 179-184 ◽  
Author(s):  
M.K. Nielsen ◽  
H. Bechmann ◽  
M. Henze
Keyword(s):  
Deterministic Model ◽  
Wastewater Treatment Plants ◽  
Practical Implementation ◽  
Aeration Tank ◽  
Reliable Technique ◽  
Correct Model ◽  
Line Identification ◽  
On Line ◽  
Plant Capacity ◽  
Tank Settling

The use of aeration tank settling during high hydraulic loads on large wastewater treatment plants has previously been demonstrated as a reliable technique and proven valuable. The paper proposes a simplified deterministic model to predict the efficiency of the method. It is shown that a qualitatively correct model can be established. The simplicity of the model allows for on-line identification of the necessary parameters, so that no maintenance is needed to use of the on-line model for control. The practical implementation on three plants indicates that implementation of STAR with ATS control gives 50% increase of plant capacity for 3% extra cost.

Improvement of a recirculating plant by introducing star control

1995 ◽  
Vol 31 (2) ◽  
pp. 171-180 ◽  
Author(s):  
Marinus K. Nielsen ◽  
Tine B. Önnerth
Keyword(s):  
Wastewater Treatment ◽  
Real Time ◽  
Wastewater Treatment Plants ◽  
Control Strategies ◽  
Biological Nutrient Removal ◽  
Practical Implementation ◽  
Real Time Control ◽  
Dynamic Identification ◽  
Time Control ◽  
On Line

During the last 20 years, control of wastewater treatment plants has developed from very simple to advanced computer control methods based on on-line measurements. Fortunately, both on-line equipment and computer system technology are still developing fast and have become applicable at WWTPs. The use of on-line measurements for real time control is advantageous at most plants over 15.000 personal equivalent performing biological nutrient removal. Control strategies have demonstrated their efficiency at several Scandinavian wastewater treatment plants. Experience shows that the applied control strategies are efficient and robust for practical implementation, provide savings in energy and chemical consumption and decreases the nitrogen content in the effluent. Experience from a recirculating BNR plant using the STAR concept for advanced real time control is described. The on-line nutrient measurements and excitation of the processes through control strategies have improved the process understanding. Control has reduced the consumption of energy by about 30% and eliminated the need for external carbon addition, as well as improved the effluent quality of total nitrogen from the plant. The new measurements and data handling methods will make it possible to perform dynamic identification of activity in recirculating plants (Nielsen et.al., 1994), and hence give information as to which control strategies improve the biomass activity or favour desired cultures of micro-organisms.

Development of a new system for control and optimization of small wastewater treatment plants using oxidation-reduction potential (ORP)

1998 ◽  
Vol 38 (3) ◽  
pp. 307-314 ◽  
Author(s):  
T. Zipper ◽  
N. Fleischmann ◽  
R. Haberl
Keyword(s):  
Pilot Plant ◽  
Reduction Potential ◽  
Wastewater Treatment Plants ◽  
Control Strategies ◽  
Aeration Tank ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
Suitable Parameter ◽  
On Line ◽  
Time Cycle

For the development of new control strategies for small activated sludge systems (<500 P.E.) the oxidation-reduction potential (ORP) has been tested as a suitable parameter. Batch and continuous experiments in a pilot plant with alternating nitrification and denitrification phases proved the relation between the actual load and the behaviour of ORP in the aeration tank. Using a two-point controller, increasing load correlated with an extension of aerated phases in relation to unaerated phases. Decreasing load equalled to a decrease of the ratio of nitrification time-cycle time. On the basis of these results an ORP controller has been developed allowing both automatic setup and on-line adaption. Operational results from a pilot plant are presented, including effluent quality and energy efficiency.

Automatic buffer capacity based sensor for effluent quality monitoring

1996 ◽  
Vol 33 (1) ◽  
pp. 81-87
Author(s):  
L. Van Vooren ◽  
P. Willems ◽  
J. P. Ottoy ◽  
G. C. Vansteenkiste ◽  
W. Verstraete
Keyword(s):  
Wastewater Treatment ◽  
Buffer Capacity ◽  
Wastewater Treatment Plants ◽  
Data Interpretation ◽  
Full Scale ◽  
Quality Monitoring ◽  
Effluent Quality ◽  
Capacity Curves ◽  
On Line

The use of an automatic on-line titration unit for monitoring the effluent quality of wastewater plants is presented. Buffer capacity curves of different effluent types were studied and validation results are presented for both domestic and industrial full-scale wastewater treatment plants. Ammonium and ortho-phosphate monitoring of the effluent were established by using a simple titration device, connected to a data-interpretation unit. The use of this sensor as the activator of an effluent quality proportional sampler is discussed.

Upgrading to nutrient removal by means of internal carbon from sludge hydrolysis

1994 ◽  
Vol 29 (12) ◽  
pp. 31-40 ◽  
Author(s):  
Pia Prohaska Brinch ◽  
Kim Rindel ◽  
Kathryn Kalb
Keyword(s):  
Reaction Rate ◽  
Wastewater Treatment Plants ◽  
Secondary Treatment ◽  
N Removal ◽  
Sludge Hydrolysis ◽  
Speed Up ◽  
On Line ◽  
Full Scale Tests ◽  
Biological Phosphorus ◽  
Hydrolysis Of

Due to the introduction of stricter nutrient effluent standards, many existing wastewater treatment plants performing only primary or secondary treatment are about to be upgraded. As the space available at the plants is, however, often limited, processes are required which will accommodate the need for increased treatment capacity without requiring much more space. In the hydrolysis of primary or pre-precipitated sludge direct-degradable organic carbon is produced which can speed up the reaction rate and increase both biological phosphorus and nitrogen removal. Full-scale tests with dosing of hydrolysate for biological P and N removal, respectively, have shown that this is a most viable process. The use of on-line monitoring has improved the process further.

The Staging of Large Wastewater Treatment Plants - A “Modular” Approach

1992 ◽  
Vol 25 (4-5) ◽  
pp. 67-73
Author(s):  
H. Fleckseder ◽  
L. Prendl ◽  
H. Meulenbroek
Keyword(s):  
Wastewater Treatment ◽  
Driving Force ◽  
Wastewater Treatment Plants ◽  
Aeration Tank ◽  
Modular Approach ◽  
Central European ◽  
Plant Hydraulics ◽  
The World ◽  
Whole Life Cycle ◽  
Over Time

The primary driving force for re-investments in wastewater treatment plants in Austria - and also other countries in Central Europe - is at present not an increase in load to treatment but a marked increase in effluent requirements to be fulfilled. (The re-investments necessary for sludge handling and treatment remain outside this paper.) Within a period of 20 years, the load specific requirements on aeration tank volume rose five- to tenfold, when Lv = 2.0 kg BOD5/(m3d) was the starting value, and roughly doubled for final clarifiers. In addition, the importance of the application and expansion of primary sedimentation decreased as well. This development over time in Central European countries as well as the need to utilize previous investments as long as possible - 35 to 60 years for civil works are common as periods of depreciation - indicate that investments in new plant at any location in the world have to consider the possible whole life cycle of a plant and that plant hydraulics becomes the “key hook” for expandability.

Components of a model-based operation system for wastewater treatment plants

1999 ◽  
Vol 39 (4) ◽  
pp. 103-111 ◽  
Author(s):  
Frank Obenaus ◽  
Karl-Heinz Rosenwinkel ◽  
Jens Alex ◽  
Ralf Tschepetzki ◽  
Ulrich Jumar
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plants ◽  
Operation System ◽  
Model Based ◽  
Measuring Devices ◽  
Crucial Component ◽  
Simulation Calculation ◽  
On Line ◽  
Main Components

This report presents the main components of a system for the model-based control of aerobic biological wastewater treatment plants. The crucial component is a model which is linked to the actual processes via several interfaces and which contains a unit which can immediately follow up the current process state. The simulation calculation of the model is based on data which are yielded by on-line measuring devices. If the sensors should fail at times, there are available a number of alternative concepts, some of which are based on the calculations of artificial neural networks or linear methods.

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.

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