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.

Techniques for and Experience with Biological Nutrient Removal – Danish Long-Term Operating and Optimization Experience

1991 ◽  
Vol 24 (10) ◽  
pp. 211-216 ◽  
Author(s):  
Erik Bundgaard ◽  
Jan Pedersen
Keyword(s):  
Wastewater Treatment Plants ◽  
Batch Reactor ◽  
Biological Nutrient Removal ◽  
Biological Processes ◽  
Biological Phosphorus Removal ◽  
N Removal ◽  
And Control ◽  
Biological Phosphorus ◽  
P Removal

New Danish legislation demands that, by 1993, all wastewater treatment plants serving more than 15,000 PE must reduce total nitrogen and total phosphorus to 8 mg/l and 1.5 mg/l, respectively. On the basis of full-scale experience from more than 35 existing plants with nitrogen removal and 5 plants with biological phosphorus removal, these targets seem quite realistic. The plants are operated in accordance with the Danish-developed methods BIO-DENITRO (N removal) and BIO-DENIPHO (N and P removal). These-methods offer most of the advantages of both the Sequencing Batch Reactor and the recirculation systems but eliminate some of the disadvantages such as intermittent operation and discharge, and internal recirculation. Further developments towards improved process performance and control are achieved through the development of new plant types utilizing hydrolyzed sludge as an additional carbon source and through the application of mathematical models for simulation of the biological processes under various operating and load conditions.

Reduction of nutrient emission by sludge hydrolysis

1997 ◽  
Vol 35 (10) ◽  
pp. 79-85 ◽  
Author(s):  
Kjaer Andreasen ◽  
Gert Petersen ◽  
Henrik Thomsen ◽  
Rune Strube
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plants ◽  
Cost Benefit Analysis ◽  
Cost Benefit ◽  
Primary Sludge ◽  
Biological Sludge ◽  
Nutrient Emission ◽  
Sludge Hydrolysis ◽  
Cost Efficient ◽  
Hydrolysis Of

Biological sludge hydrolysis was demonstrated in full scale at three Danish wastewater treatment plants. For primary sludge the hydrolysis yield expressed in terms of filtrable COD varied from 9–16% of the total COD in the sludge (WTPs 1 & 2) and for the hydrolysis of activated sludge a yield of 2.5% of the total COD was found. The addition of hydrolysate was demonstrated to improve the biological P removal considerably. No effect on the nitrogen removal could be identified due to a favourable wastewater composition during the demonstration phase. A cost-benefit analysis showed that biological sludge hydrolysis may be a cost efficient process that should be considered in connection with the upgrading of wastewater treatment plants to nutrient removal.

Upgrading Wastewater Treatment Plants with Anaerobic Selectors

1990 ◽  
Vol 22 (7-8) ◽  
pp. 35-43
Author(s):  
K. D. Tracy ◽  
S. N. Hong
Keyword(s):  
Phosphorus Removal ◽  
Wastewater Treatment Plants ◽  
Full Scale ◽  
High Rate ◽  
Nitrogen Control ◽  
Biological Phosphorus Removal ◽  
Conventional Activated Sludge ◽  
And Performance ◽  
Activated Sludge Processes ◽  
Biological Phosphorus

The anaerobic selector of the A/0™ process offers many advantages over conventional activated sludge processes with respect to process performance and operational stability. This high-rate, single-sludge process has been successfully demonstrated in full-scale operations for biological phosphorus removal and total nitrogen control in addition to BOD and TSS removal. This process can be easily utilized in upgrading existing treatment plants to meet stringent discharge limitations and to provide capacity expansion. Upgrades of two full-scale installations are described and performance data from the two facilities are presented.

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.

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.

Cyclization and acid-catalyzed hydrolysis of O-benzoylbenzamidoximes

1986 ◽  
Vol 51 (12) ◽  
pp. 2786-2797
Author(s):  
František Grambal ◽  
Jan Lasovský
Keyword(s):  
Reaction Rate ◽  
Kinetic Isotope ◽  
Acid Base Equilibrium ◽  
Mineral Acids ◽  
Kinetics Of Formation ◽  
Acid Catalyzed ◽  
Ph Scale ◽  
Kinetics Of ◽  
Hydrolysis Of ◽  
Derivatives Of

Kinetics of formation of 1,2,4-oxadiazoles from 24 substitution derivatives of O-benzoylbenzamidoxime have been studied in sulphuric acid and aqueous ethanol media. It has been found that this medium requires introduction of the Hammett H0 function instead of the pH scale beginning as low as from 0.1% solutions of mineral acids. Effects of the acid concentration, ionic strength, and temperature on the reaction rate and on the kinetic isotope effect have been followed. From these dependences and from polar effects of substituents it was concluded that along with the cyclization to 1,2,4-oxadiazoles there proceeds hydrolysis to benzamidoxime and benzoic acid. The reaction is thermodynamically controlled by the acid-base equilibrium of the O-benzylated benzamidoximes.

Enhanced biological phosphorus removal process implemented in membrane bioreactors to improve phosphorous recovery and recycling

2003 ◽  
Vol 48 (1) ◽  
pp. 87-94 ◽  
Author(s):  
B. Lesjean ◽  
R. Gnirss ◽  
C. Adam ◽  
M. Kraume ◽  
F. Luck
Keyword(s):  
Phosphorus Removal ◽  
Theoretical Calculations ◽  
Enhanced Biological Phosphorus Removal ◽  
Biological Phosphorus Removal ◽  
P Limitation ◽  
Batch Tests ◽  
P Content ◽  
On Line ◽  
Biological Phosphorus ◽  
P Removal

The enhanced biological phosphorus removal (EBPR) process was adapted to membrane bioreactor (MBR) technology. One bench-scale plant (BSP, 200-250 L) and two pilot plants (PPs, 1,000-3,000 L each) were operated under several configurations, including pre-denitrification and post-denitrification without addition of carbon source, and two solid retention times (SRT) of 15 and 26 d. The trials showed that efficient Bio-P removal can be achieved with MBR systems, in both pre- and post-denitrification configurations. EBPR dynamics could be clearly demonstrated through batch-tests, on-line measurements, profile analyses, P-spiking trials, and mass balances. High P-removal performances were achieved even with high SRT of 26 d, as around 9 mgP/L could be reliably removed. After stabilisation, the sludge exhibited phosphorus contents of around 2.4%TS. When spiked with phosphorus (no P-limitation), P-content could increase up to 6%TS. The sludge is therefore well suited to agricultural reuse with important fertilising values. Theoretical calculations showed that increased sludge age should result in a greater P-content. This could not be clearly demonstrated by the trials. This effect should be all the more significant as the influent is low in suspended solids.

scholarly journals Thermochemical Heat Storage in a Lab-Scale Indirectly Operated CaO/Ca(OH)2 Reactor—Numerical Modeling and Model Validation through Inverse Parameter Estimation

2021 ◽  
Vol 11 (2) ◽  
pp. 682
Author(s):  
Gabriele Seitz ◽  
Farid Mohammadi ◽  
Holger Class
Keyword(s):  
Numerical Model ◽  
Gas Flow ◽  
Reaction Rate ◽  
Heat Storage ◽  
Bulk Material ◽  
Fixed Bed ◽  
Experimental Results ◽  
Fixed Bed Reactor ◽  
Thermochemical Heat Storage ◽  
Speed Up

Calcium oxide/Calcium hydroxide can be utilized as a reaction system for thermochemical heat storage. It features a high storage capacity, is cheap, and does not involve major environmental concerns. Operationally, different fixed-bed reactor concepts can be distinguished; direct reactor are characterized by gas flow through the reactive bulk material, while in indirect reactors, the heat-carrying gas flow is separated from the bulk material. This study puts a focus on the indirectly operated fixed-bed reactor setup. The fluxes of the reaction fluid and the heat-carrying flow are decoupled in order to overcome limitations due to heat conduction in the reactive bulk material. The fixed bed represents a porous medium where Darcy-type flow conditions can be assumed. Here, a numerical model for such a reactor concept is presented, which has been implemented in the software DuMux. An attempt to calibrate and validate it with experimental results from the literature is discussed in detail. This allows for the identification of a deficient insulation of the experimental setup. Accordingly, heat-loss mechanisms are included in the model. However, it can be shown that heat losses alone are not sufficient to explain the experimental results. It is evident that another effect plays a role here. Using Bayesian inference, this effect is identified as the reaction rate decreasing with progressing conversion of reactive material. The calibrated model reveals that more heat is lost over the reactor surface than transported in the heat transfer channel, which causes a considerable speed-up of the discharge reaction. An observed deceleration of the reaction rate at progressed conversion is attributed to the presence of agglomerates of the bulk material in the fixed bed. This retardation is represented phenomenologically by mofifying the reaction kinetics. After the calibration, the model is validated with a second set of experimental results. To speed up the calculations for the calibration, the numerical model is replaced by a surrogate model based on Polynomial Chaos Expansion and Principal Component Analysis.

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