A process and model concept for microbial wastewater transformations in gravity sewers

1998 ◽  
Vol 37 (1) ◽  
pp. 233-241 ◽  
Author(s):  
T. Hvitved-Jacobsen ◽  
J. Vollertsen ◽  
P. H. Nielsen
Keyword(s):  
Organic Matter ◽  
Activated Sludge ◽  
Conceptual Model ◽  
Model Concept ◽  
Aerobic Conditions ◽  
Anaerobic Processes ◽  
Activated Sludge Model ◽  
Microbial System ◽  
Gravity Sewer ◽  
Further Development

A fundamental and conceptual description of the microbial system in sewers in terms of wastewater organic matter transformations is presented. The description is examplified being under gravity sewer conditions and a conceptual model including main aerobic transformations is shown. The conceptual model of the microbial system basically agrees with the activated sludge model, (Henze et al., 1987). The model can be extended, e.g. to include anaerobic processes and processes taking place in resuspended sewer sediments under aerobic conditions. The concept for modelling transformations of wastewater during transport in sewers is recommended as the basis for further development.

Optimizing the Step-Feed Ratio and Modeling the Effluents of Aerobic Tank with ASM1 in ECOSUNIDE Process

2012 ◽  
Vol 178-181 ◽  
pp. 526-530
Author(s):  
Ruo Gu Li ◽  
Yan Qiu Zhang
Keyword(s):  
Organic Matter ◽  
Activated Sludge ◽  
Ammonia Nitrogen ◽  
Feed Ratio ◽  
Optimum Ratio ◽  
Matlab Simulink ◽  
Activated Sludge Model ◽  
Model Based ◽  
Autotrophic Bacteria ◽  
Optimum Model

The step feed model based on the Activated Sludge Model No.1 (ASM1) and the optimum model of the ammonia nitrogen (SNH) removal in wastewater were established. Four aeration tanks under the different step feed ratios were simulated by Matlab Simulink. The results show that single-feeding is conducive to the removal of readily biodegradable substrate (SS) and the growth of heterotrophic organisms (XBH), and to lower the biodegradable substrate (XS) at the same time. The SS, XS, and SNH concentrations are 1.36, 5.98, and 3.02 mg/L respectively in effluent. However, the step-feeding is conducive to the SNH removal, and the autotrophic bacteria (XBA) growth. Under the step feed ratio (25/25/25/25%), the SS, XS, and SNH concentrations are 2.64, 10.79, and 2.61 mg/L respectively. Under the optimum ratio (28.7/23.6/20.4/27.2%), step-feeding could further facilitate the removal of SNH and hinder the removal of organic matter, their concentrations are 2.70, 10.98, and 2.47 mg/L respectively.

Application of Activated Sludge Model No. 3 for the Modeling of Organic Matter Biodegradation at Thermophilic Temperatures

2007 ◽  
Vol 79 (5) ◽  
pp. 554-560 ◽  
Author(s):  
Róbert Kovács ◽  
Zsolt Csikor ◽  
Ferenc Házi ◽  
Pál Miháltz
Keyword(s):  
Organic Matter ◽  
Activated Sludge ◽  
Activated Sludge Model

The Activated Sludge Model No. 2: biological phosphorus removal

1995 ◽  
Vol 31 (2) ◽  
pp. 1-11 ◽  
Author(s):  
W. Gujer ◽  
M. Henze ◽  
T. Mino ◽  
T. Matsuo ◽  
M. C. Wentzel ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Phosphorus Removal ◽  
Biological Nutrient Removal ◽  
Final Report ◽  
Full Model ◽  
Biological Phosphorus Removal ◽  
Activated Sludge Model ◽  
Further Development ◽  
Biological Phosphorus ◽  
Activated Sludge Systems

The Activated Sludge Model No. 2 is introduced as a further development of Activated Sludge Model No. 1. Model No. 2 introduces phosphorus accumulating organisms (PAO) and allows us to simulate the behaviour of biological nutrient removal activated sludge systems. Typical wastewater composition and a set of stoichiometric and kinetic parameters are provided in order to make reasonable predictions. The model has not yet been calibrated or verified in any full-scale application. This report contains a simplified version of the full Model No. 2; the full model is published in the final report of the Task Group (Henze et al., 1994).

Dissolved oxygen in gravity sewers – measurement and simulation

2002 ◽  
Vol 45 (3) ◽  
pp. 35-44 ◽  
Author(s):  
G. Gudjonsson ◽  
J. Vollertsen ◽  
T. Hvitved-Jacobsen
Keyword(s):  
Organic Matter ◽  
Dissolved Oxygen ◽  
Conceptual Model ◽  
Low Temperatures ◽  
Bulk Water ◽  
Diurnal Variations ◽  
Strictly Aerobic ◽  
Upstream Station ◽  
Measuring Campaign ◽  
Gravity Sewer

Dissolved oxygen (DO) concentrations were during 2 months continuously measured in an intercepting sewer. Measurements were made upstream and downstream in a 3.6 km gravity sewer. DO showed significant diurnal variations mainly caused by changes in the organic matter composition of the wastewater. At low temperatures the gravity sewer was strictly aerobic. However, towards the end of the measuring campaign, DO concentrations decreased as temperature increased and the sewer became anaerobic part of the day. A conceptual model that takes into account bulk water and biofilm DO uptake as well as reaeration was used to simulate the DO measured. Using measurements from the upstream station as input, the model was calibrated to yield good validation results of the DO at the downstream station.

Pond Treatment of Rettery Wastewaters

1987 ◽  
Vol 19 (12) ◽  
pp. 79-83
Author(s):  
K. Bartoszewski ◽  
A. Bilyk
Keyword(s):  
Activated Sludge ◽  
Treatment Process ◽  
New Technology ◽  
Treatment Plant ◽  
Anaerobic Treatment ◽  
Cod Removal ◽  
Experimental Results ◽  
Aerobic Conditions ◽  
Aerobic Stabilization ◽  
In Series

Rettery wastewaters were treated in anaerobic and aerobic ponds. Anaerobic treatment yielded efficiencies of BOD5 and COD removal as low as 20%. The treatment process conducted under aerobic conditions in aerated and stabilizing ponds arranged in series took from 18 to 20 days and gave efficiencies of BOD5 and COD removal amounting to 90%. The experimental results were interpreted by virtue of the Eckenfelder equation. Excess activated sludge was subjected to aerobic stabilization in a separate tank. A new technology was suggested for the existing obsolete industrial treatment plant.

The Use of Anoxic Selectors for the Control of Low F/M Activated Sludge Bulking

1989 ◽  
Vol 21 (6-7) ◽  
pp. 609-619 ◽  
Author(s):  
Y.-J. Shao ◽  
David Jenkins
Keyword(s):  
Organic Matter ◽  
Activated Sludge ◽  
Pilot Plant ◽  
Detention Time ◽  
Substrate Removal ◽  
Batch System ◽  
Sludge Bulking ◽  
N Removal ◽  
Soluble Substrate ◽  
Activated Sludge Systems

Laboratory and pilot plant experiments on anoxic selector activated sludge systems were conducted on two wastewaters in some cases supplemented with nitrate, acetate or glucose. To prevent bulking sufficient anoxic selector detention time and nitrate levels must be available to reduce selector effluent soluble COD to below 100 mg/l and to reduce readily metabolizable organic matter to virtually zero (< 1 mg/l). Soluble COD/NO3-N removal stoichiometry is in the range 6.0-6.7. Selector systems have elevated soluble substrate removal and denitrification rates compared to CSTR systems. These rates are not affected greatly by temperature (20-25°C) for CSTR sludges but are for selector sludges. Upon exhaustion of nitrate in a selector soluble COD leaks out of the activated sludge in significant amounts. Thiothrix sp. and type 021N denitrify only to NO2 and at much slower rates than Zoogloearamigera does to N2. A sequencing batch system provides an optimistic estimate of the SVI that can be obtained by an anoxic selector system.

Hydrolysis of organic wastewater particles in laboratory scale and pilot scale biofilm reactors under anoxic and aerobic conditions

1998 ◽  
Vol 38 (8-9) ◽  
pp. 179-188 ◽  
Author(s):  
K. F. Janning ◽  
X. Le Tallec ◽  
P. Harremoës
Keyword(s):  
Organic Matter ◽  
Mass Balance ◽  
Particulate Organic Matter ◽  
Removal Rate ◽  
Pilot Scale ◽  
Laboratory Scale ◽  
Synthetic Wastewater ◽  
Aerobic Conditions ◽  
Biofilm Reactors ◽  
Hydrolysis Of

Hydrolysis and degradation of particulate organic matter has been isolated and investigated in laboratory scale and pilot scale biofilters. Wastewater was supplied to biofilm reactors in order to accumulate particulates from wastewater in the filter. When synthetic wastewater with no organic matter was supplied to the reactors, hydrolysis of the particulates was the only process occurring. Results from the laboratory scale experiments under aerobic conditions with pre-settled wastewater show that the initial removal rate is high: rV, O2 = 2.1 kg O2/(m3 d) though fast declining towards a much slower rate. A mass balance of carbon (TOC/TIC) shows that only 10% of the accumulated TOC was transformed to TIC during the 12 hour long experiment. The pilot scale hydrolysis experiment was performed in a new type of biofilm reactor - the B2A® biofilter that is characterised by a series of decreasing sized granular media (80-2.5 mm). When hydrolysis experiments were performed on the anoxic pilot biofilter with pre-screened wastewater particulates as carbon source, a rapid (rV, NO3=0.7 kg NO3-N/(m3 d)) and a slowler (rV, NO3 = 0.3 kg NO3-N/(m3 d)) removal rate were observed at an oxygen concentration of 3.5 mg O2/l. It was found that the pilot biofilter could retain significant amounts of particulate organic matter, reducing the porosity of the filter media of an average from 0.35 to 0.11. A mass balance of carbon shows that up to 40% of the total incoming TOC accumulates in the filter at high flow rates. Only up to 15% of the accumulated TOC was transformed to TIC during the 24 hour long experiment.

scholarly journals A NEW CONCEPTUAL MODEL FOR THE DEVELOPMENT OF PROCESS TECHNOLOGY IN PROCESS INDUSTRY: A POINT OF DEPARTURE FOR THE TRANSFORMATION OF THE "PROCESS DEVELOPMENT PROCESS" INTO A FORMAL WORK PROCESS?

2000 ◽  
Vol 04 (03) ◽  
pp. 319-346 ◽  
Author(s):  
THOMAS LAGER
Keyword(s):  
Conceptual Model ◽  
Development Process ◽  
Process Development ◽  
Process Industry ◽  
Process Technology ◽  
Work Process ◽  
Starting Point ◽  
Three Phase ◽  
Further Development ◽  
A Company

In an exploratory survey to R&D managers in different sectors of European Process Industry, the importance and present use of a formal work process for process development has been studied. A new conceptual three-phase model for the "process development process", including the identification of production needs, process development and transfer of results to production, was also tested. The results show that only 44% of the companies in the study presently use a formal work process for process development, but the need for such a process is considered to be high. Good support was given for the new conceptual model as a starting point for further development of a company-specific "process development process".

Comparison of two treatments for the removal of selected organic micropollutants and bulk organic matter: conventional activated sludge followed by ultrafiltration versus membrane bioreactor

2011 ◽  
Vol 63 (4) ◽  
pp. 733-740 ◽  
Author(s):  
E. Sahar ◽  
M. Ernst ◽  
M. Godehardt ◽  
A. Hein ◽  
J. Herr ◽  
...  
Keyword(s):  
Organic Matter ◽  
Activated Sludge ◽  
Membrane Fouling ◽  
Membrane Bioreactor ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Macrolide Antibiotics ◽  
Organic Micropollutants ◽  
Removal Rates ◽  
Conventional Activated Sludge

The potential of membrane bioreactor (MBR) systems to remove organic micropollutants was investigated at different scales, operational conditions, and locations. The effluent quality of the MBR system was compared with that of a plant combining conventional activated sludge (CAS) followed by ultrafiltration (UF). The MBR and CAS-UF systems were operated and tested in parallel. An MBR pilot plant in Israel was operated for over a year at a mixed liquor suspended solids (MLSS) range of 2.8–10.6 g/L. The MBR achieved removal rates comparable to those of a CAS-UF plant at the Tel-Aviv wastewater treatment plant (WWTP) for macrolide antibiotics such as roxythromycin, clarithromycin, and erythromycin and slightly higher removal rates than the CAS-UF for sulfonamides. A laboratory scale MBR unit in Berlin – at an MLSS of 6–9 g/L – showed better removal rates for macrolide antibiotics, trimethoprim, and 5-tolyltriazole compared to the CAS process of the Ruhleben sewage treatment plant (STP) in Berlin when both were fed with identical quality raw wastewater. The Berlin CAS exhibited significantly better benzotriazole removal and slightly better sulfamethoxazole and 4-tolyltriazole removal than its MBR counterpart. Pilot MBR tests (MLSS of 12 g/L) in Aachen, Germany, showed that operating flux significantly affected the resulting membrane fouling rate, but the removal rates of dissolved organic matter and of bisphenol A were not affected.

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