OPTIMISATION OF W ASTEW A TER TREATMENT PLANTS BY MEANS OF COMPUTER MODELS

1994 ◽  
Vol 30 (4) ◽  
pp. 181-190 ◽  
Author(s):  
René Dupont ◽  
Ole Sinkjær
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Pilot Plant ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Operational Strategies ◽  
Nitrification Process ◽  
Computer Based ◽  
Calibration Tool ◽  
Denitrification Process

The objective of the work presented is to demonstrate how computer based models can be used to improve the effluent quality from wastewater treatment plants by optimisation of the operation. The investigation was carried out in connection with pilot plant investigations at Damhusllen Wastewater Treatment Plant in order to establish the design basis for upgrading the treatment plants in the city of Copenhagen. Calibration of the model was done with thorough characterisation of the wastewater and the activated sludge as the primary calibration tool. Special attention was paid to the nitrification process, which by previous investigations was shown to be occasionally inhibited. Model constants for the nitrification process were detennined from experiments. Default constants were used for nearly all other constants. The pilot plant was optimized with the calibrated model. Different operational strategies for improvement of the denitrification process were tested. The denitrification process was operated relatively poorly at the time for the optimisation. The calibration showed that it was possible to calibrate the model using the characterization of the wastewater and the activated sludge as the primary calibration tool. Further it was shown that the calihrated model could be used as a tool for optimising the operation of the pilot plant. The suggested operation correlated well with the practical realisable operation.

Using metazoa to reduce sludge production

1997 ◽  
Vol 36 (11) ◽  
pp. 171-179 ◽  
Author(s):  
J. H. Rensink ◽  
W. H. Rulkens
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Domestic Wastewater ◽  
Brewery Wastewater ◽  
Trickling Filters ◽  
Starting Point ◽  
Nitrification Process ◽  
Sludge Production

Pilot plant experiments have been carried out to study the mineralization of sludge from biological wastewater treatment plants by worms such as Tubificidae. Trickling filters filled with lava slags were continuously fed with a certain quantity of excess activated sludge of a Dutch brewery wastewater treatment plant (Bavaria) by recirculation during 10 to 14 days. At the starting point of each experiment the trickling filters were inoculated with Tubificidae. Recirculation of sludge showed that use of Tubificidae resulted in a COD reduction of the sludge (mixed liquor) of 18–67–. Without worms this reduction was substantially lower. The sludge production in a pilot activated sludge system for treating settled domestic wastewater reduced from 0.40 to 0.15 g MLSS/g COD removed when Tubificidae were added to the system. The lower amounts of sludge were always accompanied by an increase of nitrate and phosphate concentration in the wastewater. There was no disturbance of the nitrification process. Application of Tubificidae or other worms may have interesting potential for practical application.

scholarly journals Investigation of Activated Sludge Process

2017 ◽  
Vol 9 (4) ◽  
pp. 413-418
Author(s):  
Aušra Mažeikienė ◽  
Julita Starenko
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plant ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Biological Indicators ◽  
Ammonium Nitrogen ◽  
Sources Of Pollution ◽  
Treated Sewage ◽  
Nitrification Process

It is important to control not only the large wastewater treatment plants work, but also the work of individual small wastewater treatment plants for the protection of environment. Individual small wastewater treatment plants can become the local sources of pollution, when they are not functioning properly. Sewage purification indicators are not always the same as declared at wastewater treatment plants documentation in real conditions, so it is important to control the properly work of individual small wastewater treatment plants. The work of the small wastewater treatment plant AT-6 was analyzed by the treated sewage results (BDS7, SM, NH4-N, NO3-N, NO2-N, PO4-P), the quality of activated sludge, biological indicators and enzymatic activity in this article. The nitrification process was not going very well by the results of research, because there was the 72 mg/l concentration of ammonium nitrogen remaining in the cleaned wastewater. The morphological study of the activated sludge has confirmed the hypothesis that the necessary conditions for nitrification process were not established. The oxygen supply was increased and the small wastewater treatment plant functioning become more efficient, because nitrification process started working properly – there was less than 1 mg/l of ammonium nitrogen remaining in the cleaned wastewater.

OPTIMIZING OPERATION OF WASTEWATER TREATMENT PLANTS BY OFFLINE AND ONLINE COMPUTER SIMULATION

1994 ◽  
Vol 30 (2) ◽  
pp. 165-174 ◽  
Author(s):  
Ralf Otterpohl ◽  
Thomas Rolfs ◽  
Jörg Londong
Keyword(s):  
Computer Simulation ◽  
Wastewater Treatment ◽  
Activated Sludge ◽  
Nitrogen Removal ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Historical Analysis ◽  
Computer Work ◽  
Biological Phosphorus Removal ◽  
Wide Range

Computer simulation of activated sludge plant for nitrogen removal has become a reliable tool to predict the behaviour of the plant Models including biological phosphorus removal still require some practical experience but they should be available soon. This will offer an even wider range than today's work with nitrogen removal. One major benefit of computer simulation of wastewater treatment plants (WTP) is the optimization of operation. This can be done offline if hydrographs of a plant are collected and computer work is done with “historical” analysis. With online simulation the system is fed with hydrographs up to the actual time. Prognosis can be done from the moment of the computer work based on usual hydrographs. The work of the authors shows how accuratly a treatment plant can be described, when many parameters are measured and available as hydrographs. A very careful description of all details of the special plant is essential, requiring a flexible simulation tool. Based on the accurate simulation a wide range of operational decisions can be evaluated. It was possible to demonstrate that the overall efficiency in nitrogen removal and energy consumption of ml activated sludge plant can be improved.

Suspended carrier technology allows upgrading high-rate activated sludge plants for nitrogen removal via process intensification

2000 ◽  
Vol 41 (4-5) ◽  
pp. 5-12 ◽  
Author(s):  
E.v. Münch ◽  
K. Barr ◽  
S. Watts ◽  
J. Keller
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Residence Time ◽  
Nitrogen Removal ◽  
Wastewater Treatment Plant ◽  
Pilot Plant ◽  
Treatment Plant ◽  
Carbon Removal ◽  
Suspended Carrier ◽  
Plastic Media

The Oxley Creek wastewater treatment plant is a conventional 185,000 EP BOD removal activated sludge plant that is to be upgraded for nitrogen removal to protect its receiving water bodies, the Brisbane River and Moreton Bay. Suspended carrier technology is one possible way of upgrading this activated sludge wastewater treatment plant for nitrogen removal. Freely moving plastic media is added to the aeration zone, providing a growth platform for nitrifying bacteria and increasing the effective solids residence time (SRT). This paper presents the results from operating a pilot plant for 7 months at the Oxley Creek WWTP in Brisbane, Australia. Natrix Major 12/12 plastic media, developed by ANOX (Lund, Sweden), was trialed in the pilot plant. The pilot plant was operated with a mixed liquor suspended solids concentration of 1220 mg/L and a total hydraulic residence time of 5.4 hours, similar to the operating conditions in the full-scale Stage 1&2 works at the Oxley Creek WWTP. The plastic carriers were suspended in the last third of the bioreactor volume, which was aerated to a DO setpoint of 4.0 mg/L. The first third of the bioreactor volume was made anoxic and the second third served for carbon removal, being aerated to a DO setpoint of 0.5 mg/L. The results from the pilot plant indicate that an average effluent total inorganic nitrogen concentration (ammonia-N plus NOx−N) of less than 12 mg/L is possible. However, the effluent ammonia concentrations from the pilot plant showed large weekly fluctuations due to the intermittent operation of the sludge dewatering centrifuge returning significant ammonia loads to the plant on three days of the week. Optimising denitrification was carried out by lowering the DO concentration in the influent and in the carbon removal reactor. The results from the pilot plant study show that the Oxley Creek WWTP could be upgraded for nitrogen removal without additional tankage, using suspended carrier technology.

Model-based evaluation of nitrogen removal in a tannery wastewater treatment plant

2004 ◽  
Vol 50 (6) ◽  
pp. 251-260 ◽  
Author(s):  
M.S. Moussa ◽  
A.R. Rojas ◽  
C.M. Hooijmans ◽  
H.J. Gijzen ◽  
M.C.M. van Loosdrecht
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Computer Modelling ◽  
Treatment Plant ◽  
Domestic Wastewater ◽  
Plant Performance ◽  
Accurate Estimation ◽  
Model Parameters ◽  
Biological Tests

Computer modelling has been used in the last 15 years as a powerful tool for understanding the behaviour of activated sludge wastewater treatment systems. However, computer models are mainly applied for domestic wastewater treatment plants (WWTPs). Application of these types of models to industrial wastewater treatment plants requires a different model structure and an accurate estimation of the kinetics and stoichiometry of the model parameters, which may be different from the ones used for domestic wastewater. Most of these parameters are strongly dependent on the wastewater composition. In this study a modified version of the activated sludge model No. 1 (ASM 1) was used to describe a tannery WWTP. Several biological tests and complementary physical-chemical analyses were performed to characterise the wastewater and sludge composition in the context of activated sludge modelling. The proposed model was calibrated under steady-state conditions and validated under dynamic flow conditions. The model was successfully used to obtain insight into the existing plant performance, possible extension and options for process optimisation. The model illustrated the potential capacity of the plant to achieve full denitrification and to handle a higher hydraulic load. Moreover, the use of a mathematical model as an effective tool in decision making was demonstrated.

Controlling Activated Sludge Process Using EFOR

1992 ◽  
Vol 26 (3-4) ◽  
pp. 783-790
Author(s):  
J. Pedersen
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Simulation Program ◽  
Activated Sludge Process ◽  
Activated Sludge Model

A newly developed simulation program, based on the Activated Sludge Model No. 1, has been investigated for its controlling abilities. The program is capable of simulating most of the control types which have been applied to wastewater treatment plants. The program was tested on a nitrifying and a denitrifying treatment plant. The results showed that the model makes good simulations of the applied controls.

Experience with Two-Stage Activated Sludge Plants for Industrial Wastewaters in Korea

1992 ◽  
Vol 25 (4-5) ◽  
pp. 427-428 ◽  
Author(s):  
R. Schulze-Rettmer ◽  
S. S. Kim ◽  
S. S. Son
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plant ◽  
Pilot Plant ◽  
Treatment Plant ◽  
Activated Sludge Process ◽  
Two Stage ◽  
Industrial Wastewaters ◽  
Textile Dyeing ◽  
One Year

The two-stage activated sludge process (AB-process, i.e. adsorption activated sludge process) invented by Boehnke was successfully applied to several municipal and industrial wastewaters in Korea. The first large wastewater treatment plant for the combined effluents of 22 textile dyeing companies was constructed in Taegu and started operation in 1989. Two years earlier pilot plant runs were performed. The AB-process proved to be superior to any other activated sludge process. BOD was reduced from 1200 mg/l down to 24 mg/l. In the meantime in Korea several further AB-process treatment plants were constructed, the overall planning and constructing period being not longer than one year.

scholarly journals LCA of a Membrane Bioreactor Compared to Activated Sludge System for Municipal Wastewater Treatment

Membranes ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 421
Author(s):  
Dimitra C. Banti ◽  
Michail Tsangas ◽  
Petros Samaras ◽  
Antonis Zorpas
Keyword(s):  
Wastewater Treatment ◽  
Life Cycle ◽  
Activated Sludge ◽  
Membrane Bioreactor ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Real Data ◽  
Municipal Wastewater Treatment ◽  
Conventional Activated Sludge

Membrane bioreactor (MBR) systems are connected to several advantages compared to the conventional activated sludge (CAS) units. This work aims to the examination of the life cycle environmental impact of an MBR against a CAS unit when treating municipal wastewater with similar influent loading (BOD = 400 mg/L) and giving similar high-quality effluent (BOD < 5 mg/L). The MBR unit contained a denitrification, an aeration and a membrane tank, whereas the CAS unit included an equalization, a denitrification, a nitrification, a sedimentation, a mixing, a flocculation tank and a drum filter. Several impact categories factors were calculated by implementing the Life Cycle Assessment (LCA) methodology, including acidification potential, eutrophication potential, global warming potential (GWP), ozone depletion potential and photochemical ozone creation potential of the plants throughout their life cycle. Real data from two wastewater treatment plants were used. The research focused on two parameters which constitute the main differences between the two treatment plants: The excess sludge removal life cycle contribution—where GWPMBR = 0.50 kg CO2-eq*FU−1 and GWPCAS = 2.67 kg CO2-eq*FU−1 without sludge removal—and the wastewater treatment plant life cycle contribution—where GWPMBR = 0.002 kg CO2-eq*FU−1 and GWPCAS = 0.14 kg CO2-eq*FU−1 without land area contribution. Finally, in all the examined cases the environmental superiority of the MBR process was found.

scholarly journals Initiating Biodegradation of Polyvinylpyrrolidone in an Aqueous Aerobic Environment: Technical Note / Zainicjowanie Biodegradacji Poliwinylopirolidonu W Środowisku Wodno-Tlenowym: Notatki Techniczne

2013 ◽  
Vol 20 (1) ◽  
pp. 199-208 ◽  
Author(s):  
Marketa Julinova ◽  
Jan Kupec ◽  
Roman Slavik ◽  
Maria Vaskova
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Municipal Wastewater ◽  
Waste Treatment ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Technical Note ◽  
Aerobic Biodegradation ◽  
Municipal Wastewater Treatment

Abstract A synthetic polymer, polyvinylpyrrolidone (PVP - E 1201) primarily finds applications in the pharmaceutical and food industries due to its resistance and zero toxicity to organisms. After ingestion, the substance passes through the organism unchanged. Consequently, it enters the systems of municipal wastewater treatment plants (WWTP) without decomposing biologically during the waste treatment process, nor does it attach (through sorption) to particles of activated sludge to any significant extent, therefore, it passes through the system of a WWTP, which may cause the substance to accumulate in the natural environment. For this reason the paper investigates the potential to initiate aerobic biodegradation of PVP in the presence of activated sludge from a municipal wastewater treatment plant. The following agents were selected as the initiators of the biodegradation process - co-substrates: acrylamide, N-acethylphenylalanine and 1-methyl-2-pyrrolidone, a substance with a similar structure to PVP monomer. The biodegradability of PVP in the presence of co-substrates was evaluated on the basis of biological oxygen demand (BOD) as determined via a MicroOxymax O2/CO2/CH4 respirometer. The total substrate concentration in the suspension equaled 400 mg·dm-3, with the ratio between PVP and the cosubstrate being 1:1, while the concentration of the dry activated sludge was 500 mg·dm-3. Even though there was no occurrence of a significant increase in the biodegradation of PVP alone in the presence of a co-substrate, acrylamide appeared to be the most effective type of co-substrate. Nevertheless, a recorded decrease in the slope of biodegradation curves over time may indicate that a process of primary decomposition was underway, which involves the production of metabolites that inhibit activated sludge microorganisms. The resulting products are not identified at this stage of experimentation.

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