Enhancement of 2,4-dichlorophenol degradation in conventional activated sludge systems bioaugmented with mixed special culture

2004 ◽  
Vol 38 (1) ◽  
pp. 245-253 ◽  
Author(s):  
Xiangchun Quan ◽  
Hanchang Shi ◽  
Hong Liu ◽  
Pingping Lv ◽  
Yi Qian
Keyword(s):  
Activated Sludge ◽  
Conventional Activated Sludge ◽  
Activated Sludge Systems

New approaches to minimize excess sludge in activated sludge systems

2001 ◽  
Vol 44 (10) ◽  
pp. 203-208 ◽  
Author(s):  
G.-H. Chen ◽  
S. Saby ◽  
M. Djafer ◽  
H.-K. Mo
Keyword(s):  
Activated Sludge ◽  
Activated Sludge Process ◽  
Conventional System ◽  
Excess Sludge ◽  
Active Sludge ◽  
New Approaches ◽  
Conventional Activated Sludge ◽  
Sludge Settleability ◽  
Activated Sludge Systems ◽  
Sludge Production

This paper presents three new approaches to reduce excess sludge production in activated sludge systems: 1) modification of conventional activated sludge process with insertion of a sludge holding tank in the sludge return line; 2) chlorination of excess sludge so as to minimize excess sludge production; and 3) utilization of a metabolic uncoupler, 3, 3′, 4′, 5-Tetrachlorosalicylanilide (TCS) to maximize futile activity of sludge microorganisms thereby leading to a reduction of sludge growth. Pilot study was carried out to evaluate this modified activated sludge process (OSA). It has been confirmed that the OSA process is effective in reducing excess sludge; particularly when the ORP level in the sludge holding tank was kept at -250 mV, more than 50% of the excess sludge was reduced. This process can maintain the effluent quality and even perform with a better sludge settleability than a conventional system. Experimental work on the second approach showed that chlorination treatment of excess sludge at a chlorine dose of 0.066 g Cl2/g MLSS reduced the excess sludge by 60%, while concentration of THMS was found below 200 ppb in the treated sludge. However, such sludge chlorination treatment sacrificed sludge settleability. Thus, it is not feasible to introduce the chlorination step to a conventional system. The third approach confirmed that addition of TCS could reduce sludge growth effectively if the TCS concentration is greater than 0.4 ppm. A 0.8-ppm concentration of TCS actually reduced excess sludge by 45%. It was also experimentally demonstrated that presence of TCS increases the portion of active sludge microorganisms over the entire microbial population.

Oxygen transfer in activated sludge – new insights and potentials for cost saving

2011 ◽  
Vol 63 (12) ◽  
pp. 3034-3038 ◽  
Author(s):  
J. Henkel ◽  
P. Cornel ◽  
M. Wagner
Keyword(s):  
Activated Sludge ◽  
Nutrient Removal ◽  
Oxygen Transfer ◽  
Transfer Rate ◽  
Oxygen Transfer Rate ◽  
Organic Load ◽  
Current Opinion ◽  
Conventional Activated Sludge ◽  
Current State ◽  
Activated Sludge Systems

The α-factor has the greatest impact on the calculation of the required standard oxygen transfer rate (SOTR) in activated sludge systems equipped with submerged aeration systems. Knowing the dependencies of the α-factor leads to a better design of the aeration devices and, consequently, to a more efficient use of aeration energy. Applying the current state of knowledge about oxygen transfer leads to the conclusion that, in contrast to current opinion, simultaneous aerobic stabilization requires the same SOTR as conventional activated sludge systems with advanced nutrient removal, even though a higher organic load is degraded.

Comparison of linear alkylbenzene sulfonates removal in conventional activated sludge systems and membrane bioreactors

2004 ◽  
Vol 50 (5) ◽  
pp. 219-225 ◽  
Author(s):  
H. De Wever ◽  
S. Van Roy ◽  
C. Dotremont ◽  
J. Müller ◽  
T. Knepper
Keyword(s):  
Activated Sludge ◽  
Membrane Bioreactors ◽  
Operating Conditions ◽  
Biological Degradation ◽  
Linear Alkylbenzene ◽  
Conventional Activated Sludge ◽  
Operational Variables ◽  
Linear Alkylbenzene Sulfonates ◽  
Model Components ◽  
Activated Sludge Systems

The potential of a membrane bioreactor (MBR) and a conventional activated sludge (CAS) system to remove polar micropollutants was evaluated using linear alkylbenzene sulfonates (LAS) as model components. Removal efficiencies over 97% were achieved in both reactor systems. The appearance of biological breakdown metabolites and the respirometric response of the sludges to LAS addition indicated that LAS removal was due to biodegradation, rather than sorption phenomena. The effect of operational variables, such as hydraulic retention time, LAS composition and hydrophobicity of the membrane used in the MBR, was negligible in the range tested. A stepwise increase in LAS influent concentration resulted in higher residual effluent concentrations but did not change the procentual removal efficiency. Because an increase in LAS and SPC effluent concentration occurred to a larger extent in the CAS than in the MBR under similar operating conditions, MBRs may turn out to be be more robust with respect to biological degradation of micropollutants than CAS.

Sludge production in membrane bioreactors under different conditions

2000 ◽  
Vol 41 (10-11) ◽  
pp. 251-258 ◽  
Author(s):  
J. Wagner ◽  
K-H. Rosenwinkel
Keyword(s):  
Activated Sludge ◽  
Pilot Plant ◽  
Membrane Bioreactors ◽  
Conventional Activated Sludge ◽  
Theoretical Approaches ◽  
One Year ◽  
Conventional Systems ◽  
The University ◽  
Activated Sludge Systems ◽  
Sludge Production

With membrane bioreactors, the production of surplus sludge is lower than with conventional activated sludge systems, a fact that has been confirmed in a large number of analyses. There is, however, no consensus about the dimension of the reactions and their respective causes. In order to examine these, at the University of Hanover a pilot plant with a capacity of 220 l was run for one year without any extraction of surplus sludge. The plant was started with 2 g MLSS/l; after one year, this value had risen to approximately 18 g MLSS/l. In order to be able to set the plant for different sludge loads (0.04 to 0.2 kg COD/(kg MLSS · d)), the wastewater was artificially stocked up. The emerging result was that in contrast to conventional systems the sludge growth was lower, but still continuously existing. Then, comparisons with theoretical approaches were run – among others with the ASM1-Model – which confirmed the findings. One possible reason could be the different biocoenoses, which was assumed to be the cause after several microscopic examinations had been run.

Distribution of ammonia-oxidizing bacteria in sewage activated sludge: analysis based on 16S rDNA sequence

2004 ◽  
Vol 50 (8) ◽  
pp. 9-14 ◽  
Author(s):  
T. Limpiyakorn ◽  
Y. Shinohara ◽  
F. Kurisu ◽  
O. Yagi
Keyword(s):  
Activated Sludge ◽  
16S Rdna ◽  
Treatment Process ◽  
Sewage Treatment ◽  
Pcr Amplification ◽  
Ammonia Oxidizing Bacteria ◽  
Conventional Activated Sludge ◽  
Process Configuration ◽  
Nitrosomonas Oligotropha ◽  
Activated Sludge Systems

This study carried out analysis of ammonia-oxidizing bacteria (AOB) communities in 12 sewage activated sludge systems standing in eight sewage treatment plants located in Tokyo. The systems were different in the treatment process configuration: anaerobic/anoxic/aerobic (A2O), anaerobic/aerobic (AO), and conventional activated sludge (AS) processes. AOB communities were analyzed by sequences of 16S rDNA amplicons, which were separated by denaturing gradient gel eletrophoresis (DGGE) after specific polymerase chain reaction (PCR) amplification. The results demonstrated that low ammonium concentrations in the influents of the 12 sewage activated sludge systems resulted in the dominance of Nitrosomonas oligotropha-like sequences. Further, Nitrosomonas europaea- and Nitrosomonas cryotolerans-like sequences were recovered from only one A2O system of which the influent contained higher ammonium and chloride concentrations than those of other systems. Nitrosomonas communis-like sequences were found in every A2O and AO system, but mostly not found in every AS system. In summary, influent characteristics and treatment process configuration affected the AOB communities in the 12 sewage activated sludge systems.

scholarly journals Removal of bacterial and viral indicator organisms in full-scale aerobic granular sludge and conventional activated sludge systems

2020 ◽  
Vol 6 ◽  
pp. 100040 ◽  
Author(s):  
Mary Luz Barrios-Hernández ◽  
Mario Pronk ◽  
Hector Garcia ◽  
Arne Boersma ◽  
Damir Brdjanovic ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Granular Sludge ◽  
Full Scale ◽  
Aerobic Granular Sludge ◽  
Indicator Organisms ◽  
Conventional Activated Sludge ◽  
Activated Sludge Systems

New anaerobic process of nitrogen removal

2006 ◽  
Vol 54 (8) ◽  
pp. 163-170 ◽  
Author(s):  
S. Kalyuzhnyi ◽  
M. Gladchenko ◽  
A. Mulder ◽  
B. Versprille
Keyword(s):  
Activated Sludge ◽  
Electron Donor ◽  
Nitrogen Removal ◽  
Laboratory Testing ◽  
Oxidation Reaction ◽  
Loading Rate ◽  
Nitrogen Loading ◽  
Ammonium Oxidation ◽  
Conventional Activated Sludge ◽  
Activated Sludge Systems

This paper reports on successful laboratory testing of a new nitrogen removal process called DEAMOX (DEnitrifying AMmonium OXidation) for the treatment of strong nitrogenous wastewater such as baker's yeast effluent. The concept of this process combines the recently discovered ANAMMOX (ANaerobic AMMonium OXidation) reaction with autotrophic denitrifying conditions using sulfide as an electron donor for the production of nitrite within an anaerobic biofilm. The achieved results with a nitrogen loading rate of higher than 1, 000 mg/L/d and nitrogen removal of around 90% look very promising because they exceed (by 9–18 times) the corresponding nitrogen removal rates of conventional activated sludge systems. The paper describes also some characteristics of DEAMOX sludge, as well as the preliminary results of its microbiological characterization.

Upgrading of activated sludge systems for nitrogen removal by application of the LINPOR®-CN process

1994 ◽  
Vol 29 (12) ◽  
pp. 167-176 ◽  
Author(s):  
M. R. Morper
Keyword(s):  
Activated Sludge ◽  
Performance Improvement ◽  
Plastic Foam ◽  
Active Biomass ◽  
Conventional Activated Sludge ◽  
Porous Plastic ◽  
Nitrogen Pollutants ◽  
Highly Porous ◽  
Activated Sludge Systems ◽  
Simultaneous Elimination

LINPOR®-systems are modified activated sludge plants, where the aeration tanks contain a certain quantity of highly porous plastic foam particles, which serve as a carrier material for active biomass. Thus a substantial performance improvement is achieved as compared to conventional activated sludge systems without having to renounce the well proven elements of the activated sludge technology. The LINPOR®-CN process for the simultaneous elimination of organic and nitrogen pollutants is particularly suitable for upgrading existing plants, because it can be made to fit into existing tanks with no or only little change of the once installed facilities.

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