A kinetic model incorporating energy spilling for substrate removal in substrate-sufficient batch culture of activated sludge

1999 ◽  
Vol 52 (5) ◽  
pp. 647-651 ◽  
Author(s):  
Y. Liu ◽  
G. H. Chen ◽  
J. L. Rols
Keyword(s):  
Kinetic Model ◽  
Activated Sludge ◽  
Batch Culture ◽  
Substrate Removal ◽  
Energy Spilling

scholarly journals KINETIC MODEL OF SUBSTRATE REMOVAL AND METABOLISM BY ACTIVATED SLUDGE

1983 ◽  
Vol 1983 (339) ◽  
pp. 89-98
Author(s):  
Katsumi MORIYAMA ◽  
Youichi AWAYA ◽  
Hidetoshi KUME
Keyword(s):  
Kinetic Model ◽  
Activated Sludge ◽  
Substrate Removal

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.

Quantification of the kinetic differences between communities isolated from completely mixed activated sludge systems operated with or without a selector using a novel respirometric method

1994 ◽  
Vol 30 (11) ◽  
pp. 255-261 ◽  
Author(s):  
Barth F. Smets ◽  
Timothy G. Ellis ◽  
Stephanie Brau ◽  
Richard W. Sanders ◽  
C. P. Leslie Grady
Keyword(s):  
Oxygen Consumption ◽  
Activated Sludge ◽  
Physiological Changes ◽  
Biodegradation Kinetics ◽  
Substrate Removal ◽  
Biomass Yields ◽  
Selection For ◽  
Single Oxygen ◽  
Activated Sludge Systems

This study quantified the kinetic differences in microbial communities isolated from completely mixed activated sludge (CMAS) systems that were operated either with or without an aerobic selector preceding the main reactor. A new respirometric method was employed that allowed the determination of biodegradation kinetics from single oxygen consumption curves, thereby minimizing physiological changes to the examined communities during the assay. Results indicated that increased values for Ks and μmax for acetate, phenol, and 4-chlorophenol degradation were measured in the CMAS system operated with a selector. The biomass yields on acetate, phenol, and 4-chlorophenol were very similar in both systems. These findings indicate that the operation of CMAS systems with aerobic selectors may result in the selection for degrading populations with higher Ks and μmax values for both biogenic and xenobiotic organic compounds, and that substrate storage in the selector only partially contributes to increased substrate removal rates.

Minimization of activated sludge production by chemically stimulated energy spilling

2000 ◽  
Vol 42 (12) ◽  
pp. 189-200 ◽  
Author(s):  
G.-H. Chen ◽  
H.-K. Mo ◽  
S. Saby ◽  
W.-k. Yip ◽  
Y. Liu
Keyword(s):  
Activated Sludge ◽  
Growth Yield ◽  
Dry Weight ◽  
Staining Technique ◽  
Microbial Culture ◽  
Dapi Staining ◽  
E Coli ◽  
Energy Spilling ◽  
Activated Sludge Processes ◽  
Sludge Production

Minimization of excess sludge production in activated sludge processes has been pursued around the world in order to meet stringent environmental regulations on sludge treatment and disposal. To achieve this goal, physical, chemical, and biological approaches have been proposed. In this paper, a chemical compound, 3,3′,4′,5-tetrachlorosalicylanilide (TCS) was tested for enhancing microbial energy spilling of the sludgeso as to minimize its growth. In order to examine this, an exploratory study was conducted using both batch and continuous activated sludge cultures. Batch experiments with these two cultures were carried out at different initial concentrations of TCS. It has been confirmed that an addition of TCS is effective in reducing the production of both the sludge cultures, particularly the continuous culture where the observed growth yield was reduced by around 70%, when the initial TCS concentration was 0.8 ppm. Meanwhile, the substrate removal activity of this culture was found not to be affected at this TCS concentration. To further evaluate the TCS effect, a pure microbial culture of E. coli was employed. Batch experiment results with this culture implied that TCS might be able to reduce the cell density of E. coli drastically when an initial TCS concentration was greater than 0.12 ppm. It was also found that TCS was not toxic to this type of bacteria. Microscopic examinations with a 4′, 6-diamidino-2-phenylindole (DAPI) staining technique revealed that TCS neither affected the cell division nor altered the cell size of E. coli. However, both the cell ATP content and the cell dry weight were reduced significantly with the addition of TCS.

Response of activated sludge to the presence of 2,4-dichlorophenol in a batch culture system

2006 ◽  
Vol 41 (8) ◽  
pp. 1758-1763 ◽  
Author(s):  
Guo-Wei Chen ◽  
Han-Qing Yu ◽  
Hui-Xiong Liu ◽  
De-Qian Xu
Keyword(s):  
Activated Sludge ◽  
Batch Culture ◽  
Culture System

Determination of Kinetic Constants of Activated Sludge Microorganisms

1985 ◽  
Vol 17 (2-3) ◽  
pp. 259-272 ◽  
Author(s):  
J. S. Čech ◽  
J. Chudoba ◽  
P. Grau
Keyword(s):  
Activated Sludge ◽  
Mixed Culture ◽  
Removal Rate ◽  
Mixed Cultures ◽  
Kinetic Constants ◽  
Type Reactor ◽  
Substrate Removal ◽  
Velocity Coefficient ◽  
Mixed Reactor

A respirometric method for measuring kinetic constants of activated sludge microorganisms by means of a simple respirometer was developed and tested by using two types of mixed culture. It has been found that both the maximum substrate removal rate and the half-velocity coefficient are basically lower with the mixed cultures cultivated in a completely-mixed reactor /filamentous/ than with those cultivated in a selector-type reactor /nonfilamentous/.

The assessment of different operating strategies for minimising activated sludge deflocculation under temperature transient conditions

2004 ◽  
Vol 50 (3) ◽  
pp. 67-77 ◽  
Author(s):  
F. Morgan-Sagastume ◽  
D. Grant Allen
Keyword(s):  
Activated Sludge ◽  
Oxygen Demand ◽  
Pulp Mill ◽  
Temperature Shift ◽  
Batch Reactors ◽  
Substrate Removal ◽  
Removal Capacity ◽  
Floc Structure ◽  
Fundamental Research ◽  
Operating Strategies

Three operating strategies were tested for decreasing activated sludge deflocculation due to temperature shifts from 30° to 45°C: magnesium sludge enrichment, increased sludge retention time (33 d), and spikes of an easily degradable substrate (methanol). The temperature shifts were conducted sequentially in 4 parallel lab-scale sequencing batch reactors (SBRs) treating kraft pulp mill effluent. Three SBRs operated at an SRT = 20 days, and in one of them the sludge was not manipulated, thus, serving as a reference SBR. The temperature shift was associated with decreased soluble chemical oxygen demand (SCOD) removals, decreased sludge settleability and substrate removal capacity, and increased effluent suspended solids (ESS) and turbidity levels. The shift also increased the sludge specific respiration rates and reduced the sludge substrate removal capacity. Sludge deflocculation was assessed as floc solubilisation (increased effluent SCOD levels) and floc fragmentation (increase in effluent solids smaller than 50 mm). Mg enrichment of the sludge and methanol spikes reduced the ESS levels (in 9 and 25%), and the three operating strategies decreased effluent turbidity (in 22-35%) compared to the maximum levels from the non-manipulated reactor (44 mg ESS/L). The stronger sludge floc structure achieved by magnesium enrichment and a high sludge age of 33 days was unsuccessful in significantly decreasing deflocculation. The mechanisms involved in sludge deflocculation require further fundamental research.

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