scholarly journals Determination of sorption properties of micropollutants: What is the most suitable activated sludge inhibition technique to preserve the biomass structure?

2014 ◽  
Vol 242 ◽  
pp. 260-268 ◽  
Author(s):  
Pierre Hamon ◽  
Maud Villain ◽  
Benoît Marrot
Keyword(s):  
Activated Sludge ◽  
Sorption Properties ◽  
Biomass Structure ◽  
Inhibition Technique

Acetylene inhibition for measuring denitrification rates in activated sludge

1994 ◽  
Vol 30 (6) ◽  
pp. 161-167 ◽  
Author(s):  
Sara Hallin ◽  
Mikael Pell
Keyword(s):  
Activated Sludge ◽  
Process Data ◽  
Acetylene Inhibition ◽  
Potential Denitrification ◽  
Acetylene Inhibition Technique ◽  
Best Response ◽  
Utilisation Rate ◽  
Full Capacity ◽  
Inhibition Technique

A method of determining the actual and potential denitrification rates in activated sludge samples by measuring accumulation of nitrous oxide after inhibition by acetylene was adapted and applied.Rates obtained with the acetylene inhibition technique were compared with those calculated through mass balances of total nitrogen from process data as well as those measured as nitrate utilisation.The acetylene inhibition technique was a reliable method for determination of denitrifying activity.The influence of acetate, ethanol, methanol and nitrate additions was examined.Acetate gave the best response upon denitrification followed by ethanol and methanol.The bacteria in the activated sludge could not denitrify at full capacity due to limitations in the supply of electron donors.The actual rates measured with the acetylene inhibition technique corresponded to the rates obtained from process data.The potential rates, determined with additions of acetate and nitrate in excess (240 mg l−1 and 28 mg N l−1), were 3–7 times higher than the actual rates and the rates calculated from process data.There is, thus, a potential for a more rapid denitrification rate.The potential denitrification rate measured with the acetylene inhibition technique was equivalent to the nitrate utilisation rate.

Respirometry for determination of the influents SS-concentration

1996 ◽  
Vol 33 (1) ◽  
pp. 311-323 ◽  
Author(s):  
A. Witteborg ◽  
A. van der Last ◽  
R. Hamming ◽  
I. Hemmers
Keyword(s):  
Experimental Design ◽  
Activated Sludge ◽  
Substrate Concentration ◽  
Full Scale ◽  
Activated Sludge Process ◽  
Respiration Rates ◽  
On Line ◽  
Large Measurement ◽  
Set Up

A method is presented for determining influent readily biodegradable substrate concentration (SS). The method is based on three different respiration rates, which can be measured with a continuous respiration meter which is operated in a cyclic way. Within the respiration meter nitrification is inhibited through the addition of ATU. Simulations were used to develop the respirometry set-up and decide upon the experimental design. The method was tested as part of a large measurement programme executed at a full-scale plant. The proposed respirometry set-up has been shown to be suitable for a semi-on-line determination of an influent SS which is fully based on the IAWQ #1 vision of the activated sludge process. The YH and the KS play a major role in the principle, and should be measured directly from the process.

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.

Operational Determination of the Activated Sludge Process Using Neural Networks

1992 ◽  
Vol 26 (9-11) ◽  
pp. 2461-2464 ◽  
Author(s):  
R. D. Tyagi ◽  
Y. G. Du
Keyword(s):  
Neural Network ◽  
Neural Networks ◽  
Steady State ◽  
Activated Sludge ◽  
Feedforward Neural Network ◽  
Training Data ◽  
Activated Sludge Process

A steady-statemathematical model of an activated sludgeprocess with a secondary settler was developed. With a limited number of training data samples obtained from the simulation at steady state, a feedforward neural network was established which exhibits an excellent capability for the operational prediction and determination.

Innovative methods for sludge characterization in biological phosphorus removal systems

1999 ◽  
Vol 39 (6) ◽  
pp. 37-43 ◽  
Author(s):  
Damir Brdjanovic ◽  
Mark C. M. van Loosdrecht ◽  
Christine M. Hooijmans ◽  
Takashi Mino ◽  
Guy J. Alaerts ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Phosphorus Removal ◽  
Chemical Measurement ◽  
Biological Phosphorus Removal ◽  
Ongoing Research ◽  
Innovative Methods ◽  
Sludge Characterization ◽  
Biological Phosphorus

This paper describes several techniques and methods for sludge characterization which are recently developed and used in our ongoing research on biological phosphorus removal (BPR): (i) chemical measurement of the poly-hydroxy-alkanoate (PHA) content of the biomass, (ii) bioassay for glycogen determination in BPR systems, (iii) determination of the fraction of denitrifying phosphorus accumulating organisms (DPAOs) in P-removing sludge, (iv) determination of the aerobic and anoxic ATP/NADH2 ratio (δ value) in BPR systems, and (v) determination of the glycogen accumulating organisms (GAOs) / phosphorus accumulating organisms (PAOs) ratio in activated sludge.

Dimensioning of Aerated Grit Chambers and Use as a Highly Loaded Activated Sludge Process

1989 ◽  
Vol 21 (4-5) ◽  
pp. 13-22
Author(s):  
Jorg Londong
Keyword(s):  
Activated Sludge ◽  
Pilot Scale ◽  
Air Injection ◽  
Activated Sludge Process ◽  
Cross Section Area ◽  
Section Area ◽  
Degree Of Separation ◽  
Highly Loaded ◽  
Adsorption Stage

The aerated grit chamber has long been used to separate sand from sewage. Nevertheless, there are no definite and uniform recommendations for dimensioning, and there is little information in the literature about the degree of separation attainable. Thus, principles for dimensioning and the possible degree of separation are derived from measurements of large pilot scale plants, two-dimensional models, and existing aerated grit chambers. The following values for dimensioning were found in this work: a detention period of about 20 minutes; a width to depth ratio (w/d) of about 0.8; a minimal and maximal cross section area between 1 and about 7 m2; a flow velocity of 20 cm/s at the bottom of the aerated grit chamber. Simple formulae for the determination of the required amount of air can be given in relation to the w/d ratio, the depth of air injection and the kind of aeration used (fine or coarse bubble). The simultaneous use of an aerated grit chamber as an adsorption stage (highly loaded activated sludge process) is possible without additional air being required to maintain the velocity at the bottom of the grit chamber. For purely aerobic operation, however, the amount of air has to be increased.

Determination of Some Kinetic Parameters by Respirometry

1992 ◽  
Vol 26 (9-11) ◽  
pp. 2535-2538 ◽  
Author(s):  
M. Roš ◽  
M. Dular
Keyword(s):  
Reaction Time ◽  
Activated Sludge ◽  
Kinetic Parameters ◽  
Oxygen Transfer ◽  
Dynamic Method ◽  
Research Work ◽  
Substrate Utilisation ◽  
Relative Standard ◽  
Temperature Constant

Individual kinetic parameters such as BOD, biodegradation of wastewater, reaction time, maximal substrate rate can be determined by respirometry. For the determination of main respirometric parameters (STBOD, BODr, reaction time, etc.) overall oxygen transfer coefficient, KLa, is needed. This parameter can be determined with dynamic method in an open respirometer at limited conditions (constant temperature, constant stirring conditions). It was found out that KLa is dependent upon concentration of the activated sludge; it can be determined with about 2% of relative standard deviation. The objective of our research work was determination of maximal exogenous oxygen uptake, re max and maximal substrate utilisation, µmax, which is very important kinetic parameter at wastewater treatment. These parameters show us the maximal substrate (wastewater) utilisation for appointed activated sludge.

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