Sludge chemical composition changes under uni-directional freezing

1996 ◽  
Vol 34 (3-4) ◽  
pp. 525-531 ◽  
Author(s):  
W. T. Huang ◽  
I. L. Chang ◽  
D. J. Lee ◽  
S. G. Hong
Keyword(s):  
Chemical Composition ◽  
Activated Sludge ◽  
High Speed ◽  
Ftir Spectra ◽  
Ice Formation ◽  
Waste Activated Sludge ◽  
Chemical Compositions ◽  
Low Speed ◽  
Directional Freezing ◽  
Composition Changes

The chemical compositions changes for waste activated sludge at different freezing speeds were analyzed via FTIR spectra. With a high speed of freezing, the chemical compositions are little influenced by the action of ice formation, which with a low speed of freezing, the chemical compositions are largely affected. The prerequisite for sufficient dewaterability improvement is found as the global floc migration owing to the ice front formation, which releases some ECPs (basically cellulose) from the sludge and after the resulting cake structure ultimately.

Using the Method of Phyto-testing to Determine the Hazard Class of Waste

2019 ◽  
Vol 23 (9) ◽  
pp. 49-53
Author(s):  
L.V. Popova ◽  
P.S. Repin ◽  
V.I. Korchagin ◽  
R.N. Plotnikova
Keyword(s):  
Chemical Composition ◽  
Root Growth ◽  
Activated Sludge ◽  
Waste Activated Sludge ◽  
Distilled Water ◽  
Hazard Class ◽  
Effective Threshold ◽  
Long Period

The application of the method of phyto-testing to determine the hazard class of the waste (waste activated sludge from sludge beds, sawdust from natural acacia wood, beer malt spent, fresh chicken dung, sunflower husk), subjected to storage for several months. The values of the minimum effective (threshold) dilution, which has the effect of inhibiting root growth by 20 %, and the values of medium-effective dilution, inhibiting growth by 50 % compared to distilled water were determined. For sunflower husk and beer malt spent, a contradiction was established between the approved hazard class according to the FCCW and a certain hazard class according to the method of MP 2.1.7.2297-07, which indicates a change in the chemical composition of the waste that has been stored for a long period of time.

Do You Name Speedy Objects Faster Than Slow Objects: SPEEDED NAMING OR NAMING SPEED? THE AUTOMATIC EFFECT OF OBJECT SPEED ON PERFORMANCE

2018 ◽  
Author(s):  
Moshe Shay Ben-Haim ◽  
Eran Chajut ◽  
Ran Hassin ◽  
Daniel Algom
Keyword(s):  
High Speed ◽  
Mental Representations ◽  
Reading Aloud ◽  
Naming Task ◽  
Naming Speed ◽  
Low Speed ◽  
Everyday Objects ◽  
Pictures And Words

we test the hypothesis that naming an object depicted in a picture, and reading aloud an object’s name, are affected by the object’s speed. We contend that the mental representations of everyday objects and situations include their speed, and that the latter influences behavior in instantaneous and systematic ways. An important corollary is that high-speed objects are named faster than low-speed objects despite the fact that object speed is irrelevant to the naming task at hand. The results of a series of 7 studies with pictures and words support these predictions.

Activated Sludge Exocellular Material Extraction Methods and Problems

1974 ◽  
Vol 9 (1) ◽  
pp. 250-261
Author(s):  
D.F. Carr ◽  
J. Ganczarczyk
Keyword(s):  
Activated Sludge ◽  
High Speed ◽  
Sewage Treatment ◽  
Dry Weight ◽  
Extraction Methods ◽  
Volatile Material ◽  
Bacterial Cultures ◽  
Volatile Solids ◽  
Pure Bacterial Cultures ◽  
Material Extraction

Abstract Activated sludge samples from two Toronto sewage treatment plants were subjected to the extraction of exocellular material by means of 9 different methods suggested for this purpose. Some of those methods, originally developed for pure bacterial cultures, were modified for the application to activated sludge. The amount of exocellular material obtained varied for Lakeview sludges from 0.4 to 3.2% of their dry volatile solids, and for Humber sludges from 0.3 to 5.3%. It has been found that extractions by the use of sulphuric acid, high-speed centrifugation and sodium hydroxide, were not suitable for the studied material. Especially surprising was the ineffectiveness of high-speed centrifugation to yield any measurable amounts of extract. The boiling water extraction is recommended for further studies on activated sludge exocellular material. The material extracted from activated sludge is very complex in nature. Generally more polysaccharide than protein was extracted, but the remaining volatile material may form up to 70% of the dry weight.

Comparison of Aerobic and Anoxic-Aerobic Digestion of Waste Activated Sludge

1985 ◽  
Vol 17 (8) ◽  
pp. 1475-1478 ◽  
Author(s):  
A P. C. Warner ◽  
G. A. Ekama ◽  
G v. R. Marais
Keyword(s):  
Experimental Data ◽  
Activated Sludge ◽  
Waste Activated Sludge ◽  
Activated Sludge Process ◽  
Cycle Times ◽  
Waste Sludge ◽  
Volatile Solids ◽  
In Series ◽  
Flow Through ◽  
Theoretical Simulations

The laboratory scale experimental investigation comprised a 6 day sludge age activated sludge process, the waste sludge of which was fed to a number of digesters operated as follows: single reactor flow through digesters at 4 or 6 days sludge age, under aerobic and anoxic-aerobic conditions (with 1,5 and 4 h cycle times) and 3-in-series flow through aerobic digesters each at 4 days sludge age; all digesters were fed draw-and-fill wise once per day. The general kinetic model for the aerobic activated sludge process set out by Dold et al., (1980) and extended to the anoxic-aerobic process by van Haandel et al., (1981) simulated accurately all the experimental data (Figs 1 to 4) without the need for adjusting the kinetic constants. Both theoretical simulations and experimental data indicate that (i) the rate of volatile solids destruction is not affected by the incorporation of anoxic cycles and (ii) the specific denitrification rate is independent of sludge age and is K4T = 0,046(l,029)(T-20) mgNO3-N/(mg active VSS. d) i.e. about 2/3 of that in the secondary anoxic of the single sludge activated sludge stystem. An important consequence of (i) and (ii) above is that denitrification can be integrated easily in the steady state digester model of Marais and Ekama (1976) and used for design (Warner et al., 1983).

Electro-Dewatering Waste Activated Sludge: Lessons Learned from Real World Cases

2008 ◽  
Vol 2008 (3) ◽  
pp. 226-235
Author(s):  
Roger Paradis ◽  
Abderrahmane Dermoune ◽  
Scott F. McKay ◽  
Dany Sarrazin Sullivan
Keyword(s):  
Activated Sludge ◽  
Real World ◽  
Lessons Learned ◽  
Waste Activated Sludge
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