Masters Theses


"The objective of this investigation was to evaluate the use of ultrasonic energy, pH adjustment, and addition of polyelectrolytes in dewatering coagulant sludges. Emphasis was placed on the effects of the ultrasonic power output level and period of conditioning, the chemical conditioning of the sludge, and the type and origin of the sludge. Dewatering is thought to be the most practical approach for reducing the volume of coagulant sludges and efforts are being made to improve their dewatering characteristics.

An experimental system consisting of a magnetically stirred sludge reservoir, sonifier and reaction chamber, polymer feeder, and collection cylinder was developed for this study. The dewaterability of 3 conditioned sludges, 2 alum and 1 iron, before and after sonification was evaluated by vacuum filtration, centrifugation, and settling tests; and specific resistance, TS, and turbidity served as control parameters.

Chemical conditioning of all sludges significantly improved their dewatering characteristics, and further improvement was possible by the use of ultrasonic conditioning; the effect of treatment was greater on alum sludge than it was on iron sludge. Conditioning for vacuum filtration required a lower ultrasonic power input over a shorter period of time than did treatment for centrifugation and settling; however, the resulting improvement in dewaterability when compared to the unsonified sample was less"--Abstract, page ii.


Grigoropoulos, Sotirios G.

Committee Member(s)

Jennett, J. Charles
Siehr, Donald J.


Civil, Architectural and Environmental Engineering

Degree Name

M.S. in Civil Engineering


United States. Environmental Protection Agency. Office of Water Programs


This investigation was supported in part by Professional Training Grant No. 1P2-278-01 and T-900121 from the Office of Water Programs, Environmental Protection Agency.


University of Missouri--Rolla

Publication Date



vii, 95 pages

Note about bibliography

Includes bibliographical references (pages 82-85).


© 1973 Stanley Louis Klemetson, All rights reserved.

Document Type

Thesis - Restricted Access

File Type




Subject Headings

Sewage -- Purification -- Activated sludge process
Water treatment plant residuals -- Drying

Thesis Number

T 2894

Print OCLC #


Electronic OCLC #


Link to Catalog Record

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