Masters Theses


"The feasibility of utilizing the thermal energy from an electric power plant to operate an activated sludge process at elevated temperatures (above 40°C) was assessed.

The practicality of using this heat was determined from a heat transfer analysis and the operation of the activated sludge process was evaluated from laboratory studies of a batch process treating domestic and synthetic sewage.

The tank size for a thermophilic activated sludge chamber could be reduced by 40 to 50% as compared to ambient temperatures. For thermophilic processes a temperature of 55°C is recommended because the transition phase between mesophiles and thermophiles is around 45°C and maximum growth rate occurs at 55°C. The effluent suspended solids after an hour and a half of settling was about 25 mg/1.

Only about 10% of the thermal energy in the power plant cooling water is utilizable for increasing sewage temperatures to the thermophilic range. The additional boiler steam output required would be 7 to 33% for sewage flow rates of 20 to 100 MGD.

The basic proposal described above was found to be technically feasible but the economic analysis was considered to be beyond the scope of this research. It was felt that such a proposal has application but additional research is needed"--Abstract, page ii.


Wixson, Bobby G.

Committee Member(s)

Modesitt, Donald E.
Howell, Ronald H. (Ronald Hunter), 1935-


Civil, Architectural and Environmental Engineering

Degree Name

M.S. in Civil Engineering


United States. Federal Water Pollution Control Administration


During the time period in which this study was performed, the author was on a Professional Trainee Appointment under grant IP2-WP-278-0l, T-900121 from the Water Quality Office, United States Environmental Protection Agency.


University of Missouri--Rolla

Publication Date



ix, 119 pages

Note about bibliography

Includes bibliographical references (pages 103-110).


© 1973 Peter J. Dawson, All rights reserved.

Document Type

Thesis - Open Access

File Type




Subject Headings

Sewage -- Purification -- Activated sludge process
Sewage sludge -- Effect of high temperatures on
Thermophilic microorganisms

Thesis Number

T 2852

Print OCLC #


Electronic OCLC #