Record Display for the EPA National Library Catalog
RECORD NUMBER: 57 OF 177
|OLS Field Name||OLS Field Data|
|Main Title||Effect of recycling thermophilic sludge on the activated sludge process /|
|Author||Prakasam, T. B. S. ; Soszynski, S. ; Zenz, D. R. ; Lue-Hing, C. ; Blyth, L.|
|CORP Author||Metropolitan Water Reclamation District of Greater Chicago, IL.;Environmental Protection Agency, Cincinnati, OH. Risk Reduction Engineering Lab.|
|Publisher||U.S. Environmental Protection Agency, Risk Reduction Engineering Laboratory,|
|Report Number||EPA/600/2-90/037; EPA-R-811925|
|Subjects||Sewage sludge--Illinois. ; Sewage sludge digestion.|
|Additional Subjects||Activated sludge process ; Sludge digestion ; Sewage treatment ; Thermophiles ; Aeration ; Oxidation ; High temperature tests ; Substitutes ; Dewatering ; Performance evaluation ; Waste recycling ; Biological treatment ; Biotechnology ; Mesophilic conditions|
|Collation||278 pages : illustrations ; 28 cm|
A full-scale investigation was undertaken at Chicago's Hanover Park Water Reclamation Plant (WRP) to study whether the net sludge production from the WRP could be reduced by implementing a scheme developed by W. Torpey et al. (1984). In this process, sludge is withdrawn from a thermophilic digester operated in series with a mesophilic digester and partially recycled into the aeration tanks of the activated sludge system. The Hanover Park WRP, which has a design flow capacity of 45,420 million cu m per day (12 mgd), was split into a control section and an experimental section. The two sections were operated similarly except the thermophilic drawoff was recycled into the aeration tanks of the experimental section from a digester system consisting of mesophilic and thermophilic digesters operated in series. A reduction in net sludge production of about 10 percent was achieved at 40 percent recycle of thermophilic sludge into the aeration tanks at the Hanover Park WRP. This was a much smaller reduction than obtained by Torpey et al. Sludge dewatering properties were not improved. The recycling produced no adverse effects on quality of the treated wastewater.
Caption title. "Sept. 1990." Includes bibliographical references (page 6). "EPA/600/2-90/037." Microfiche.