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FOULING OF FINE PORE DIFFUSED AERATORS: AN INTER- PLANT COMPARISON
Citation:
Baillod, C. R. AND K. Hopkins. FOULING OF FINE PORE DIFFUSED AERATORS: AN INTER- PLANT COMPARISON. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/R-94/103 (NTIS 94-200912), 1994.
Impact/Purpose:
Information.
Description:
There has been increasing interest in fine pore aeration systems, along with concerned about diffuser fouling and the subsequent loss of aeration efficiency. The objective of this study was to assess the relative fouling tendency of fine bubble diffusers t nine activated sludge treatment plants. Secondary objective was to relate fouling to mixed liquor and process parameters. Standardized diffuser test header containing four removable diffusers was installed at each of the participating plants. Diffusers were periodically removed and tested for oxygen transfer efficiency (OTE), bubble release vacuum (BRV), dynamic wet pressure (DWP), foulant accumulation, and increase in OTE after acid cleaning. The results of this study showed that an increase in BRV was generally accompanied by a decrease in oxygen transfer efficiency, an accumulation of foulant, and an increase in DWP loss through the diffuser. The plants were classified according to their degree of fouling (as measured by BRV). The classifications were: heavily fouling, moderately fouling, fouling, and lightly fouling. The secondary objective was to relate fouling tendency to process parameters. Observations at individual plants suggested that high organic loads enhanced fouling, although interplant comparison suggested a weak association between fouling and organic load. This report was submitted in partial fulfillment of Cooperative Agreement No. CR812167 by the American Society of Civil Engineers under subcontract to Michigan Technological University under the partial sponsorship of the U.S. Environmental Protection Agency. The work reported herein was conducted over the period of 1986-1988. Project summary may be ordered as EPA/600/S-94/001).