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OXYGEN TRANSFER EFFICIENCY SURVEYS AT THE JONES ISLAND TREATMENT PLANTS - 1985-1988
Citation:
Warriner, R. OXYGEN TRANSFER EFFICIENCY SURVEYS AT THE JONES ISLAND TREATMENT PLANTS - 1985-1988. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/R-94/094 (NTIS 94-200821), 1994.
Impact/Purpose:
information
Description:
Ceramic plate diffusers were among the earliest forms of fine pore diffusers used for oxygen transfer in activated sludge treatment. They have been successfully used for over 60 years in the Jones Island West Plant of the Milwaukee Metropolitan Sewerage District and, since initial start-up, in the Jones Island East Plant and the South Shore Plant. Surveys of performance of these diffusers in all three plants were included in the EPA/ASCE Fine Pore Aeration Project. This report presents the results of off-gas sampling surveys carried our at the original Jones Island West Plant and in the newly rehabilitated East Plant. The West Plant basins were scheduled for rehabilitation in 1989-90. Twenty-one (21) basin surveys were carried out in the West Plant and 30 in the East Plant. For the West Plant basins, which contained the original ceramic diffusers with 15 feet of submergence, installed in 1923 and 1924, the median value of standardized oxygen transfer efficiency, alphaF(SOTE), was 11.8%. or the East Plant basins, which contained diffusers with 14 feet of submergence, installed in 1983, the median value of alphaF(SOTE) was 15.3%. Cleaning history was noted for each basin at the time of each off-gas survey. n effect of time-in-service since cleaning on oxygen transfer efficiency was not documented by these surveys; however, there was an indication that short-term improvement occurred in the East Plant. Since alpha is unknown and varies widely between surveys, and possibly during surveys, it is difficult to separate alpha effects from fouling (F) effects on oxygen transfer efficiency. For the most part, extended periods of basin operation have no measurable effect on performance.