Full Description

The Detroit Water and Sewerage Department (DWSD) has undertaken a program of developing individual waterplant needs assessments and prioritization of construction projects for theSpringwells (540-mgd), Northeast (300-mgd) and Southwest (240-mgd) WaterTreatment Plants (WTP). As a result of these Needs Assessments, DWSD will beconsidering rehabilitation of filtration facilities for each of these plants,maintaining existing filtration capacity in some cases and increasing capacity inothers.For example, DWSD is considering an increase in capacity for the Northeast WTP,from 300 to 340-mgd, which would require construction of additional filters, or ahigher approved filter loading rate. For the Springwells WTP, the needsassessment has looked at maintaining the plant rated capacity of 540-mgd. Ahigher filter rate would allow for increased flexibility in the operation andmaintenance of the plant. For Southwest, the needs assessment has recommendedthe filtration process be converted from a declining rate to a constant rateoperation. The pilot study was commissioned to investigate, among other things,increased filter rates with several media configurations. Additionally, the effectsof intermediate ozonation on the filter process were also investigated, in bothwarm and cold water conditions. This paper discusses the conclusions to be drawn from the pilot testingperformed. These conclusions include the interactions between ozonation, filterrates, filter configurations and temperature. The paper also discusses the use offilter aid polymer and doses, and when polymer use might be beneficial ordetrimental to extending the filter run. Termination of filter runs on headloss orturbidity breakthrough, and the causes for each, are also discussed. Includes tables, figures.

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Edition: Vol. - No. Published: 11/15/2004 Number of Pages: 18File Size: 1 file , 2 MB