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The City of Fairborn, Ohio, located roughly 70 miles northeast of Cincinnati, has a water service areapopulation of 32,000. The community's primary source of water is the 5.0 million gallons per day (mgd)Fairborn Water Treatment Plant (FWTP). The FWTP obtains raw water from four wells located in a wellfield adjacent to the Mad River. These sources, though not considered under the influence of surfacewater, have elevated levels of iron and manganese. Treatment presently consists of iron and manganeseremoval via oxidation through aeration, followed by settling, permanganate and polymer addition, ANDby gravity filtration by conventional sand media and chlorination. Unfortunately, the current treatmentprocess has been only marginally successful in removing iron and manganese. To optimize iron and manganese removal at the existing FWTP and reduce or eliminate the use ofexpensive oxidants like permanganate, the City authorized the construction of a pilot plant. The pilotplant consisted of two, four-inch clear PVC columns constructed within the FWTP's filter gallery. Byconstructing the plant in this location, the water supplied to the pilot tubes (including backwash water)was identical to that supplied to the plant's existing filters. The pilot study investigated iron andmanganese removal by various media, flow rates and oxidation methods. Media analyzed in the pilotplant included conventional sand (activated to induce a Natural Greensand Effect or NGE), greensandand pyrolusite. Oxidation methods included the use of aerated versus non-aerated water and the additionof chlorine prior to filtration.This paper describes the results of the FWTP pilot tests. The effectiveness of the various media atvarious filtration rates are then examined. The optimal filter medium is presented and revised operatingprocesses recommended. Finally, the cost savings associated with implementing these recommendationsplantwide are projected. Includes 6 references, table, figures.

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Edition: Vol. - No. Published: 06/15/2003 Number of Pages: 13File Size: 1 file , 510 KB