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dc.contributor.authorOcciano, Suzanneen_US
dc.date.accessioned2014-03-14T21:41:57Z
dc.date.available2014-03-14T21:41:57Z
dc.date.issued1988-12-05en_US
dc.identifier.otheretd-08012012-040338en_US
dc.identifier.urihttp://hdl.handle.net/10919/44082
dc.description.abstractThe removal mechanisms of soluble manganese [Mn (1l)] through mixed-media filters were investigated. Experimentation was directed toward the continuous supply of an oxidant during column filter studies. Free chlorine (HOCl, OC1â ) was chosen to increase soluble manganese removal efficiency because chlorine is readily available and inexpensive. Filter media from four different water treatment plants were used in this study. Continuous-flow filter columns were operated in the presence and absence of 2.0 milligrams per Liter (mg/ L) free chlorine. Maintaining constant influent manganese concentrations of 1.0 mg/L and flow rates of 2.5 gallons per minute per foot squared (gpm/ft2), the operational pH values of 6-6.2, 7.8 and 8.8 were investigated. Results indicate that a continuous feed of free chlorine (2 mg/L) applied to the filter columns could increase manganese (II) removal efficiency. However, the amount and oxidation state of the MnOx(S) surface coating initially on the media and the influent pH had major influences upon the uptake of soluble manganese. From numerous Mn (II) uptake studies with different media and varying pH conditions, oxide-coated filter media continuously regenerated with free chlorine could result in increased soluble manganese removal through adsorption upon the MnOx(s) surface coating and subsequent oxidation directly on the media surface. The relationships of manganese removal and chlorine consumed were also explored. To further investigate the mechanisms of free chlorine oxidation for the removal of reduced manganese, pH 5.0 backtitrations were conducted following exhaustion of the filter media. The exposure of such low pll conditions to columns operated in the presence and absence of HOCI would ascertain if oxidation of the adsorbed Mn2+ was always occurring, regardless of an oxidant feed. Results indicated that in the absence of HOCI, the mechanisms for manganese removal on oxide-coated filter media were adsorption only. With the additional of HOCI, the adsorbed Mn2+ is oxidized directly on the surface of the media, thereby, continuously regenerating the surface oxide coating. Additional work was begun to ascertain if free chlorine could be used as a viable alternative to potassium permanganate (KMnO4) regeneration of oxide-coated filter media. Preliminary findings indicate from column cycling experiments that free chlorine could be used to regenerate oxide-coated filter media prior to backwashing.en_US
dc.format.mediumBTDen_US
dc.publisherVirginia Techen_US
dc.relation.haspartLD5655.V855_1988.O224.pdfen_US
dc.subjectWateren_US
dc.subject.lccLD5655.V855 1988.O224en_US
dc.titleThe mechanism for free chlorine oxidation of reduced manganese in mixed-media filtersen_US
dc.typeThesisen_US
dc.contributor.departmentEnvironmental Sciences and Engineeringen_US
dc.description.degreeMaster of Scienceen_US
thesis.degree.nameMaster of Scienceen_US
thesis.degree.levelmastersen_US
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen_US
thesis.degree.disciplineEnvironmental Sciences and Engineeringen_US
dc.contributor.committeechairKnocke, William R.en_US
dc.contributor.committeememberBoardman, Gregory D.en_US
dc.contributor.committeememberHoehn, Robert C.en_US
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-08012012-040338/en_US
dc.date.sdate2012-08-01en_US
dc.date.rdate2012-08-01
dc.date.adate2012-08-01en_US


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