Effect Of Goethite And Hematite On Anaerobic Methane Production Of Sodium Acetate

The effects of typical iron oxide (natural goethite and synthetic goethite andtheir calcined producton in air atmosphere) on the release of methane wereinvestigated, in which the anaerobic biochemical system mainly consisted ofdissimilatory iron-reducing bacteria (DIRB) and methane-producing bacteria (MPB)with sodium acetate as carbon source of anaerobic microorganisms. Furthermore, itwas investigated that the effects of different dosages of natural goethite and naturaloolitic hematite on the variation of the release of methane in the anaerobicfermentation process. The mechanisms of the release of CH4promoted by goethiteand hematite in the anaerobic fermentation were preliminarily explored.To explore the effects of natural goethite (NGt) and synthetic goethite (SGt) andtheir calcined producton in air atmosphere on the release of methane in the DIRB-MPB system, the CH4and CO2gas production were monitored, total organic carbon(TOC), total inorganic carbon (TIC), Fe(Ⅱ) concentration, pH, redox potential (ORP)in the aqueous phase of the experimental process were determined as well as the X-raydiffraction (XRD) analyses of the solid phase. Moreover, the analyses of the minerals byspecific surface area (BET), XRD, X-ray fluorescence (XRF) were conducted. Resultsshowed that the maximum cumulative production of methane was obtained in advance of60-81days by the addition of goethite and hematite and about28%-65%of CO2waseffectively reduced compared with the control samples. The production of methane wasmost quickly in SGt+MPB+DIRB system. The maximum CH4gas production was obtainedin the SHt+MPB+DIRB system while the minimum CO2gas production was observed inthe SGt+MPB system. Furthermore, the analysis of solid production after the reactionshowed that both of goethite and hematite can fix part of CO2by the formation of siderite.To explore the effects of natural goethite (NGt) and natural oolitic hematite(NHt) on the variation of the release of methane in the anaerobic fermentationprocess, the CH4and CO2gas production were monitored by adding different dosagesof natural goethite and natural oolitic hematite into the system. Results showed thatNHt was more effectively than NGt to promote the release of CH4. With the increase ofNGt content, the rate of CH4gas production in the anaerobic fermentation process was alsoincreased.