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dc.contributor.advisorPeak, Derek
dc.creatorBulmer, David Roy 1990-
dc.date.accessioned2019-02-05T18:18:34Z
dc.date.available2019-02-05T18:18:34Z
dc.date.created2018-12
dc.date.issued2019-02-05
dc.date.submittedDecember 2018
dc.identifier.urihttp://hdl.handle.net/10388/11871
dc.description.abstractThe addition of citrate into biostimulatory amendment solutions for the in-situ bioremediation of petroleum hydrocarbons is a relatively new concept. Research has shown that addition of citrate in combination with phosphate can potentially decrease P sorption and thus increase P mobility and bioavailability. In this thesis, soil cores from a hydrocarbon-contaminated site were first characterized to determine soil characteristics. The soil cores had a high clay content with heterogeneous soil layers, leading to the hypothesis that preferential flow paths are likely dominant in transport onsite. As a manipulative experiment, soil Ca levels were modified via three treatments, Ca Saturated, Ca Depleted, and the control soil to ascertain the effect of Ca upon citrate and P retention. X-ray fluorescence (XRF) and x-ray diffraction (XRD) confirmed the change in total Ca levels as well as differences in mineralogy of the treated soils. In chapter three, phosphate adsorption isotherms and citrate desorption isotherm experiments were designed to quantify the relationships among soil Ca, P adsorption, and the concentration of citrate (0-50mM) at equilibrium conditions. The results demonstrated that high citrate levels (above 5mM) would allow less P to be adsorbed onto the soil surface. Phosphorus K-edge XANES were measured on soil samples treated with citrate and Ca to determine the relationship between chemical speciation and citrate interactions. The research led to the discovery that higher than expected (>5mM) levels of citrate were required to get a significant desorption in P; higher levels of soil Ca were correlated with more adsorbed P. In chapter four, kinetics experiments combined with a spectroscopic approach yielded a better understanding of the citrate-phosphate-calcium reaction dynamics. By using the Pseudo Second order model, all parameters from the kinetics experiments were highly correlated to model experimental values. The major finding of the kinetic study was that soil Ca level strongly influenced citrate desorption effectiveness. Overall this thesis showed that the connection between Ca, citrate, and P was important in determining rates and mechanisms of chemical interaction and to be able to build and apply a model to the system.
dc.format.mimetypeapplication/pdf
dc.subjectPhosphate
dc.subjectCitrate
dc.subjectPseudo second order
dc.subjectAdsorption, Precipitation
dc.subjectBioremediation
dc.subjectTransport
dc.titleCHEMICAL INTERACTIONS OF CITRATE, CALCIUM AND PHOSPHATE IN A CALCAREOUS SASKATCHEWAN SUBSOIL
dc.typeThesis
dc.date.updated2019-02-05T18:18:35Z
thesis.degree.departmentSoil Science
thesis.degree.disciplineSoil Science
thesis.degree.grantorUniversity of Saskatchewan
thesis.degree.levelMasters
thesis.degree.nameMaster of Science (M.Sc.)
dc.type.materialtext
dc.contributor.committeeMemberSi, Bing
dc.contributor.committeeMemberSiciliano, Steven
dc.contributor.committeeMemberNiu, Catherine H
dc.creator.orcid0000-0003-3500-3853


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