Biosorption is a property of certain types of inactive, dead biomass to bind and concentrate heavy metals from even very dilute aqueous solutions. It may be used for purification of metal containing industrial waste effluents. The issues related to the biosorption process design and optimization were addressed by (1) equilibrium isotherm relationships, (2) biosorption process rate and (3) breakthrough time in a continuous-flow biosorption column. This work investigates these three aspects for the biosorption of the heavy metals uranium and cadmium on protonated Sargassum fluitans seaweed biomass. / Biosorption uptakes of uranium and cadmium were evaluated by determining their isotherms at different solution pH values. It was established that the state of uranium in aqueous solution and ion exchange play an important role in the biosorption of uranium. A new equilibrium biosorption isotherm model based on ion exchange of uranium complex ion species was developed. The new model is capable of predicting the effect of proton as an exchanged species and of the metal speciation on the biosorption uptake for a equilibrium batch biosorption system. / The end-point titration method was applied in the experimental determination of the biosorption uptake rates of uranium and cadmium at different pH levels. A one-dimensional intraparticle diffusion rate model reflected well the controlling step in the uranium and cadmium ion transport inside the biosorbent. The PDEs of this new model were solved numerically by the Galerkin Finite Element Method (GFEM). / Biosorption of uranium was examined in a continuous-flow fixed-bed column at the feed pH 2.5. The biomass binding capacity for the uranium before the breakthrough was as high as 105 mg/g biomass. The elution with diluted hydrochloric acid produced an overall uranium concentration factor of about 25--30. A mass transfer model based on the external and intraparticle diffusion was developed to describe the column sorption performance. The model equations were solved by the Orthogonal Collocation (OC) numerical method. The model-calculated breakthrough curves agreed well with the experimental ones, indicating the potential of the model for process design and optimization.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.36736 |
| Date | January 1999 |
| Creators | Yang, Jinbai, 1964- |
| Contributors | Volesby, B. (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Doctor of Philosophy (Department of Chemical Engineering.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001764652, proquestno: NQ64698, Theses scanned by UMI/ProQuest. |
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