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Title:	Cellulose from kenaf core fibers facilitated with activated carbon and magnetic particles of CoFe2o4/Fe3o4 for dye adsorption
Authors:	Seyedehmaryam Moosavi (P78676)
Supervisor:	Sarani Zakaria , Prof. Dr.
Keywords:	Cellulose Polymer Kenaf Universiti Kebangsaan Malaysia -- Dissertations
Issue Date:	10-Apr-2017
Description:	Cellulose is relatively stable polymer with high axial stiffness and high crystallinity. Cellulose based products (hydrogel, aerogel and beads) has been used in many applications such as dye removal. Magnetic adsorbents have gained much attention as they can readily be removed from the aqueous medium using externally applied magnetic field upon adsorption of pollutants. Moreover, activated carbon (AC) was used for improving the adsorption capacity of dyes. Cellulose hydrogel was synthesized with dissolving of bleached kenaf pulp, into the NaOH/Urea aqueous solution and mixed with crosslinker. The cellulose aerogel was prepared by drying the cellulose hydrogel in a freeze dryer. In this study, the effects of crosslinker percentage (3-9 %) on the morphological, thermal and mechanical properties of synthesized cellulose hydrogel and aerogel were characterized. The acoustic properties of prepared cellulose aerogel were determined using impedance tube. Magnetic CoFe2O4 nanocrystals were synthesized using hydrothermal method from mixing cobalt (II) chloride hexa hydrate (CoCl2-6 H2O) solution and iron (II) sulfate hepta hydrate (FeSO4-7H2O) solution. The mixed solution was mixed and heated in oven at 200 ºC for 2, 3, 4 and 5 h. The modification of cellulose beads was done by immersed with total of 12 wt. % of AC in cellulose solution, and mixed homogeneously. While, magnetic cellulose beads was produced with modification of AC with 5 wt. % of Fe3O4 and CoFe2O4. The adsorption performances of the modified regenerated cellulose beads functionalized with AC, and magnetic cellulose beads (MCB) of AC-Fe3O4 and AC-CoFe2O4 were studied in terms of removing MB dyes from aqueous solution. The adsorption experiments were conducted at different pHs (3, 5, 7 and 9), temperatures (20 ºC, 40 ºC and 60 ºC) and initial adsorbate concentrations (500, 400, 300, 200 and 100 mg/L). For improving the MB dye removal, Fenton oxidation was performed as a catalyst. Moreover, the reusability study of MCB adsorbents using Fenton oxidation was investigated. To investigate in depth the mechanism of adsorption on the surface of adsorbent beads well, the kinetics models (pseudo-first order, pseudo-second order and intraparticle diffusion) were used to fit the experimental data. The kinetics of the adsorption was studied to fit well with the pseudo-second-order model. Adsorption-Fenton oxidation improved the time of dye removal onto the MCB. The adsorption capacity of the adsorbents was reduced less than 5% after seven cycles of adsorption-oxidation. The magnetic sensitivity of MCB under external magnetic field provided an easy way for separation from water. MCB could be used as effective adsorbents for the removal of MB dye.,Certification of Master's/Doctoral Thesis" is not available
Pages:	138
Publisher:	UKM, Bangi
Appears in Collections:	Faculty of Science and Technology / Fakulti Sains dan Teknologi

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