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1. Thue, Pascal Silas. Preparation and characterization of microwave–assisted activated carbons from biomass and application for the removal of Emerging Organic Contaminants (EOCs) in aqueous media.

Degree: 2017, Universidade do Rio Grande do Sul

In this thesis activated carbons from lignocellulosic biomass were prepared via microwave– assisted pyrolysis, characterized and applied into the removal of Emerging Organic Contaminants (EOCs) in aqueous media. A scientific understanding of the three-step preparation of activated carbons (AC) using first-row transition metals as activating agents by microwaves heating is also provided. The mixtures obtained after preparation step were pyrolysed in a microwave system in less than 11 min. Afterwards a 6 mol L-1 HCl was used to treat the pyrolysed materials, under reflux, to eliminate the inorganic components—producing activated carbons. This technology allows producing activated carbons with high porosity. Elemental analysis, FTIR, UV-Vis DRS, SEM, N2 adsorption/desorption curves, TGA, XRD Xray fluorescence, pHzpc, hydrophobic properties, total acidity and basicity groups were used to characterise biomass, intermediary materials and activated carbons. Results showed that the metals were bound successfully in different amounts with surface functional groups of the wood biomass through ion exchange and surface complexation interaction during the impregnation step. However, MWAC prepared with Zn2+ showed higher pore volumes and surface areas, which was related to their high adsorption capacity (qe). The samples prepared with the mixtures biomass: inorganic components (20% lime + 80% ZnCl2 or 20% lime + 40% ZnCl2 + 40% FeCl3) at different ratios were used for the complete adsorption study of phenol (PhOH) and o-cresol from aqueous solution. Results indicated that adsorption kinetic was very fast and equilibrium contact time was attained in the first 10 min for both molecules. Pseudo first-order, pseudo-second order and Avrami fractional-order kinetic models were used to probe the kinetic of adsorption. Among the three models; Avrami fractional-order kinetic model best described the adsorption kinetics of PhOH and o-cresol onto the activated carbons. The main interaction of PhOH or o-cresol with the activated carbons should be governed by hydrophobic interactions, hydrogen bonds, polar interactions and electron donor-acceptor interaction. While desorption experiment showed that activated carbons can be regenerated easily using a mixture of EtOH (10 or 50%) + NaOH (5 M). Additionally, MWAC prepared with CuCl2, CoCl2 and NiCl2 also exhibited high adsorption capacity. The adsorption order of the molecules is as shown: 2-nitro phenol > Bisphenol A > hydroquinone > 4-nitro phenol > 2-naphtol > paracetamol > caffeine > resorcinol. However, ZnCl2 demonstrate to be the best activating agent, which allows for the development of materials of high porosity as well as good adsorptive properties, and this trend is followed subsequently by CuCl2, CoCl2, and NiCl2.

Nesta tese, carvões ativos (AC) oriundos de biomassa lignocelulósica foram preparados por pirólise assistida por microondas, caracterizados e aplicados na remoção de contaminantes orgânicos emergentes (EOCs) em meio aquoso. Foram estudadas as três etapas da preparação dos…

Advisors/Committee Members: Lima, Éder Cláudio.

Subjects/Keywords: Remoção de contaminantes; Soluções aquosas; Adsorção; Carvão ativado : Adsorção

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APA (6th Edition):

Thue, P. S. (2017). Preparation and characterization of microwave–assisted activated carbons from biomass and application for the removal of Emerging Organic Contaminants (EOCs) in aqueous media. (Thesis). Universidade do Rio Grande do Sul. Retrieved from http://hdl.handle.net/10183/171686

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Thue, Pascal Silas. “Preparation and characterization of microwave–assisted activated carbons from biomass and application for the removal of Emerging Organic Contaminants (EOCs) in aqueous media.” 2017. Thesis, Universidade do Rio Grande do Sul. Accessed January 16, 2018. http://hdl.handle.net/10183/171686.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Thue, Pascal Silas. “Preparation and characterization of microwave–assisted activated carbons from biomass and application for the removal of Emerging Organic Contaminants (EOCs) in aqueous media.” 2017. Web. 16 Jan 2018.

Vancouver:

Thue PS. Preparation and characterization of microwave–assisted activated carbons from biomass and application for the removal of Emerging Organic Contaminants (EOCs) in aqueous media. [Internet] [Thesis]. Universidade do Rio Grande do Sul; 2017. [cited 2018 Jan 16]. Available from: http://hdl.handle.net/10183/171686.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Thue PS. Preparation and characterization of microwave–assisted activated carbons from biomass and application for the removal of Emerging Organic Contaminants (EOCs) in aqueous media. [Thesis]. Universidade do Rio Grande do Sul; 2017. Available from: http://hdl.handle.net/10183/171686

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

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