Doutorado em Química
URI Permanente para esta coleção
Nível: início
Ano de início: 2014
Conceito atual na CAPES: 5
Ato normativo: Homologação da 85ª Reunião do CTC-ES, Parecer CNE/CES nº 163/2005.
Processo nº 23001.000081/2005-56 do Ministério da Educação.
Publicado no DOU 28/07/2005, seção 1, página 11)
Periodicidade de seleção: Anual
Área(s) de concentração: Química
Url do curso: https://quimica.vitoria.ufes.br/pt-br/pos-graduacao/PPGQ/detalhes-do-curso?id=956/a>
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- ItemAvaliação da qualidade de águas superficiais: uma abordagem local com proposta de mitigação por adsorção em fase sólida(Universidade Federal do Espírito Santo, 2024-12-17) Rocha, Ana Kelly Simões; Costa, Vinicius Câmara; Lima, Maria Tereza Weitzel Dias Carneiro de; https://orcid.org/0000-0002-8731-5093; Rosa, Thalles Ramon; Costa, Eline Nayara Dantas da; Costa, José Arnaldo Santana; Athayde, Geisamanda Pedrini BrandãoThe assessment of surface water quality through continuous monitoring has received increased attention in recent years due to the increasing degradation of aquatic environments. This monitoring is essential to support Contaminated Area Management (CAM) studies, which include important steps such as the preliminary and detailed assessment of aquatic environments. The deltaic region of the Doce River, a floodplain highly vulnerable to contamination, is affected by mining, agricultural and industrial activities, and possibly by the effects of the Fundão dam collapse in 2015. Thus, the city of Degredo, which belongs to the deltaic region, was addressed in a specific case study, which identified high concentrations of Al, Ba, B, Co, Fe, P, Mn, Ni and Zn in the waters of points P1 and P3, above the CONAMA 357/2005 and IRMA legislation, constituting Potentially Toxic Elements (PTEs). A simulated Human Health Risk Assessment (HHRA) at this site ranged from "insignificant" to "low", with water ingestion as the main route of exposure. In addition, analyses showed that contamination levels increased after the dam breach (IPTTh between 0.40 and 23.73), contrary to the expected trend. The adsorption process was used as an alternative for the remediation of water contaminated by EPTs, using the CA-CaCO3 adsorbent, synthesised by dispersing CaCO3 on a porous carbon support derived from biomass. This material contained 12 wt% of nanocrystalline CaCO3 particles. The adsorbent and pure CA showed high efficiency, removing 99.9% of Fe2+, Mn2+, Cd2+, Ni2+, Zn2+ and Pb2+ ions in 20 min under optimised conditions (pH = 6.00 and adsorbent mass = 100 mg). Structural and chemical analyses (XRD, TG, SEM-EDX, mapping and ICP-OES) of CA and CA-CaCO3 helped to understand the structural and chemical characteristics of these materials, while kinetic and isothermal analyses showed that the process occurs by chemisorption. Thus, this work is linked to concepts of risk management, sustainability and circular economy, and provides an efficient and cost-effective alternative for the remediation of water contaminated by EPTs.
- ItemRemoção do corante preto reativo 5 em solução aquosa por adsorção e/ou oxidação eletroquímica(Universidade Federal do Espírito Santo, 2025-02-27) Paquini, Lucas Destefani; Profeti, Demetrius ; https://orcid.org/0000-0003-4565-3331; http://lattes.cnpq.br/5030262115789096; Ribeiro, Josimar ; https://orcid.org/0000-0002-9544-1647; http://lattes.cnpq.br/1265145498501171; https://orcid.org/0000-0003-1285-8031; http://lattes.cnpq.br/3239593331960071; Lima, Fabio Henrique Barros de ; https://orcid.org/0000-0001-5501-2429; http://lattes.cnpq.br/8978509213666235; Costa, Carla Regina ; https://orcid.org/0000-0002-7057-6393; http://lattes.cnpq.br/0088443679133064; Cestarolli, Dane Tadeu ; https://orcid.org/0000-0003-1453-9499; http://lattes.cnpq.br/6247805873454988; Ferreira, Rafael de Queiroz ; https://orcid.org/0000-0002-5190-8508; http://lattes.cnpq.br/5053247764430323The expansion of the textile sector has played a fundamental role in accelerating industrialization on a global scale. However, this industry has caused significant environmental impacts, particularly due to the improper disposal of effluents with high contamination loads, including azo dyes, with reactive black 5 (RB-5) being one of the most concerning. Thus, the search for effective decontamination methods is essential, among which adsorption and electrochemical advanced oxidation processes stand out as promising strategies for the removal of these pollutants. This study investigated adsorption and electrochemical oxidation applied to RB-5 removal in synthetic effluents. In the adsorption process, a C/TiO2 composite was developed and characterized. X-ray diffraction (XRD) analysis indicated that both the composite and the TiO₂ support predominantly exhibited anatase phases. Scanning electron microscopy (SEM) revealed morphological changes in the material after adsorption. The specific surface area of the adsorbent was approximately 54.24 m2 g–1, while Fourier-transform infrared spectroscopy (FTIR) confirmed the presence of various functional groups, some of which were related to the dye structure after adsorption. The point of zero charge (pHPZC) indicated favorable adsorption conditions for pH ≤ 7.47. After fitting to nonlinear equations, the Sips model best described the adsorption equilibrium. On the other hand, the adsorption kinetics followed the Avrami fractional order model, suggesting an adsorption governed by multiple stages. Thermodynamically, adsorption was classified as endothermic, entropy-controlled, and exergonic. The electrochemical oxidation process involved the development and characterization of dimensionally stable anode (DSA) with the Ti/IrO2-SnO2-Ta2O5 configuration. XRD analysis of the electrodes revealed characteristic phases of IrO2, SnO2, Ti, and Ta2O5, while SEM images displayed the typical "cracked mud" morphology. Cyclic voltammetry (H2SO4) evidenced the capacitive behavior of the electrodes, with a roughness factor ranging from 0.3260 to 0.6812. Electrochemical mass spectrometry (EC-MS) confirmed the predominance of electrogenerated molecular chlorine (Cl2) over the oxygen evolution reaction, especially under high Sn/Ta ratios and acidic pH conditions. Ion chromatography (IC) allowed the quantification of Cl⁻ and ClO⁻, while electrochemical impedance spectroscopy (EIS) evidenced that Cl₂/HOCl formation occurs at potentials above 1.25 V vs. Ag/AgCl, with lower charge transfer resistance (Rtc) in compositions containing up to 10% Ta. The chemical and structural stability of the electrodes was confirmed by the nearly constant solution resistance (Rs) and double-layer capacitance (Cdl), which indicated rough and porous surfaces. The RB-5 dye degradation process was efficient, with apparent rate constants ranging from 0.00121 to 0.00571 s–1, being most effective in the Ir/Sn/Ta 30:70:00, 30:65:05, and 30:60:10 electrodes. The chemical oxygen demand (COD) removal varied between 71.72% and 32.47%, and energy consumption was lower (0.482 kWh m–3) for compositions with lower Ta content. The results highlight the feasibility of both techniques (adsorption and electrochemical oxidation) for the treatment of industrial effluents containing dyes