Browsing by Author "Murari, Gabriella Frade"

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    Partition study of textile dye remazol yellow gold RNL in aqueous two-phase systems.
    (2015) Alvarenga, Juliana Maria de; Fideles, Renata Aparecida; Silva, Maira Vieira da; Murari, Gabriella Frade; Taylor, Jason Guy; Lemos, Leandro Rodrigues de; Rodrigues, Guilherme Dias; Mageste, Aparecida Barbosa
    The removal of organic dye pollutants from wastewater produced by the textile industry is a complex problem that presents potential health risks to the general public. Remazol Yellow Gold RNL (YR) dye is readily used to dye cellulose base materials and the methods developed for its removal from aqueous systems are either inefficient or too expensive to be adopted by smaller textile manufactures. Our approach is based on aqueous two-phase system (ATPS) using salts and either polymers or ionic liquids to extract Remazol Yellow Gold RNL from wastewater. Parameters such as the nature of the electrolyte, molecular mass of polymer and tie line length (TLL) on the dye partition coefficient (KYR) were all evaluated. A phase diagram for the polyethylene glycol (PEG 4000 g mol_1) and magnesiumsulfate system at 298.15 Kwas obtained and used to study the partitioning of YR. The KYR values demonstrate the potential of both systems for the removal of dyes from industrial effluents. The partition mechanismwas discussed based on the Haynes model and using the of Gibbs standard energy change (DtrG_). The driving force (enthalpy and/or entropy) that governs the partitioning of the dye depends on the nature of the ATPS. The optimized conditions that gave the best system was successfully applied to the removal of YR from wastewater obtained from a local textile manufacturer. The high KYR values in the presence of the effluent demonstrate the potential and robustness of the ATPS for the treatment of effluents from textile industries.
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    Use of aqueous two-phase PEG-salt systems for the removal of anionic surfactant from effluents.
    (2017) Murari, Gabriella Frade; Penido, Jussara Alves; Silva, Heriveltom Morais da; Baeta, Bruno Eduardo Lobo; Aquino, Sergio Francisco de; Lemos, Leandro Rodrigues de; Rodrigues, Guilherme Dias; Mageste, Aparecida Barbosa
    Linear alkylbenzene sulfonates (LAS) are synthetic anionic surfactants that are extensively used in many industries. As a result, large volumes of effluents containing high levels of these compounds are discharged into water bodies, causing risks to aquatic flora and fauna. Then, there is a need for environmentally safe and economically viable technologies for the removal of LAS from aqueous matrices. The present work evaluates the use of aqueous two-phase systems (ATPS) composed of PEG and sulfate salts for this purpose, considering the effects of tie line length (TLL), molar mass of polymer, and type of cation-forming salt on the partitioning behavior of LAS. All the LAS partition coefficient (KLAS) values were greater than unity, and the LAS extraction efficiencies (%ELAS) were higher than 97%. The system consisting of PEG 1500 þ (NH4)2SO4 þ H2O provided the highest KLAS (1083.34) and %ELAS (99.9%), indicating that the method provided good extraction of LAS to the top phase. This system was applied using a real effluent sample in laboratory-scale experiments as well as in bench-scale batch trials. The results obtained at the laboratory scale showed %ELAS values greater than 98%, while the best KLAS value obtained in the batch experiments was 8.50 (±1.75) (%ELAS ¼ 78.17%). These values demonstrated the potential of ATPS for the removal of LAS from industrial effluents.
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    O uso de sistemas aquosos bifásicos formados por polímero PEG e sal para remoção de um surfactante aniônico de efluentes.
    (2016) Murari, Gabriella Frade; Mageste, Aparecida Barbosa; Santos, Igor José Boggione; Gurgel, Leandro Vinícius Alves
    Surfactantes, tal Alquilbenzeno sulfonato linear (LAS) são compostos anfifílicos amplamente utilizados na indústria. No entando, a presença de LAS no meio ambiente é cada vez mais comum, causando impacto negativo na flora e fauna. Com a necessidade de utilizar tecnologias ecologicamente corretas para remoção de poluentes, este trabalho avalia o uso de sistemas aquosos bifásicos (SABs) compostos por polímero PEG e sais sulfato na remoção de LAS de matrizes aquosas. O SAB além de ser ambientalmente seguro ainda é economicamente viável, uma vez que seus componentes são atóxicos, não inflamáveis, podem ser reciclados e apresentam baixo custo, além disso, o componente principal do sistema é a água. Foram determinados o coeficiente de partição de LAS (KLAS) e a eficiência de extração de LAS (%ELAS) nos SABs estudados. O efeito do comprimento da linha de amarração (CLA), da massa molar do polímero e do cátion formador do sal sobre o comportamento de partição de LAS foram estudados. Todos os valores de KLAS foram maiores que a unidade e os valores de %ELAS obtidos foram acima de 99%, indicando que o LAS se concentrou na fase superior dos SABs. O sistema composto por PEG 1500 + (NH4)2SO4 + H2O apresentou o maior valor de KLAS (1083,34) e de %ELAS (99,9%). Este sistema foi usado para estudos de pré-concentração de LAS na fase superior e mostrou que é possível remover LAS com uma eficiência acima de 99% e gerar menores volumes de resíduos com uma alta concentração de surfactante. Foram realizados experimentos na presença de um efluente real em experimentos de batelada e em escala de bancada. Os experimentos em escala de bancada resultaram em valores de %ELAS maiores que 98% e o KLAS obtido nos experimentos em batelada foi 9,52 (%ELAS = 78,17%). Esses valores indicam que há um potencial aplicação do SAB na remoção de LAS de efluentes industriais.