Planejamento experimental do estudo de adsorção de Ácido Tânico (AT) em Poliuretano (PU) para remoção de íons metálicos

• Autor(a) principal: Ferreira, Paula Rogéria da Silva
• Data de Publicação: 2017
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFMT
• Texto Completo: http://ri.ufmt.br/handle/1/4271
• topic: Planejamento experimental; Gravimetria; Espectrometria de UV-VIS; Superfície de resposta; CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA; Experimental planning; Gravimetry; Spectrometry UV-VIS; Response surface

Recent research has indicated viable alternatives for the treatment of industrial waste, enabling the implementation of low cost methods, and the use of materials that do not impact on the environment. Industrial pollutants containing potentially toxic metal ions are costly to industry, however, they are responsible for pretreatment and removal of toxic ions, before being released into effluents or sewage. Adsorption processes using biodegradable adsorbent materials have been presented as relevant alternatives for the reuse of metallic ions in water bodies and in sewage networks. In this perspective, the present study used chemometric tools to analyze the behavior of tannic acid (AT) immobilization in biodegradable polyurethane (PU) foams, based on vegetable oil (castor oil). Initially, a preliminary study was carried out, applying the 2k order factorial design, in the immobilization of TA in the PU's. The following variables were evaluated: temperature (30 ° C, 60 ° C), adsorbent dosage (10 units and 20 units), pH (5 and 8), contact time (12h and 26h) and molar concentration of AT , 01 mol L-1 and 0.1 mol L-1 ). The responses were obtained and evaluated through two analytical techniques, gravimetry and Absorption Spectrometry in the UV-Vis region. The most significant effects of adsorbent, pH, AT concentration and contact time, were evaluated by Central Composite Planning (PCC) for the immobilization of AT in PUs, evaluating the response obtained by UV-VIS. It was also observed that the gravimetric method presented results of low precision and accuracy, due to the variables of PU swelling. The PCC was applied in the multi-element analysis of Pb2+ and Hg2+ ions in different experimental conditions of adsorbed AT in PU. The instrumental technique to obtain two metal ion response was the ICP-OES technique. The evaluation of the metals, were from the remaining metal solution and that of the adsorbent. The remaining metal solution having an amount of adsorbed metal of Hg2+ and Pb2+ 59.93% and 51.48%, respectively. In addition, the evaluation of the adsorbent system PU-AT-M, allowed better conclusions about the behavior of the metals and to assist in future studies of retention of metals present in industrial systems.