2019-11-072019-11-072013FEITOSA, Renan da Silva. Síntese e caracterização de hidróxido duplo lamelar do sistema Zn/Al-[CO3] e sua aplicação na adsorção de nitrato. Orientador: José Augusto Martins Corrêa. 2013. 44 f. Trabalho de Curso (Bacharelado em Geologia) - Faculdade de Geologia, Instituto de Geociências, Universidade Federal do Pará, Belém, 2013. Disponível em: https://bdm.ufpa.br/jspui/handle/prefix/2436. Acesso em:.https://bdm.ufpa.br/jspui/handle/prefix/2436The most common water pollution in urban areas is a nitrate, mainly caused by human actions. The maximal concentration established at the drinking water protocol elaborated by Ministry of Health is 50 milligrams of nitrate per liter. Consumption above this level can cause diseases in humans, such as cancer in adults and methemoglobinemia in infants. It is of great interest to develop new methods that are able to reduce or remove these contaminants such as adsorption method. The layer double hydroxides (LDHs) are synthetic or natural minerals composed of plates with metal hydroxides positively charged anions that are stabilized and interlayer anions and water. These compounds have different physical and chemical properties like thermal stability, ion exchange capacity, porosity and high surface area, and electrochemical properties "memory effect". These properties allow this composts to be used in various applications, mainly as adsorbents, catalysts and anti-acids. The objective of this work was to synthesize, characterize and apply a LDH on the sorption of nitrate. The synthesis of this material was made by the co-precipitation method with variable pH, using zinc as a divalent cation, and aluminum as trivalent cation, with carbonate anion occupying the interlamelar apace and sodium hydroxide solution as the pH controller. The synthesized material was characterized by X-ray diffraction, scanning electron microscopy, the term gravimetric analysis and Infrared spectroscopy analysis. The HDLs synthesized show a pattern similar to hydrotalcite, with basal reflections (003) and (006) that characterize the material as being lamellar. The HDLs shown a good structural order, with basal spacing equal to 7.54032 Ǻ, Ǻ 7.53840, 7.53653 and 7.54187 Å Ǻ, obtained the ratios 0.33, 0 , 29, .25, .22, respectively. These values of basal spacing agree with the expected value for LDHs intercalated with carbonate. The results of infrared spectroscopy for all synthesized LDHs are similar. The compounds shown a broad and intense band at about 3400 cm-1, which is attributed to stretching vibration of O-H bond, referring to the hydroxyl group of the brucite layer. The presence of a shoulder at 3000 cm-1 is attributed to hydrogen bonding between water and anion in the interlayer. The main absorption bands were identified among anions 1350 cm-1 and 1600 cm-1. The thermo gravimetric analysis showed a similar behavior. Three stages were identified. The first stage begins at room temperature until 220°C involves the removal of adsorbed water in samples, the second stage (220° C to 400°C) is related to the decomposition of part of the hydroxyl groups and the third and last stage (400°C until 850°C) is related to decomposition of the remaining hydroxyl and the carbonate anion intercalated. Material was heated, equally divided and placed in contact with a solution containing various concentrations of nitrate, which was quantified by chromatography. Results of experiments with sorption showed that LDH is a moderate sorbent for treatment of effluents contaminated with excess nitrate.Acesso AbertoAdsorçãoHidróxido duplo lamelarNitratoCNPQ::CIENCIAS EXATAS E DA TERRA::GEOCIENCIAS::GEOLOGIA::GEOQUIMICATrabalho de Curso - Graduação - Monografia