Aplicação da perlita expandida modificada com ortofenantrolina na remoção do negro de eriocromo T em águas residuais geradas em laboratórios de ensino de química

In this study, we carried out the study of Eriochrome black T removal using expanded perlite modified orthophenanthroline by adsorption technique. The study of the adsorption process was performed by investigating the effect of the initial dye concentration, contact time and pH range of the solution (acidic and alkaline) in the adsorption process, for a so-called synthetic effluent (aqueous solution of black eriochrome T) and a real effluent (generated from the test for determining the water hardness, by complexation titration). The materials were characterized by Thermogravimetry / Differential Thermal Analysis (TG / DTA), absorption spectroscopy in the infrared (IR), X-ray Diffraction (XRD) and scanning electron microscopy (SEM). By analysis of XRD observed thinking on orthophenanthroline the modified expanded perlite. And by IR analysis showed an increase in intensity and a detailed enlargement of the absorption band related to the axial deformation of the OH bond of silanol groups of perlite (Si-OH). In the equilibration time of the study, in the evaluated time range (5-230 min) was not possible to observe the existence of a balance of time, probably attributed to the type of interaction between the Eriochrome black-T and the expanded perlite modified orthophenanthroline, being an interaction of surface origin. In the study effect of the initial concentration of the adsorbate in the case 2,0x10-4 mol / L natural pH (pH 5) gave the highest removal percentage value of eriochrome T black color with 63.74 % removal in 20 minutes of contact. In evaluating the effect of varying the pH of Eriochrome black T solution in the adsorption process, it was found that the more acidic the environment, the greater the percentage stain removal, being a result of acid-base interaction between the adsorbate and the adsorbent. In T Eriochrome black removal study in real effluent we used the optimized conditions by studying with synthetic sewage. The dye removal at pH 10, natural pH of the effluent was no significant reaching the maximum amount of color removal percentage of 8.12%, obtained already at pH 3 with maximum color removal 100.00% of color, once more proving that eriochrome black T and effectively interact better with the adsorbent at acid pH values (pH 5 or 3), and most efficiently at pH 3. thus one can mention that the perlite expanded (an amorphous aluminosilicate naturally acid) modified with orthophenanthroline (one Bronsted base) consists of a master and effective removal of coloring material in the acid-type aqueous solution, the conditions expressed in this study, can be applied as an adsorbent of this dye also mums real effluent.

Política de formação de professores: variação do locus de formação e a experiência do CEFET-RN

The present article discusses the directives of the policies of the initial teachers’ formation introduced in Brazil in the 1990’s. These directives have brought new directions and demands, both to the formation institutions and to teachers’ formation. This work analyzes the enlargement and the variation of the formation locus, a topic criticized by the teaching educators for enabling different and flexible models which have taken to a more technical and instrumental formation to the detriment of a theoretical and practical solid formation. In a general way, the study reveals that the CEFET’s use as a space of teachers’ formation has given priority to the quantitative aspects, the optimization of the resources and the instrumentation of the educators’ formation, even though under the speech of the quality of the educational process. Differently, the operationalization of this policy at CEFET-RN has favored a formative model, which has joined research, extension and teaching, guaranteeing the specificity of a solid formation, as well as the articulation between theory and practice and the sense of investigation, necessary characteristics to the formation of a devoted educator with the quality of public education.

Testicular volume and reproductive status of Wild Callithrix jacchus

ARAÚJO, Arrilton ; SOUSA, Maria Bernardete Cordeiro . Testicular volume and reproductive status of Wild Callithrix jacchus. International Journal of Primatology, v.29, p.1355–1364, 2008. DOI 10.1007/s10764-008-9291-4

Revitalização urbana de centros históricos: uma revisão de contextos e propostas: a Ribeira como estudo de caso

This dissertation focuses on the theme of urban revitalization in historical centers. It starts from a survey of international and national concepts and experiences about the subject, in special, the historical center of Ribeira, in Natal, Brazil. It gives more attention to local management and it is dedicated to the study of objectives and actions developed, basically, by two segments that manage works in the district. Companhia Docas do Rio Grande do Norte aims at the economical development of the state and it implies the enlargement of capacity of loading and unloading of the harbor of Natal and the Natal city counsil aims at urban preservation and revitalization. It was analysed speeches ans projects related to Ribeira and it was discovered that Natal has done very little to revitalize its historical center in the last two dacades. It analyses what seemed, or at least, should be a conflict of interests between incompatible projects, revealing both conciliatory proceedings and connivance between the participants in decision making. The conclusion directs attentions to the threat to historical building in the city and the importance of enhancing discussion about the future of our historical sites