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Effluents from textile processes, when discarded of inappropriately, have been shown to be a major environmental concern. In this way, different methods can be used, among them adsorption is an economical and efficient technique in the removal of dyes. Therefore, we propose to analyze the adsorptive capacity of bacterial cellulose (CB) against effluents containing the dye Remazol Black B (RBB). CB was produced by the bacterium Gluconacetobacter hansenii and characterized by the techniques of FTIR, DRX, TGA / DTG and pH (PCZ). The RBB removal tests were initially performed at different pHs. From the best experimental condition, new tests were performed at temperatures of 30, 40, 60 and 100 ± 2 °C, 150 rpm, pH 3.5, using 0.5 g of adsorbent in the concentrations of dye from 25 to 65 mg•L -1 . The kinetic study showed that the system balance was achieved in 80 minutes. The experimental data were better described by the pseudosecond order model. The equilibrium results showed that the experimental data fit the Langmuir model (qmax 17.513 mg•g -1 ). The thermodynamic parameters of adsorption showed that the process is exothermic, not spontaneous and also presented low system randomness. The activation energy (Ea) was 23.8 kJ•mol -1 characterizing physical adsorption. The residual water was not toxic to animal or microbial cells. Bacterial cellulose proved to be a good low-cost adsorbent, easy to acquire and which can be used in the adsorption process.

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The economic growth of the textile sector in Brazil has contributed to the generation of new jobs, qualification of the workforce and better living conditions for the population. However, due to the high activity of the sector, large volumes of toxic effluents have been generated which, if improperly disposed of, cause serious environmental damage. Therefore, alternatives in the treatment of effluents are interesting to increase the availability of this resource. A technique that has stood out, for being efficient, easy to operate and economical, is adsorption, a passive capture process where pollutants are deposited on the surface of materials. Thus, the work aimed to carry out a comparative study of the influence of pH in the removal of the dyes Remazol Black (RB), Remazol Red (RR) and Remazol Yellow (RGY) using different mixed adsorbents constituted by the fungus Aspergillus niger grown in orange peel in two different culture media. Six types of adsorbents (three for each culture medium) were produced and were treated with acid, base and without treatment. These were subjected to adsorption tests at different pHs (2, 7 and 9), using a solution (25 mg.L-1) volume of 100 mL, 0.5 g of biomass, rotation 150 rpm, 30 oC. The results showed that the adsorbents produced were able to adsorb the dyes RB, RGY, RR at different pHs. The best adsorption condition was obtained at pH 2 and the adsorbents were treated with acid, showing a promising alternative for the treatment of textile effluents.

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The cnidarians represent an important phylum of zoology, consisting of aquatic animals almost always of marine origin. The representatives of this phylum have important functions, being fundamental in the food chain of many animals, in addition to being important predators, responsible for maintaining the environmental balance. However, the interest in the cnidarian phylum is also related to the numerous accidents caused by some of its representatives, such as caravels and jellyfish, which intensifies the need to address this content more comprehensively in the classroom. For this, teaching resources represent important tools that can help teachers and students in the teaching-learning process, making the approach more pleasurable, didactic, and complete. One of these tools are photographs, which are classified as non-verbal language, effectively contributing to the teaching process, as well as to scientific-technological discoveries, which can be used in any learning environment. In this sense, students from the 5th year of Elementary School, from the city of Paudalho/Pernambuco, participated in a study on cnidarians, where the previous knowledge they obtained on the subject was evaluated, and how the use of tools such as drawings and figures could contribute for the construction of their knowledge about the phylum. The applied methodology, called indirect observation, boosted the understanding of the content, as well as contributed to the development of creativity and observation in the classroom. In addition, this tool boosted the development of cognitive conflicts, since students were able to relate preexisting knowledge with new information obtained during the class, which is fundamental in the science teaching process, whose main objective is to make the student relate the content covered in the classroom, with their daily lives, mobilizing students to expand their knowledge. These attitudes make the teaching of zoology something concrete and certainly more pleasurable, ensuring that good teaching strategies can break down barriers in science teaching.

O descarte de efluentes têxteis não tratados nos meios aquosos pode ocasionar em um rápido esgotamento do oxigênio dissolvido, o que resulta em um desequilíbrio noecossistema. São vários os métodos utilizados na remoção de cor, e, dentre eles, a adsorção vem se mostrando como um método de tratamento simples, barato e eficiente. O objetivo deste trabalho consiste em avaliar a habilidade da biomassa mista de Aspergillus niger e capim elefante (Penissetum purpureum Schum) na remoção do corante Remazol Vermelho de uma solução aquosa sintética sob difrentes condições de temperatura (30, 40 e 50 °C), concentrações variando entre 25 e 105 mg/L, tempo de adsorção de 0 a 200 minutos e pH 2.0. O estudo cinético foi caracterizado pelo modelo de pseudo-segunda ordem. Já o modelo de Langmuir se mostrou o melhor ajuste linear das isotermas de adsorção, apresentando uma capacidade de adsorção de 3,42 mg g-1. A esponteneidade da reação de adsorção foi avaliada através daenergia lvire de Gibbs. O estudo termodinâmico indicou que a adsorção é favorável e espontânea, além de que o aumento da temperatura ocasiona em uma redução na capacidade de adsorção. Estes resultados obtidos em efluentes sintéticosdemonstram que o adsorvente misto produzido neste estudo é uma alternativa promissora no tratamento de efluentes contaminados com Remazol Vermelho.

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