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Dye effluents cause diverse environmental problems. Methylene blue (MB) dye stands out since it is widely used in the textile industry. To reduce the pollution caused by the MB, we developed biosorbents from tucumã seeds, where the in natura seeds were treated with NaOH (BT) and H3PO4 (AT) solutions and characterized by Boehm titration, point of zero charges, FTIR, TGA, BET, and SEM. It was observed that the acid groups predominate on the surface of the three biosorbents. The process was optimized for all biosorbents at pH = 8, 7.5 g/L, 240 min, C0 = 250 mg/L, and 45 ℃. BT was more efficient in removing MB (96.20%; QMax = 35.71 mg/g), while IT and AT removed around 60% in similar conditions. The adsorption process best fits Langmuir and Redlich-Peterson isotherms, indicating a hybrid adsorption process (monolayer and multilayer) and pseudo-second-order kinetics. Thermodynamic data confirmed an endothermic and spontaneous adsorption process, mainly for BT. MB was also recovered through a desorption process with ethanol, allowing the BT recycling and reapplication of the dye. Thus, an efficient and sustainable biosorbent was developed, contributing to reducing environmental impacts.

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The potential of pyrolyzed Mytella falcata shells as an adsorbent for removing methylene blue dye molecules from aqueous solutions was investigated. The study found that the adsorbent produced at 600 °C of pyrolysis temperature, with an adsorbent mass of 0.5 g, particle diameter of 0.297-0.149 mm, and pH 12.0, demonstrated the highest dye molecule removal efficiency of 82.41%. The material's porosity was observed through scanning electron microscopy, which is favorable for adsorption, while Fourier-transform infrared spectroscopy and X-Ray diffraction analysis analyses confirmed the presence of calcium carbonate in the crystalline phases. The pseudo-second order model was found to be the best fit for the data, suggesting that the adsorption mechanism involves two steps: external diffusion and diffusion via the solid pores. The Redlich-Peterson isotherm model better represented the equilibrium data, and the methylene blue adsorption was found to be spontaneous, favorable, and endothermic. The hydrogen peroxide with UV oxidation was found to be the most efficient method of regeneration, with a regeneration percentage of 63% achieved using 600 mmol.L-1 of oxidizing agents. The results suggest that pyrolyzed Mytella falcata shells could serve as an ecologically viable adsorbent alternative, reducing the amount of waste produced in the local environment and at the same time removing pollutants from the water. The material's adsorption capacity remained almost constant in the first adsorption-oxidation cycles, indicating its potential for repeated use.

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The development of industrial process in line with the circular economy and the environmental, social and corporate governance (ESG) is the foundation for sustainable economic development. Alternatives that make feasible the transformation of residues in added value products are promising and contribute to the repositioning of the industry towards sustainability, due to financial leverage obtained from lesser operational costs when compared with conventional processes, therefore increasing the company competitivity. In this study, it is presented a promising and innovative technology for the recycling of agro-industrial residues, the sugarcane bagasse and the high-pressure water boiler effluent, in the development of a low-cost adsorbent (HC-T) using the hydrothermal carbonization processes and its application in the adsorption of herbicide Diuron and Methylene Blue dye from synthetic contaminated water. The hydrothermal carbonization was performed in a Teflon contained inside a sealed stainless-steel reactor self-pressurized at 200°C, biomass-to-effluent (m/v) ratio of 1:3 and 24 h. The synthesized material (HC) was activated in an oven at 450°C for 10 min, thus being named adsorbent (HC-T) and characterized by textural, structural and spectroscopic analyses. The low-cost adsorbent HC-T presented an 11-time-fold increase in surface area and ∼40% increase in total pore volume in comparison with the HC material. The kinetic and isotherm adsorption experiment results highlighted that the HC-T was effective as a low-cost adsorbent for the removal of herbicide Diuron and Methylene Blue dye from synthetic contaminated waters, with an adsorption capacity of 35.07 (63.25% removal) and 307.09 mg g-1 (36,47% removal), respectively.

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The purpose of this work is to make use of vegetables that, although widely found in nature, there are few applications. The weeds used here, Cyanthilium cinereum (L.) H. Rob (CCLHR) and Paspalum maritimum (PMT) found in the Amazon region of Belém state of Pará-Brazil, contribute to the problem of water contamination by the removal of the methylene blue dye through the biosorption process, taking advantage of other materials for economic viability and processing. The influences of parameters such as, biosorbent dose, contact time, and initial concentration of dye were examined. The characterizations were realized using SEM to verify the morphology of the material and spectroscopy in the FTIR region. As for the adsorption mechanism, the physical adsorption mechanism prevailed. The time required for the system to reach equilibrium for both biosorbents was from 50 min, following a kinetics described by the pseudo-second order model. The adsorption isotherm data for PMT were better adjusted to the Langmuir model and the biosorption capacity (qmax) value was (56.1798 mg/g). CCLHR was better adjusted to the Freundlich model and its maximum biosorption capacity was 76.3359 mg/g. Thus, these weed species are promising for the biosorption of methylene blue dye in effluents.

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AIM: The aim of current research was to find out the sealing ability of two commonly used sealers in the presence and absence of smear layer at different time interval. MATERIAL AND METHODS: Total of 180 single rooted vital teeth were used. Transversal section was made with the help of digital slow speed cutting saw to divide the root and crown part. After removal of crown roots part was instrumented and prepared. The 180 teeth were randomly divided into two equal groups (n=90) 1 and 2. In group 1 the smear layer was kept intact but it was removed from group 2 with EDTA (17%). Group 1 was then divided into two sub-groups, A1, A2. Group 2 was again separated into two sub-groups, B1 and B2. Each sub-group contained of 45 samples. In sub-groups A1 and B1, AH Plus sealer, in sub-groups A2 and B2, Ketac-endo sealer and cold lateral condensation technique was used for obturation with gutta percha. All samples were kept in an incubator at 37°C for 24 hours, with help of nail polish/varnish all samples root surfaces was painted only excluding apical area after words each sub group were further divided in to three groups of 15 to represent immersion periods of 7,15 and 30 days. All samples were then kept in 5 % methylene blue dye solution at 37o c for their respective time periods. After specific time period, the roots of every group were cut longitudinally and evaluate under a stereomicroscopes to evaluate apical micro leakage in millimeter. Data was subjected to Repeated measure ANOVA with post-hoc analysis using Tukey and bonferroni tests. RESULTS: Overall analysis indicated significant reduction in sealing ability canals in with and without smear layer over different time periods (p <0.0001). CONCLUSION: Current study has concluded that AH plus sealer provides significantly better seal in the absence of smear layer than in the presence of smear layer in addition it gave better seal than Ketac-Endo sealer in the absence and presence of smear layer.

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The qualitatives and quantitatives comparison of the Indirect Fluorescent antibody technique for canine toxoplasmosis was made comparing the obtained results with the M.B.D. test results. Eighty serum specimens were examined and the agreement between qualitative results was over 94%, and there was good agreement among antibody titers in quantitative values. The IFI test detected higher titers than M.B.D. test. The sensitivity and specifity of the both techniques appears to be equal.

As avaliações quantitativas e qualitativas da prova de imunofluorescência indireta para a toxoplasmose canina foram realizadas comparativamente à prova de Sabin-Feldman. Foram examinados 80 soros por ambos os métodos, tendo sido encontrado 94% de concordância entre os resultados qualitativos e, também, uma boa concordância entre os valores de anticorpos, tendo a prova de IFI detectado níveis de anticorpos ligeiramente superiores. Ambas as provas aproximam-se muito quanto à sensibilidade e especificidade e a prova de IFI dispensa o uso de fator acessório e toxoplasma vivo.

RESUMEN

The qualitatives and quantitatives comparison of the Indirect Fluorescent antibody technique for canine toxoplasmosis was made comparing the obtained results with the M.B.D. test results. Eighty serum specimens were examined and the agreement between qualitative results was over 94%, and there was good agreement among antibody titers in quantitative values. The IFI test detected higher titers than M.B.D. test. The sensitivity and specifity of the both techniques appears to be equal.

As avaliações quantitativas e qualitativas da prova de imunofluorescência indireta para a toxoplasmose canina foram realizadas comparativamente à prova de Sabin-Feldman. Foram examinados 80 soros por ambos os métodos, tendo sido encontrado 94% de concordância entre os resultados qualitativos e, também, uma boa concordância entre os valores de anticorpos, tendo a prova de IFI detectado níveis de anticorpos ligeiramente superiores. Ambas as provas aproximam-se muito quanto à sensibilidade e especificidade e a prova de IFI dispensa o uso de fator acessório e toxoplasma vivo.