Direct red 83 textile dye degradation using photoperoxidation and photo-fenton: kinetic studies, toxicity and neural networks modeling

Textile dyes have been observed in aquatic matrices that receive effluents from different textile industries. These compounds have the peculiarity of being resistant to the physical, chemical and biological treatments commonly used in wastewater treatment plants. Thus, alternative treatments such as advanced oxidative processes (AOP) have been considered in order to promote the degradation of this type of pollutant, being the photoperoxidation and photo-Fenton processes the most used. Therefore, the present work evaluated the efficiency of these AOP in the degradation of direct red 83 dye. It was found a greater efficiency of the photoperoxidation process, especially in the degradation of functional groups observed at 289 nm. This AOP presented a pseudo first order reaction kinetics, with rapid decay in the first minutes. The MLP (5-21-2) neural network model was able to satisfactorily predict the degradation of the dye under study. Finally, it was found that the proposed process showed no adverse effects when studying the toxicity in bacteria

Evaluation of the degradation potential of different advanced oxidation processes for a textile dye mixture: a kinetic study with mathematical modeling and toxicological tests

Studies and research have been developed around the world on environmental pollution. Among the most diverse types of pollutants, textile dyes have attracted attention in the Brazilian Northeast. These compounds, besides being persistent, resist to the conventional treatments applied in the wastewater treatment plants. Thus, the present study evaluated the degradation of the mixture of direct red 23, direct red 227 and direct orange 26 dyes by advanced oxidation processes (AOPs). It was observed that the homogeneous AOPs were more efficient, being able to degrade 100% of the chromophoric groups after the optimization of the variables [H2O2], [Fe] and pH. The reaction kinetics for the photo-Fenton process followed a pseudo-first order non-linear model, with rapid decay of the concentrations in the first 60 min. Aiming to have a methodology capable of predicting the degradation efficiency for the studied processes, it was verified that the artificial neural networks MLP 4-9-3 and MLP 5-6-3 well represent the data from the homogeneous and heterogeneous processes, respectively. A toxicity study was carried out using seeds, bacteria and microcrustaceans and it was found that the intermediate compounds formed during the treatment process act differently for each of them

Schiff bases complexed with iron and their relation with the life cycle and infection by Schistosoma mansoni

Funding Information: This work was supported by the Support Foundation of São Paulo (FAPESP) [No. 2014/12568-4] and National Counsel of Technological and Scientific Development (CNPq) [No. 100763/2015-4] received by JV da Silva. Acknowledgments Publisher Copyright: Copyright © 2022 da Silva, Moreira, Montija, Feitosa, Correia, Domingues, Soares, Allegretti, Afonso and Anibal.Introduction: The trematode Schistosoma mansoni causes schistosomiasis, and this parasite’s life cycle depends on the mollusk Biomphalaria glabrata. The most effective treatment for infected people is administering a single dose of Praziquantel. However, there are naturally resistant to treatment. This work has developed, considering this parasite’s complex life cycle. Methods: The synthetics compound were evaluated: i) during the infection of B. glabrata, ii) during the infection of BALB/c mice, and iii) during the treatment of mice infected with S. mansoni. Results and Discussion: For the first objective, snails infected with miracidia treated with compounds C1 and C3 at concentrations of 25% IC50 and 50% IC50, after 80 days of infection, released fewer cercariae than the infected group without treatment. For the second objective, compounds C1 and C3 did not show significant results in the infected group without treatment. For the third objective, the mice treated with C3 and C1 reduced the global and differential cell count. The results suggest that although the evaluated compounds do not present schistosomicidal properties when placed in cercariae suspension, they can stimulate an immune reaction in snails and decrease mice’s inflammatory response. In general, we can conclude that compound C1 and C3 has an anti-schistosomicidal effect both in the larval phase (miracidia) and in the adult form of the parasite.publishersversionpublishe

Avaliação cinética e ecotoxicológica da degradação do corante têxtil direct orange 26 por processos Fenton e foto-Fenton/solar

The presence of color in textile effluents has been studied because of the need for more effective treatments. Therefore, advanced oxidative processes (AOP) have been used in the degradation of dyes, as well as in the conversion of organic matter. This study evaluated the degradation of the direct orange 26 textile dye by Fenton and photo-Fenton processes (with natural solar radiation). A statistical analysis, based on factorial 23 indicated the best working conditions, being: [H2O2] = 100 mg·L-1 and pH 3-4, for both AOP in that the [Fe] =  1 e 5 mg·L-1, for photo-Fenton and Fenton, respectively. The results of the kinetic studies demonstrated a good fit to the nonlinear kinetic model proposed by Chan and Chu, with values of R2 > 0,996 (photo-fenton) and R2 > 0,939 (Fenton). The tests performed to evaluate the chemical oxygen demand indicated conversions of 62.05% (Fenton) and 66.41% (photo-Fenton). Finally, the ecotoxicity study indicated that the post-treatment samples were non-toxic to the bacteria Escherichia coli and Proteus mirabilis but showed growth inhibition for Lactuca sativa (Fenton and photo-Fenton) seeds and for Brassica juncea and Portulaca grandiflora (Fenton).A presença de cor em efluentes têxteis tem sido alvo de estudo, devido a necessidade de tratamentos mais eficazes. Diante disso, processos oxidativos avançados (POA) têm sido utilizados na degradação de corantes, assim como na conversão da matéria orgânica. Este estudo avaliou a degradação do corante têxtil laranja direto 26 via processos Fenton e foto-Fenton (com radiação solar natural). Uma análise estatística, baseada em planejamentos fatoriais 23 indicaram as melhores condições de trabalho, sendo elas: [H2O2] = 100 mg·L-1 e pH 3-4, para ambos os POA em quanto que a [Fe] =  1 e 5 mg·L-1, para o foto-Fenton e o Fenton, respectivamente. Os resultados dos estudos cinéticos demonstraram um bom ajuste ao modelo cinético não-linear proposto por Chan e Chu apresentando R2 > 0,996 (foto-Fenton) e R2 > 0,939 (Fenton). Os ensaios realizados para avaliação da demanda química de oxigênio indicaram conversões de 62,05% (Fenton) e 66,41% (foto-Fenton). Por fim, o estudo de ecotoxicidade indicou que as amostras pós-tratamento não são tóxicas para as bactérias Escherichia coli e Proteus mirabilis, mas apresentou inibição do crescimento para sementes de Lactuca sativa (Fenton e foto-Fenton) e para Brassica juncea e Portulaca grandiflora (Fenton)

Association of advanced oxidative and adsorptive processes for dye treatment in the sanitizer industry: kinetic, equilibrium and toxicity evaluation

The presence of dyes in wastewater can cause several damages to the environment. Aiming at its removal, advanced oxidative processes (AOP) and adsorption (ADS) have been used. In this work, the removal of acid blue dye 80 (AA80) by AOP (photoperoxidation (PP) and photo-Fenton (PF)) and by ADS was evaluated, individually and combined. The use of the PP/UV-C system led to degradations of 72.7 and 83.8% for the λ of 334 and 622 nm, respectively. The PP/LED system did not degrade. For the PF process, > 90% degradation was obtained for both radiations. The [Fe] (1 mg.L-1) and [H2O2] (90 mg.L-1)were optimized for the PF/LED system. As for the PF/UV-C system, the optimal [H2O2] was 60 mg.L-1. The experimental data fit well with the Chan and Chu (2003) kinetic model with R2>0.94. The kinetic data showed a better fit to the pseudo-second order model (R2>0.90), while equilibrium was reached in 30 min with removal of 62.45 (λ=334 nm) and 83.22% (λ=622 nm), being well represented by the Langmuir and Sips models. Finally, the combined study promoted a 7% increase in AA80 removal, achieving an improvement in the final toxicity of the treated matrix when compared to isolated AOP systems.

Núcleos de Ensino da Unesp: artigos 2010: volume 4: as disciplinas escolares, os temas transversais e o processo de educação

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

NEOTROPICAL XENARTHRANS: a data set of occurrence of xenarthran species in the Neotropics

Xenarthrans—anteaters, sloths, and armadillos—have essential functions for ecosystem maintenance, such as insect control and nutrient cycling, playing key roles as ecosystem engineers. Because of habitat loss and fragmentation, hunting pressure, and conflicts with domestic dogs, these species have been threatened locally, regionally, or even across their full distribution ranges. The Neotropics harbor 21 species of armadillos, 10 anteaters, and 6 sloths. Our data set includes the families Chlamyphoridae (13), Dasypodidae (7), Myrmecophagidae (3), Bradypodidae (4), and Megalonychidae (2). We have no occurrence data on Dasypus pilosus (Dasypodidae). Regarding Cyclopedidae, until recently, only one species was recognized, but new genetic studies have revealed that the group is represented by seven species. In this data paper, we compiled a total of 42,528 records of 31 species, represented by occurrence and quantitative data, totaling 24,847 unique georeferenced records. The geographic range is from the southern United States, Mexico, and Caribbean countries at the northern portion of the Neotropics, to the austral distribution in Argentina, Paraguay, Chile, and Uruguay. Regarding anteaters, Myrmecophaga tridactyla has the most records (n = 5,941), and Cyclopes sp. have the fewest (n = 240). The armadillo species with the most data is Dasypus novemcinctus (n = 11,588), and the fewest data are recorded for Calyptophractus retusus (n = 33). With regard to sloth species, Bradypus variegatus has the most records (n = 962), and Bradypus pygmaeus has the fewest (n = 12). Our main objective with Neotropical Xenarthrans is to make occurrence and quantitative data available to facilitate more ecological research, particularly if we integrate the xenarthran data with other data sets of Neotropical Series that will become available very soon (i.e., Neotropical Carnivores, Neotropical Invasive Mammals, and Neotropical Hunters and Dogs). Therefore, studies on trophic cascades, hunting pressure, habitat loss, fragmentation effects, species invasion, and climate change effects will be possible with the Neotropical Xenarthrans data set. Please cite this data paper when using its data in publications. We also request that researchers and teachers inform us of how they are using these data

Núcleos de Ensino da Unesp: artigos 2008

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq