Araticum (Annona crassiflora) seed powder (ASP) for the treatment of colored effluents by biosorption

Dyes are widely used in many industrial sectors, many contain harmful substances to human health, and their release into the environment entails several environmental problems, generating a major worldwide concern as water resources are increasingly limited. The development of cheap and efficient biosorbents that remove these pollutants is of utmost importance. In this study, powdered seeds of the araticum fruit (Annona crassiflora) were used in the biosorption of crystal violet (CV) dye from aqueous solutions and simulated textile effluents. Through the characterization techniques, it can be observed that the material presented an amorphous structure, containing an irregular surface composed mainly by groups containing carbon, hydrogen, and oxygen. CV biosorption was favored at the natural pH of the solution (7.5) for a dosage of 0.7 g L⁻¹ of araticum seed powder. The pseudo-second-order model was the most suitable to represent the biosorption kinetics in the removal of the CV. Biosorption capacity reached equilibrium in the first minutes at the lowest concentrations, and, at the highest, after 120 min. The equilibrium data were well represented by the Langmuir model, with a maximum biosorption capacity of 300.96 mg g⁻¹ at 328 K. Biosorption had a spontaneous and endothermic nature. In the treatment of a simulated effluent, the biosorbent removed 87.8% of the color, proving to be efficient. Therefore, the araticum seeds powder (ASP) can be used as a low-cost material for the treatment of colored effluents containing the crystal violet (CV) dye

Application of Beauveria bassiana spore waste as adsorbent to uptake acid red 97 dye from aqueous médium

The adsorption of acid red 97 dye (RED 97) by the waste of the filamentous fungus Beauveria bassiana was analyzed. The adsorbent was obtained as a waste of a fermentative process, and characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT–IR), X–ray powder diffractometry (XRD), and specific surface area (BET). After the characterization, adsorption tests were carried out to determine the ideal conditions of pH, adsorbent mass, and contact time for the process. Adsorption isotherms, thermodynamic studies, and the treatment of textile effluent were also investigated. The adsorbent characterization allowed the visualization of its amorphous structure, with irregular and heterogeneous particles. The pore diameter was 51.9 nm and the surface area was 0.247 m2 g−1. 1.2 g L−1 of the adsorbent and pH of 2.0 were the ideal conditions for RED 97 adsorption. The pseudo–second–order kinetic model was the most appropriate to represent the experimental data, being the equilibrium reached in about 110 min. The Langmuir model was the most suitable to represent the equilibrium data, with maximum adsorption capacity of 194.1 mg g−1 at 45 °C. The adsorption processes was thermodynamically spontaneous, favorable, and exothermic. In the treatment of a real textile effluent, 5 g L−1 of the spores was capable to decolorize 70% of the solution. Therefore, spore wastes of Beauveria bassiana were promising for RED 97 adsorption

Preparação, caracterização e avaliação catalítica do compósito Fe2O3/grafite em reação foto-Fenton

Neste trabalho, compósito Fe2O3/grafite foi preparado e usado como um catalisador em reação foto-Fentonpara a descoloração de solução aquosa contendo o corante amaranto sob irradiação de luz visível. Amostrascom diferentes teores de Fe2O3 suportados sobre grafite foram preparadas e caracterizadas por difração deraios-X (DRX), adsorção-dessorção de N2 e microscopia eletrônica de varredura (MEV). O aumento do teorde ferro nos compósitos resultou em uma superior área de superfície específica. Através da metodologia desuperfície de respostas gerada a partir do Delineamento Composto Central Rotacional (DCCR), verificou-seuma eficiência máxima de descoloração da solução de corante de 93% nas condições experimentais ótimasde reação foto-Fenton (pH = 2,5, quantidade de catalisador = 0,35 g L-1 e razão molar H2O2/Ʃ elementos mineralizáveis:4,7). Portanto, o compósito Fe2O3/grafite pode ser utilizado como um potencial catalisador foto-Fenton para a degradação do corante amaranto em efluentes líquidos.Palavras-chave: foto-Fenton; compósito, Fe2O3/grafite, descoloração, amaranto, DCCR

Investigation of the reaction pathway for degradation of emerging contaminant in water by photo-Fenton oxidation using fly ash as low-cost raw catalyst

In this work, fly ash from a Brazilian thermal power plant was employed as a low-cost raw catalyst for Procion red degradation by photo-Fenton process. The ash was characterized by X-ray fluorescence (XRF), X-ray diffraction (XRD), nitrogen adsorption/desorption isotherms (BET), Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectrometry (EDX). The material had an iron content of 4.10 wt%, distributed homogeneously on the solid surface. The ash particles showed mainly spherical morphology between 0.5 and 20 µm. The catalyst presented promising activity, reaching 93% of dye decolorization at 60 min of reaction, and 85% of organic load removal at 240 min. The predominant oxidizing species involved on the degradation of dye molecules during the photo-Fenton reaction were the hydroxyl radicals (HO·). The material showed remarkable stability and reusability after five successive cycles of reuse. The reaction intermediates were identified by LC/MS analysis and a reaction pathway was proposed

Solid wastes from the enzyme production as a potential biosorbent to treat colored effluents containing crystal violet dye

Sugarcane bagasse, a largely available waste worldwide, was submitted to solid-state fermentation (SSF) using the fungus Metarhizium anisopliae, aiming to produce enzymes. The solid waste generated from SSF was tested as an alternative biosorbent to treat colored effluents containing crystal violet (CV) dye. The biosorbent, here named BW (bagasse waste), was characterized, and experimental tests were performed to verify the influence of pH and dosage on the CV biosorption. Isotherms and biosorption kinetics were performed, and the biosorption thermodynamic parameters were determined. The potential of BW was also evaluated for the treatment of a simulated textile effluent. The maximum biosorption capacity was 131.2 mg g−1 at 328 K, and the Liu was the most appropriate model to represent equilibrium data. The biosorption was spontaneous and endothermic. The use of BW in the simulated effluent showed that it is an efficient material, reaching color removal values of 85%. Therefore, the sugarcane bagasse generated from SSF can be considered a potential biosorbent to remove CV from textile effluents. This finding is relevant from the total environment viewpoint, since, at the same time, SSF generates enzymes and a solid waste, which in turn can be used as biosorbent to treat colored effluents

Poluição atmosférica proveniente da queima de combustíveis derivados do petróleo em veículos automotores

The pollution generated in large urban centers follows mainly from burning fossil fuels, basically gasoline and diesel, which are mineral substances formed by carbon compounds from the decomposition of organic materials, what take millions of years. Therefore, they are considered non-renewable resources. The fuel burning occurs incompletely when employed in heat engines and automotive vehicles, and this process results in release of a large amount of carbon monoxide and carbon dioxide emissions, making these great villains regarding to global warming and the greenhouse effect. It is worth noting that these fuels feed the industrial, electrical and transport of most world economies. This work aims to raise issues related to air pollution from motor vehicles use.A poluição gerada nos grandes centros urbanos tem origem principalmente pela queima de combustíveis fósseis, basicamente gasolina e diesel, que são substâncias de origem mineral formadas pelos compostos de carbono, provenientes da decomposição de materiais orgânicos, a qual perdura milhões de anos. Logo, são considerados recursos naturais não renováveis. A queima destes combustíveis acontece de forma incompleta quando utilizados em máquinas térmicas e veículos automotores, e este processo resulta no lançamento de uma grande quantidade de monóxido e dióxido de carbono (gás carbônico) na atmosfera, fazendo destes grandes vilões no que se refere ao aquecimento global e efeito estufa. Vale salientar que estes combustíveis alimentam os setores industrial, elétrico e de transportes de grande parte das economias do mundo. Este trabalho tem como finalidade levantar aspectos ligados à poluição atmosférica decorrente da utilização de veículos automotores

DIAGNÓSTICO PARA O GERENCIAMENTO DOS RESÍDUOS SÓLIDOS EM OFICINA MECÂNICA: ESTUDO DE CASO EM CONCESSIONÁRIA DO MUNICÍPIO DE FREDERICO WESTPHALEN – RS

http://dx.doi.org/10.5902/2236130810933O setor mecânico tem crescido continuamente associado ao crescimento na produção e venda de veículos novos no país, ocorrendo assim, um grande aumento da frota de veículos. Com a maior circulação destes, cresce também a necessidade de ter oficinas mecânicas para atender essa a demanda, oficinas estas, que realizam diversos serviços como a troca de peças e lubrificantes, ajustes no motor e serviços de manutenção elétrica. Destes serviços, das oficinas mecânicas, resultam resíduos como os óleos usados, as peças metálicas, as estopas e embalagens contaminadas com óleo, entre outros. Tendo em vista o potencial poluidor dessa atividade, que gera consideráveis quantidades de resíduos perigosos, bem como a necessidade da correta gestão destes resíduos, o presente trabalho faz uma análise da gestão dos resíduos da oficina de uma concessionária, localizada no norte do estado do RS, através de um o diagnóstico da gestão dos resíduos sólidos, a fim de propor um melhor gerenciamento para adequação do setor

Biosorption of crystal violet dye using inactive biomass of the fungus Diaporthe schini

An inactive biomass of a new fungus recently discovered, Diaporthe schini, was evaluated for the biosorption of crystal violet (CV) in simulated textile effluents. The characterization assays were performed using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and N2 adsorption/desorption isotherms. The influences of pH and biosorbent dosage on the biosorption capacity were evaluated. Kinetics, equilibrium and thermodynamic studies were also carried out. Characterization techniques showed an amorphous biosorbent, with a rough surface containing irregular particles and surface area of 6.5 m2 g-1. The most adequate values of pH and biosorbent dosage were 7.5 and 0.4 g L-1, respectively. The Elovich kinetic model and the Sips equilibrium model were suitable to fit the experimental data. The biosorption capacity increased with temperature, reaching a maximum biosorption capacity of 642.3 mg g-1 at 328 K. The biosorption was a spontaneous and endothermic process. Diaporthe schini inactive biomass was an interesting biosorbent to treat colored effluents, presenting efficiencyof 87% in the decolorization of a simulated dye house effluent.Fil: Grassi, Patrícia. Universidade Federal de Santa Maria; BrasilFil: Reis, Caroline. Universidade Federal de Santa Maria; BrasilFil: Drumm, Fernanda C.. Universidade Federal de Santa Maria; BrasilFil: Georgin, Jordana. Universidade Federal de Santa Maria; BrasilFil: Tonato, Denise. Universidade Federal de Santa Maria; BrasilFil: Escudero, Leticia Belén. Universidad Nacional de Cuyo. Facultad de Ciencias Exactas y Naturales. Laboratorio de Química Analítica para Investigación y Desarrollo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza; ArgentinaFil: Kuhn, Raquel. Universidade Federal de Santa Maria; BrasilFil: Jahn, Sérgio L.. Universidade Federal de Santa Maria; BrasilFil: Dotto, Guilherme L.. Universidade Federal de Santa Maria; Brasi

Submerged cultivation of Nigrospora sp. in batch and fed-batch modes for microbial oil production

Microbial lipids are a valuable source of potential biofuels and essential polyunsaturated fatty acids. The optimization of the fermentation conditions is a strategy that affects the total lipid concentration. The genus Nigrospora sp. has been the target of investigations based on its potential bioherbicidal action. Therefore, this study developed a strategy to maximize the biomass concentration and lipid accumulation by Nigrospora sp. in submerged fermentation. Different media compositions and process variables were investigated in shaken flasks and bioreactor in batch and fed-batch modes. Maximum biomass concentration and lipid accumulations were 40.17 g/L and 21.32 wt% in the bioreactor, which was 2.1 and 5.4 times higher than the same condition in shaken flasks, respectively. This study presents relevant information to the production of fungal lipids since few investigations are exploring the fed-batch strategy to increase the yield of fungi lipids, as well as few studies investigating Nigrospora sp. to produce lipids