Biosorption of BF-4B Reactive Red Dye by using Leaves of Macrophytes Eichhornia crassipes

The removal potential on BF-4B reactive red dye by Eichhornia crassipes dried leaves has been investigated. Furthermore, the influence of process parameters such as solution pH, agitation, and particle size on the dye adsorption efficiency was assessed. Both kinetic and equilibrium experiments were performed in batch operation of the system. Kinetic results demonstrated that the equilibrium state was achieved after 45 min process time. The kinetic experimental data were best described by applying a pseudo-second order model that evaluated the value of rate constant 0.22 g/mg/min and an equilibrium dye concentration 8.20 mg/g. A set of isotherm models, taken from knowledge database, was tested in order to represent the equilibrium adsorption data. The Langmuir model performed the best when fitting experimental data where the maximum adsorption capacity of 20.38 mg/g was achieved. The results demonstrated that the E. crassipes has good potential to be used as a biosorbent in industrial treatment systems to remove reactive dyes from textile effluents

Otimização do processo foto-fenton com irradiação UV no tratamento de efluentes de indústria de processamento de subprodutos de alimentos

Neste trabalho, foi investigada a remoção de poluentes orgânicos do efluente de uma indústria de transformação alimentícia com base na técnica foto-Fenton, utilizando irradiação artificial, em escala laboratorial. Como fontes de irradiação UV, foram fixadas três lâmpadas comerciais de mercúrio acima do reator foto-Fenton dentro de uma caixa isolada. Foi aplicado um planejamento fatorial 23 a fim de otimizar o processo foto-Fenton baseado na avaliação dos valores da demanda química de oxigênio (DQO), da cor e da turbidez. O modelo estatístico de segunda ordem proposto resultou em um bom ajuste linear, com as variáveis pH inicial e as concentrações de Fe2+ e H2O2 sendo estatisticamente significativas para a remoção da DQO e da cor. O melhor desempenho do processo foto-Fenton artificial foi alcançado para as concentrações de Fe2+ = 0,26 g L-1 e H2O2 = 22,0 g L-1, e o pH inicial em 3,0. Nestas condições, o processo obteve ótima eficiência na remoção dos parâmetros com apenas 10 minutos de reação, apresentando 93% na redução da DQO, 95% de descoloração e 98% de redução da turbidez

Avaliação da remoção dos poluentes do efluente de curtume tratado pelos processos Eletro-Fenton e foto-Fenton

Neste trabalho foi avaliada a eficiência dos processos eletro-Fenton e foto-Fenton na remoção dos parâmetros físico-químico da DQO, cor e turbidez, assim como o nível de toxicidade, no tratamento do efluente de curtume. O processo da eletro-Fenton apresentou eficiência de remoções de 75, 92 e 90%, da DQO, cor e turbidez, respectivamente. O processo foto-Fenton alcançou remoções de aproximadamente 100% da DQO, cor e turbidez. Para ambos os processos obteve-se uma redução da toxicidade do efluente tratado, apresentando em 45 min uma DL50 24 e 19% para a eletro-Fenton e foto-Fenton, respectivamente. Ambos os processos podem ser considerados eficientes, podendo ser desenvolvidos e aplicados em escalas industriais

Tilapia scales : characterization and study of Cu(II) removal by ion exchange with Ca(II)

A biosorbent material based on tilapia scales for the removal of Cu(II) ions was investigated. Modifications in the biosorbent caused by retention of Cu(II) and by the pH effect were evaluated separately in order to comprehend how the removal process occurs. For that, a physico-chemical characterization of the scales was performed before and after the Cu(II) removal. The results obtained from the characterization and biosorption tests led to the conclusion that the Ca–Cu ions exchange was responsible for purifying the solution. Furthermore, the tilapia scales were efficient, removing 95% of Cu(II) with 1 g of adsorbent (surface area ≈ 3 m2)551186198CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESNão temNão temThe authors gratefully acknowledge CAPES (Commission for the Improvement of Higher Education Personnel), CNPq (National Council for Scientific and Technological Development), UNIOESTE (West Paraná State University), and the Araucaria Foundatio

Removal of Copper Ions by Non-living Aquatic Macrophytes Egeria Densa

In this work, the removal potential of Cu2+ ions by non-living macrophytes Egeria densa has been studied. Adsorption kinetic and equilibrium tests were carried out in flasks under batch operations and controlled pH and temperature. The biosorption kinetic results have shown that Cu2+ ions removal rate was at its maximum at the beginning of the process. The equilibrium state was achieved after 60 min, and the Cu2+ ions removal was higher than 70% for the given experimental conditions. The kinetic biosorption data were better fitted by using a pseudo second order model. The equilibrium data at pH 5 were better described by the Langmuir isotherm than the Freundlich one, with a maximum metal content value of 1.47 mequiv⋅g-1 and an adsorption rate value of 3.73 l⋅mequiv-1. The kinetic parameters values were in agreement with other biosorbents data published in the literature, indicating that the macrophytes E. densa have a good potential to be used as biosorbent material in industrial effluent treatment system