Abstract:Recebido em 8/7/11; aceito em 23/12/11; publicado na web em 23/3/12 CONSIDERATIONS ABOUT THE PREPARATION OF SAMPLES CONTAINING ESTROGENIC MICROPOLLUTANTS. In this work, the materials used in the recovery of estrogens from aqueous matrices by filtration and solid phase extraction were evaluated. The results showed that glass-fiber filters allow a recovery and repeatability compatible with this type of analysis, whereas cellulose esters lead to significant losses of the analytes, mainly due to adsorption process… Show more
“…The flasks were shaken at 25 • C and 150 rpm in an orbital shaker for predetermined contact times, followed by filtration using glass fiber membrane filters (GF-3, 0.45 µm, Macharey Nagel, Düren, Germany). The estrone residual concentrations were determined using HPLC-DAD [23]. A commercial activated carbon (CAC) sample (analytical grade, Dinâmica, Indaiatuba, Brazil) was also used for comparison.…”
Section: Application Of the Activated Biocharmentioning
In Brazil, a significant part of the biomass is unused, contributing to environmental pollution. The tannin industry commonly extracts tannins from the bark of Acacia mearnsii or black wattle, leaving a significant residue of 70% (w w−1). This study investigates the conversion of black wattle bark into a porous carbonaceous material to efficiently remove organic pollutants. Using ZnCl2 as a chemical activation reagent, the experiments varied the impregnation time, carbonization rates, and temperatures. Additional experiments aimed to increase the specific surface area (SSA). X-ray diffraction (XRD) analysis showed the formation and removal of ZnO, which increased porosity. Scanning electron microscopy (SEM) showed an irregular morphology with pores. Fourier-transform infrared (FTIR) spectroscopy indicated characteristic bands, and electron paramagnetic resonance (EPR) detected organic free radicals. The SSAs exceeded 1000 m2 g−1, averaging 1360 m2 g−1, with a maximum of 1525 m2 g−1. Micropores (1.4 nm) were consistent. The structure of the material and the high SSA suggest a potential for efficient removal of aromatic impurities by π–π interactions. This approach addresses the issue of biomass waste, provides a solution for environmental remediation, and represents a transformative strategy for biomass utilization.
“…The flasks were shaken at 25 • C and 150 rpm in an orbital shaker for predetermined contact times, followed by filtration using glass fiber membrane filters (GF-3, 0.45 µm, Macharey Nagel, Düren, Germany). The estrone residual concentrations were determined using HPLC-DAD [23]. A commercial activated carbon (CAC) sample (analytical grade, Dinâmica, Indaiatuba, Brazil) was also used for comparison.…”
Section: Application Of the Activated Biocharmentioning
In Brazil, a significant part of the biomass is unused, contributing to environmental pollution. The tannin industry commonly extracts tannins from the bark of Acacia mearnsii or black wattle, leaving a significant residue of 70% (w w−1). This study investigates the conversion of black wattle bark into a porous carbonaceous material to efficiently remove organic pollutants. Using ZnCl2 as a chemical activation reagent, the experiments varied the impregnation time, carbonization rates, and temperatures. Additional experiments aimed to increase the specific surface area (SSA). X-ray diffraction (XRD) analysis showed the formation and removal of ZnO, which increased porosity. Scanning electron microscopy (SEM) showed an irregular morphology with pores. Fourier-transform infrared (FTIR) spectroscopy indicated characteristic bands, and electron paramagnetic resonance (EPR) detected organic free radicals. The SSAs exceeded 1000 m2 g−1, averaging 1360 m2 g−1, with a maximum of 1525 m2 g−1. Micropores (1.4 nm) were consistent. The structure of the material and the high SSA suggest a potential for efficient removal of aromatic impurities by π–π interactions. This approach addresses the issue of biomass waste, provides a solution for environmental remediation, and represents a transformative strategy for biomass utilization.
“…Em consonância a este panorama, estudos utilizando os processos oxidativos avançados (POA), estão sendo explorados e, por sua vez, vem demonstrando significativa importância para a degradação dos POE (FERNANDES et al, 2011;LIZ et al, 2012) Desta forma são expressivos os casos de contaminações de solos, águas superficiais e subterrâneas, águas potáveis, escoamento superficial e percolação, provocando danos a saúde de animais e humanos, por pesticidas em diferentes países, inclusive no Brasil (CORREIA et al, 2007;CANELA, 2007;KUSTER et al, 2010;MARTINAZZO et al, 2011). Pa m 3 mol -1 , pressão de vapor 2,89 x 10 -7 mmHg e massa molecular de 215,68 g mol -1 , um herbicida seletivo utilizado no controle pré e pós-emergente de ervas daninhas, especialmente em culturas de cana-de-açúcar, sorgo e milho (OTURAN et al, 2009 (LEGRINI et al, 1993).…”
Section: Lista De Abreviaturasunclassified
“…Desta forma, métodos objetivando o tratamento dos IE tornam-se significativamente importantes. Os métodos mais utilizados e descritos na literatura são aqueles envolvendo as técnicas de adsorção e processos oxidativos avançados (FERNANDES et al, 2011;LIZ et al, 2012). Alum et al (2004) analisaram a degradação do 17β-estradiol (E2) frente à ozonização de solução padrão com concentração de 100 nM (27,2 μg L -1 ), e dosagem inicial de ozônio de 1,5 mg L -1 .…”
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