Stability of polymeric membranes to UV exposure before and after coating with TiO2 nanoparticles

Acknowledgments: Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP, Nº 2019/ 04319-9), Associate Laboratory for Green Chemistry—LAQV, Unidade de Tecnologia de Células Animais do iBET e à Paula Alves, iNOVA4Health—UIDB/Multi/04462/2020, a program financially supported by Fundação para a Ciência e Tecnologia/Ministério da Educação e Ciência, through national funds is acknowledged. Funding from INTERFACE Program, through the Innovation, Technology and Circular Economy Fund (FITEC), is also gratefully acknowledged. Funding Information: Funding: Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP, Nº 2019/04319-9), Associate Laboratory for Green Chemistry—LAQV (through projects UIDB/50006/2020 and UIDP/ 50006/2020), Fundação para a Ciência e a Tecnologia through the project PTDC/EAM-AMB/30989/2017, Unidade de Tecnologia de Células Animais do iBET, iNOVA4Health—UIDB/Multi/04462/2020. Funding Information: Funda??o de Amparo ? Pesquisa do Estado de S?o Paulo (FAPESP, N? 2019/04319-9), Associate Laboratory for Green Chemistry?LAQV (through projects UIDB/50006/2020 and UIDP/ 50006/2020), Funda??o para a Ci?ncia e a Tecnologia through the project PTDC/EAM-AMB/30989/2017, Unidade de Tecnologia de C?lulas Animais do iBET, iNOVA4Health?UIDB/Multi/04462/2020. Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland.The combination of photocatalysis and membrane filtration in a single reactor has been proposed, since the photocatalytic treatment may degrade the pollutants retained by the membrane and reduce fouling. However, polymeric membranes can be susceptible to degradation by UV radiation and free radicals. In the present study, five commercial polymeric membranes were exposed to ultraviolet (UV) radiation before and after applying a sol–gel coating with TiO2 nanoparticles. Membrane stability was characterized by changes in hydrophilicity as well as analysis of soluble substances and nanoparticles detached into the aqueous medium, and by Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), and energy-dispersive X-ray spectrometry (EDS) for structural, morphological, and elemental distribution analysis, respectively. The TiO2 coating conferred photocatalytic properties to the membranes and protected them during 6 h of UV radiation exposures, reducing or eliminating chemical and morphological changes, and in some cases, improving their mechanical resistance. A selected commercial nanofiltration membrane was coated with TiO2 and used in a hybrid reactor with a low-pressure UV lamp, promoting photocatalysis coupled with cross-flow filtration in order to remove 17α-ethinylestradiol spiked into an aqueous matrix, achieving an efficiency close to 100% after 180 min of combined filtration and photocatalysis, and almost 80% after 90 min.publishersversionpublishe

Bionanocompósito à base de resíduo de levedura e magnetita : síntese, caracterização e aplicação na sorção de Cu(II) em meio aquoso

Um biossorvente preparado com resíduos de levedura impregnados com nanopartículas de magnetita foi sintetizado, caraterizado e aplicado na sorção de íons Cu(II) em meio aquoso. Este subproduto da indústria sucroalcooleira foi utilizado devido à sua abundância, baixo valor agregado, e à presença de diversos sítios ativos em sua superfície, tornando-o uma alternativa viável para descontaminação de efluentes. O material nanomodificado (NPM) foi obtido pelo método de coprecipitação, no qual sais de Fe(II) e Fe(III) foram titulados com NH4OH. Após a síntese, a impregnação de magnetita sobre a levedura (BL) foi conduzida adicionando-se esta biomassa na suspensão de NPMs, sob aquecimento e agitação constantes, para formação do bionanocompósito, BL-NPM. Este, assim como BL e NPM puros, foram caracterizados pelas técnicas DRX, FTIR e MEV. Os testes de sorção de Cu(II) com BL, NPM e BL-NPM foram conduzidos em batelada. Nestes, após agitação, houve a separação de fases da mistura Cu(II)-biossorvente para análise do sobrenadante e determinação de Cu por FAAS. Os modelos isotérmicos de Langmuir, Freundlich e Dubinin-Radushkevich foram ajustados aos dados experimentais, e mostraram que a sorção entre biossorvente e Cu(II) foi favorável para todos os materiais, onde NPM e BL apresentaram afinidades semelhantes por Cu(II), e BL-NPM melhor adsorveu o analito. A caracterização por DRX permitiu a determinação das estruturas cristalinas dos nanomateriais, em contraste com a estrutura amorfa de BL. Os espectros de FTIR entre 4000 e 400 cm−1, indicaram a presença de bandas de N–H, C–H, C=O, N–O, O–H, C–C, e Fe-O (para os nanomateriais). Através das imagens de MEV, 7000X, foi possível verificar a eficiência de síntese de BL-NPM por impregnação de NPM em BL.Fil: José, Julia C. . Universidade Federal de Sao Carlos (Brasil).Fil: Debs, Karina. B.. Universidade Federal de Sao Carlos (Brasil).Fil: Labuto, Geórgia. Universidade Federal de Sao Carlos (Brasil).Fil: Carrilho, Elma. N. V. M.. Universidade Federal de Sao Carlos (Brasil)

ESTUDO DO ASSOREAMENTO DO RESERVATÓRIO TANQUE GRANDE, GUARULHOS (SP)

O reservatório Tanque Grande, implantado na bacia homônima de 7,75 km2 , localizada ao norte do município de Guarulhos (SP), é um dos reservatórios de abastecimento municipal, atendendo a uma população de cerca de 40.000 habitantes. Apesar de sua importância ambiental e estratégica, o reservatório tem sido afetado pelo assoreamento de seu contribuinte principal, o ribeirão Tanque Grande, reduzindo a sua capacidade de armazenamento. Com o objetivo de avaliar o assoreamento do reservatório, foram pesquisados depósitos de assoreamento e a produção específica de sedimentos da principal bacia contribuinte. Os depósitos, com cerca de 30.500 m3 (ou 45.800 t), são constituídos de material silto-argiloso, e ocupam cerca de 35% do volume do reservatório. Datação radiométrica pelo método do 210Pb confirmou o início da deposição com o início do enchimento do reservatório em cerca de 50 anos, indicando uma produção bruta de sedimentos de 916 t/ano e uma produção específica de 118 t/ km2 .ano. As estradas foram identificadas como sendo a principal área-fonte de sedimentos, bem como meio de sua transferência ao ribeirão Tanque Grande. Palavras-chave: assoreamento de reservatório, produção específica, volumetria de depósitos

Metals and no-metals in sediments from a non-polluted mangrove: Cardoso Island, Cananéia, SP

This work aims to assess the spatial distribution and the seasonal behavior of metals, no-metals, physical and chemical variables and provide a pre-impact geochemical scenario from non-polluted mangrove sediments of a transect at the Cardoso Island (Cananéia, São Paulo State, Brazil) extending 340 m long landward. Triplicate samples from eight stations were collected in December 2001 and June 2002. Conductivity, pH, temperature, salinity and dissolved oxygen from the sediment interstitial water were checked in field using a Horiba U-10 probe. Metals and no-metals concentrations were obtained employing an inductively coupled plasma optical emission spectrometer (ICP OES) Vista-RL-Varian, radial vision. The sediments reflected two distinct intertidal segments: a “lower plain” (LP) and an “upper plain” (UP). The LP, which comprises the first 100 m landward from the bay, is a muddy environment with higher metal concentration and seasonally more stable than the UP. This latter, extending until the upper boundary of the intertidal zone, is a more oxygenated sandy flat with lower metal concentration. The distinct behavior of the geochemistry pattern observed along the transect in December and June is interpreted as associated with seasonal pluviometric fluctuations. The low metal concentrations denote low anthropogenic interference in the area, one of the most well preserved Brazilian coastal regions. It can be used as reference area to comparative studies involving similar ecosystems and, in the future, to check the environmental state of this mangrove flat.This work aims to assess the spatial distribution and the seasonal behavior of metals, no-metals, physical and chemical variables and provide a pre-impact geochemical scenario from non-polluted mangrove sediments of a transect at the Cardoso Island (Cananéia, São Paulo State, Brazil) extending 340 m long landward. Triplicate samples from eight stations were collected in December 2001 and June 2002. Conductivity, pH, temperature, salinity and dissolved oxygen from the sediment interstitial water were checked in field using a Horiba U-10 probe. Metals and no-metals concentrations were obtained employing an inductively coupled plasma optical emission spectrometer (ICP OES) Vista-RL-Varian, radial vision. The sediments reflected two distinct intertidal segments: a “lower plain” (LP) and an “upper plain” (UP). The LP, which comprises the first 100 m landward from the bay, is a muddy environment with higher metal concentration and seasonally more stable than the UP. This latter, extending until the upper boundary of the intertidal zone, is a more oxygenated sandy flat with lower metal concentration. The distinct behavior of the geochemistry pattern observed along the transect in December and June is interpreted as associated with seasonal pluviometric fluctuations. The low metal concentrations denote low anthropogenic interference in the area, one of the most well preserved Brazilian coastal regions. It can be used as reference area to comparative studies involving similar ecosystems and, in the future, to check the environmental state of this mangrove flat

Efficient degradation of solid yeast biomass from ethanol industry by Fenton and UV-Fenton processes applying multivariate analysis

<div><p>Abstract Organic agro-industrial residues have been successfully used as biosorbents and promoting new uses from agricultural wastes benefits the economy. However, the allocation of a solid waste biosorbent after the sorption of contaminants has limited their effective application on a large scale as an alternative treatment of water and wastewaters. One solution could be degradation to convert the biosorbent material and adsorbed organic contaminants into environmental friendly compounds suitable for discharge. This study used an experimental design to evaluate the Fenton degradation of yeast biomass (YB) from the alcohol industry as a potential biosorbent. The efficiency of degradation was monitored according to the degraded mass (DM) and total organic carbon (TOC) remaining in the solution. The ANOVA showed an error of 9.7% for the effects and the media of interaction for the employed model for DM. Conducting the experiments with the best-predicted conditions (60 min, 25 g of YB, pH 3, 8,000 mg L-1 H2O2 and 40 mg L-1 Fe2+) with 30 W UV irradiation resulted in a YB reduction of 72 ( 2% with a TOC of 30 ( 2%. This suggests that an advanced oxidative process is an alternative for degradation of a biosorbent after sorption.</p></div