Textile effluent is rich in hydrolyzed dyes that need to be removed. This study presents an evaluation of the potential of the enzyme horseradish peroxidase to remove the hydrolyzed dyes Reactive Blue 21 (RB 21) and Reactive Red 195 (RR 195) from cotton fiber and the effluent of the dyeing process. The parameters pH, dye concentration and temperature were evaluated to determine the optimal conditions to remove the dyes. The studies of removal of the dyeing effluent led to an increase of degradation for all tested colors. The use of the enzyme horseradish peroxidase as a biocatalyst can be a viable technological alternative to remove some hydrolyzed dyes.
TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractThe development process of new technologies in drilling fluids has established that the fluid should have viscosity control and clays inhibition. Some other aspects as fluid loss control and grout thickness had become almost that decurrent of the action of the main products. The search of a highly inhibitive water-based drilling fluid (WBDF) system has been a continuous purpose in the drilling fluid industry.We have designed and developed new materials that will improve the inhibition capacity of water-based fluid, besides favoring a complete rheology and fluid loss control of the system. Parameter viscosity reached great evolution in the last decades with the implantation of high performance polymer, capable of substituting the bentonite. Through this, the fluid with low solid became the key of the success in perforation fluids.The developed system consists of an environment-friendly cationic polymer as shale inhibitor, a fluid-loss control, and a polymer that provides viscosity and gel structure. Components were designed for high performance water-based drilling fluids, and present the versatility to be used as much with industrial water, as seawater or saltwater, maintaining the fluid performance. This work will discuss some properties of this system, comparing with the traditional system used by Petrobras -Brazil.
The aim of this work was to remove the dyes Reactive Blue 221 (RB 221) and Reactive Blue 198 (RB 198) of synthetic effluent using the immobilized enzyme horseradish peroxidase (HRP) in Ca-alginate beads. Experimental parameters affecting the dye removal process such as the effect of pH, temperature, hydrogen peroxide concentration, mass capsules, and reuse were evaluated, and a numerical model of mass transfer was developed. A maximum removal of 93 and 75%, respectively, for the dyes RB 221 and RB 198, at pH 5.5 and temperature of 30 °C, concentration of hydrogen peroxide of 43.75 μM for dye RB 221 and 37.5 μM for the dye of RB 198 was obtained. A removal reaction of 180 min for RB 221 and 240 min for RB 198 was observed. Three reuse cycles of use of immobilized enzyme were achieved for both dyes. The numerical model proposed led to a good fit compared to experimental data. The HRP enzyme immobilized in Ca-alginate capsules showed a great potential for biotechnological applications, especially for the removal of reactive dyes.
Reactive dyes are complex structures that cause environmental damage when discarded. The aim of this study was to evaluate the reuse of effluent from an enzyme‐catalyzed dyeing process. The main parameters that influence the degradation of the mixture of dyes using the enzyme horseradish peroxidase were studied using response surface methodology: enzyme, hydrogen peroxide, and dye concentrations as well as the pH. The best conditions for the synthetic effluent were then applied to the reuse of the effluent from the dyeing process in laboratory and pilot scales. In the studies in pilot scale a high colour intensity was obtained (ΔE* value of 0.6) and a good washing fastness (4.0). The results obtained indicate that peroxidases could be used for colour removal on an industrial scale to save water and energy in the post‐dyeing process, reusing part of this effluent with the same efficiency as that of a traditional process.
Neste trabalho apresentamos uma alternativa para a dosagem do teor de silicone (polidimetilsiloxano) em antiespumantes por meio da técnica de espectroscopia no infravermelho com transformada de Fourier (FT-IR), com a utilização do acessório de reflectância total atenuada (ATR). Os espectros foram registrados na faixa espectral de 2500 a 780 cm-1, com resolução de 4 cm-1 e 128 varreduras. A calibração de um modelo linear por meio da utilização do método de mínimos quadrados parciais (PLS) aplicado aos espectros foi capaz de determinar satisfatoriamente a concentração de silicone nas amostras. Este método é de extrema importância para indústrias produtoras de antiespumantes siliconados, uma vez que o desempenho de tais produtos geralmente é avaliado em função da viscosidade dos mesmos. Muitas vezes no processo de fabricação de tais produtos ocorre uma homogeneização incompleta do silicone no solvente, o que leva a resultados de viscosidade que não são representativos das amostras analisadas. A determinação da concentração do teor de silicone é uma importante ferramenta para o Controle Estatístico de Processo (CEP), pois evita o desperdício de matérias-primas empregadas na fabricação dos antiespumantes.
The development process of new technologies in drilling fluids has established that the fluid should have viscosity control and clays inhibition.Some other aspects as fluid loss control and grout thickness had become almost that decurrent of the action of the main products.The search of a highly inhibitive water-based drilling fluid (WBDF) system has been a continuous purpose in the drilling fluid industry. We have designed and developed new materials that will improve the inhibition capacity of water-based fluid, besides favoring a complete rheology and fluid loss control of the system.Parameter viscosity reached great evolution in the last decades with the implantation of high performance polymer, capable of substituting the bentonite.Through this, the fluid with low solid became the key of the success in perforation fluids. The developed system consists of an environment-friendly cationic polymer as shale inhibitor, a fluid-loss control, and a polymer that provides viscosity and gel structure.Components were designed for high performance water-based drilling fluids, and present the versatility to be used as much with industrial water, as seawater or saltwater, maintaining the fluid performance. This work will discuss some properties of this system, comparing with the traditional system used by Petrobras - Brazil. Introduction The Drilling fluids play several functions in drilling well.If the mud properties are incorrect, safety and economics may be severely compromised.To each drilling fluid, its behaviors are major guarantee of drilling operation success[1–2].In selecting the most suitable type of drilling fluid, many different factors must be considered.What is required is a mud system that provides lowest overall cost of drilling each hole section.When drilling through the reservoir, the main purpose to minimize damaging reactions between the mud and reservoir. Many problems are caused by incompatibility between water and shales.This may be solved by using oil/water emulsion mud or 100% oil mud.This isolates water from shales and prevents hydration[1,3].However, oil muds are becoming increasingly difficult to use in some areas due to environmental concerns and government regulations changes.Water-based drilling fluids (WBDF) may use various chemical inhibitors to control reactive shales.These special drilling fluids are formulated to provide lubricity, inhibition, solids suspension and borehole stability.They also have to protect pay zones by forming an effective filter cake to control fluid loss, stay intact during completion operations and clean up easily[4–5]. Several researches have been developed to minimize the shale hydration by WBDF.The KCl addition on these kinds of fluids works by changing places with sodium atoms in the clay structure and, as potassium ion is smaller than sodium ion, this causes the clay structure to shrink rather than expand1.A recent development is the use of soluble silicates in clay stabilization.These are soluble at high pH, but precipitate out of solution if the pH drops. Tiny amounts enter the pore space between crystals, the pH drops, silicate precipitates and form a barrier to further water penetration.Use of silicates seems to cause the clay to harden over time1.Systems using a blend between KCl and glycols as inhibitors in WBDF have been Applied7–8.In these systems, xanthan gum and dextrin were used as viscosifying and loss filtrate control respectively.Other useful chemicals include polymers.Clay crystals have electrostatic charges on their faces and edges.If a polymer molecule also has opposing charges along its length, polymer sticks to the clay crystal and prevent water from reaching it[1].This is the principle of water-based cationic drilling fluids. The development of a WBDF, which could exhibit similar drilling characteristic to an invert emulsion drilling fluid, has been an ongoing endeavor of the drilling fluid industry[9–10].Different WBDF systems have been developed over the past ten years aiming to approach the drilling performance of an oil based mud.However, the developed fluids have not been completely successful in inhibiting the hydration of highly water sensitive clays.The cationic polymer systems used actually give a more oil based fluid-like inhibition.But, the cationic polymer toxicity (generally an organ chloride material) and their incompatibility with other anionic additives for water drilling fluids, have limited the system success.
RESUMO: O efluente têxtil contém corantes sintéticos hidrolisados que podem causar um grande impacto quando descartados em ambientes aquáticos. Os corantes naturais tornam o processo de tingimento uma rota de menor impacto ambiental, principalmente porque são produzidos a partir de plantas e animais. O objetivo deste trabalho é degradar o corante carmim de cochonilha utilizando a enzima Horseradish peroxidase (HRP). Os efeitos das principais condições que influenciam o processo, como pH, concentração de corante, enzima e peróxido de hidrogênio, foram estudados. A otimização do processo foi feita utilizando a metodologia da superfície de resposta e posteriormente foi realizado um segundo planejamento 2 4 completo para obtenção da condição ótima de degradação. As concentrações de enzima e peróxido de hidrogênio, corante e pH foram determinadas. Foi utilizado um limite de confiança de 95% foi obtido um ajuste ao modelo de 89%.
Multiferroics have engendered increasing interest because of their many potential applications for micro-or nano-electronic devices, magnetic storage elements and interesting fundamental physics. The term "multiferroic" means coexistence of ferroelectric and magnetic ordering in a single phase or multiphase material. However, the two ordering parameters are mutually exclusive because ferroelectricity and magnetism require different filling states of the d-shells of transition metal ions. Empty d-shells mainly exist in ferroelectricity, while partially filled d-shells are required in magnetism. Therefore multiferroics are rare. It exists several different microscopic mechanisms which may cause multiferroic behaviour. One of the most interesting is when a spontaneous polarization exists in a spiral or cycloidal magnetic structure. Accordingly, one strategy to find new multiferroic materials is to look for magnetic systems with that kind of magnetic structures. The complex metal oxides Mn 3 TeO 6 and Co 3 TeO 6 have been prepared both as single crystals by chemical transport reaction and as polycrystalline powders by a solid state reaction route. The crystal structure and magnetic properties have been investigated using a combination of x-ray and neutron powder diffraction, electron microscopy, calorimetric and magnetic measurements. It has been shown that at room temperature Mn 3 TeO 6 adopts a trigonal structure, space group R-3 (a= 8.8679(1)Å, c= 10.6727(2)Å) and Co 3 TeO 6 the monoclinic spacegroup C 2/c (a=14.7830(2)A, b=8.8395(1)A, c=10.3426(2)A). A long-range magnetically ordered state has been identified through variable temperature neutron diffraction and magnetic susceptibility measurements. The magnetic structure for the two compounds is very different. Mn 3 TeO 6 has an incommensurate helix structure while Co 3 TeO 6 shows a complicated but commensurate spin structure.
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