Search

This study aimed to identify the possibility of using rapeseed husks (RH) as an unconventional sorbent for removing acidic (AR18, AY23) and basic (BR46, BV10) dyes from aqueous solutions. Its scope included, i.a.: sorbent characterization (FTIR, pHPZC), determination of pH effect on dye sorption effectiveness (pH 2–11), analysis of dye sorption kinetics (pseudo-first order model, pseudo-second order model, intraparticular diffusion model), and the determination of the maximum sorption capacity (Langmuir 1 and 2, and Freundlich isotherms). The sorption effectiveness of acidic dyes (AR18, AY23) onto RH was the highest at pH = 2, whereas that of the basic dyes BR46 and BV10 was most effective at pH = 6 and pH = 3, respectively. The time needed to reach the sorption equilibrium of dyes onto RH depended on their initial concentration and ranged from 120 to 150 min for the acidic dyes and from 150 to 180 min for the basic dyes. The maximum sorption capacity (Qmax) of RH towards AR18 and AY23 was 49.37 mg/g and 41.52 mg/g, respectively, and towards BR46 and BV10 it was 59.07 mg/g and 20.93 mg/g, respectively. The obtained Qmax values were compared with the results achieved for other sorbents (literature data). This comparison demonstrated that the sorption capacity of rapeseed husks towards the analyzed dyes was higher compared to that of some types of activated carbons. [ABSTRACT FROM AUTHOR]

A time-saving, one-step polyacrylamide gel preparation method enabling simultaneous preparation of separating and stacking gels was previously reported, but the boundary between the separating and stacking gels was often not well defined. As such, determining whether the gel preparation failed is difficult before SDS-PAGE is carried out. To address this issue, a one-step polyacrylamide gel preparation method was developed in which the stacking gel is colored to allow better visualization of the border between the stacking and separating gels. This new one-step method saves time and achieves comparable performance for SDS-PAGE and western blotting to that obtained with conventional gels. [Display omitted] • The separating and stacking gel boundary of conventional one-step SDS-PAGE gels can be unclear. • Dye was added to the stacking gel of the one-step gel. • A colored stacking gel helps confirm successful gel preparation before SDS-PAGE. • The new one-step gel performed comparably to conventional one- and two-step gels. [ABSTRACT FROM AUTHOR]

This study aimed to identify the possibility of using rapeseed husks (RH) as an unconventional sorbent for removing acidic (AR18, AY23) and basic (BR46, BV10) dyes from aqueous solutions. Its scope included, i.a.: sorbent characterization (FTIR, pHPZC), determination of pH effect on dye sorption effectiveness (pH 2–11), analysis of dye sorption kinetics (pseudo-first order model, pseudo-second order model, intraparticular diffusion model), and the determination of the maximum sorption capacity (Langmuir 1 and 2, and Freundlich isotherms). The sorption effectiveness of acidic dyes (AR18, AY23) onto RH was the highest at pH = 2, whereas that of the basic dyes BR46 and BV10 was most effective at pH = 6 and pH = 3, respectively. The time needed to reach the sorption equilibrium of dyes onto RH depended on their initial concentration and ranged from 120 to 150 min for the acidic dyes and from 150 to 180 min for the basic dyes. The maximum sorption capacity (Qmax) of RH towards AR18 and AY23 was 49.37 mg/g and 41.52 mg/g, respectively, and towards BR46 and BV10 it was 59.07 mg/g and 20.93 mg/g, respectively. The obtained Qmax values were compared with the results achieved for other sorbents (literature data). This comparison demonstrated that the sorption capacity of rapeseed husks towards the analyzed dyes was higher compared to that of some types of activated carbons.

The quality of natural waters could be deteriorated by organic pollutants which can impose a risk to the ecosystem as well as human health. These organic contaminants are often needed to be removed with adequate techniques. In this study, the photocatalysts of CdO nanoparticles (NPs), Ag–CdO nanocomposites (NCs), and Ag–CdO/polyaniline (PANI) NCs were successfully synthesized in order to investigate their degradation performance against 3′,3″,5′,5″-tetrabromophenolsulfonphthalein (bromophenol blue, BPB) dye. The crystal structure, functional groups, morphological change, and degradation efficiency of as-synthesized photocatalysts were characterized using XRD, FTIR, SEM and UV-Visible spectroscopic techniques respectively. The SEM result showed that the surface morphology of the nanomaterials seems the agglomerated micron-scaled grains as compared to CdO NPs and Ag–CdO NCs. The FT-IR spectrum demonstrated the absorption peaks which strongly confirmed that Ag–CdO NCs surface was successfully modified with PANI. The highly sharp and intensive XRD patterns attributed to the cubic structure for CdO NPs and Ag–CdO NCs structures with decreasing crystalline size from 40.58 nm to 36.43 nm and 10.29 nm upon CdO NPs photocatalyst surface treatment with Ag metal and PANI. The decreased particle size brought about to narrow the bandgap from 2.76 eV to 1.61 eV and 1.58 eV respectively. Among the synthesized photocatalysts, Ag–CdO/PANI NCs exhibited the best degradation efficiency of 97.30 % at pH 6, 10 ppm concentration of dye, 0.140 g of catalyst load, and 210 min irradiation time. Moreover, the kinetics of photodegradation of model dye at optimum conditions followed pseudo-second order reaction with the rate constant of 8.56 × 10-2 M-1min-1. The results suggested that, the developed treatment method for this particular dye could be applicable for the treatment of wastewater samples containing acidic dyes.

Two simple, sensitive, accurate, precise and reproducible extractive colorimetric methods were developed for estimation of Telmisartan in bulk and pharmaceutical dosage form. These methods are based on the formation of colored ion-pair complex of Telmisartan with Bromocresol green (BCG) and Bromocresol purple (BCP) dyes in acidic medium. The complex was extracted in chloroform and estimated quantitatively at 421 nm and 411 nm for BCG and BCP dyes respectively. For estimation of TMS present in the sample, estimation was also done by using Smartphone Application known as PhotoMetrix Pro. Beer Lambert's law was obeyed over a range of 4-12 µg/ml for TMS with BCG dye by UV (r²= 0.9997) and PhotoMetrix (r²= 0.997) and for BCP dye it was obeyed over a range of 2-10 µg/ml by UV (r²= 0.999) and PhotoMetrix (r²= 0.998). The developed method was successfully applied for estimation of TMS in three commercial product tablet formulation without interference from common additives. The developed method was validated according to ICH Q2 guideline for linearity, range, accuracy, and precision. Comparison for both method UV and PhotoMetrix was done by performing t-test, and results show that there is no significant difference between both methods and hence Photometrix can be used as an alternative to UV for routine analysis of TMS. [ABSTRACT FROM AUTHOR]

In this work, the bio-nanohybrids of magnesium-aluminum layered double hydroxide intercalated with zwitterionic histidine (His-LDH) was synthesized. The crystal phase, morphology, and nanostructure of the as-prepared His-LDH were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), and nitrogen adsorption–desorption methods. The His-LDHs were used to remove anionic dyes, including Congo red (CR), indigo carmine (IC) and sunset yellow FCF (SY) from aqueous solutions. The detailed investigation of the kinetics and the adsorption isotherms of CR, IC and SY from aqueous solutions showed that the dyes adsorb rapidly, in accordance with a pseudo-second-order kinetics and a Freundlich adsorption isotherm model. The remarkably high adsorption capacity of the dyes on the His-LDH (efficiency of CR removal, 99.98%; maximum specific removal q max , 1112 mg g −1 ; efficiency of IC removal, 98.98%; q max , 625 mg g −1 ; and efficiency of SY removal, 99.78%; q max , 400 mg g −1 ) is rationalized on the basis of electrostatic interactions as well as π-π and H-bonding interactions between the His-LDH adsorbent and the acidic dyes. Adsorption experiments indicate that the resulting His-LDH has great potential applications as an environmentally friendly material for the swift removal of acidic dyes from aqueous solutions. [ABSTRACT FROM AUTHOR]

Biosorption of acidic dyes using the live fern Azolla filliculoides was studied in a discontinuous system. Dye parameters, dye initial concentration and contact time were studied in temperature range of 25-30 ºC and pH=7. It was shown that increasing the 23initial concentration of dye and its contact time resulted in decreasing the dye taking quantity by the absorbent. Also, type of dye has an effective role in the process. The highest dye taking capacity was reported in the concentration of 15 mg/L that was 64.52%, 37.53%, and 32.98% for acidic red 14, blue 25, and yellow 17 dyes respectively. Adsorption isotherm models of Langmuir, Freundlich, Dubinin- Radushkovich, and Temkin were analyzed in different concentrations. Adsorption kinetic data were considered by kinetic models of pseudo-first-order and pseudo-secondorder.

Directly dyed nylon 6, 6 fabrics usually demand recourse to an after-treatment of synthetic tannins (a.k.a. syntans) to improve the fastness of dyeings to water and perspiration. However, the synthesis of commercial syntans requires highly acidic conditions and results in a huge amount of acidic waste effluent after reaction, which has caused severe pollution to the environment. Herein, we report an eco-friendly and feasible strategy to prepare a syntan in one pot in excellent yield via the multicomponent reaction of bisphenol S, formaldehyde and sodium phenolsulfonate in aqueous solution using NaOH as catalyst at 100 °C. This strategy can easily obtain a competent syntan bath for after-treatment to the dyed fabrics by dilution and neutralization, while at the same time ensuring much reduced discharge of acidic effluent to the environment after reaction. Compared to current commercial syntans, this new syntan demonstrates a comparable and satisfactory fixing performance on the dyed fabrics in terms of the level of color fastness of the treated fabrics to washing, rubbing, seawater as well as acidic and basic perspiration. [ABSTRACT FROM AUTHOR]

For the purposes of this study, activated carbon was derived from pine-cone by a chemical-thermal process. Initially, its chemical and physical properties were determined before it was used for the removal of Acid Black 1 and Acid Blue 113 dyes. A batch sorption study was carried out in order to obtain the optimum isotherm model. The monolayer maximum saturation capacities of AB1 and AB113 dyes based on Langmuir isotherm model were determined to be 458 mg dye/g carbon and 286 mg dye/g carbon, respectively. Adsorption of dyes was also studied in a continuous-flow state using a fixed-bed column of activated carbon. The effects of operating variables such as flow rate, bed depth, and dye concentration on the column operation were studied. Data confirmed that the breakthrough curves depended on flow rate, bed depth, and initial dye concentration. Column behavior was investigated using Thomas Model and model parameters were determined by a non-linear regression method. The Langmuir and Freundlich isotherm models were used to fit the experimental data. The best fit of the adsorption isotherm data was obtained using the Langmuir model for both dyes. The results showed that Thomas Model was suitable for the description of breakthrough curves under the experimental condition. The column adsorption capacity was also compared with equilibrium adsorption capacities for each dye.

A rapid and simple method was established for the determination of acidic dyes in pharmaceutical capsules using solid-phase extraction and high-performance liquid chromatography with a diode array detector. The capsules were dissolved in water using an ultrasonic bath at 55 ± 5°C, and pH was adjusted to 1 with 0.2 mol/L hydrochloric acid. The resulting solution was purified using a weak anion exchange solid-phase extraction cartridge. Chromatographic separation was performed on a reversed phase C18 column with gradient elution using acetonitrile and 20 mmol/L aqueous ammonium acetate (pH = 4.5) as the mobile phase. The chromatography was monitored at 420, 480, 520, and 600 nm. Under the optimized conditions, the recoveries of the analytes were from 60.5 ± 1.59 to 99.1 ± 0.84%. The intraday and interday relative standard deviations were from 0.29 to 10.6% and from 1.08 to 10.8%, respectively. The limits of quantification were between 0.11 and 0.50 µg/g. [ABSTRACT FROM PUBLISHER]

Copyright of Wool Textile Journal is the property of National Wool Textile Science & Technology Information Center and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Biomagnetic material (MFC) was synthesized via simple co-precipitation and used as biosorbent for the removal of acid red 25 (AR25) under optimized conditions. The characteristics of MFC were studied using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), vibrating sample magnetometer (VSM), Boehm titration and scanning electron microscopy (SEM). Optimum removal of AR25 was achieved at pH=5.0. The equilibrium data were well described by the Sips and Freundlich models. Taguchi methodology was employed to optimize the biosorption experiments. 411.56 mg/g and 96.8% were obtained as the biosorption capacity and removal efficiency, respectively, at the optimum conditions of ionic strength (0.5 M), influent volume (300 L) and MFC dosage (4 g). The contact time for removal of 96% AR25 in two-stage batch system is 400.8 min which is lower than the single-stage treatment process (895 min). [ABSTRACT FROM AUTHOR]

This paper investigates the effect of nanoparticles on some new features of silver/zinc loaded nanocomposite fabrics. These fabrics have been fabricated from continuous nanocomposite multifilament yarns produced on a pilot plant melt spinning process with the take-up speed of 2000 m.min-1. According to the results, the dyeability of nanocomposite fabrics with acidic dyes increased as compared to the pure PP. The electrostatic interaction between negatively charged group of acidic dye molecules and positively charged silver nanoparticles can improve dyeability. The results indicated close relationship between the abrasion resistance of fabrics and tensile properties of produced yarns including tenacity, modulus, and rupture work. The results also showed the increasing of the water vapor permeability at temperatures above 25°C and decreasing permeability at temperatures below 25°C for nanocomposite fabrics containing 0.1 wt% silver/zinc. This simplifies removing of body heat and sweat and consequently offers more comfort for garment, tent, curtain, etc. at temperatures above 25°C. On the other hand, lower vapor permeability at a low temperature protects the body from cool weather through preventing loss of the body heat and weather flow. This nanocomposite fabric can smartly adapt the permeability with human body requirements by changing the environment temperatures. [ABSTRACT FROM AUTHOR]

The association of dyes, particularly acidic dyes with health related problems is not a new phenomenon. A lot of well established literature is already available on the role of dyes as a major cause in skin and respiratory diseases. The adsorbents which are of low cost, locally available and are relatively new for their acidic dyes removal capacity from aqueous solutions were investigated. Bagasse, cow dung, groundnut shells, pea shells, used tea leaves, wheat straw were used in their charcoal form whereas brick kiln ash and cement kiln ash adsorbents were used as such for the removal of acid violet 17, acid violet 49, acid violet 54, acid blue 15 and acid red 119. The effects of various experimental parameters, initial pH, dye concentration, sorbent dosage, ion strength, contact time were examined and optimal experimental conditions were decided. At initial basic pH more than 8.0, all the five dyes studied could be removed effectively. The isothermal data for adsorption followed the Freundlich and Langmuir models. The adsorption results in this study indicated that all the adsorbents were attractive candidates for removing acidic dyes from dye wastewater.

In the present study, Oreganum onites L. stalks in natural and chemically modified with HNO3 and H3PO4 used as adsorbent for removal of both acidic and basic dyes from waters. The adsorption was studied as a function of pH and contact time by batch method. All tested biosorbents were characterized by FT-IR, scanning electron microscopy, and measuring the pH dependence of the zeta potential. The adsorption isotherms were fitted to Langmuir isotherm. The maximum adsorption capacity of dyes was 280.73 mg g−1 for Basic Red 18, 147.06 mg g−1 for methylene blue and 112.36 for Acid Red 111, which is comparable to that of other lignocellulosic materials. The modification process was considerably increased the biosorption capacity of lignocellulosic material, resulting in a 56-63% increase in the biosorption capacity of basic dyes and a 125% increase in the biosorption capacity of acidic dye. The present study illustrated that the most effective factors in the adsorption of basic dye were surface charge and acidic groups on lignocellulosic biosorbents, while non-electrostatic forces as well as electrostatic forces were also effective in the adsorption of acidic dye. In conclusion, Oreganum stalks can be considered as a very prospective adsorbent for the removal of tested basic and acidic dyes. [ABSTRACT FROM AUTHOR]

Abstract: Secretory vesicles have low pH and have been classically identified as those labelled by a series of acidic fluorescent dyes such as acridine orange or neutral red, which accumulate into the vesicles according to the pH gradient. More recently, several fusion proteins containing enhanced green fluorescent protein (EGFP) and targeted to the secretory vesicles have been engineered. Both targeted fluorescent proteins and acidic dyes have been used, separately or combined, to monitor the dynamics of secretory vesicle movements and their fusion with the plasma membrane. We have now investigated in detail the degree of colocalization of both types of probes using several fusion proteins targeted to the vesicles (synaptobrevin2-EGFP, Cromogranin A-EGFP and neuropeptide Y-EGFP) and several acidic dyes (acridine orange, neutral red and lysotracker red) in chromaffin cells, PC12 cells and GH3 cells. We find that all the acidic dyes labelled the same population of vesicles. However, that population was largely different from the one labelled by the targeted proteins, with very little colocalization among them, in all the cell types studied. Our data show that the vesicles containing the proteins more characteristic of the secretory vesicles are not labelled by the acidic dyes, and vice versa. Peptide glycyl-L-phenylalanine 2-naphthylamide (GPN) produced a rapid and selective disruption of the vesicles labelled by acidic dyes, suggesting that they could be mainly lysosomes. Therefore, these labelling techniques distinguish two clearly different sets of acidic vesicles in neuroendocrine cells. This finding should be taken into account whenever vesicle dynamics is studied using these techniques. [ABSTRACT FROM AUTHOR]

[Display omitted] • The stainless-steel wires were coated with PVA/Chitosan electrospun nanofibers. • The fiber-in-tube SPME followed by HPLC-UV was used for determination of red dyes. • This is a green technique using natural polymer and non-toxic solvents. • The factor optimization was performed using OVAT and experimental design methods. • The analytes were determined in pomegranate, red grape, and sour cherry juice. In this research, a green approach of filled in-tube solid phase microextraction (FIT-SPME) followed by HPLC-UV was introduced for extraction and determination of acidic red dyes (Amaranth, Ponceau 4R, Allura red, Carmoisine, and Erythrosine) in juice samples. In this way, stainless-steel wires were coated with chitosan as a natural polymer and polyvinyl alcohol as a safe co-polymer by electrospinning method, to achieve nanofibers with high surface area and porosity. Then, all fibers were put inside the lumen of a stainless-steel tube to make the extraction medium. The effective parameters on the extraction efficiency including desorption solvent type, extraction time, extraction flow rate, desorption flow rate, and desorption solvent volume were optimized by one variable at a time and experimental design approaches. Under the optimum conditions, the method showed good dynamic linearity in the range of 1.0–750.0 μg L−1 with LODs in the range of 0.3–7.6 μg L−1 and coefficient of determinations higher than 0.9943. The intra-day and inter-day RSDs were in the range of 2.5–9.5 % and 7.3–12.7 %, respectively. Finally, this technique was applied to the extraction and determination of the analytes in different beverage samples such as pomegranate, red grape, and sour cherry juice with acceptable and satisfying results. [ABSTRACT FROM AUTHOR]