Sorption Of Crystal Violet Research Articles

Hypo-osmotic Stress Increases Permeability of Individual Barriers in Escherichia coli Cell Envelope, Enabling Rapid Drug Transport.

Survival of foodborne Gram-negative bacteria during osmotic stress often leads to multidrug resistance development. However, despite the concern, how osmoadaptation alters drug penetration across the Gram-negative bacterial cell envelope has remained inconclusive for years. Here, we have investigated drug permeation and accumulation inside hypo-osmotically shocked Escherichia coli. Three different quaternary ammonium compounds (QACs) are used as cationic amine-containing drug representatives; they also serve as envelope permeability indicators in different assays. Propidium iodide fluorescence reveals cytoplasmic accumulation and overall envelope permeability, while crystal violet sorption and second harmonic generation (SHG) spectroscopy reveal periplasmic accumulation and outer membrane permeability. Malachite green sorption and SHG results reveal transport across both the outer and inner membranes and accumulation in the periplasm as well as cytoplasm. The findings are found to be complementary to one another, collectively revealing enhanced permeabilities of both membranes and the periplasmic space in response to hypo-osmotic stress in E. coli. Enhanced permeability leads to faster QACs transport and higher accumulation in subcellular compartments, whereas transport and accumulation both are negligible under isosmotic conditions. The QACs' transport rates are found to be highly influenced by the osmolytes used, where phosphate ion emerges as a key facilitator of transport across the periplasm into the cytoplasm. E. coli is found viable, with morphology unchanged under extreme hypo-osmotic stress; i.e., it adapts to the situation. The outcome shows that the hypo-osmotic shock to E. coli, specifically using phosphate as an osmolyte, can be beneficial for drug delivery.

Adsorptive exclusion of crystal violet dye using barium encapsulated alginate/carbon composites: characterization and adsorption modeling studies.

The present study is devoted to the removal of crystal violet dye using the synthesized barium alginate/carbon composites abbreviated as BA (barium alginate), BAAC (barium alginate/activated carbon), BASC (barium alginate/starch carbon), and BASSC (barium alginate/starch carbon modified with CTAB). The adsorptive removal of crystal violet as a function of contact time, pH of solution, composite dose, initial dye concentration, and temperature was studied. The uptake of crystal violet (CV) dye for the composites was recorded in the range of 36 mg g-1 to 50 mg g-1 at pH 8.03 ± 0.03 for an equilibrium time of 120 min. The adsorption kinetics and isotherms in compliance with the CV sorption onto BA/carbon composites corroborated the utmost fit of pseudo-second-order and Freundlich isotherm models, respectively. The recycling process was achieved using the barium alginate-treated bead carbons for different initial CV dye concentrations of 10-30 mg L-1 with a scope of zero disposal. The practicability of BA/carbon composites in a groundwater sample spiked with 30 mg L-1 of CV was successfully achieved with a removal efficiency of about 65-74%. Characterization studies for the composites using FTIR, SEM (with EDS), XRD, TGA, and BET were carried out and discussed in the paper.

Synthesis and application of treated activated carbon for cationic dye removal from modelled aqueous solution

Use of activated carbon (AC) prepared from rice husk and treated with anionic surfactant is investigated to eliminate cationic dye crystal violet (CV) using modelled dye solution. AC modified with anionic surfactant sodium lauryl sulfate (ACSLS) and other two surfactant namely sodium dodecyl sulfonate and hexadecyl trimethyl ammonium bromide were used for the analysis. Optimum ACSLS was analyzed and characterized using BET, XRD, SEM accompanied with XEDS, FTIR, HR-TEM and zeta potential, which confirms the sorption of CV onto ACSLS. Influence of pH, dose of adsorbent, concentration of initial dye, contact time, additive salts as well as actual water samples were investigated. Presence of NH4+, Ca2+, Mg2+, Na2+, Ca2+and K+cations in dye solution were having negligible (less than 4 %) influence on dye removal capacity. Study of mass transfer parameters revealed intra particle diffusion and film diffusion both played their part, whereas other kinetic studies has shown that experimental data fitted best with Pseudo 2nd order rate. Isotherm studies accompanied with error analysis revealed that Langmuir isotherm controls the adsorption equilibrium with highest capacity of CV adsorption with optimum operating conditions as pH = 6, temperature = 318 K, adsorbent dose = 100 mg/L and dye concentration = 30–60 mg/L. Study of thermodynamics and temperature analysishave shown that the sorption reaction was favourable and spontaneous with rise in temperature and endothermic in nature. Column studies are reported for varying rate of flow, depth of bed and dye concentrations along with analysis of column experimental data with various models like Yoon-Nelson, Thomas, Bohart-Adam and Clark model. Reusability (no. of cycles) of used adsorbent was studied using regeneration experiments. Analysis inferred that AC modified using surfactants can be a useful technique for enhanced adsorption capacity of dyes from aqueous solution andnot much work has been reported on use of anionic surfactant modified AC for dye removal process.

Novel insights into the nanoadsorption mechanisms of crystal violet using nano-hazelnut shell from aqueous solution

This paper discusses the nanoadsorption mechanisms of crystal violet (CV) using a nano-hazelnut shell (nano-HS) from an aqueous solution. The effect of various factors such as pH, temperature, and initial CV concentration on the adsorption process was also evaluated. The physical and chemical characterizations of hazelnut shells (HS) and nano-HS were studied using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and transmission electron microscope (TEM). Various functional groups including OH, CO, CH, and CO were identified that are facilitated the CV sorption onto the adsorbents. Additionally, the SEM revealed the adsorbents as a heterogeneous structure with deep cavities and high porosity, which is thought to play a vital role in capturing and binding the CV ions onto the surface of the adsorbent. The optimum pH in this study was reported to be 10. While Langmuir isotherm was identified as the best-suited model to describe the adsorption process, with a 93% and 96% correlation coefficient for HS and nano-HS, respectively. 181.82 mg/g was the maximum adsorption capacity for HS and 294.12 mg/g for nano-HS at 45 °C. Additionally, the positive value of changes in enthalpy for HS (21.912 kJ/mol) indicated the reaction was endothermic while the negative value (−47.541 kJ/mol) for nano-HS signifies that the CV adsorption onto was an exothermic reaction. The Gibbs free energy was found to increase with smaller nanoparticle sizes. On the other hand, the effects of particle size on the enthalpy and the entropy were increased.

Fabrication and characterization of a novel (GO/PAA/PAM) nanocomposite as effective adsorbent for cationic dyes

In this work, we study the modification of graphene oxide with polyacrylic acid and acrylamide (GO/PAA/PAM) through free radical single polymerization step to adsorb methylene blue (MB) and crystal violet (CV)-dyes in single and binary-systems from aqueous media. (GO/PAA/PAM) was characterized before and after adsorption processes. Thermogravimetric analysis provides useful data about the functionalization process, where the polymers will be bounded with the GO at the surface OH groups and the composite mainly composed of the polymers chains. The adsorption kinetic obeys the pseudo-second-order for the two dyes in the single and binary systems. Moreover, according to Langmuir isotherm in the single systems, the sorption of CV (357.14 mg g−1) is more than MB (344.8 mg g−1). On contrary, in the binary system, the MB (323.56 mg g−1) is preferably adsorbed by the (GO/PAA/PAM) composite than CV (172.41 mg g−1). Furthermore, the (GO/PAA/PAM) composite exhibited acceptable recycling over five runs. Finally, a real dye sample was applied to appreciate the efficiency of the prepared material in the industrial field. This novel composite can be used on a large scale for purification, remediation, and numerous industrial processes due to its promising properties.

Journey from ceramic waste to highly efficient toxic dye adsorption from aqueous solutions via one-pot synthesis of CaSO4 rod-shape with silica

Fine calcium oxide (CaO) which is the main component in the fine lime and considered as a waste byproduct from the steel manufacturing industry is converted into a potential composite to be used as an adsorbent. A facile and simple impregnation between CaO and silica in the presence of H2SO4 is utilized to achieve a one-step synthesis of a highly efficient CaO-based rod-shape composite with silica (CRCS). The suitability of using this composite in hazardous crystal violet (CV) cationic dye removal from aqueous solution was evaluated in series batch experiments. The synthesized composite was characterized using various techniques including XRD, SEM, TEM, EDX, FT-IR, and Raman to determine the adsorbent physicochemical properties. Influences of various operating parameters such as contact time, initial dye concentration, adsorbent dosage, agitation speed, initial pH, and reaction temperature were examined. The results of the experimental data well fitted Langmuir and the pseudo-first-order kinetic model. Based on the thermodynamic parameters, the sorption of CV onto CRCS is a spontaneous and endothermic process. The prepared CRCS also exhibited easily regeneration and recycling at least for ten adsorption–desorption runs. This study offers new insights into promising waste management technology that is efficiently applied to treat dye-contaminated water.

Novel Application of Mineral By-Products Obtained from the Combustion of Bituminous Coal–Fly Ash in Chemical Engineering

The aim of this work was the chemical modification of mineral by-products obtained from the combustion of bituminous coal (FA) treated with hydrogen peroxide (30%), used as an adsorbent for the removal of Cr(III) and Cd(II) ions and crystal violet (CV) from a mixture of heavy metal and organic dye in a solution containing either Cr(III)–CV or Cd(II)–CV. Fourier transform infrared (FT-IR), thermogravimetric analysis (TG), scanning electron microscopy–energy dispersive spectroscopy (SEM-EDS), and X-ray diffraction (XRD) analyses suggested that the mechanism of Cr(III)–CV or Cd(II)–CV sorption onto FA–H2O2 includes ion-exchange and surface adsorption processes. The effect of pH on the adsorption equilibrium was studied. The maximum adsorption was found for pH values of 9. The values of the reduced chi-square test (χ2/degree of freedom (DoF)) and the determination coefficient R2 obtained for the sorbate of the considered isotherms were compared. Studies of equilibrium in a bi-component system by means of the extended Langmuir (EL), extended Langmuir–Freundlich (ELF), and Jain–Snoeyink (JS) models were conducted. The estimation of parameters of sorption isotherms in a bi-component system, either Cr(III)–CV or Cd(II)–CV, showed that the best-fitting calculated values of experimental data for both sorbates were obtained with the JS model (Cr(III) or CV) and the EL model (Cd(II) or CV). The maximum monolayer adsorption capacities of FA–H2O2 were found to be 775, 570 and 433 mg·g−1 for Cr, Cd and CV, respectively. Purification water containing direct Cr(III) or Cd(II) ions and CV was made with 90%, 98% and 80% efficiency, respectively, after 1.5 h. It was found that the chemical enhancement of FA from coal combustion by H2O2 treatment yields an effective and economically feasible material in chemical engineering for the treatment of effluents containing basic dyes and Cr(III) and Cd(II) ions.

Sono-sorption efficiencies and equilibrium removal of triphenylmethane (crystal violet) dye from aqueous solution by activated charcoal

In this present work, the sorption of crystal violet (CV) pigment from laden aqueous solution carried out via ultrasound-assisted. The sorption of CV on activated charcoal was performed in the existence and absence of ultrasound. Using of combined ultrasound/activated charcoal process gave high CV decolorization than using sorption or sonolysis alone because of the synergistic process achieved in this combined system. Experiments were performed at different initial pigment concentration and temperature. The sorption isotherms were achieved by the Freundlich, Langmuir, D–R and Temkin isotherm model. The sorption of CV onto activated charcoal demonstrated more suitable for Langmuir than the Freundlich isotherm model. The maximum monolayer sorption capacity was 50.1 mg/g. The thermodynamic parameters, namely the entropy, Gibbs free energy and enthalpy of the CV sorption process were determined. The enthalpy and free energy indicate an exothermic, feasible and spontaneous process. It has been shown that the proposed combined ultrasound/activated charcoal process may be useable in the treatment of pigment solution from textile wastewater.

Application of bio-alkyd resin for the removal of crystal violet and methylene blue dyes from wastewater

A new bio-alkyd resin containing carboxylated carbon, prepared from the biomass of olive trees, was successfully synthesized and characterized. X-ray diffraction results indicated that the sorbent has some crystals with an average crystallite size of 26.21 nm. The sorbent has an acidic character, which is mainly governed by carboxylic groups (1.7 mmol/g) and contains 71.16% carbon and 28.84% oxygen, as revealed by EDX analysis. The sorption behavior of methylene blue and crystal violet from aqueous solution onto the sorbent was investigated under various experimental conditions. Higher removal percentages of the dyes (90–96%) were observed at pH ranges of 5–6.5 and 9.5–11. The experimental sorption data showed a good correlation with the Langmuir isotherm model and the maximum monolayer sorption capacity to crystal violet and methylene blue were 289.3 and 310.3 mg g−1, respectively. The surface electrical conductivity value of the sorbent (σ = 0.27 × 10−6 Ω−1 cm−1) decreased after the sorption of CV and MB to 0.03 × 10−6 and 0.0075 × 10−6 Ω−1 cm−1. The sorption kinetic data were best described by the pseudo-second-order equation. The sorption of crystal violet was an endothermic process unlike that of methylene blue. Both dyes were removed from wastewater with satisfactory results. The limits of detection and quantitation were 2.0–2.6 and 3.5–4.9 and 6.8–8.5 and 11.7–16.2 μg L−1 for CV and MB, respectively. The relative standard deviation (RSD%, n = 6) values were in the range of 1.00–2.2%.

Mechanistic understanding of crystal violet dye sorption by woody biochar: implications for wastewater treatment.

Dye-based industries, particularly small and medium scale, discharge their effluents into waterways without treatment due to cost considerations. We investigated the use of biochars produced from the woody tree Gliricidia sepium at 300°C (GBC300) and 500°C (GBC500) in the laboratory and at 700°C from a dendro bioenergy industry (GBC700), to evaluate their potential for sorption of crystal violet (CV) dye. Experiments were conducted to assess the effect of pH reaction time and CV loading on the adsorption process. The equilibrium adsorption capacity was higher with GBC700 (7.9mgg-1) than GBC500 (4.9mgg-1) and GBC300 (4.4mgg-1), at pH 8. The CV sorption process was dependent on the pH, surface area and pore volume of biochar (GBC). Both Freundlich and Hill isotherm models fitted best to the equilibrium isotherm data suggesting cooperative interactions via physisorption and chemisorption mechanisms for CV sorption. The highest Hill sorption capacity of 125.5mgg-1 was given by GBC700 at pH 8. Kinetic data followed the pseudo-second-order model, suggesting that the sorption process is more inclined toward the chemisorption mechanism. Pore diffusion, π-π electron donor-acceptor interaction and H-bonding were postulated to be involved in physisorption, whereas electrostatic interactions of protonated amine group of CV and negatively charged GBC surface led to a chemisorption type of adsorption. Overall, GBC produced as a by-product of the dendro industry could be a promising remedy for CV removal from an aqueous environment.

Artocarpus altilis (breadfruit) skin as a potential low-cost biosorbent for the removal of crystal violet dye: equilibrium, thermodynamics and kinetics studies

Artocarpus altilis (Breadfruit) skin shows great potential as an effective low-cost biosorbent for the removal of toxic crystal violet (CV) dye. Curve fitting of adsorption equilibrium data obtained under optimized conditions, followed by error analysis, for different isotherms, namely Langmuir, Freundlich, Temkin, Dubinin–Radushkevich, Redlich–Peterson, and Sips, demonstrates that the Langmuir and the Sips adsorption isotherm models show the best agreement with maximum biosorption capacities (q max) of 145.8 and 150.1 mg g−1, respectively, which are superior to most reported biosorbents. Breadfruit skin, whose point of zero charge is at pH 4.7, characterized by X-ray fluorescence (XRF) spectroscopy, scanning electron microscopy (SEM) and Fourier transform infra red (FTIR) spectroscopy before and after treatment of CV provides further support for adsorption. Thermodynamic studies indicate that the adsorption of CV by BS was both spontaneous and endothermic, while kinetics studies show that the sorption of CV on BS follows the pseudo-second-order kinetics with a contribution from intraparticle diffusion.

Biodegradation of p-nitrophenol sorbed onto crystal violet-modified organoclay by Arthrobacter sp. 4Hβ

Organoclays are effective sorbents for removal of organic contaminants from water, but their regeneration capacity limits their practical use as a biotechnological process for bioremediation. Here, the sorption of p-nitrophenol (PNP) to crystal violet (CV)-modified montmorillonite and its biodegradation by the bacterium Arthrobacter sp. 4Hβ were studied in a batch aqueous system. The degree of PNP sorption was dependent on the degree of CV modification (loaded at 80 % or 100 % of the clay's cation-exchange capacity-CVM80 and CVM100, respectively). CV sorption to the clay reduced its toxicity to bacteria. PNP at an initial concentration of 0.72 mM was degraded at rates of 65 % and 42 % in CVM80 and CVM100 suspensions, respectively. Both free and CV-clay-adsorbed PNP concentrations were reduced by the bacteria at rates proportional to the degree of CV modification. Three successive cycles of PNP reloading-degradation in the organoclay suspension demonstrated the potential of this matrix's regeneration and reuse toward maximal removal efficiency of organic pollutants.

Kinetic Modeling of Methylene Blue and Crystal Violet Dyes Adsorption on Alginate-Fixed Water Hyacinth in Single and Binary Systems

Removal of Methylene Blue (MB) and Crystal Violet (CV) dyes from monocomponent and binary aqueous solutions by water hyacinth-E. Crassipes roots fixed on alginate (a low-cost adsorbent) has been investigated. The extent of adsorption was evaluated as a function of solution pH, initial dye concentration, and bead biomass loading. Kinetic sorption data were analysed by widely used models: pseudo-first-order, pseudo-second-order, Elovich, and intraparticle diffusion models. The results showed that pseudo-second-order model better described the biosorption experimental data than the pseudo-first-order kinetic model for both dyes, whilst the Elovich model fitted the biosorption experimental data at lower dye concentrations. The intraparticle diffusion model indicated that sorption of CV and MB was characterized by rapid surface adsorption coupled with slow film diffusion process at higher initial dye concentration and at all initial bead biomass loading. The range of mean free energy values confirmed physical adsorption as the mechanism for dye removal from solution.

Estudo da sorção do corante catiônico violeta cristal por espuma de poliuretano em meio aquoso contendo dodecilsulfato de sódio

This work presents a detailed study about the sorption of crystal violet (CV) cationic dye onto polyether type polyurethane foam (PUF). The sorption process was based on the formation of an ionic-pair between cationic dye and dodecylsulfate anion (SDS), which presented high affinity by PUF. Set-up employed in the study was built up by adjusting a 200 mg cylinder of PUF to the arm of an overhead stirrer. The system was characterized in relation to equilibrium and kinetic aspects and it was modeled by employing Langmuir and Freundlich isotherms. Obtained results showed that the ratio between SDS and MB concentrations played an important role on the sorption process. According to results found it was possible to retain up to 3.4 mg of dye from 200 mL of a 5.0 x 10-5 mol L-1 CV solution containing 1.25 x 10-4 mol L-1 SDS, which represented a removal efficiency of around 92%.

Simultaneous sorption of crystal violet and 2-naphthol to bentonite with different CECs

This work was to examine the feasibility and efficiency to use bentonite for simultaneous removal of cationic dyes and hydrophobic organic carbons (HOCs) from water. The sorption capacities of crystal violet (CV) on two bentonites and one activated carbon were compared. Simultaneous sorption of CV and 2-naphthol on the two bentonites were tested, and the removal efficiencies of 2-naphthol by the simultaneous sorption method and by CV modified bentonite was also compared. The experimental results in this study showed that the bentonite is more effective in sorption of CV than the activated carbon. With the sorption of CV, bentonite surfaces were altered from hydrophilicity to hydrophobicity, and thus 2-naphthol could be simultaneously removed. The aromatic effect between CV and 2-naphthol was supposed to be the primary driving force for the sorption of 2-naphthol. The simultaneous sorption method was shown to be more effective in the sorption of 2-naphthol than the CV modified bentonite. Results of this work could provide novel information for the treatment of wastewater containing both cationic dyes and HOCs.

Sorption of Selected Cationic and Neutral Organic Molecules on Palygorskite and Sepiolite

AbstractPalygorskite and sepiolite show a high sorption capacity for organic molecules. Adsorption of 2 organic cations, methylene blue (MB) and crystal violet (CV), by palygorskite and sepiolite were examined. The maximum sorption of MB and CV far exceeded the cation exchange capacity (CEC) of these minerals. This shows that, besides the contribution of free negative sorption sites (P-), the sites satisfied with sorption of single cations (PXi0) and neutral sorption sites (N) on clay surfaces may contribute to the sorption of organic cations. The number of neutral sites was determined by examining the sorption of 2 neutral organic molecules, triton-X 100 (TX100) and 15 crown ether 5 (15C5), and by application of the Langmuir isotherm.To determine the contribution of different sites, an adsorption model that applies the Gouy-Chapman equation and takes into account the formation of different clay-organic complexes in a closed system was employed. Application of this model to sorption data provided the calculation of binding coefficients for neutral sites, as well as the surface potential of the minerals at different sorbate concentrations.At sorption maxima, for both palygorskite and sepiolite, the contribution of neutral sites for sorption of organic cations was the highest, followed by the PXi0 sites in case of CV sorption, while in sorption of MB the contribution of P- sites was the second highest. The Fourier transform infrared (FTIR) patterns of clay-organic cation complexes compared with pure clays confirm that the sorption of organic cations is by silanol groups located at the edge of fibrous crystals, which account for neutral sorption sites.

Equilibrium sorption of crystal violet by carboxymethylated cellulose with low degree of substitution

Cellulose fabric samples were carboxymethylated for different duration. The degree of substitution was changing through a maximum value during the reaction time.