Adsorbent For Removal Of Crystal Violet Research Articles

Crystal violet adsorption on industrial waste (hog fuel ash): equilibrium kinetics with process optimization by response surface modeling

The adsorptive removal of crystal violet from aqueous solution utilizing hog fuel ash, an industrial solid waste, available abundantly is reported in this article. The adsorbent is characterized by various physicochemical methods. Batch experiments are performed as functions of different process variables. The maximum removal (99.99%) was observed at equilibrium time (90 min). Results follow Freundlich isotherm (among five isotherms) and pseudo-second-order kinetics (among four kinetic models). The observed adsorption capacity of 17.002 mg/g is higher than many other reported waste materials. A three-factor full factorial central composite design scheme is adopted for optimizing different process variables and their interactions. The maximum removal predicted by response surface modeling is 99.99%, while corresponding experimental value is 99.13 ± 0.8895% (mean ± standard deviation of five replicates). The removal improves in the presence of NaCl (by 5%) and at higher temperature. Results on the effect of temperature favor spontaneity of adsorption and physisorption that follows from isotherm studies. The temperature effect is investigated exploiting the seasonal variation that does not seem to have been reported before and is the novelty of the present study. The advantages of the present investigation are the use of the adsorbent without pre-treatment, final pH falling well within the safe discharge limit and increased removal in the presence of NaCl. This study could be extended for gainful utilization of the industrial solid waste for similar application.

Novel air agitated tapered adsorber for crystal violet removal on biomass combustion residue with process optimization using response surface modeling

• Used raw biomass combustion residue for adsorptive removal of Crystal Violet following energy and cost saving approach.

Optimization of cellulose and sugarcane bagasse oxidation: Application for adsorptive removal of crystal violet and auramine-O from aqueous solution

Cellulose (Cel) and sugarcane bagasse (SB) were oxidized with an H3PO4-NaNO2 mixture to obtain adsorbent materials with high contents of carboxylic groups. The oxidation reactions of Cel and SB were optimized using design of experiments (DOE) and response surface methodology (RSM). The optimized synthesis conditions yielded Cox and SBox with 4.8mmol/g and 4.5mmol/g of carboxylic acid groups, respectively. Cox and SBox were characterized by FTIR, TGA, PZC and solid-state 13C NMR. The adsorption of the model cationic dyes crystal violet (CV) and auramine-O (AO) on Cox and SBox in aqueous solution was investigated as a function of the solution pH, the contact time and the initial dye concentration. The adsorption of CV and AO on Cox was described by the Elovich equation and the pseudo-first-order kinetic model respectively, while the adsorption of CV and AO on SBox was described by the pseudo-second-order kinetic model. Adsorption isotherms were well fitted by the Langmuir and Konda models, with maximum adsorption capacities (Qmax) of 1117.8mg/g of CV and 1223.3mg/g of AO on Cox and 1018.2mg/g of CV and 682.8mg/g of AO on SBox. Desorption efficiencies were in the range of 50–52% and re-adsorption capacities varied from 65 to 81%, showing the possibility of reuse of both adsorbent materials.

Kinetic and thermodynamic study on adsorption characteristics of ash derived from distilled waste of aromatic crop Mentha piperita: a low-cost efficient adsorbent for crystal violet removal

Kinetic and thermodynamic study on adsorption characteristics of ash derived from distilled waste of aromatic crop Mentha piperita: a low-cost efficient adsorbent for crystal violet removal

Leptothrix sp. sheaths modified with iron oxide particles: Magnetically responsive, high aspect ratio functional material

Smart materials of biological origin are attracting a lot of attention nowadays, especially as catalysts, carriers or adsorbents. Among them, magnetically modified biomaterials are especially important due to their response to external magnetic field. This report demonstrates that naturally occurring micrometer sized, high aspect ratio material (native and autoclaved Leptothrix sp. sheaths) efficiently bind synthetically prepared magnetite and maghemite nanoparticles and their aggregates. Magnetic modification of Leptothrix sheaths enables to prepare a promising material for advanced biotechnology and environmental technology applications. The prepared magnetically responsive sheaths were tested as inexpensive adsorbent for crystal violet removal from aqueous solutions. The observed maximum adsorption capacity was 243.1mg of dye per 1g of adsorbent.

Magnetically modified bacterial cellulose: A promising carrier for immobilization of affinity ligands, enzymes, and cells

Bacterial cellulose (BC) produced by Komagataeibacter sucrofermentans was magnetically modified using perchloric acid stabilized magnetic fluid. Magnetic bacterial cellulose (MBC) was used as a carrier for the immobilization of affinity ligands, enzymes and cells. MBC with immobilized reactive copper phthalocyanine dye was an efficient adsorbent for crystal violet removal; the maximum adsorption capacity was 388mg/g. Kinetic and thermodynamic parameters were also determined. Model biocatalysts, namely bovine pancreas trypsin and Saccharomyces cerevisiae cells were immobilized on MBC using several strategies including adsorption with subsequent cross-linking with glutaraldehyde and covalent binding on previously activated MBC using sodium periodate or 1,4-butanediol diglycidyl ether. Immobilized yeast cells retained approximately 90% of their initial activity after 6 repeated cycles of sucrose solution hydrolysis. Trypsin covalently bound after MBC periodate activation was very stable during operational stability testing; it could be repeatedly used for ten cycles of low molecular weight substrate hydrolysis without loss of its initial activity.

Characterizing acidic fly ash with and without biomass combustion residue for adsorptive removal of crystal violet with optimization of mixed adsorbent by response surface modeling

In this article, removal of crystal violet (CV) by adsorption on acidic fly ash collected from an Indian wet ESP with and without biomass combustion residue (BCR), another industrial waste is reported. Initially, fly ash was characterized by its solid density, slurry pH, particle size, pHPZC, Brauner–Emmette–Teller (BET) surface area and pore volume analyses, scanning electron microscopy, Fourier transform infrared spectroscopy and X-ray diffraction. The pHPZC and BET surface area of fly ash were 3.30 and 8.57 m2/g, respectively. Batch results revealed high removal (98.33 %) with equilibrium time and optimum dose of 90 min and 7 g/50 mL, respectively. Later, experiments were repeated with the mixed adsorbent (1:1 mass ratio of fly ash and BCR) showing the equilibrium time of 10 min with ~100 % removal. The mixed adsorbent enhanced the adsorption capacity from 1.125 to 9.146 mg/g, i.e., almost by 9 times. Investigations were carried out at various mass fractions of fly ash showing maximum removal of 99.16 % at a mass fraction of 0.1. The response surface modeling revealed the optimum mass fraction and initial concentration of CV of 0.5 and 125 mg/L, respectively, to achieve 94.93 % removal. The corresponding experimental removal observed was 95.99 ± 0.3374 % (mean ± SD of five replicates). The mixed adsorbent showed twofold benefits in the proposed use through extensive pH analyses, such as improving the removal efficiency and maintaining the solution pH well within the safe discharge limit. Experimental results followed the Freundlich isotherm and pseudo-second order kinetics with negligible intra-particle diffusion for both acidic fly ash and mixed adsorbent.

Adsorptive Removal of Crystal Violet on Biomass Combustion Residue: Equilibrium, Isotherm, Kinetics, and Mass Transfer Analyses

Adsorptive Removal of Crystal Violet on Biomass Combustion Residue: Equilibrium, Isotherm, Kinetics, and Mass Transfer Analyses

Application of a new carboxylate-functionalized sugarcane bagasse for adsorptive removal of crystal violet from aqueous solution: Kinetic, equilibrium and thermodynamic studies

A new carboxylate-functionalized sugarcane bagasse (SMA) was prepared via a solvent-free procedure involving esterification of sugarcane bagasse with Meldrum's acid. The optimized conditions provided SMA with a percent weight gain of 86.0% and 4.69±0.20mmol/g of carboxylic acid groups. SMA was characterized by FTIR, TGA, elemental analysis and SEM. Kinetic experiments showed that the amount of crystal violet adsorbed increased with increasing temperature and equilibrium was reached at 12h. Adsorption kinetics followed a pseudo-second-order model. The Arrhenius and Eyring models were used to obtain the activation energy and changes in free energy, enthalpy, and entropy of activation for the adsorption process. The calculated activation energy (14.14kJ/mol) suggested physical adsorption of CV onto SMA. The equilibrium data were well fitted to the Langmuir and Sips isotherms. Maximum adsorption capacity was 692.1mg/g at 45°C. Thermodynamic parameters such as changes in free energy, enthalpy and entropy were also determined.