Adsorption of methyl orange from aqueous solution by aminated pumpkin seed powder: Kinetics, isotherms, and thermodynamic studies.

Adsorption of anionic dyes on spent tea leaves modified with polyethyleneimine (PEI-STL)

Increasing amount of dyes in an ecosystem has propelled the search of various methods for dye removal. Amongst all the methods, adsorption occupies a prominent place in dye removal. Keeping this in mind, many adsorbents used for the removal of hazardous anionic azo dye Congo red (CR) from aqueous medium were reviewed by the authors. The main objectives behind this review article are to assemble the information on scattered adsorbents and enlighten the wide range of potentially effective adsorbents for CR removal. Thus, CR sorption by various adsorbents such as activated carbon, non-conventional low-cost materials, nanomaterials, composites and nanocomposites are surveyed and critically reviewed as well as their sorption capacities are also compared. This review also explores the grey areas of the adsorption performance of various adsorbents with reference to the effects of pH, contact time, initial dye concentration and adsorbent dosage. The equilibrium adsorption isotherm, kinetic and thermodynamic data of different adsorbents used for CR removal were also analysed. It is evident from a literature survey of more than 290 published papers that nanoparticle and nanocomposite adsorbents have demonstrated outstanding adsorption capabilities for CR. Graphical abstract ᅟ.

Adsorptive amputation of hazardous azo dye Congo red from wastewater: a critical review.

Kinetic, equilibrium and thermodynamic study on the removal of Congo Red from aqueous solutions by adsorption onto apricot stone

An agricultural by-product, wheat straw, was treated using cetyltrimethyl ammonium bromide (CTAB) to improve adsorption capacity for the removal of Congo red dye (CR, anionic dye) from aqueous solutions in batch mode. The effect of contact time, CR concentration and temperature on adsorption was presented. The results showed that it was in favor of adsorption at pH 4–5 and lower temperature. Adsorption capacity of MWS for CR is 665 mg/g at 303 K. Three kinetic models, pseudo-first-order kinetic model, pseudo-second-order kinetic model and Elovich model, were selected to fit the kinetic data and pseudo-first-order kinetic model was best. Three adsorption isotherm models, Langmuir, Freundlich and Temkin, were used to fit the experimental data and Langmuir model was better available. The process was exothermic and spontaneous according to thermodynamic parameters. It was concluded that MWS be promising to adsorb anionic dye from solution.

Adsorption of Congo red from aqueous solutions using cationic surfactant modified wheat straw in batch mode: Kinetic and equilibrium study

In this paper, the characterization of wheat straw (WS) and cetyl trimethyl ammonium bromide (CTAB) modified wheat straw (MWS) was determined by Fourier transform infrared spectroscopy (FTIR) and X-ray fluorescence (XRF), indicating that CTAB had entered into the structure of WS successfully. Then, MWS was used as adsorbent for the removal of methyl orange dye (MO, anionic dye) from aqueous solution in batch mode. The experiments were carried out by exploring the most suitable conditions including solution pH, MWS dosage, dye initial concentration, temperature, and contact time. Biosorption capacity of MWS for MO is 50.4 mg g−1 at 303 K under the optimum condition of pH of 3, MWS dosage of 1.00 g L−1, contact time of 520 min. The Freundlich and Temkin models were all successful in depicting the equilibrium. The kinetic process can be predicted well by the Elovich, pseudo-second-order and intraparticle diffusion model. In addition, the thermodynamics parameters indicated the biosorption process was...

Biosorption of methyl orange from aqueous solutions using cationic surfactant-modified wheat straw in batch mode

The natural wheat straw (NWS) was modified by ethylenediamine and the modified wheat straw (MWS) was used as adsorbent for removal of congo red (CR) from aqueous solution. Analysis of FTIR and nitrogen element showed that amino group was introduced to NWS. A batch system was applied to study the behavior of CR adsorption on MWS. Experiments were carried out as function of pH, adsorbent dosage, contact time and dye concentration. The equilibrium adsorption data were analyzed by Langmuir, Freundlich, Redlich–Peterson models and Koble-Corrigan. Redlich–Peterson and Koble-Corrigan models provided the best correlation. The adsorption capacities from Langmuir model were 68.6 mg g–1 at 293 K. Adsorption kinetic data were fitted using the pseudo-first-order kinetic model, pseudo-second-order kinetic model, Elovish model and intraparticle diffusion model. The results showed that the Elovish model was best to fit the kinetic process, which suggested that ion exchange was one of main mechanism. The effective diffusi...

Yubin Jiao

Papers

Biosorption of methyl orange from aqueous solutions using cationic surfactant-modified wheat straw in batch mode

Adsorption of congo red using ethylenediamine modified wheat straw