http://www.eng.uwo.ca/research/grc/pdfs/2011/Boparai_et_al_Kinetics.pdf

Kinetics and thermodynamics of cadmium ion removal by adsorption onto nano zerovalent iron particles.

https://cyberleninka.org/article/n/13265.pdf

Kinetics and equilibrium study for the adsorption of textile dyes on coconut shell activated carbon

Simultaneous removal of Cd(II) and ionic dyes from aqueous solution using magnetic graphene oxide nanocomposite as an adsorbent

The discharge of metals and dyes poses a serious threat to public health and the environment. What is worse, these two hazardous pollutants are often found to coexist in industrial wastewaters, making the treatment more challenging. Herein, we report an EDTA-cross-linked β-cyclodextrin (EDTA-β-CD) bifunctional adsorbent, which was fabricated by an easy and green approach through the polycondensation reaction of β-cyclodextrin with EDTA as a cross-linker, for simultaneous adsorption of metals and dyes. In this setting, cyclodextrin cavities are expected to capture dye molecules through the formation of inclusion complexes and EDTA units as the adsorption sites for metals. The adsorbent was characterized by FT-IR, elemental analysis, SEM, EDX, ζ-potential, and TGA. In a monocomponent system, the adsorption behaviors showed a monolayer adsorption capacity of 1.241 and 1.106 mmol g(-1) for Cu(II) and Cd(II), respectively, and a heterogeneous adsorption capacity of 0.262, 0.169, and 0.280 mmol g(-1) for Methylene Blue, Safranin O, and Crystal Violet, respectively. Interestingly, the Cu(II)-dye binary experiments showed adsorption enhancement of Cu(II), but no significant effect on dyes. The simultaneous adsorption mechanism was further confirmed by FT-IR, thermodynamic study, and elemental mapping. Overall, its facile and green fabrication, efficient sorption performance, and excellent reusability indicate that EDTA-β-CD has potential for practical applications in integrative and efficient treatment of coexistenting toxic pollutants.

EDTA-Cross-Linked β-Cyclodextrin: An Environmentally Friendly Bifunctional Adsorbent for Simultaneous Adsorption of Metals and Cationic Dyes

The kinetics and mechanism of methylene blue adsorption onto raw pine cone biomass (Pinus radiata) was investigated under various physicochemical parameters. The extent of the methylene blue dye adsorption increased with increases in initial dye concentration, contact time and solution pH but decreases with the amount of adsorbent, salt concentration and temperature of the system. Overall the kinetic studies showed that the methylene blue adsorption process followed pseudo-second-order kinetics among various kinetic models tested. The different kinetic parameters including rate constant, half-adsorption time and diffusion coefficient are determined at different physicochemical conditions. Equilibrium data were best represented by Langmuir isotherm among Langmuir and Freundlich adsorption isotherm. The maximum monolayer adsorption capacity of pine cone biomass was 109.89 mg/g at 30°C. The value of separation factor, R
 L, from Langmuir equation and Freundlich constant, n, both give an indication of favourable adsorption. Thermodynamic parameters such as standard Gibbs free energy (∆G
 0), standard enthalpy (∆H
 0), standard entropy (∆S
 0) and the activation energy (A) were calculated. A single-stage batch absorber design for the methylene blue adsorption onto pine cone biomass has been presented based on the Langmuir isotherm model equation.

Equilibrium, Kinetics and Mechanism of Removal of Methylene Blue from Aqueous Solution by Adsorption onto Pine Cone Biomass of Pinus radiata

Simultaneous adsorption of dyes and heavy metals from multicomponent solutions using fly ash

The sol-gel process is an inorganic polymerization considered a promising route for the design of new materials for optical, electrical, (bio)- medical and solar energy applications. Special attention is focused on the design of silica-based material by of sol-gel process. The aim of the paper is to investigate, in order to understand, the role of some important parameters (precursors type, pH, catalysts, temperature etc.) in sol-gel routes. It is proved that the textural and structural material properties are strongly influenced by synthesis and processing parameters.

http://webbut.unitbv.ro/BU2011/Series%20I/BULETIN%20I%20PDF/Milea%20CA.pdf

The influence of parameters in silica sol-gel process

Tungsten oxide--fly ash oxide composites in adsorption and photocatalysis.

Tandem structures involving CuInS2, TiO2 and SnO2 thin films were prepared by Robotic spray pyrolysis and were optimized in terms of composition and deposition temperatures. The compounds have structural compatibility (crystalline structures and crystallites sizes) and good homogeneity. The crystalline structures were investigated by X-ray diffraction and the morphology by atomic force microscopy and scanning electron microscopy. The wettability properties and the surface energy were calculated based on contact angle measurements using two liquids with different polarities (glycerol and ethylene glycol). The components in the tandem systems have suitably positioned the energy of the conduction and valance bands, limiting charge recombination, therefore, the sample containing all three semiconductors has the highest mineralization efficiency (95.3% removal of total organic carbon) under UV + Vis irradiation, mimicking solar radiation. Long term use of the photocatalytic films (up to 36 h) proved the need to design the process with interim washing steps for preserving the photocatalytic efficiency by avoiding surface clogging.

Cristina Bogatu

Papers

Simultaneous adsorption of dyes and heavy metals from multicomponent solutions using fly ash

The influence of parameters in silica sol-gel process

Tungsten oxide--fly ash oxide composites in adsorption and photocatalysis.

Solar-activated tandem thin films based on CuInS2, TiO2 and SnO2 in optimized wastewater treatment processes

CZTS-TiO2 thin film heterostructures for advanced photocatalytic wastewater treatment