Adsorption of copper (II) onto molecular sieves NaY

A B S T R A C TThe adsorption of uranium (VI) from aqueous solutions on synthesised zeolite NaY has been studied and the effect of the solution pH, the initial concentration C, the solid/liquid ratio R and the temperature T was investigated. The adsorption process has been modelled using a 2 3 full factorial design in order to study the influence of the main effects and interaction parameters and to optimise the adsorption process. The pH is the most significant parameter affecting uranium (VI) ions' distribution on zeolite NaY. The equilibrium isotherm has been found to follow the Langmuir model. Kinetic studies showed that the pseudo-second-order model correlates our experimental data. Thermodynamic parameters showed the exothermic heat of adsorption and the spontaneity of the adsorption process.

Section: Thermodynamics Studiesmentioning

confidence: 90%

Modelling and adsorption studies of removal uranium (VI) ions on synthesised zeolite NaY

Houhoune

Nibou

Amokrane

et al. 2013

“…Thus to avoid any possible hydroxide formation, the initial pH for the sorption studies is selected as 5. Similar optimum pH was selected for the removal of Cu 2+ and Cd 2+ ions elsewhere [20,21].…”

Section: Sorption Data (Effect Of Concentration and Temperature)mentioning

confidence: 99%

Synthesis, physical characteristics, and Cd²⁺sorption studies of amorphous Fe(OH)₃

Waseem

Mustafa

Akhtar

et al. 2013

A B S T R A C TThis work investigates the physical characteristics of amorphous Fe(OH) 3 synthesized by precipitation method for the sorption studies of Cd 2+ ions. The exchange of surface protons was determined by potentiometric titration method. The particle size distribution shows the agglomeration of smaller particles and also the presence of nanoparticles. Batch sorption studies are performed with respect to concentration, pH, and temperature of the solution. The adsorption of Cd 2+ ions is found to increase with increasing concentration and temperature of the solution. To interpret the sorption data, Langmuir and Freundlich models are used. The values of both the adsorption enthalpy DH and entropy DS are found to be positive, suggesting that sorption process is endothermic and spontaneous in nature. The Fe dissolved from the solid is found to be less than 1 mg/L, which proves the integrity of the adsorbent. Further, the mechanism of the sorption reaction is also explored.

“…Since aluminum has one less positive charge than silicon, the framework usually has a net negative charge and is balanced by the exchangeable cation (K + , Na + , Mg 2+ , and Ca 2+ ) [17]. Therefore, ion exchange capability of natural zeolite makes it favorable for water treatment to remove unwanted ions, mainly cations [18,19]. In the case of anions, a surface functionalization has been applied in order to allow the retention of anions [20,21].…”

Section: Introductionmentioning

confidence: 99%

Study on the removal of nitrate in groundwater from Căpuş, Cluj county by natural zeolite of Mirşid and granular activated carbon

Moşneag

Popescu

Neamţu

et al. 2014

A B S T R A C TThis paper focuses on a comparative study regarding the performance of natural zeolite from Mirşid (NZM) and granular activated carbon (GAC), respectively, for treatment process of contaminated groundwater from Cȃpuş, Cluj region for nitrate removal. The effect of pH, conductivity, contact time, and nitrate concentration have been studied. The Langmuir and Freundlich models were used to fit the experimental data and these showed good correlations with the Freundlich model, providing a better description of the equilibrium (higher R 2 value). Textural analysis was employed in order to determine the specific surface area, and pore size distribution of the used activated carbon and natural zeolite. The adsorbents (GAC and NZM) were characterized by using Fourier transform infrared spectroscopy and x-ray powder diffraction.