Even if granular media filtration effectively reduces the turbidity of water, its limited surface functionalities and physical properties may constrain its ability to effectively remove critical contaminants from water. In our research, we successfully synthesized a new type of porous material – multiple coated GO/sand (M-GO/S) by integrating ordinary river sand with graphite oxide (GO) for the adsorptive removal of calcium ions in terms of water softening. Prior investigations confirmed it could remove water turbidity and fluoride simultaneously. M-GO/S was characterized using microscopic and spectroscopic techniques. The results indicate the presence of an uneven coating of graphite oxide, and the nanocomposite contains oxygencontaining functional groups. Under given conditions, the M-GO/S nanocomposite demonstrated remarkable efficacy in removing 75% of calcium ions (a higher removal percentage than commercial coal powdered activated carbon) from simulated hard water: pH 8, 5.0 g dosage, 50 mg/L calcium ions, and 20 min contact time. The isotherm and kinetic data revealed that the adsorption mechanism primarily comprises multilayer adsorption by means of a chemical sorption process. The mechanism of the proposed M-GO/S nanocomposite for removing calcium ions from hard water is elucidated using (XPS) analysis. The presence of (-O-Ca-O-) chemical bonds on the surface of the nanocomposite after equilibration with calcium ions suggests the occurrence of chemical interactions between the calcium ions and oxygen-containing functional groups of the M-GO/S. Consequently, the synthesized M-GO/S nanocomposite can be identified as a promising candidate for hard water treatment.
2
Dostęp do pełnego tekstu na zewnętrznej witrynie WWW
The paper examines single- and multicomponent adsorption onto granular activated carbon. The quantities adsorbed in the study were determined using HPLC with UV detection. The experimental data were analysed using the Langmuir, the Freundlich and the Sips adsorption isotherms. With a single component being adsorbed, high coefficients of determination and low mean square errors indicated that the Sips isotherm fitted the adsorption equilibrium well. Further experiments were carried out using aqueous solutions containing two or three adsorbed components in different proportions. For these solutions, the literature methods of predicting multicomponent equilibrium using single-component data did not yield positive results. Assuming that in the investigated range of concentrations no competitive adsorption occurred, the authors propose a method for calculating the equilibrium concentrations in the liquid phase using the equations obtained for individual components. The results achieved correspond very well to the experimental data.
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.