Removal of copper (II) and nickel (II) from aqueous media using silica aerogel modified with amino propyl triethoxysilane as an adsorbent: equilibrium, kinetic, and isotherms study

Abstract

A B S T R A C TThis study focused on the adsorption of copper (II) and nickel (II) from aqueous solutions onto silica aerogel modified with amino propyl triethoxysilane as a compound containing amino functional group. The batch experiments were conducted at various conditions including contact time, pH, adsorbent dose, and adsorbate content. The results showed that the equilibrium time occurred within 5 h for Ni(II) and 24 h for Cu(II) and the maximum adsorption capacity for both the ions happened at a pH of 6. The kinetic and isotherm adsorption of the modified silica aerogel fitted well to pseudo-second order model and Langmuir model, respectively. The Langmuir isotherm model results showed that the maximum adsorption capacity (Q m ) of the modified adsorbent was 47.6 mg/g for Cu(II) and 27.7 mg/g for Ni(II). Experimental data analysis by Dubinin-Radushkevich isotherm also illustrated that the metals adsorption onto the sorbent was physical in nature. With regard to the sorption capacity obtained by the modified silica aerogel, it can be considered as an efficient sorbent in the removal of the metal ions.

Preparation, Characterization, and Application of Silica Aerogel for Adsorption of Phenol: An In-Depth Isotherm Study

“…The pore sizes are different, including macropores (50 to 1000 nm), mesopores (2 to 50 nm), and micropores (0.2 to 2 nm). Faghihian et al (14) also defined the surface of prepared silica aerogel inconsistent and heterogeneous.…”

“…There are various methods for phenol removal from aqueous solutions, such as Fenton-based technologies (3), ozonation (4), coagulation (5), biological processes (6), adsorption (7), electro-oxidation (8), and electrocoagulation (9). ity (up to 99%), and high modification capability (12)(13)(14). Up to now, this adsorbent has been widely applied to remove various toxic compounds, such as heavy metals (14), Benzene, Toluene, Ethylbenzene, and Xylenes (BTEX) compounds (15), dyes (11), and so on.…”

“…ity (up to 99%), and high modification capability (12)(13)(14). Up to now, this adsorbent has been widely applied to remove various toxic compounds, such as heavy metals (14), Benzene, Toluene, Ethylbenzene, and Xylenes (BTEX) compounds (15), dyes (11), and so on. As far as the authors are aware, however, there is a limited knowledge about the adsorptive behavior of silica aerogel for phenol removal under various conditions of operation.…”

Removal of a common textile dye, navy blue (NB), from aqueous solutions by combined process of coagulation–flocculation followed by adsorption

“…where q e (mg/g) and C e (mg/L) are the equilibrium adsorption capacity of adsorbent and dye concentration at equilibrium time, respectively, b (L/mg) is the equation constant, and q m (mg/g) is the maximum adsorption capacity of adsorbent (monolayer) [1,23]. q m and b can be obtained from the slope and intercept of linear plot of C e /q e against C e , respectively.…”

“…So, this process can be combined with the other treatment processes to enhance dye removal from wastewater. Among the various methods, adsorption process, because of high removal efficiency, simplicity and extensive utilization, is an appropriate technique to remove dye pollutants from aqueous media [14,[20][21][22][23]. In recent years, many studies have been conducted on the dye adsorption by different absorbents such as fly ash, peat, wood powder, coir pith, lignin, clay, bottom ash, zeolite, calcine alunite, peanut hull, rice husk, brown seaweed, cellulose, silica gel, bagasse pith, maize cob, orange peel, and waste red mud [2,11,16,20,21,24,25].…”