Adsorption isotherm and thermodynamic studies of As(III) removal from aqueous solutions using used cigarette filter ash

Abstract

In the present paper, used cigarette filter ash was prepared and used as an active adsorbent to remove As(III) ions from aqueous solutions. The prepared adsorbent structure was identified by scanning electron microscopy analysis, Brunauer–Emmett–Teller method and energy-dispersive X-ray spectroscopy analysis. The influence of contact time, pH, adsorbent dose and initial concentration of As(III) on the removal of As(III) was assessed. Several isotherm models were checked to illustrate the adsorption equilibrium. The adsorption equilibrium data adapted well with the Langmuir isotherm model. The maximum adsorption capacity of 33.33 mg/g was acquired from the Langmuir isotherm. The calculated thermodynamic variables verified that the adsorption process is spontaneous and endothermic.

Assessment of ampicillin removal efficiency from aqueous solution by polydopamine/zirconium(iv) iodate: optimization by response surface methodology

“…The adsorption equilibrium constant, K c , was calculated using eqn (13) and following the method reported by Milonjic. 91,92…”

Ionic Liquid Agar–Alginate Beads as a Sustainable Phenol Adsorbent

“…The other thermodynamic parameters such as the standard enthalpy change (Δ H °, kJ mol − 1 ) and standard entropy change (Δ S °, kJ mol − 1 K − 1 ) for phenol adsorption were calculated via the van’t Hoff plot ( lnK ° against 1/ T ), assuming constant Δ H ° as given in Equation (8). Equation (9) represents the mathematical formula for determining the equilibrium constant [ 38 ]: where K° is the equilibrium constant obtained from the ratio of q and C f when adsorption experiments were run at various temperature, R is the universal gas constant (8.314 J/mol K) and T is the temperature ( K ). Figure 15 displays the Van’t Hoff plot, which gives Δ H ° and Δ S ° from the slope and intercept, respectively.…”

“…The other thermodynamic parameters such as the standard enthalpy change (∆H • , kJ mol −1 ) and standard entropy change (∆S • , kJ mol −1 K −1 ) for phenol adsorption were calculated via the van't Hoff plot (lnK • against 1/T), assuming constant ∆H • as given in Equation (8). Equation ( 9) represents the mathematical formula for determining the equilibrium constant [38]:…”

Modification of halloysite nanotubes by hydroxyl terminated triazine‐based dendritic polymer for efficient adsorptive removal of Cd (II) from aqueous media

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