Kinetic and thermodynamic study of phosphate removal from water by adsorption onto (Arundo donax) reeds

Abstract

The adsorption of phosphate ion onto natural reed (Arundo donax) was studied in this work. The effect of phosphate initial concentration, adsorbent dose, pH, temperature, and salt addition on adsorption uptake was investigated. The results showed that the adsorption uptake is directly proportional to the phosphate ion initial concentration and inversely proportional to the adsorbent's dose and temperature. A maximum adsorption capacity of 16.2 mg/g was observed at neutral pH. The addition of sodium and potassium chlorides has decreased the adsorption uptake. The adsorption isotherms agree better with the Langmuir model. The negative values of (ÁG) and (ÁH) obtained from the thermodynamic study, indicted that the adsorption process is spontaneous and exothermic. The experimental adsorption data were analyzed using three kinetic models: pseudo-first order, pseudo-second order, and intra-particle diffusion model. The pseudo-second-order model presented the best fit with a determination coefficient (R 2 ) higher than 0.99 and a minimum normalized standard deviation.

Investigation of Taguchi optimization, equilibrium isotherms, and kinetic modeling for phosphorus adsorption onto natural zeolite of clinoptilolite type

“…The values of maximum adsorption capacity criterion (b L ) ranged from about 40 to 50 mg g −1 . Similar ranges reported by Abdelhay et al. (2017) for the adsorption of phosphate onto natural reed.…”

Mordenite‐Type Zeolite from Waste Coal Fly Ash: Synthesis, Characterization and Its Application as a Sorbent in Metal Ions Removal

“…The values of ΔS 0 are found positive for both the metal ions, which indicate the affinity of sorbent towards the sorbet species. Positive ΔS 0 values also suggest increase in degree of freedom and randomness at the solid‐liquid interface …”

Synthesis of hydrochar supported zero-valent iron composites through hydrothermal carbonization of granatum and zero-valent iron: potential applications for Pb2+ removal

“…Isotherms adsorption (298.15 K) 0.05 g hydrochar (HC-25, HC-75 and HC) and 0.01 g ZVI were loaded into tubes containing a Pb 2þ solution at initial concentrations of 10, 20, 40, 80, 100, 150 and 200 mg/L. Mixtures were allowed to react for 24 h. The non-linear forms of Langmuir (4) and Freundlich ( 5) isotherm models were used to fit the experimental data (Tran et al 2017;Abdelhay et al 2018).…”