Efficient Removal of Ni(II) from Aqueous Solution by Date Seeds Powder Biosorbent: Adsorption Kinetics, Isotherm and Thermodynamics

Abstract

Adsorption investigations in batch approaches were performed to explore the biosorption of Ni(II) ions from aqueous solutions on date seeds powder. The effects of pH, particle size, initial concentration of Ni(II) ions, adsorbent mass, temperature, and contact on the adsorption efficacy were studied. The maximum removal obtained was 90% for an original Ni(II) ion solution concentration of 50 ppm was attained at pH 7 after 30 min and with 0.30 g of an added adsorbent. The four adsorption models, namely Freundlich, Langmuir, Dubinin–Radushkevich (D–R), and Temkin were examined to fit the experimental findings. The adsorption system obeys the Freundlich model. The system was found to follow the pseudo-second order kinetic model. Thermodynamic factors; entropy (ΔS°), enthalpy (ΔH°), and Gibbs free energy (ΔG°) changes were also assessed. Results proved that adsorption of Ni(II) ions is exothermic and spontaneous. Sticking probability value was found to be less than unity, concluding that the process is dominated by physical adsorption.

Evaluation of the Adsorption Efficiency on the Removal of Lead(II) Ions from Aqueous Solutions Using Azadirachta indica Leaves as an Adsorbent

“…Values of A and B were determined from the slope and intercept of Equation (6) and Figure 10c and are shown in Table 3. The b t value was 318 J/mol, indicating physical adsorption processes [21].…”

“…The effect of the initial concentration of Pb(II) ions on the adsorption efficiency is presented in Figure 9, where it is evident that the adsorption efficiency of Pb(II) ions decreased as the initial Pb(II) ion concentration increased. The decrease in adsorption efficiency can be attributed to the deficiency of sufficient adsorption sites for accumulating the large increase of metal ions available in the solution [21].…”

“…The adsorption isotherm models were investigated to explore the interaction mechanism of Pb(II) ions on the adsorbent sites [1,21]. The adsorption isotherm models were analyzed by specific parameters, whose values express the surface characteristics and affinity of the adsorbent towards heavy metal ion adsorption [21]. Out of numerous isotherm models, four were examined for this study, namely, Freundlich, Langmuir, Temkin, and Dubinin-Radushkevich (D-R) models.…”

“…This model suggests an exponential drop in adsorption energy upon completion of the adsorption centers of the adsorbent. The linear equation of the Freundlich model is shown by Equation 7 [21]:…”

Single and competitive sorption potential of date seed‐derived biochar during removal of lead (II) and cadmium (II) ions

“…Date seed contributes to 11%–18% of the total weight of date fruit and currently posing disposal problems 16 . In an attempt to explore alternative use of date seeds, researchers have examined the sorption ability of date seeds 17,18 . Also, due to elevated lignocellulose composition, date seeds were identified as an efficient feedstock for activated carbon 19,20 .…”