Kinetic and equilibrium study of Ni(II) sorption from aqueous solutions onto Peganum harmala-L

Abstract

In this study, the adsorption behavior of Ni(II) in an aqueous solution system using natural adsorbent Peganum harmala-L was measured via batch mode. The prepared sorbent was characterized by scanning electron microscope, Fourier transform infrared spectroscopy, N 2 adsorptiondesorption and pH zpc . Adsorption experiments were carried out by varying several conditions such as contact time, metal ion concentration and pH to assess kinetic and equilibrium parameters. The equilibrium data were analyzed based on the Langmuir, Freundlich, Temkin and Dubinin-Radushkevich isotherms. Kinetic data were analyzed using the pseudo-firstorder, pseudo-second-order and intra-particular diffusion models. Experimental data showed that at contact time 60 min, metal ion concentration 50 mg/L and pH 6, a maximum amount of Ni(II) ions can be removed. The experimental data were best described by the Langmuir isotherm model as is evident from the high R 2 value of 0.988. The adsorption capacity (q m ) obtained was 68.02 mg/g at an initial pH of 6 and a temperature of 25°C. Kinetic studies of the adsorption showed that equilibrium was reached within 60 min of contact and the adsorption process followed the pseudo-first-order model. The obtained results show that P. harmala-L can be used as an effective and a natural low-cost adsorbent for the removal of Ni(II) from aqueous solutions.

Utilization of fruit processing industry waste as green activated carbon for the treatment of heavy metals and chlorophenols contaminated water

“…The results show that the activated carbon has a large adsorption capacity for the removal of the investigated metals in a relatively short period of time, which is consistent with other studies that have investigated the adsorption of ions on alternative adsorbents (Li et al, 2010;Ghasemi et al, 2014a;Coelho et al, 2014). Based on these results it can be observed that the adsorption of metal ions occurs in two phases.…”

Adsorptive removal of cobalt ions on raw and alkali-treated lemon peels

“…5b) did not give a straight line passing through the origin, indicating that intraparticle diffusion was not the only rate determining step. The graph shows three portions: the initial linear portion due to the rapid external surface adsorption of solute on available binding sites of the sorbent; the next linear part due to gradual adsorption where intraparticle diffusion is the rate controlling step; and in the third part, due to very low adsorbate concentrations in the solution, the intraparticle diffusion starts to slow down leading to equilibrium as shown by the plateau region (Ghasemi et al 2014). ?…”

Adsorption of heavy metals from multi-metal aqueous solution by sunflower plant biomass-based carbons

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