Kinetic and Equilibrium Isotherms Studies of Adsorption of Pb(II) from Water onto Natural Adsorbent

Abstract

In this research dobera leaves (DL), an agricultural waste, available in large quantity in south region of Saudi Arabia, were used as low-cost adsorbent for removal of metal ions such as Pb(II). Batch operation was used to study the equilibrium behavior of DL. The effects of initial concentration of Pb(II), solution pH, contact time and adsorbent dose were evaluated. To study the kinetics of adsorption of Pb(II) onto DL, pseudo-first-order, pseudo-second-order and intra-particle diffusion were used. Adsorption process undergoes pseudo-second-order kinetic as proved by the high value of R 2. Furthermore, to design the equilibrium data of adsorption of process, four adsorption isotherm models such as Langmuir, Freundlich Temkin and Dubinin-Radushkevich (D-R) were used. It is found that Langmuir equation has the highest value of R 2 (0.999) compared with other models. In presences of a mixture of Pb(II)/Ni(II), DL were found to be selective for Pb(II) ions with a high adsorptive capacity of 83 mg/g and show favorable adsorption with RL < 1. In addition, preliminary results indicate that DL are very effective adsorbent for the removal of Pb(II) ions (>90%) from drinking water with less competition of other ions present in water.

Kinetics study of Removal Doxycycline drug from aqueous solution using Aluminum Oxide surface

“…The intra-particle diffusion plot shows that the adsorption occurs in 3 steps, the first is the faster sorption of DOH on the available external surface of Al 2 O 3 , the second part was refer to the intra particle diffusion and at the last equilibrium stage, intra particle diffusion incept start slow because of the lower concentrations of DOH and less sorption site and intra particle diffusion was not the only rate limiting mechanism in the adsorption process and it was one of the ratelimiting steps in the adsorption process, as is evident from the Fig. 8b [31].…”

Preparation of methacrylamide-functionalized crosslinked chitosan by free radical polymerization for the removal of lead ions

“…The Langmuir isotherm model assumes only a monolayer of adsorbate is formed at maximum adsorption. The surface of adsorbent is structurally homogenous and all sites are identical and energetically equivalent (Elmorsi, Mohamed, Shopak, & Ismaiel, 2014). The linearized equation of Langmuir model is represented as below: (4) where q max is the maximum adsorption at monolayer (mg g -1 ), C e is the equilibrium concentration of Pb(II) (mg L -1 ), q e is the amount of Pb(II) adsorbed per unit weight of the modified chitosan bead at equilibrium concentration (mg g -1 ) and b is the Langmuir constant related to the affinity of binding sites (L mg -1 ) and is a measure of the energy of adsorption (Jaros, Kamiński, Albińska, & Nowak, 2005).…”

Isotherms and Kinetic Studies on the Adsorption of Cd(II) onto Activated Carbon Prepared from Coconut (Cocos nucifera) Shell

“…Figure 2 is the SEM images of activatedcarbon prepared by using H 3 PO 4 as an activation agent. In the SEM image of Figure 2, a number of pores with different diameters are observed [20]. This development of porous structure may be attributed to the dehydrating effect of H 3 PO 4 .…”