Kinetics and Isotherm Analysis of Basic Dyes Adsorption onto Almond Shell (Prunus dulcis) as a Low Cost Adsorbent

Abstract

The feasibility of using an agricultural byproduct, almond shell (Prunus dulcis), as an adsorbent in removal of basic dyes, namely, methylene blue (MB), methyl violet (MV), and toluidine blue O (TB), were evaluated in a batch adsorption process. The adsorption characteristics of MB, MV, and TB onto almond shell (AS) were investigated with respect to the changes in initial pH of dye solutions, contact time, initial dye concentration, and temperature. The dye adsorption equilibria were rapidly attained after 30 min of contact time. The adsorption kinetics were analyzed using pseudofirst-order, pseudosecond-order, Elovich, and intraparticle diffusion models and the adsorption data were well described by the pseudosecond-order model. The equilibrium adsorption data were interpreted in terms of the Langmuir, Freundlich, Temkin, and Dubinin−Radushkevich (D-R) isotherm models. The monolayer adsorption capacity of AS was found to be 51.02 mg·g−1 for MB, 76.34 mg·g−1 for MV, and 72.99 mg·g−1 for TB by using the Langmuir model equation. The thermodynamic parameters proved that the present adsorption process was feasible, spontaneous and endothermic in nature in the temperature range of (5 to 40) °C.

Kinetic and Isotherm Analysis of Cu(II) Adsorption onto Almond Shell (Prunus Dulcis)

“…As seen in the figure, a period of 60 minutes was found to be sufficient for removal of Cu(II) with almond shell. Some of the previous researches similarly reported 60 minutes contact time for heavy metal removal with almond shell [15]; in other studies lower [16,17] and higher [14,18] contact times were also reported.…”

Adsorption and desorption characteristics of adlay bran free phenolics on macroporous resins

“…The pseudo-first-order model is generally applicable over the initial stage of an adsorption process, while the pseudo-second-order model assumes that the rate-limiting step is chemisorption and predicts the behavior over the whole range of adsorption (Duran, Ozdes, Gundogdu, & Senturk, 2011). All these equations, including derived parameters such as correlation coefficient and dynamic parameters, were summarized in Table 2.…”

“…Langmuir isotherm model had been used successfully for many adsorption processes of monolayer solid-liquid adsorption (Sandhu & Gu, 2013). Freundlich isotherm model, known as an empirical formula, is derived to model the multilayer and heterogeneous surface adsorption (Duran et al, 2011). The thermodynamic parameters of adlay bran free phenolics on XAD-16, SP-207 and SP-825 resins were shown in Table 3.…”

Pore-expanded MCM-41 for CO2 adsorption: Experimental and isotherm modeling studies

“…A wide variety of equilibrium isotherm models (Langmuir, Freundlich, Brunauer-Emmett-Teller, Redlich-Peterson, DubininRadushkevich (D-R), Temkin, Toth, Koble-Corrigan, Sips, Khan, Hill, Flory-Huggins and Radke-Prausnitz isotherm), have been formulated till date to describe the experimental sorption data [20,21]. Among the existing theoretical adsorption models, Langmuir is the simplest one to describe the adsorption on homogeneous surface.…”