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Representation of adsorption isotherm models. Plot of Ce/qe with respect to Ce: Langmuir model (a), plot of ln qe against ln Ce: Freundlich model (b), plot of qe vs ln Ce: Temkin model (c) of CY dye adsorption onto Gypsum in a 70 mg L -1 CY aqueous solution, pH = 7.0, gypsum dose = 7 g L -1 , time of contact = 100 min., temperature = 25 ± 1.0 °C, rotational speed = 200 rpm
Source publication
This article describes how selectively anionic organic molecules could be removed from aqueous medium using naturally available gypsum (GS) adsorbent. Gypsum (CaSO 4 .2H 2 O) shows strong interactions with anionic dye molecules while it dos not show any affinity towards cationic dye molecules. We have shown the removal efficiency of gypsum taking c...
Contexts in source publication
Context 1
... K L (L.mg −1 ) denotes Langmuir adsorption constant , Q m denotes optimum adsorption capacity in units of mg g −1 . Figure 9a shows the C e /q e vs C e plot concerning adsorption of CY dye on gypsum adsorbent. The estimated values of the above-mentioned quantities are tabulated in Table 2. ...
Context 2
... e is plotted against the values of ln C e and a linear graph is obtained (Fig. 9b). In Table 2, the constants evaluated from the graph are tabulated. Finally, CY adsorption data were fitted with Temkin isotherm which provides information about adsorbent-adsorbate interaction on the basis of Heat of adsorption. It is considered that change in heat of adsorption of all molecules decreases linearly with the increase of ...
Context 3
... this equation, K T denotes the equilibrium binding constant (L mg −1 ) and B l corresponds to the heat of adsorption. The B l is defined as B l = RT b which contains the universal gas constant R (J K −1 mol −1 ) and temperature T in kelvin. A plot of q e vs ln C e is shown in Fig. 9c and the constants Table 2. The Freundlich isotherm gave the best correlation with the experimental data (r 2 = 0.99). This observation indicates the heterogeneous nature of gypsum surface and the adsorption of CY proceeds by the formation of multilayer coverage at the outer surface of the ...
Context 4
... K L (L.mg −1 ) denotes Langmuir adsorption constant , Q m denotes optimum adsorption capacity in units of mg g −1 . Figure 9a shows the C e /q e vs C e plot concerning adsorption of CY dye on gypsum adsorbent. The estimated values of the above-mentioned quantities are tabulated in Table 2. ...
Context 5
... e is plotted against the values of ln C e and a linear graph is obtained (Fig. 9b). In Table 2, the constants evaluated from the graph are tabulated. Finally, CY adsorption data were fitted with Temkin isotherm which provides information about adsorbent-adsorbate interaction on the basis of Heat of adsorption. It is considered that change in heat of adsorption of all molecules decreases linearly with the increase of ...
Context 6
... this equation, K T denotes the equilibrium binding constant (L mg −1 ) and B l corresponds to the heat of adsorption. The B l is defined as B l = RT b which contains the universal gas constant R (J K −1 mol −1 ) and temperature T in kelvin. A plot of q e vs ln C e is shown in Fig. 9c and the constants Table 2. The Freundlich isotherm gave the best correlation with the experimental data (r 2 = 0.99). This observation indicates the heterogeneous nature of gypsum surface and the adsorption of CY proceeds by the formation of multilayer coverage at the outer surface of the ...
Citations
... Pervious work reported that NUF is rich in gypsum (CaSO 4 .2H 2 O) Shamshuddin 2019;Hanafi et al., 2021). According to Hassan et al. (2021), gypsum has a high affinity to metal ions and potentially removes toxic metal ions from wastewater. Thus, the gypsum properties in NUF, allow it to act as a retention material for the developing PDF; it could serve as a potential natural adsorbent for the disposal facility, adsorbing metal ions which will later retard ion transport into groundwater, while simultaneously reducing the volume of NUF residue needing to be disposed of at the DSF. ...
... performed rapid adsorption and selective separation of methyl blue cationic dye from aqueous solution using gypsum. Hassan et al (2021) precipitated gypsum to remove water-soluble chlorazole yellow and methyl blue. Gypsum can also be used to remove reactive red 1 (RR1) as done by (Obunwo et al., 2012). ...
... In the neutral pH (pH 7), the forces of attraction and repulsion were sidestepped and the optimum sequestration of the dye molecules to the sorbent surface sites was a result of the Van der Waals forces acting as an intermolecular force of attraction between the molecules of DB 106 dye molecules and the sorbent active surface sites (Shabaan et al. 2020). The same phenomenon noticed under the impact of pH on the adsorption DB106 dye molecules in this study was reported also in the studies by Salama et al. (2022) and Hassan et al. (2021), where the best sorption of anionic dye molecules was observed at pH 7. ...
Zinc oxide nanoparticles (ZnO-NPs) have in recent times shown effective adsorption capability for the confiscation of colour contaminants from aqueous environments (aquatic ecosystems or water bodies) due to the fact that ZnO contains more functional groups. Direct blue 106 (DB106) dye was selected for this present study as a model composite due to its wide range of uses in textiles (cotton and wools), woods, and paper industries, as well as their therapeutic applications, along with its
potential for impairments. This study therefore focuses on the use of DB106 dye as a model composite due to its wide range of uses in textiles (cotton and wools), woods, and paper industries, as well as their therapeutic applications and their potential for impairments. Furthermore, the surface functionalization, shape, and composite pore size were revealed by TEM, FTIR, UV, and BET techniques. The current study uses green synthesis method to prepare ZnO-NPs as an adsorbent for the DB106 dye molecules adsorption under various conditions using the batch adsorption process. The adsorption of DB106 dye to the ZnO-NPs biosorbent was detected to be pH-dependent, with optimal adsorption of DB106 (anionic) dye particles observed at pH 7. DB106 dye adsorption to the synthesized ZnO-NPs adsorbent was distinct by means of the linearized Langmuir (LNR) and pseudo-second-order (SO) models, with an estimated maximum adsorption capacity (Qm) of 370.37 mg/g.
Phosphogypsum (PG) is a solid waste generated during the wet process of phosphoric acid production. The environmental-friendly disposal and recycling of PG is vital in the field of environmental solid waste treatment. In this study, PG is used for adsorbent of dyes in wastewater to achieve the goal of recycling waste with waste. Surfactant-modified phosphogypsum (ODBAC@PG) was prepared using octadecyl dimethyl benzyl ammonium chloride (ODBAC) as modifier. ODBAC@PG exhibits high adsorption capability for anionic dyes (methyl blue (MeB) and indocyanine carmine (IC)). The pseudo-second-order kinetic model fits the kinetic experimental data for the adsorption of two organic anionic dyes. Langmuir adsorption isotherm fits the adsorption characteristics of MeB and IC on ODBAC@PG, exhibiting a monolayer adsorption pattern. Thermodynamic parameters indicate the spontaneous and exothermic properties of MeB and IC on ODBAC@PG. MeB and IC have antagonistic effects on each other in binary adsorption system. High adsorption capacity after six cycles of experiments demonstrates the high reusability of ODBAC@PG. The nature for the adsorption includes electrostatic interaction, hydrogen bond and hydrophobic interaction. Using ODBAC@PG for dyes wastewater treatment can accomplish the goal of treating waste with waste and turning waste into treasure.
