4-8 Pseudo-first-order kinetic plots for the adsorption of reactive yellow C8G on MLP at different aqueous dye concentrations. 4-10 Second-order kinetic plot for the adsorption of reactive yellow C8G on MLP at various aqueous dye concentrations. 4-1 1 Second-order kinetic plots for the adsorption of reactive red on MLP at various concentrations of aqueous dye solution 32 4-12 Langmuir isotherm for the adsorption of reactive red C8G on.
General
Physical adsorption is associated with a decrease in the free energy and entropy of the adsorption system and therefore this process is exothermic. As mentioned previously, an important source of information on adsorption and its mechanism, in addition to the calorimetric measurements of heat of adsorption, is the adsorption isotherm. The fact that the adsorption isotherm is an integral feature of a concrete adsorption system is.
Colorant
This means that all information derived from an adsorption isotherm only deals with a concrete adsorbent and adsorbate. They are widely used in many industries such as textile, paper, leather and mineral processing. The number is significantly less than for textile fibers because a little dye goes a long way.
Classification Systems for Dyes
This is because many dyes are made from known carcinogens, such as benzidine and other aromatic compounds (Fu and Viraraghavan, 200 1)10. Unfortunately, most of these dyes escape conventional wastewater treatment processes and persist in the environment due to their high stability to light, temperature, water, detergents, chemicals, soap and other parameters such as bleach and sweat15. The variable parameters such as pH, adsorbent dose and initial concentration of adsorbate were checked.
Literature Review
General
- Zeolites
In distillation the property applied is volatility, in absorption it is solubility, in extraction it is distribution coefficient. The process by which adsorption takes place is due to net negative charge on the structure of minerals, and it is this negative charge that gives the clay mineral the ability to adsorb positively charged species. Most of Their sorption properties depend on their high surface area and high porosity3 2.1.2 Siliceous materials.
The use of these minerals was based on the chemical reactivity of their hydrophilic surface and the mechanical stability resulting from the presence of silanol groups. But among all these, silica beads are given special attention when using the material as an adsorbent 3638• However, Ahmed 39 reports that the main problem with this type of application is their low resistance to alkaline solutions, their use is limited to pH media lower than 8. However, clinoptilolite, a mineral of the heulandite group, is the most and frequently investigated material, as it has a high selectivity for some contaminants.
Intensive research has been done on the use and application of zeolite as an adsorbent in the removal of trace amounts of pollutants such as heavy metal ions and phenols due to their cage-like structures suitable for ion exchange 4143.
Color removal using activated carbons from solid waste
Agricultural waste materials used as low cost adsorbent
Recent literature on dye removal methods from wastewater focuses on MB adsorption. Rengaraj et al.57 developed rubber seedbed activated carbon for the removal of phenols using batch and column operations. Bagasse pulp is mainly composed of cellulose, pentosan and lignin 59. Research was carried out on the adsorption of dyes, Astrazone blue, Maxillon red and Telon blue using bagasse pith 60 Based on cost analysis, they showed that bagasse pulp is economically attractive than commercially available activated carbon.
Biosolid matter (sludge) from a sewage treatment plant was used as an adsorbent in the removal of basic dyes Basic blue 3, Basic red 22 and Basic black 9 from aqueous solutions61. 0 from aqueous solutions 62 The results showed that the maximum adsorption capacity of magnetic cells differs significantly for individual dyes; the highest value was found for aniline blue. The removal of the basic dye Rhodamine - B using tapioca shell activated carbon as an adsorbent was also investigated.
The soil was used as an adsorbent for the removal of dyes, Methylene Blue, Malachite Green and Rhodamine - B from aqueous solutions. The activated carbon of the jackfruit peel was used as an adsorbent to remove a basic dye, Rhodamine - B from aqueous solution 64 The activated carbon of the jackfruit peel was also used as an adsorbent to remove a dye, Malachite green, from aqueous solution 65 Removal of acid dyes using groundnut shell powder activated with zinc chloride solution was investigated as an adsorbent 66. The neem leaf powder was used to remove three water-soluble dyes namely brilliant green, congo red and methylene blue from aqueous medium 67 Removal of acid red 183 from aqueous solution was investigated by activated carbon, crude kaolinite and montmorillonite under using an agitated batch adsorber. 68 Rice bran-based activated carbon and guava seed activated carbon, followed by pyrolysis were also used as adsorbents to remove dyes from aqueous solutions.
In the present work, Maogani leaf powder (MLP) is used as an adsorbent for the removal of acidic dyes from aqueous solution as a model system.
Preparation of Adsorbent
Preparation of Adsorbate Solution
Batch Adsorption Experiments
The supernatant solutions were analyzed using a UV-visible spectrometry (Helios Gamma Spectrophotometer, UVG-152411) by monitoring the absorbance changes at a wavelength of maximum absorbance 001 nm for Reactive Yellow C8G and 548 nni for Reactive.
Adsorption Isotherm Studies
Scanning Electron Microscopy
Backscattered electrons (BSE) are beam electrons that are reflected from the sample by elastic scattering. BSEs are often used in analytical SEMs along with characteristic X-ray spectra because the intensity of the BSE signal is strongly related to the atomic number (Z) of the specimen. These characteristic X-rays are used to identify the composition and measure the abundance of elements in the sample.
Glassware and Apparatus
Effect ofpH
- Effect of pH on Reactive RedM5B
- Effect of pH on Reactive Yellow C8G
Effect of Adsorbent Dose
Effect of Initial Concentration and Contact Time
- Reactive Yellow C8G
The MLP surface can contain a large number of active sites and dye uptake can be related to the active sites. The higher rate of sorption in the initial period may be due to the increased number of vacancies available in the initial phase, resulting in increased concentration gradients between the adsorbate in solution and the surface of the adsorbatein adsorbatein. Over time, this concentration decreases due to the accumulation of dye particles on empty sites, which causes a decrease in the rate of sorption.
The ink concentration is slightly higher than reactive yellow C8G, but the capacity trend is almost.
Morphological Studies
Kinetic Study
450 min and a medium percent removal indicated that MLP possessed a normal degree of affinity for dyes Reactive yellow and Reactive red. The kinetics of both reactive yellow and reactive red dyes adsorption on MLP are verified with respect to the. The Lagergren diagrams for reactive yellow and reactive red are depicted in Figure 4-8 and Figure 4-9, respectively.
If the two do not match, it is necessary to test the validity of the second-order kinetics given by the equation8°. The second-order kinetic plots t/q,vst for a constant amount of MLP (1 gIL) and different dye concentrations of Reactive yellow and reactive red are shown in Figures 4-10 and 4-1, respectively. The values obtained from first-order kinetic and second-order kinetic for reactive yellow and reactive red are summarized in Table 4-1 through Table 4-4.
Figure 4-10 Second-order kinetic plots for adsorption of reactive yellow C8G on MLP at different concentrations of the aqueous dye solution. Figure 4-1 1 Second-order kinetic plots for adsorption of reactive red on MLP at different concentrations of the aqueous dye solution. Therefore, the validity of the pseudo-first-order model for the kinetics of adsorption of reactive red on MLP was not good and could not be established with certainty.
Therefore, it is more likely that the adsorption of reactive yellow and reactive red dyes on MLP could occur via a second-order mechanism.
Adsorption Isotherms The Langmuir isotherm equation
Reactive yellow and reactive red adsorption on MLP followed both the Langmuir isotherm (Figure 4-12 and Figure 4-13) and the Freundlich isotherm (Figure 4-14 and Figure 4-15), respectively. The Langmuir plots for reactive yellow have good linearity, R 0.93 to 0.95, and the adsorption capacity (qm) of the Langmuir monolayer decreased from 67.11 to 0.93 mg/g for MLP. To predict whether the adsorption process by MLP is favorable or unfavorable to the Langmuir type adsorption process, the isotherm form can be classified by the term "R1", a dimensionless constant separation factor.284142 The dimensionless parameter, RL, had values in the range of for reactive yellow and for reactive red, consistent with the requirement for a favorable adsorption process defined by 0 < R < 1.
This study found that the powder made from mature, dried leaves of the Mahogani tree (SwiteniaMahogani) could be a useful biosorbent for removing dyes from water. It is therefore more likely that the adsorption of reactive yellow and reactive red dyes on MLP occurs via a second-order mechanism. iv) Adsorption of reactive yellow and reactive red dyes on MLP was consistent with both Langmuir and Freundlich isotherms. The monolayer adsorption capacity (qrn) of Langmuir decreased from 67.11 toll.93 mg/g for reactive yellow and from 12.39 to 2.09 mg/g for reactive red, with the MLP amount varying from 0.5 to 1. 0 g/L. The adsorption equilibrium parameter, for reactive yellow, h, ranged from 0.028 to 0.034 L/mg, with the increase in MLP amount and a similar trend observed for reactive red. The adsorption capacity.
2013, "Preparation of Banana Leaf Activated Carbon by Microwave Induced Activation for Boron and Total Iron Removal from Landfill Leachate". 2013, "Batch adsorption of semiaerobic landfill leachate with granular activated carbon prepared by microwave heating". 2011, "Adsorption of Textile Dyes on Pine Cone from Dyed Wastewater: Kinetic, Equilibrium and Thermodynamic Studies".
2013, Microwave Preparation of Pumpkin Seed Hull Activated Carbon and Its Application for Adsorptive Removal of 2,4-Dichlorophenoxyacetic Acid.” Stephen Inbaraj B, Sulochana N Use of fruit peel carbon (JPC) for adsorption of rhodamine-B from a basic dye aqueous solution" Indian Journal of Chemical Technology, Vol 13, pp 17-23. N Removal of methylene blue , a basic dye from aqueous solutions by adsorption using teak bark powder (Tectona grandis).
