Investigation of kinetics and equilibrium isotherms of Direct Red 12B dye adsorption on hazelnut shells (original) (raw)
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Desalination, 2010
Cashew nut shell (CNS)a novel, low cost adsorbent prepared from agricultural waste has been utilized as the adsorbent for the removal of Congo red (CR) dye from an aqueous solution. The effect of pH, adsorbent dose, initial dye concentration, time and temperature on adsorption was studied. The results indicate that CNS can be employed as a low cost alternative compared to other commercial adsorbents in the removal of dyes from wastewater. The experimental data were analyzed by Langmuir, Freundlich, Redlich-Peterson, Koble-Corrigan, Sips, Toth, Temkin and Dubinin-Radushkevich adsorption isotherms. The characteristic parameters for each isotherm and related correlation coefficients have been determined using MATLAB 7.1. Thermodynamic parameters such as ΔG o , ΔH o and ΔS o have also been evaluated and it has been found that the sorption process was feasible, spontaneous and exothermic in nature. Pseudo-first-order, pseudosecond-order and intraparticle diffusion models were used to fit the experimental data. Kinetic parameters, rate constants, equilibrium sorption capacities and related correlation coefficients, for each kinetic model were calculated and discussed. It was shown that the adsorption of CR could be described by the pseudosecond-order equation, suggesting that the adsorption process is a presumably chemisorption.
E3S Web of Conferences
In many countries, water pollution from industrial wastewater is a serious problem. This type of pollution can have a harmful impact on the environment, to reduce the effects of these pollutants, several physico-chemical methods are implemented, in particular adsorption on bioadsorbents, it is a common process to remove traces of pollutants from water, the aim of our work is to realize a comparative experimental study of isotherms and adsorption kinetics of methylene blue (MB) on three substrates: sugar cane bagasse (SCB), almond shell (AS) and walnut shell (WS). The results of equilibrium kinetics show that walnut shell (WS) binds better to methylene blue than other substrates. The results also show that the adsorption kinetics are described by the expression of the pseudo-second order model. The isotherms of adsorption of methylene blue (MB) by sugarcane bagasse (SCB), walnut shell (WS) and almond shell are perfectly described by Langmuir's model and that walnut shell adsorbs ...
Equilibrium studies for the Adsorption of Acid Red 14 and Direct Yellow 86 Dyes Aqueous Solution
This article describe the adsorption of acidic and direct dyes, namely Acid Red 14 (AR14) and Direct Yellow 86 (DY86), from aqueous solution onto activated carbon from walnut shell (ACW) as an eco-friendly and low cost adsorbent. Laboratory prepared ACW were characterized by Barrett-Joiner-Halenda (BJH) and Brunauer-Emmett-Teller (BET) pore structural parameters. The effect of various experimental parameters such as initial dye concentrations, pH and ACW doses were investigated in a batch adsorption technique. Optimum conditions for removal of dyes were found to be pH=1 and 1g of adsorbent dosage in equilibrium time of 48 h. It is shown that, lower equilibrium uptake further increase in temperature, because of the exothermic dyes biosorption process. The plot of the removal versus adsorbent dosage shows the effect of the different frequency of ACW dyes. Equilibrium adsorption isotherms were measured and the experimental data were analyzed using Langmuir, Freundlich and Temkin isotherm equations. It was found that data for DY86 Temkin isotherm is preferred (R 2 =0.93), while for AR14, the Freundlich isotherm is more applicable (R 2 =0.65). The ACW might be successfully used for the removal of dyes from liquid industrial wastewater.
Experimental Study of Methylene Blue Dye Adsorption Using Cashewnut Shell as an Alternate Adsorbent
Journal of emerging technologies and innovative research, 2017
Colored compounds are the most easily recognizable pollutants in the environment because of their appearance. Most of the industries such as textile, paper, carpet, and printing use dyes and pigments to color their products. Due to their good solubility, synthetic dyes are common water pollutants and they may frequently be found in trace quantities in industrial wastewater. However, the discharge of dye-bearing wastewater into natural streams and rivers possess a severe problem, as dyes impart toxicity to aquatic life and are damaging the aesthetic nature of the environment. However, wastewater containing dyes is very difficult to treat, since the dyes are recalcitrant organic molecules, resistant to aerobic digestion, and are stable to light, heat and oxidizing agents due to their structure and molecular size. Adsorption techniques have gained favor in recent years because of their proven efficiency in the removal of pollutants from effluents too stable for conventional treatment methods. Apart from the high quality product obtained, the processes have proved economically feasible. In many textile processing industries, activated carbon is used as a sorbent to remove dyes in wastewater due to its excellent adsorption ability. For the study presented here Activated carbon (Commercial), Charcoal (Cashew-nut shell) and Charcoal (Wood) were used as an adsorbent. The experimental investigations have been made to find the effect of various parameters on the change in concentration of dye and to find the inexpensive alternative adsorbents in order to decrease the cost of treatment.
Adsorption Isotherms of Congo red dye on groundnut shell and sorghum husk
Abstact Using of low cost absorbent is necessary in order to prevent environmental problem. Most of the different methods of water treatments are very expensive, therefore attention most be given to use of cheap absorbent for water treatment. In this research work, sorghum husk and groundnut shell were used to remove Congo red dye in water at the laboratory scale. Batch studies were carried out to determine the adsorption equilibrium of Congo red dye on the two different adsorbent and also to verify the reported data using Langmuir, Freundlich and Temkin isotherm. The studies shows that for the adsorption of Congo red dye on sorghum husk and Congo red dye on groundnut shell, Freundlich isotherm fitted well the experimental data due to high R2 values of 0.983 and 0.9720 respectively. The Temkin binding energy (bT) are positive for the two experiment, indicating that the process is endothermic.
Modeling of adsorption isotherms and kinetics of reactive dye from aqueous solution by peanut hull
Chemical Engineering Journal, 2011
Adsorption of Reactive Black 5 (RB5) in aqueous solution by peanut hull was studied by using Placket-Burman (PB) and Central Composite Design (CCD). Four out of the 7 factors (initial dye concentration, initial solution pH, amount of adsorbent, temperature, particle size, shaking speed and contact time) studied by PB design influenced the adsorption of dye. A CCD was used to develop mathematical model equation. Analysis of variance (ANOVA) showed a high coefficient of determination value (R 2 = 0.95). Linear and quadratic effects of the initial dye concentration and linear effect of peanut hull quantity were demonstrated to be very significant (P < 0.05) for RB5 adsorption. The interaction between peanut hull dose and initial dye concentration showed remarkable effect on adsorption process. The equilibrium adsorption data of RB5 on peanut hull were analyzed by Langmuir and Freundlich models. The monolayer adsorption capacity (q m) increased from 50 to 55.55 mg/g with the increase in temperature from 20 • C to 60 • C. The kinetic data were analyzed using the pseudo-first-order and pseudo-second-order adsorption kinetic models. According to these models, the rate constants were calculated for different initial dye concentrations. It can be concluded that the experimental data are well defined with pseudo-second-order kinetic model.
Study of Removal of Cationic Dyes using Palm Shell Powder as Adsorbent
Study of Removal of Cationic Dyes using Palm Shell Powder as Adsorbent , 2008
Batch sorption experiments were carried out for the removal of Methylene Blue and Rhodamine 6G from aqueous solution using Palm Shell Powder (PSP) as adsorbent. The operating variables studied were adsorbent mass, solution pH, contact time and initial dye concentration. Adsorption experiments indicated that the adsorption capacity was dependent on operating variables and the process was pH-independent above pH 4.0. Kinetic measurements showed that the process was uniform and rapid. Sorption of dye reached equilibrium in 120 min. In order to investigate the mechanism of sorption, adsorption data were modeled using the pseudofirst-order and pseudo-second-order kinetic equations. It was found that the adsorption kinetics followed a pseudo-second-order model for the dye concentration range studied in the present work, suggesting that the ratelimiting step may be chemisorption. Equilibrium isotherm was analyzed using the Langmuir and the Freundlich isotherms. The characteristic parameters for each model have been determined. The results of Banghams equation states that the adsorption of the dye is pore diffusion controlled process. The exhaustive capacity was 121.5 and 105.0mg/g for MB and Rh6G mg/g at 25 °C with PSP .The negative value of free energy change indicated the spontaneous nature of adsorption.
International Journal of Environmental Science and Technology, 2013
In the present study, Juglans regia shells were used to prepare activated carbon by acid treatment method. J. regia shell-based activated carbon was used for the adsorption of two synthetic dyes namely, a basic dye malachite green and an acid dye amido black 10B. The prepared adsorbent was crushed and sieved to three different mesh sizes 100, 600 and 1,000 lm. The adsorbent was characterized by scanning electron microscopy, surface acidity and zero-point charge. Batch experiments were carried out by varying the parameters like initial aqueous phase pH, adsorbent dosage and initial dye concentration. The equilibrium data were tested with Langmuir, Freundlich, Redlich-Peterson and Sips isotherm at three different temperatures 293, 300 and 313 K and it was found that the Freundlich isotherm best fitted the adsorption of both the dyes. Kinetic data were tested with pseudo first-order model and pseudo second-order model. The mechanism for the adsorption of both the dyes onto the adsorbent was studied by fitting the kinetic data with intraparticle diffusion model and Boyd plot. External mass transfer was found to be the rate-determining step. Based on the ionic nature of the adsorbates, the extent of film diffusion and intraparticle diffusion varied; both being system specific. Thermodynamic parameters were also calculated. Finally, the process parameters of each adsorption system were compared to develop the understanding of the best suitable system. Keywords Adsorption Á Malachite green Á Amido black Á Intraparticle diffusion Á Boyd plot Electronic supplementary material The online version of this article (
JOURNAL OF RESEARCH AND REVIEW IN SCIENCE, 2019
Introduction: The conversion and utilization of agricultural wastes in environmentally friendly processes have transformed these materials into useful rather than waste materials. Aim: This study investigates the adsorption of indigo blue dye from aqueous solution onto coconut shell, a low cost agricultural waste material in a batch process. Materials and Methods: Pulverized coconut shell was chemically modified and characterized using the Fourier Transform Infra Red spectroscopy and Scanning Electron Microscopy. Adsorption process using the chemically modified coconut shell was studied as a function of pH, initial dye concentration, adsorbent dose, and contact time. The adsorption equilibrium data were analyzed with Langmuir, Freundlich and Temkin isotherm models. Results: The results revealed that percentage of the indigo dye adsorbed from aqueous solution varied linearly with the adsorbent dose, concentration and time with maximum percentage dye adsorption of 88.4% at 70 mg dosag...
Scientific Reports, 2020
The low cost, eco-friendly and potential biomass, i.e. walnut (Juglans regia) shell powder was deployed for the removal of toxic methylene blue dye from contaminated water solution. The important characterization of the waste material was conducted by using several techniques, i.e. Scanning electron microscope, Fourier-transform infrared spectroscopy, Energy-dispersive X-ray spectroscopy, X-ray powder diffraction, Brunauer-Emmett-Teller surface area analysis, and Thermogravimetric analysis. The marked impact of various operating conditions, i.e. dose, concentration, time, pH and temperature on the adsorption process was investigated. Increasing pH resulted in an increase of percent dye adsorption, and the adsorption mechanism was occurred by electrostatic attraction between negative adsorbent surface and positive dye molecules. The equilibrium data suited with Langmuir isotherm model while the adsorption practice followed the pseudo-second-order kinetic model. Higher temperature red...