scholarly journals A Comparative Study of the Adsorption of Crystal Violet Dye from Aqueous Solution on Rice Husk and Charcoal

2020 ◽  
Vol 17 (1(Suppl.)) ◽  
pp. 0295
Author(s):  
Souad Abd Mousa

            In this work, the adsorption of crystal violet dye from aqueous solution on charcoal and rice husk has been investigated, where the impact of variable factors (contact time; the dosage of adsorbent, pH, temperature, and ionic strength) have been studied. It has been found that charcoal and rice husk have an appropriate adsorption limit with regards to the expulsion of crystal violet dye from fluid arrangements. The harmony adsorption is for all intents and purposes accomplished in 45 min for charcoal and 60 min for rice husk. The amount of crystal violet dye adsorbed (0.4 g of charcoal and 0.5 g of rice husk) increased with an increasing pH and the value of 11 is the best. The effect of temperature on the adsorption process was studied at the range (298-323) K. The test comes about were broken down by utilizing Freundlich and Tempkin isotherm models, where the Freundlich and Tempkin factors were determined, and it has been found that the adsorption isotherm obey the Freundlich isotherm. The effect of ionic strength on the adsorption process was studied also via sodium chloride electrolyte solution; the results have been revaled that the sodium ion has a positive impact on the adsorption process. The thermodynamic parameters are shown estimated as ∆H values were 2.8012 kJ mol-1 and 5.8252 kJ mol-1 for charcoal and rice husk, respectively; this behavior referred to endothermic adsorption.

2019 ◽  
Vol 233 (3) ◽  
pp. 375-392 ◽  
Author(s):  
Abdul Malik ◽  
Abbas Khan ◽  
Muhammad Humayun

Abstract The rice husk char (RHC) was prepared by keeping a known amount of the rice husk in furnace at 400°C. The product was modified with KOH and labeled as KOH modified rice husk char (KMRHC) which was used as an adsorbent for the removal of toxic dye, Orange G (OG) from aqueous media. Variation in the experimental conditions (agitation time, dye concentration, adsorbent dose, pH and temperature) play significant role in the adsorption process. The maximum adsorption capacity of OG on KMRHC was investigated as 38.8 mg/g at pH=4 using initial dye concentrations of 80 mg/L containing 2 g/L of the adsorbent dose with agitation speed of 250 rpm at 303 K. The % adsorption of dye was inspected as 96%. Thermodynamics studies of the adsorption of OG on KMRHC indicated that the value of ΔG and ΔH were negative which revealed that the adsorption process is exothermic and spontaneous process. The negative value of ΔS suggested that randomness decreases at the interface of adsorbent–adsorbate during the adsorption process. The kinetics study indicated that the experimental data of the adsorption process best fits to pseudo-second order kinetic model. The equilibrium data was tested on Langmuir, Freundlich and Temkin adsorption isotherm models. It was inspected that data follows all the three isotherm models (R2>0.91). However, the values of correlation coefficients (R2) indicated that the data is best fit to the Langmuir isotherm model (R2>0.99) which suggest for chemi-sorption process. The effect of temperature (303–343 K) shows that by varying the temperature the adsorption process is significantly affected. The general trend indicates that adsorption efficiency is higher at lower temperature as compared to higher temperature. This trend also suggests that the adsorption coefficient (K), rate of adsorption, and hence the spontaneity of adsorption process also decreases with raising the temperature.


2009 ◽  
Vol 6 (4) ◽  
pp. 1109-1116 ◽  
Author(s):  
S. Madhavakrishnan ◽  
K. Manickavasagam ◽  
R. Vasanthakumar ◽  
K. Rasappan ◽  
R. Mohanraj ◽  
...  

Carbon prepared fromRicinus CommunisPericarp (RCP) was used to remove a crystal violet dye from aqueous solution by an adsorption technique under varying conditions of agitation time, dye concentration, adsorbent dose and pH. Adsorption is influenced by pH, dye concentration, carbon concentration and contact time. Equilibrium was attained with in 60 min. Adsorption followed both Langmuir and Freundlich isotherm models. The adsorption capacity was found to be 48.0 mg/g at an initial pH of 6.8±0.2 for the particle size of 125–250 μm.


2015 ◽  
Vol 12 (1) ◽  
pp. 148-156
Author(s):  
Baghdad Science Journal

The subject of this research involves studying adsorption to removal herbicide Atlantis WG from aqueous solutions by bentonite clay. The equilibrium concentration have been determined spectra photometry by using UV-Vis spectrophotometer. The experimental equilibrium sorption data were analyzed by two widely, Langmuir and Freundlish isotherm models. The Langmuir model gave a better fit than Freundlich model The adsorption amount of (Atlantis WG) increased when the temperature and pH decreased. The thermodynamic parameters like ?G, ?H, and ?S have been calculated from the effect of temperature on adsorption process, is exothermic. The kinetic of adsorption process was studied depending on Lagergren ,Morris ? Weber and Rauschenberg equations.


2017 ◽  
Vol 13 (27) ◽  
pp. 425
Author(s):  
Azeh Yakubu ◽  
Gabriel Ademola Olatunji ◽  
Folahan Amoo Adekola

This investigation was conducted to evaluate the adsorption capacity of nanoparticles of cellulose origin. Nanoparticles were synthesized by acid hydrolysis of microcrystalline cellulose/cellulose acetate using 64% H3PO4 and characterized using FTIR, XRD, TGA-DTGA, BET and SEM analysis. Adsorption kinetics of Pb (II) ions in aqueous solution was investigated and the effect of initial concentration, pH, time, adsorbent dosage and solution temperature. The results showed that adsorption increased with increasing concentration with removal efficiencies of 60% and 92.99% for Azeh2 and Azeh10 respectively for initial lead concentration of 3 mg/g. The effects of contact time showed that adsorption maximum was attained within 24h of contact time. The maximum adsorption capacity and removal efficiency were achieved at pH6. Small dose of adsorbent had better performance. The kinetics of adsorption was best described by the pseudo-second-Order model while the adsorption mechanism was chemisorption and pore diffusion based on intra-particle diffusion model. The isotherm model was Freundlich. Though, all tested isotherm models relatively showed good correlation coefficients ranging from 0.969-1.000. The adsorption process was exothermic for Azeh-TDI, with a negative value of -12.812 X 103 KJ/mol. This indicates that the adsorption process for Pb by Azeh-TDI was spontaneous. Adsorption by Azeh2 was endothermic in nature.


2011 ◽  
Vol 86 (4) ◽  
pp. 1533-1541 ◽  
Author(s):  
Sagnik Chakraborty ◽  
Shamik Chowdhury ◽  
Papita Das Saha

Catalysts ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 346 ◽  
Author(s):  
Franco ◽  
Sacco ◽  
De Marco ◽  
Vaiano

In this work, the synthesis of zinc oxide (ZnO) photocatalyst from thermal decomposition of zinc acetate (ZnAc) nanoparticles obtained by supercritical antisolvent (SAS) precipitation was investigated. The optimization of calcination conditions of the SAS ZnAc was carried out, studying the effect of temperature (in the range 300–600 °C) on the production of ZnO nanoparticles. In particular, it was demonstrated that the organic residues in ZnO and its particle size, thus the specific surface area, strongly affect the photocatalytic performances. SAS micronization of ZnAc produces regular nanoparticles with a mean diameter of about 54.5 ± 11.5 nm, whereas unprocessed ZnAc is characterized by very large crystals. The experimental results evidenced that ZnAc prepared by SAS process calcined at 500 °C showed a regular nanometric structure (mean diameter: 65.0 ± 14.5 nm) and was revealed to be the best choice for the photocatalytic removal of crystal violet dye (CV). In fact, the photocatalytic activity performances of ZnO nanoparticles prepared by this route were higher with respect to that of ZnO from unprocessed ZnAc calcined at 500 °C (which is characterized by irregular tetrapods with mean size 181.1 ± 65.5 nm). The optimized photocatalyst was able to assure the complete CV decolorization in 60 min of UV irradiation time and a mineralization degree higher than 90% after 120 min of treatment time.


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