scholarly journals Removal of Chromium (VI) from Aqueous Solution using Charred Pomegranate Waste

2013 ◽  
Vol 29 ◽  
pp. 81-88
Author(s):  
Rajendra Prasad Gautam ◽  
Megh Raj Pokhrel

Removal of Cr(VI) from aqueous solution was studied using charred pomegranate fruit waste [CPW] as a new low cost biosorbent under batch method at room temperature. Its efficiency for removal of Cr(VI) was compared with raw pomegranate fruit waste[RPW]. Various sorption parameters such as contact time, initial concentration of Cr(VI) ion and effect of pH on the adsorption capacity of the biosorbent were studied. The adsorbent was effective for quantitative removal of Cr(VI) ions in highly acidic condition (pH=1) and equilibrium has been achieved in 2 hours. The adsorption isotherm data were fitted to Langmuir and Freundlich adsorption isotherm models and the model parameters were evaluated. Spectrophotometric method using diphenylcarbazide as a complexing reagent was used to analyze the chromium content in synthetic samples and the landfill site effluent collected from Kuleshwor, Kathmandu, Nepal.DOI: http://dx.doi.org/10.3126/jncs.v29i0.9256Journal of Nepal Chemical Society Vol. 29, 2012 Page:  81-88 Uploaded date: 12/5/2013 

2020 ◽  
Vol 2020 ◽  
pp. 1-9 ◽  
Author(s):  
Johnatan D. Castro-Castro ◽  
Iván F. Macías-Quiroga ◽  
Gloria I. Giraldo-Gómez ◽  
Nancy R. Sanabria-González

Clay minerals can be modified organically by a cationic surfactant resulting in materials known as organoclays. The organoclays have been used as adsorbents of most of the organic contaminants in the aqueous solution and oxyanions of the heavy metal. In this study, a Colombian bentonite was modified with hexadecyltrimethylammonium bromide to obtain an organobentonite, and its capacity to adsorb Cr(VI) oxyanions in the aqueous solution was evaluated. The effect of pH, stirring speed, adsorbent amount, contact time, and ionic strength were investigated at 25°C. Stirring speeds above 200 rpm, contact times greater than 120 min, and the addition of NaCl (0.1 to 2.0 mM) did not have a significant effect on Cr(VI) removal. The influence of the adsorbent amount and pH on Cr(VI) adsorption was studied by the response surface methodology (RSM) approach based on a complete factorial design 32. Results proved that the Cr(VI) adsorption follows a quadratic model with high values of coefficient of determination (R2 = 95.1% and adjusted R2 = 93.9%). The optimal conditions for removal of Cr(VI) from an aqueous solution of 50 mg/L were pH of 3.4 and 0.44 g amount of the adsorbent. The adsorption isotherm data were fitted to the Langmuir and Freundlich adsorption isotherm models, and the model parameters were evaluated. The maximum adsorption capacity of Cr(VI) onto organobentonite calculated from the Langmuir model equation was 10.04 ± 0.34 mg/g at 25°C. The results suggest that organobentonite is an effective adsorbent for Cr(VI) removal, with the advantage of being a low-cost material.


2008 ◽  
Vol 5 (3) ◽  
pp. 499-510 ◽  
Author(s):  
M. Venkata Subbaiah ◽  
S. Kalyani ◽  
G. Sankara Reddy ◽  
Veera M. Boddu ◽  
A. Krishnaiah

Removal of chromium(VI) from aqueous solution was studied using abundantly availabletrametes versicolor polyporusfungi as biosorbing medium under equilibrium and column flow conditions. Various sorption parameters such as contact time, effect of pH, concentration of Cr(VI) and amount of biomass on the adsorption capacity of the biosorbent were studied. The equilibrium adsorption data were fitted to Freundlich and Langmuir adsorption isotherm models and the model parameters are evaluated. In addition, the data were used to predict the kinetics of adsorption. The results indicated that the adsorption of Cr(VI) on fungi followed second order kinetics. The column flow adsorption data were used to predict break through curves. The fungi loaded with Cr(VI) was regenerated with 0.1 M NaOH solution and the regenerated biomass was used in the subsequent adsorptiondesorption cycles. The experimental results demonstrated that thetrametes versicolor polyporusfungi could be used as sorbent for immobilizing Cr(VI).


2011 ◽  
Vol 8 (s1) ◽  
pp. S377-S391 ◽  
Author(s):  
U. Gayathri ◽  
B. R. Venkatraman ◽  
S. Arivoli

The main purpose of this work was to exploit low cost and efficient sorbents for the removal of copper from aqueous solution usingCynodon dactyloncarbon. It was observed from the experimental results that almost 90-100% copper can be removed from the aqueous solution. Adsorption kinetics and equilibrium have been investigated as a function of initial copper ion concentration. pH, contact time and adsorbent dosage. Kinetics studies suggested that the adsorption allowed first order reaction. Equilibrium data were analyzed using Langmuir and Freundlich isotherm models. On the basis of experimental results and the model parameters, it can be concluded that the carbonaceousCynodon dactylonis effective for the removal of copper ion from aqueous solution.


2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Joshua N. Edokpayi ◽  
Samson O. Alayande ◽  
Ahmed Adetoro ◽  
John O. Odiyo

In this study, the potential for pulverized raw macadamia nut shell (MNS) for the sequestration of methylene blue from aqueous media was assessed. The sorbent was characterized using scanning electron microscopy for surface morphology, functional group analysis was performed with a Fourier-transform infrared spectrometer (FT-IR), and Brunauer–Emmett–Teller (BET) isotherm was used for surface area elucidation. The effects of contact time, sorbent dosage, particle size, pH, and change in a solution matrix were studied. Equilibrium data were fitted using Temkin, Langmuir, and Freundlich adsorption isotherm models. The sorption kinetics was studied using the Lagergren pseudo-first-order, pseudo-second-order, Elovich, and intraparticle diffusion models. The feasibility of the study was established from the thermodynamic studies. A surface area of 2.763 m2/g was obtained. The equilibrium and kinetics of sorption was best described by the Langmuir and the pseudo-second-order models, respectively. The sorption process was spontaneous (−ΔG0=28.72−31.77 kJ/mol) and endothermic in nature (ΔH0=17.45 kJ/mol). The positive value of ΔS0 (0.15 kJ/molK) implies increased randomness of the sorbate molecules at the surface of the sorbent. This study presents sustainable management of wastewater using MNS as a potential low-cost sorbent for dye decontamination from aqueous solution.


2009 ◽  
Vol 6 (3) ◽  
pp. 737-742 ◽  
Author(s):  
T. Santhi ◽  
S. Manonmani ◽  
S. Ravi

A new, low cost, locally available biomaterial was tested for its ability to remove cationic dyes from aqueous solution. A granule prepared from a mixture of leafs, fruits and twigs ofMuntingia calaburahad been utilized as a sorbent for uptake of three cationic dyes, methylene blue (MB), methylene red (MR) and malachite green (MG). The effects of various experimental parameters (e.g.,contact time, dye concentration, adsorbent dose and pH) were investigated and optimal experimental conditions were ascertained. Above the value of initial pH 6, three dyes studied could be removed effectively. The isothermal data fitted the Langmuir and Freundlich isotherm models for all three dyes sorption. The biosorption processes followed the pseudo-first order rate kinetics. The results in this study indicated thatMuntingia calaburawas an attractive candidate for removing cationic dyes from the dye wastewater.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
I. Osasona ◽  
O. O. Ajayi ◽  
A. O. Adebayo

The feasibility of using powdered cow hooves (CH) for removing Ni2+ from aqueous solution was investigated through batch studies. The study was conducted to determine the effect of pH, adsorbent dosage, contact time, adsorbent particle size, and temperature on the adsorption capacity of CH. Equilibrium studies were conducted using initial concentration of Ni2+ ranging from 15 to 100 mgL−1 at 208, 308, and 318 K, respectively. The results of our investigation at room temperature indicated that maximum adsorption of Ni2+ occurred at pH 7 and contact time of 20 minutes. The thermodynamics of the adsorption of Ni2+ onto CH showed that the process was spontaneous and endothermic. Langmuir, Freundlich, and Dubinin-Radushkevich (D-R) isotherm models were used to quantitatively analysed the equilibrium data. The equilibrium data were best fitted by Freundlich isotherm model, while the adsorption kinetics was well described by pseudo-second-order kinetic equation. The mean adsorption energy obtained from the D-R isotherm revealed that the adsorption process was dominated by physical adsorption. Powdered cow hooves could be utilized as a low-cost adsorbent at room temperature under the conditions of pH 7 and a contact time of 20 minutes for the removal of Ni(II) from aqueous solution.


2007 ◽  
Vol 124-126 ◽  
pp. 1781-1784 ◽  
Author(s):  
Yongju Jung ◽  
Jei Won Yeon ◽  
Ji Man Kim ◽  
Hyung Ik Lee ◽  
Seok Kim ◽  
...  

In this study, we modified the surface of nanoporous carbons with carboxymethylated polyethyleneimine (CM-PEI) of a high charge density in order to increase the Pt loading on the nanoporous carbons in an aqueous solution. We carried out equilibrium adsorption tests of Pt(IV) on the pure nanoporous carbon and the CM-PEI-coated carbons and evaluated the adsorption isotherm on the CM-PEI-coated carbon using various isotherm models. It was found that the adsorption of Pt(IV) onto the CM-PEI-coated carbons obeys the Langmuir isotherm model.


2008 ◽  
Vol 5 (1) ◽  
pp. 68 ◽  
Author(s):  
Patricia Miretzky ◽  
Carolina Muñoz ◽  
Alejandro Carrillo-Chávez

Environmental context. Fluoride concentrations in drinking water above 1.5 mg L–1 may be detrimental to human health. Many methods have been developed for removing excessive fluoride from drinking water. The use of an aquatic macrophyte biomass (Eleocharis acicularis) pretreated with Ca2+, a low-cost natural material, could be a technique for rural populations in developing countries that cannot afford treated or bottled water for daily consumption. Abstract. The use of an aquatic macrophyte biomass (Eleocharis acicularis) pretreated with Ca2+ as a low-cost natural material for the removal of fluoride from aqueous solution was studied. Batch experiments were carried out to determine fluoride sorption capacity and the efficiency of the sorption process under different pH, initial F– and macrophyte biomass doses. The experimental data showed good fitting to Langmuir and Freundlich isotherm models. The maximum F adsorption capacity was 0.110 mmol g–1 with an efficiency of 64.5% (pH 6.0; 5.0 g L–1 Ca-pretreated biomass). The binding of Ca2+ to the biomass increased the removal efficiency over 100%. The F– removal kinetics were rapid, less than 30 min, and best described by the pseudo-second order rate model. The rate constant, the initial sorption rate and the equilibrium sorption capacity were determined. These results may be useful for deprived rural population water supply schemes in Mexico and in other developing countries.


2014 ◽  
Vol 955-959 ◽  
pp. 2118-2122
Author(s):  
Kowit Suwannahong ◽  
Witsanusan Supa ◽  
Jutaluck Chaysuk ◽  
Torpong Kreetachat

Applying of low cost adsorbent for herbicide capturing is an important area of research in environmental field. The present work reports the adsorption potential of fly ash, a waste from power stations, for removal of herbicides namely paraquat and alachlor from aqueous solution. Batch experiment was employed to investigate the adsorption of herbicide in aqueous solution. The maximum capacity of the fly ash to adsorb paraquat and alachlor was found to be 2.02 and 1.70 mmole.g-1, respectively. The coefficient of adsorption on the basis of 3 models: Freundlich, Langmuir and Sips isotherm models were found. The results shown that the equilibrium data are better fitted by three-parameter models than two-parameter models. The experimental data agree to adsorption isotherms in the order of Sips > Langmuir > Freundlich isotherms.


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