Using Modified Fly Ash for Removal of Heavy Metal Ions from Aqueous Solution

This paper presents the characteristics of fly ash which was modified by 2-mercaptobenzothiazole (MBT) and sodium dodecyl sulfate (SDS) as the surfactants after treating with 1M NaOH solution. The change in morphology, specific surface area, crystal structure, and composition of the unmodified and modified fly ash was evaluated by FTIR, XRD, FESEM, BET, and EDX methods and techniques. The FTIR spectra of modified fly ash showed that there was no chemical reaction between the surfactants and fly ash. The XRD patterns and FESEM images indicated that modified fly ash had zeolite structure with a pore size of about 50 nm. Heavy metal ion adsorption behavior as well as adsorption isotherm models (Langmuir and Freundlich) of Cd2+ and Hg2+ ions of the unmodified and modified fly ash were also investigated and discussed. The amount of adsorbed ions of the modified fly ash was higher than that of the unmodified fly ash. The calculated results from the adsorption data according to the adsorption isotherm models of the above ions displayed that the Langmuir isotherm model was complied for the Cd2+ adsorption process while the Freundlich isotherm model was fitted for the Hg2+ adsorption process.

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The Water Adsorption Isotherm Models on Activated Alumina

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.229-231.100 ◽

2012 ◽

Vol 229-231 ◽

pp. 100-104 ◽

Cited By ~ 1

Author(s):

Yun Fei Shi ◽

Xiang Jun Liu ◽

Hui Jiao Nie ◽

Yin Shu Liu

Keyword(s):

Experimental Data ◽

Water Vapor ◽

Adsorption Isotherm ◽

Water Adsorption ◽

Isotherm Model ◽

Isotherm Models ◽

Activated Alumina ◽

Adsorption Isotherm Models ◽

Adsorption Data

The adsorption isotherm model of water vapor on activated alumina is an essential equation in designing the performance of adsorption. In this paper, the currently existed 14 isotherm models of water adsorption are summarized. The correlations among these models are analyzed. These isotherm models are evaluated by fitting the water adsorption data on Rhone-Poulenc activated alumina. The results show that AD-Toth, AD-LRC, AD-UNILAN and DMAP can fit the experimental data well.

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Determination of Adsorption Isotherm Models for the Biosorption of Chromium Using Cherry Leaves (Muntingia calabura L.)

International Letters of Natural Sciences ◽

10.18052/www.scipress.com/ilns.25.12 ◽

2014 ◽

Vol 25 ◽

pp. 12-17

Author(s):

R. Aathithya ◽

J. Rajani Sowparnika ◽

V. Balakrishnan

Keyword(s):

Heavy Metal ◽

Adsorption Isotherm ◽

Freundlich Isotherm ◽

Isotherm Models ◽

Major Threat ◽

Chromium Vi ◽

Adsorption Affinity ◽

Adsorption Isotherm Models ◽

Muntingia Calabura

Contaminations of industrial metals into the river possess major threat to environment. Chromium is a heavy metal which has the wide applications in tannery and electroplating industries. Above the permitted level of Chromium(VI) into surface water leads to severe health hazards. Therefore, biosorption is a technology used for the sorption of heavy metal. In this present study adsorption isotherm models was studied for the biosorption of chromium by cherry leaves. From the adsorption isotherms it was found that the experimental data fits well with the Langmuir isotherm than the Freundlich isotherm. The monolayer capacity Qm was fond to be 11.98 mg/l and the adsorption affinity was found to be positive which indicates the efficient biosorption of chromium

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Competitive adsorption of organic solvents using modified and unmodified calcium bentonite clay mineral

10.31221/osf.io/w9dj6 ◽

2019 ◽

Author(s):

Chem Int

Keyword(s):

Adsorption Isotherm ◽

Adsorption Capacity ◽

Organic Solvents ◽

Competitive Adsorption ◽

Correlation Factor ◽

Isotherm Model ◽

Isotherm Models ◽

High Concentration ◽

Dual Purpose ◽

Calcium Bentonite

Dodecyltrimethylammonium bromide (DTAB)–modified and unmodified calcium bentonite were both used for the competitive adsorption of aromatics (xylene, ethylbenzene and toluene) and petroleum products (gasoline, dual purpose kerosene and diesel) from their aqueous solution. Infrared spectroscopy (IR) and expansion tests (adsorption capacity and Foster swelling) measurement were performed in order to evaluate the performance of the adsorbents. The Foster swelling index and adsorption capacity of the DTAB modified calcium bentonite in the organic solvents follow the trend: xylene > ethylbenzene > toluene > gasoline > dual purpose kerosene (DPK) > diesel > water. However, the adsorption capacity of the adsorbent in diesel outweighed the adsorption capacity in DPK at high concentration of DTAB indicating that diesel has higher affinity for high DTAB concentration than DPK. The percentage removal of the solvent is directly proportional to the concentration of DTAB used in modifying the bentonite as well as the contact time between the adsorbent and the solvent, hence modified calcium bentonite adsorbed a higher percentage of organic solvents than the unmodified calcium bentonite. The adsorption characteristics of both adsorbents improved remarkably after proper agitation of the organic solvents, the unmodified calcium bentonite however adsorbed more water than the modified bentonite. Data obtained from adsorption isotherm models confirms that Freundlich adsorption isotherm model was favored more than Langmuir adsorption isotherm model with the correlation factor (R2) of the former tending more towards unity. The adsorption of ethylbenzene using DTAB modified and unmodified calcium bentonites follow a pseudo second order kinetics mechanism, suggesting that the rate determining step of adsorption involves both the adsorbent and the organic solvent.

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A systematic study for removal of heavy metals from aqueous media using Sorghum bicolor: an efficient biosorbent

Water Science & Technology ◽

10.2166/wst.2018.190 ◽

2018 ◽

Vol 77 (10) ◽

pp. 2355-2368 ◽

Cited By ~ 5

Author(s):

Khalida Naseem ◽

Zahoor H. Farooqi ◽

Muhammad Z. Ur Rehman ◽

Muhammad A. Ur Rehman ◽

Robina Begum ◽

...

Keyword(s):

Heavy Metals ◽

Heavy Metal ◽

Metal Ions ◽

Heavy Metal Ions ◽

Aqueous Media ◽

Review Article ◽

Isotherm Models ◽

Adsorption Efficiency ◽

Adsorption Isotherm Models ◽

Removal Of Heavy Metals

Abstract This review is based on the adsorption characteristics of sorghum (Sorghum bicolor) for removal of heavy metals from aqueous media. Different parameters like pH, temperature of the medium, sorghum concentration, sorghum particle size, contact time, stirring speed and heavy metal concentration control the adsorption efficiency of sorghum biomass for heavy metal ions. Sorghum biomass showed maximum efficiency for removal of heavy metal ions in the pH range of 5 to 6. It is an agricultural waste and is regarded as the cheapest biosorbent, having high adsorption capacity for heavy metals as compared to other reported adsorbents, for the treatment of heavy metal polluted wastewater. Adsorption of heavy metal ions onto sorghum biomass follows pseudo second order kinetics. Best fitted adsorption isotherm models for removal of heavy metal ions on sorghum biomass are Langmuir and Freundlich adsorption isotherm models. Thermodynamic aspects of heavy metal ions adsorption onto sorghum biomass have also been elaborated in this review article. How adsorption efficiency of sorghum biomass can be improved by different physical and chemical treatments in future has also been elaborated. This review article will be highly useful for researchers working in the field of water treatment via biosorption processing. The quantitative demonstrated efficiency of sorghum biomass for various heavy metal ions has also been highlighted in different sections of this review article.

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