Removal of Heavy Metals by Sawdust Adsorption: Equilibrium and Kinetic Studies

The decontamination of heavy metals present in aquatic bodies is a significant challenge that requires urgent attention. Analytical methods such as BET, XRF, SEM-EDX, and XRD was employed to characterize the raw clay (NT) and acid treated clay (AT). The adsorption of Cr (VI) and Fe (III) onto AT was performed using the batch method. The effects of time, adsorbent dose, temperature, and pH show that the optimal conditions are 50 min, 0.3 g, 35°C, and pH 6. The surface area of AT was 389.37 m2/g, and the adsorption equilibrium time of AT was 50 min. Langmuir isotherms had the best fit. Adsorption capacity is 18.15 and 39.80 mg/g for Cr (VI) and Fe (III) ions, respectively. An increase in area considerably improved the adsorption capacity of AT in the surface specific area. The interaction of Cr (VI) and Fe (III) ions onto AT indicated spontaneous and endothermic reaction. The chromium (VI) kinetic constant (k2 = 1.679) was faster compared to Fe (III) rate constant (k2 = 0.0526). It agreed correctly with the pseudo-second-order equation. The sum square error (SSE) value obtained confirmed the best-fit equations. The percent adsorbed for Cr (VI) and Fe (III) is 74 and 90%. The results revealed that iron has a higher affinity towards AT than chromium. The study revealed that AT could be suitable and effective in the adsorption of chromium and iron in the wastewater medium.

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The Removal of Heavy Metals from Aqueous Solution by Utilizing Modified β-Cyclodextrin Microspheres

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.113-116.632 ◽

2010 ◽

Vol 113-116 ◽

pp. 632-638

Author(s):

Feng Yu Li ◽

Xiao Mei Sun ◽

Bu Hai Li

Keyword(s):

Heavy Metals ◽

Correlation Coefficients ◽

Freundlich Isotherm ◽

Kinetic Studies ◽

Heavy Metal Concentration ◽

Second Order ◽

Batch Adsorption ◽

Order Kinetic ◽

Removal Of Heavy Metals ◽

Pseudo Second Order

Batch adsorption experiments were carried out to remove heavy metals Cu(II)and Ni(II) by pyromellitic dianhydride (PMDA) grafted β-Cyclodextrin (β-CD). The effects concerning the pH of the solution, contact time and initial heavy metal concentration were studied and discussed. The adsorption values increased significantly after a large number of carboxyl groups were gragfted on the microspheres surface. In order to investigate the mechanism of sorption, adsorption data were modeled using the pseudo-first-order and pseudo-second-order kinetic equation. It was found that kinetic studies showed good correlation coefficients for a pseudo-second-order kinetic model, confirming that the sorption rate was controlled by chemical adsorption. The equilibrium process was better described by the Langmuir isotherm than the Freundlich isotherm. XPS analysis further confirmed that the carboxyl group which grafted on the surface of the β-CD microspheres play a very important role in the removal of heavy metals.

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Kinetic studies of the removal of heavy metals from acid mine drainage by natural zeolite

International Journal of Mineral Processing ◽

10.1016/j.minpro.2011.07.004 ◽

2011 ◽

Vol 101 (1-4) ◽

pp. 42-49 ◽

Cited By ~ 47

Author(s):

T. Motsi ◽

N.A. Rowson ◽

M.J.H. Simmons

Keyword(s):

Heavy Metals ◽

Acid Mine Drainage ◽

Natural Zeolite ◽

Mine Drainage ◽

Kinetic Studies ◽

Acid Mine ◽

Removal Of Heavy Metals

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Removal of Heavy Metals from Aqueous Solutions Using Acrylic-modified Sugarcane Bagasse-based Adsorbents: Equilibrium and Kinetic Studies

BioResources ◽

10.15376/biores.9.2.3184-3196 ◽

2014 ◽

Vol 9 (2) ◽

Cited By ~ 12

Author(s):

Weiqing Kong ◽

Junli Ren ◽

Shuaiyang Wang ◽

Qifeng Chen

Keyword(s):

Heavy Metals ◽

Aqueous Solutions ◽

Sugarcane Bagasse ◽

Kinetic Studies ◽

Removal Of Heavy Metals

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Sorption of Heavy Metals with Sol-Gel Particles Containing Crude Metallothionein Extracts from Scchizosaccharomyces pombe

Water Quality Research Journal ◽

10.2166/wqrj.2007.015 ◽

2007 ◽

Vol 42 (2) ◽

pp. 123-129

Author(s):

Shirin Bahrami ◽

Amarjeet S. Bassi ◽

Ernest K Yanful

Keyword(s):

Heavy Metals ◽

Sol Gel ◽

Kinetic Studies ◽

Adsorption Kinetic ◽

Nacl Solution ◽

Protein Extract ◽

Removal Of Heavy Metals ◽

Immobilization Matrix ◽

Desorption Isotherms ◽

Zinc Adsorption

Abstract Crude metallothionein (MT) extracts from Scchizosaccharomyces pombe entrapped in sol-gels were investigated for the removal of heavy metals such as cadmium and zinc. The sol-gel provided a robust immobilization matrix for the protein extract. Adsorption and desorption isotherms were developed for both cadmium and zinc. Both metals were recovered from the sol-gel by desorption using a 1 M NaCl solution. The adsorption kinetic studies showed that cadmium and zinc adsorption followed the Langmuir isotherm. The distribution factors for cadmium and zinc were found to be 5.43 L/mg and 2.88 L/mg, respectively. Greater than 60% of Zn2+ was also removed using MT sol-gels. The experiments demonstrated that MT has a greater capacity for Cd than polyethyleneimine immobilized in the sol-gels. The adsorption capacity of MT was found to be 588.2 mg of cadmium and 434.8 mg of zinc per gram of immobilized MT, which is significantly higher than with nonbiological chelators such as polyethyleneimine or EDTA.

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