- Research article
- Open Access
Removal of crystal violet from water by magnetically modified activated carbon and nanomagnetic iron oxide
© Hamidzadeh et al.; licensee BioMed Central. 2015
- Received: 9 July 2014
- Accepted: 6 January 2015
- Published: 31 January 2015
Magnetically modified activated carbon, which synthesized by nanomagnetic iron oxide, was used for fast and effective removal of Crystal Violet from aqueous solutions. The scanning electron microscopy (SEM) images of nano-adsorbent showed that the average sizes of adsorbent are less than 100 nm. The various parameters, affecting on adsorption process, were examined including pH and temperature of dye solution, dose of adsorbent, and contact time. Then, thermodynamic parameters of sorption were calculated. Langmuir and Freundlich isotherms were used to fit the resulting data. Adsorption kinetics was consistent with a pseudo second order equation. Thermodynamic parameters of adsorption, ∆H0, and ∆S0 were calculated. Also, for further investigations, nano magnetic iron oxides was synthesized and used as adsorbent. Sorption capacities were depending on the temperature varied from 44.7 to 67.1 mg/g and from 12.7 to 16.5 mg/g for magnetically modified activated carbon and nanomagnetic iron oxide, respectively.
- Magnetically modified activated carbon
- Crystal Violet
- Langmuir isotherm
- Freundlich isotherm
- Nano magnetic iron oxide
Large amounts of dyes are produced and applied in various industries. Small amounts of dyes (less than 1 ppm for some dyes) are visible in water [1,2]. As the most of the dyes in wastewater are stable to light and oxidation and also resistant to aerobic digestion, they damage to the aquatic life .
Crystal Violet (CV) is a synthetic basic cationic dye used for various purposes including biological stain, dermatological agent, veterinary medicine, additive to poultry feed to inhibit propagation of mold, intestinal parasites, and textile dyeing industries etc. [4,5]. It is a mutagen, mitotic poison, and also proven potent carcinogen [6,7].
Various processes were developed for the dye removal from the wastewater including adsorption and biosorption [8-10], chemical and electrochemical oxidation [11-13], membrane separation process , photodegradation , etc.
Magnetic separation techniques have found important applications in environmental technology. In adsorption processes, the magnetic adsorbent can be easily separated from solution after adsorption process . The magnetizations of adsorbents such as peanut husks , sawdust , baker's yeast cells , activated coconut shell carbon  etc. were investigated for removal dyes and other concomitances. Since Activated carbon is one of most useful adsorbent for removal of dye, in this study, it was modified by nanomagnetic iron oxide for fast and effective removal of Crystal Violet. The SEM images indicated the sizes of adsorbent particles are in nano scales. Adsorbent efficiency in removal Crystal Violet was studied. The affecting parameters on adsorption process were examined. The thermodynamic and kinetic adsorption parameters of Crystal violet onto magnetically modified activated carbon were obtained while; they have not been reported in previous studies. In order to comparative studies, nanomagnetic iron oxide (that used for magnetization of activated carbon) were synthesized and used as adsorbent.
Activated charcoal was purchased from BDH Ltd Poole England. Crystal Violet dye was from Merck Darmstadt Germany. All other chemicals used in this study were of high purity and used without further purification. Double distilled water was used for all experiments.
Batch adsorption experiments with 10 ml of Crystal Violet solution (5 mg/l) were done for 1–10 mg of adsorbent, 1 to 10 min contact times, 3–9 pHs, and at 20, 30 and 40°C.
pHs of solutions were adjusted by expected values of nitric acid and sodium hydroxide solutions. Analysis of dye concentration was carried out by UV–vis spectrophotometer in 593 nm wavelength.
Where qe is adsorption capacity (mg of adsorbed dye per g of adsorbent), Ce is equilibrium concentration of dye (mg/l), v is the volume of the solution (l) and w is the mass of adsorbent (g).
Where k2 is the second order reaction rate equilibrium constant (g mg−1 min−1).
The adsorbent dosage
The contact time
pH of Crystal Violet solution
Temperature of dye solution
Dye removal was examined at different temperatures range started from 27°C (as ambient temperature) to 70°C. 10 ml of dye solution 5 mg/l was contacted to 0.01 g of magnetically modified activated carbon for 5 min at pH 5 at 27, 40, 50, 60, and 70°C.
The thermodynamic parameters of adsorption of Crystal Violet on magnetically modified activated carbon
∆G 0 (kJ/mol)
∆S 0 (kJ/mol.K)
∆H 0 (kJ/mol)
The rate constants and linear regressions of First order and Second order for adsorption of Crystal Violet on magnetically modified activated carbon and nanomagnetic iron oxide
k 1 (min −1 )
k 2 (g mg −1 min −1 )
Magnetically modified activated carbon
Nanomagnetic iron oxide
1.38 × 10−2
In order to perform further investigation, nanomagnetic iron oxide was synthesized as similar as described in experimental section, without any addition of activated carbon. In the same conditions, nanomagnetic iron oxide was used as adsorbent. The kinetic results shown in Table 2 indicated that, the kinetic of adsorption was the same as magnetically modified activated carbon with lower rate constant (k2).
The parameters of Langmuir and Freundlich isotherms at different temperatures for adsorption of Crystal Violet on magnetically modified activated carbon and nanomagnetic iron oxide
Magnetically modified activated carbon
Nanomagnetic iron oxide
In the same conditions, the experiments were performed by nanomagnetic iron oxide as the adsorbent. The obtained results listed in Table 3 show that, Langmuir and Freundlich did not well describe the adsorption isotherm model. The values of qmax increased by increasing the temperature and also were less than those for magnetically modified activated carbon.
The previous studies on magnetic adsorbents to removal Crystal Violet
10 mg cm−3
Magnetically labeled Baker's yeast cells
85.9 mg g−1
magnetically modified Saccharomyces cerevisiae subsp. uvarum cells
41.7 mg g−1
Ferrofluid modified sawdust
51.16 mg g−1
magnetically modified Chlorella Vulgaris cells
42.91 mg g−1
Magnetic fluid modified peanut husks
80.9 mg g−1
Magnetically modified spent grain
40.2 mg g−1
Magnetic carbon-iron oxide nanocomposite
81.70 mg g−1
Magnetically modified spent coffee grounds
68.1 mg g−1
Magnetically modified activated car bon
67.1 mg g−1
Nanomagnetic iron oxide
16.5 mg g−1
The results indicate that magnetically modified activated carbon have considerable potential for the removal of Crystal Violet, also the magnetic adsorbent can be simply removed from solution by using magnet or appropriate magnetic separator after adsorption process. The obtained results of this investigation implicate that this adsorbent was more able to remove dye in the less time with compared to some of studies listed in Table 4. Also we investigated Thermodynamic and kinetic studies for removal process more than other pervious works.
The resulting adsorption capacities demonstrate that, although nanomagnetic iron oxide can be as an adsorbent, but its efficiency is much lower than magnetically modified activated carbon.
The authors thank the staffs of Payam Noor University of Varamin, specially Mrs. Rezaiee and Mrs. Haj Husseini.
- Banat IM, Nigam P, Singh D, Marchant R. Microbial decolorisation of textile dye containing effluents: a review. Bioresour Technol. 1996;58:217–27.View ArticleGoogle Scholar
- Robinson T, McMullan G, Marchant R, Nigam P. Remediation of dyes in textile effluents: a critical review on current treatment technology with a proposed alternative. Bioresour Technol. 2001;77:247–55.View ArticleGoogle Scholar
- Lee CK, Low KS, Gan PY. Removal of some organic dyes by acid treat spent bleaching earth. Environ Technol. 1999;20:99–104.View ArticleGoogle Scholar
- Hao OJ, Kim H, Chiang PC. Decolorization of wastewater. Environ Sci Technol. 2000;30:449–505.View ArticleGoogle Scholar
- Eiichi I, Ogawa T, Yatome TC, Horisu H. Behavior of activated sludge with dyes. Bull Environ Contam Toxicol. 1985;35:729–34.View ArticleGoogle Scholar
- He H, Yang S, Yu K, Ju Y, Sun C, Wang L. Microwave assisted induced catalytic degradation of crystal violet in nano-nickel dioxide suspensions. J Hazard Mater. 2010;173:393–400.View ArticleGoogle Scholar
- Senthilkumaar S, Kalaamani P, Subburaam CV. Liquid phase adsorption of crystal violet on to activated carbons derived from male flowers of coconut tree. J Hazard Mater. 2006;136:800–8.View ArticleGoogle Scholar
- Garg VK, Gupta R, Yadav AB, Kumar R. Dye removal from aqueous solution by adsorption on treated sawdust. Bioresour Technol. 2003;89:121–4.View ArticleGoogle Scholar
- Mohamed MM. Acid Dye removal: comparison of surfactant modified mesoporous FSM-16 with activated carbon derived from rice husk. J Colloid Interface Sci. 2004;272:28–34.View ArticleGoogle Scholar
- Safarik I, Rego LFT, Mosiniewicz-Szablewska MBE, Weyda F, Safarikova M. New magnetically responsive yeast-based biosorbent for the efficient removal of water-soluble dyes. Enzyme Microb Technol. 2007;40:1551–6.View ArticleGoogle Scholar
- Salem IA. Activation of H2O2 by Amberlyst-15 resin supported with copper(II)-complexes towards oxidation of crystal violet. Chemosphere. 2001;44:1109–19.View ArticleGoogle Scholar
- Baban A, Yediler A, Lienert D, Kemerdere N, Kettrup A. Ozonation of high strength segregated effluents from a woollen textile dyeing and finishing plant. Dyes Pigments. 2003;58:93–8.View ArticleGoogle Scholar
- Vlyssides AG, Loizidou M, Karlis PK, Zorpas AA, Papaioannou D. Electrochemical oxidation of a textile dye wastewater using a Pt/Ti electrode. J Hazard Mater. 1999;B70:41–52.View ArticleGoogle Scholar
- Koyuncu I. Reactive dye removal in dye/salt mixtures by nanofiltration membranes containing vinylsulphone dyes: effects of feed concentration and cross flow velocity. Desalination. 2002;143:243–53.View ArticleGoogle Scholar
- Chen J, Liu M, Zhang J, Ying X, Jin L. Photocatalytic degradation of organic wastes by electrochemically assisted TiO2 photocatalytic system. J Environ Manage. 2004;70:43–7.View ArticleGoogle Scholar
- Safarikova M, Safarik I. The application of magnetic techniques in biosciences. Magn Electr Sep. 2001;10:223–52.View ArticleGoogle Scholar
- Safarik I, Safarikova M. Magnetic fluid modified peanut husks as an adsorbent for organic dyes removal. Physics Procedia. 2010;9:274–8.View ArticleGoogle Scholar
- Safarik I, Lunackova P, Mosiniewicz-Szablewska E, Weyda F, Safarikova M. Adsorption of water-soluble organic dyes on ferrofluidmodified sawdust. Holzforschung. 2007;61:247–53.View ArticleGoogle Scholar
- Safarik I, Ptackova L, Safarikova M. Adsorption of dyes on magnetically labeled baker's yeast cells. Eur Cells and Mater. 2002;3:52–5.Google Scholar
- Singh KP, Gupta S, Singh AK, Sinha S. Optimizing adsorption of crystal violet dye from water by magnetic nanocomposite using response surface modeling approach. J Hazard Mater. 2011;186:1462–73.View ArticleGoogle Scholar
- Safarik I, Nymburska K, Safarikova M. Adsorption of water-soluble organic dyes on magnetic Charcoal. J Chem Tech Biotechnol. 1997;69:1–4.View ArticleGoogle Scholar
- Ahmad R. Studies on adsorption of crystal violet dye from aqueous solution onto coniferous pinus bark powder (CPBP). J Hazard Mater. 2009;171:767–73.View ArticleGoogle Scholar
- Porkodi K, Vasanth Kumar K. Equilibrium, kinetics and mechanism modeling and simulation of basic and acid dyes sorption onto jute fiber carbon: Eosin yellow, malachite green and crystal violet single component systems. J Hazard Mater. 2007;143:311–27.View ArticleGoogle Scholar
- Safarikova M, Ptackova L, Kibrikova I, Safarik I. Biosorption of water-soluble dyes on magnetically modified Saccharomyces cerevisiae subsp. uvarum cells. Chemosphere. 2005;59:831–5.View ArticleGoogle Scholar
- Safarikova M, Rainha Pona BM, Mosiniewicz-Szablewska E, Weyda F, Safarik I. Dye adsorption on magnetically modified Chlorella Vulgaris cells. Fresen Environ Bull. 2008;17:486–92.Google Scholar
- Safarik I, Horska K, Safarikova M. Magnetically modified spent grain for dye removal. J Cereal Sci. 2011;53:78–80.View ArticleGoogle Scholar
- Safarik I, Horska K, Svobodova B, Safarikova M. Magnetically modified spent coffee grounds for dyes removal. Eur Food Res Technol. 2012;234:345–50.View ArticleGoogle Scholar
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