Abstract

The present study investigated the adsorption behaviour of Direct Orange 34, a highly toxic dye used in textile industries in Tunisia, on modified kaolinite-rich clays. A kaolin from the Sidi Bader (SDB) area was activated with hydrochloric acid to create the activated clay referred to hearafter as SDBa, or treated with FeSO4•7H2O to obtain its Fe-saturated form, Fe-SDB. The adsorbents were characterized by X-ray diffraction, X-ray fluorescence, transmission electron microscopy, BET surface area and zeta-potential measurements. The equilibrium adsorption data were analysed using the Langmuir and Freundlich isotherms. The estimated adsorption capacities (qm) for the dye were improved in the Fe-loaded samples. The good fit (R2 = 0.99) with a pseudo-second order expression suggests that the adsorption process could be effective following a chemisorption mechanism. At acidic pH, the optimum dye-retention rate was achieved for SDB (83%) after 60 min. The uptake decreased at neutral pH and increased again in alkaline media. This behaviour might be explained by the formation of covalent bonds between the OH radicals on the external surface and the negatively charged dye molecules. On the other hand, Fe impregnation increased the zeta potential of kaolinite, leading to a greater adsorption capacity compared to its natural and acid-activated counterparts. In addition, the adsorption rate increased when increasing the suspension temperature from 283 to 313 K. The modified kaolinite-rich materials showed satisfactory affinity for adsorbing this reactive dye.

Original languageEnglish
Pages (from-to)271-287
Number of pages17
JournalClay Minerals
Volume53
Issue number2
DOIs
Publication statusPublished - 1 Jan 2018

Fingerprint

Kaolin
kaolin
fixation
dye
Coloring Agents
adsorption
Adsorption
kaolinite
Zeta potential
clay
Covalent bonds
Hydrochloric Acid
Poisons
textile industry
Textile industry
hydrochloric acid
Chemisorption
X-ray fluorescence
Impregnation
Adsorbents

Keywords

  • adsorption
  • Direct Orange 34
  • kaolinite
  • modified clays
  • Tunisia

Cite this

Chargui, H. ; Hajjaji, W. ; Wouters, J. ; Yans, J. ; Jamoussi, F. / Direct Orange 34 dye fixation by modified kaolin. In: Clay Minerals. 2018 ; Vol. 53, No. 2. pp. 271-287.
@article{b8a0b65c441a4549b84387e80ab0f1d1,
title = "Direct Orange 34 dye fixation by modified kaolin",
abstract = "The present study investigated the adsorption behaviour of Direct Orange 34, a highly toxic dye used in textile industries in Tunisia, on modified kaolinite-rich clays. A kaolin from the Sidi Bader (SDB) area was activated with hydrochloric acid to create the activated clay referred to hearafter as SDBa, or treated with FeSO4•7H2O to obtain its Fe-saturated form, Fe-SDB. The adsorbents were characterized by X-ray diffraction, X-ray fluorescence, transmission electron microscopy, BET surface area and zeta-potential measurements. The equilibrium adsorption data were analysed using the Langmuir and Freundlich isotherms. The estimated adsorption capacities (qm) for the dye were improved in the Fe-loaded samples. The good fit (R2 = 0.99) with a pseudo-second order expression suggests that the adsorption process could be effective following a chemisorption mechanism. At acidic pH, the optimum dye-retention rate was achieved for SDB (83{\%}) after 60 min. The uptake decreased at neutral pH and increased again in alkaline media. This behaviour might be explained by the formation of covalent bonds between the OH radicals on the external surface and the negatively charged dye molecules. On the other hand, Fe impregnation increased the zeta potential of kaolinite, leading to a greater adsorption capacity compared to its natural and acid-activated counterparts. In addition, the adsorption rate increased when increasing the suspension temperature from 283 to 313 K. The modified kaolinite-rich materials showed satisfactory affinity for adsorbing this reactive dye.",
keywords = "adsorption, Direct Orange 34, kaolinite, modified clays, Tunisia",
author = "H. Chargui and W. Hajjaji and J. Wouters and J. Yans and F. Jamoussi",
year = "2018",
month = "1",
day = "1",
doi = "10.1180/clm.2018.18",
language = "English",
volume = "53",
pages = "271--287",
journal = "Clay Minerals",
issn = "0009-8558",
publisher = "Mineralogical Society",
number = "2",

}

Chargui, H, Hajjaji, W, Wouters, J, Yans, J & Jamoussi, F 2018, 'Direct Orange 34 dye fixation by modified kaolin', Clay Minerals, vol. 53, no. 2, pp. 271-287. https://doi.org/10.1180/clm.2018.18

Direct Orange 34 dye fixation by modified kaolin. / Chargui, H.; Hajjaji, W.; Wouters, J.; Yans, J.; Jamoussi, F.

In: Clay Minerals, Vol. 53, No. 2, 01.01.2018, p. 271-287.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Direct Orange 34 dye fixation by modified kaolin

AU - Chargui, H.

AU - Hajjaji, W.

AU - Wouters, J.

AU - Yans, J.

AU - Jamoussi, F.

PY - 2018/1/1

Y1 - 2018/1/1

N2 - The present study investigated the adsorption behaviour of Direct Orange 34, a highly toxic dye used in textile industries in Tunisia, on modified kaolinite-rich clays. A kaolin from the Sidi Bader (SDB) area was activated with hydrochloric acid to create the activated clay referred to hearafter as SDBa, or treated with FeSO4•7H2O to obtain its Fe-saturated form, Fe-SDB. The adsorbents were characterized by X-ray diffraction, X-ray fluorescence, transmission electron microscopy, BET surface area and zeta-potential measurements. The equilibrium adsorption data were analysed using the Langmuir and Freundlich isotherms. The estimated adsorption capacities (qm) for the dye were improved in the Fe-loaded samples. The good fit (R2 = 0.99) with a pseudo-second order expression suggests that the adsorption process could be effective following a chemisorption mechanism. At acidic pH, the optimum dye-retention rate was achieved for SDB (83%) after 60 min. The uptake decreased at neutral pH and increased again in alkaline media. This behaviour might be explained by the formation of covalent bonds between the OH radicals on the external surface and the negatively charged dye molecules. On the other hand, Fe impregnation increased the zeta potential of kaolinite, leading to a greater adsorption capacity compared to its natural and acid-activated counterparts. In addition, the adsorption rate increased when increasing the suspension temperature from 283 to 313 K. The modified kaolinite-rich materials showed satisfactory affinity for adsorbing this reactive dye.

AB - The present study investigated the adsorption behaviour of Direct Orange 34, a highly toxic dye used in textile industries in Tunisia, on modified kaolinite-rich clays. A kaolin from the Sidi Bader (SDB) area was activated with hydrochloric acid to create the activated clay referred to hearafter as SDBa, or treated with FeSO4•7H2O to obtain its Fe-saturated form, Fe-SDB. The adsorbents were characterized by X-ray diffraction, X-ray fluorescence, transmission electron microscopy, BET surface area and zeta-potential measurements. The equilibrium adsorption data were analysed using the Langmuir and Freundlich isotherms. The estimated adsorption capacities (qm) for the dye were improved in the Fe-loaded samples. The good fit (R2 = 0.99) with a pseudo-second order expression suggests that the adsorption process could be effective following a chemisorption mechanism. At acidic pH, the optimum dye-retention rate was achieved for SDB (83%) after 60 min. The uptake decreased at neutral pH and increased again in alkaline media. This behaviour might be explained by the formation of covalent bonds between the OH radicals on the external surface and the negatively charged dye molecules. On the other hand, Fe impregnation increased the zeta potential of kaolinite, leading to a greater adsorption capacity compared to its natural and acid-activated counterparts. In addition, the adsorption rate increased when increasing the suspension temperature from 283 to 313 K. The modified kaolinite-rich materials showed satisfactory affinity for adsorbing this reactive dye.

KW - adsorption

KW - Direct Orange 34

KW - kaolinite

KW - modified clays

KW - Tunisia

UR - http://www.scopus.com/inward/record.url?scp=85060107599&partnerID=8YFLogxK

U2 - 10.1180/clm.2018.18

DO - 10.1180/clm.2018.18

M3 - Article

AN - SCOPUS:85060107599

VL - 53

SP - 271

EP - 287

JO - Clay Minerals

JF - Clay Minerals

SN - 0009-8558

IS - 2

ER -