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ORIGINAL RESEARCH article

Front. Chem.
Sec. Photocatalysis and Photochemistry
Volume 12 - 2024 | doi: 10.3389/fchem.2024.1467438
This article is part of the Research Topic Emerging Trends in Advanced Oxidation Processes for Water Treatment View all articles

Degradation of Malachite Green by UV/H 2 O 2 and UV/H 2 O 2 /Fe 2+ Processes: Kinetics and Mechanism

Provisionally accepted
Sumaira Wilayat Sumaira Wilayat 1Perveen Fazil Perveen Fazil 2Javed A. Khan Javed A. Khan 1*Amir Zada Amir Zada 1Muhammad Ishaq ALi Shah Muhammad Ishaq ALi Shah 1Abdulaziz Al-Anazi Abdulaziz Al-Anazi 3Noor S. Shah Noor S. Shah 4Changseok Han Changseok Han 5Muhammad Ateeq Muhammad Ateeq 1
  • 1 Abdul Wali Khan University Mardan, Mardan, Khyber Pakhtunkhwa, Pakistan
  • 2 University of Karachi, Karachi, Sindh, Pakistan
  • 3 King Saud University, Riyadh, Riyadh, Saudi Arabia
  • 4 COMSATS University, Islamabad Campus, Islamabad, Islamabad, Pakistan
  • 5 Inha University, Incheon, Republic of Korea

The final, formatted version of the article will be published soon.

    This work investigated the photochemical degradation of malachite green (MG), a cationic triphenylmethane dye used as a coloring agent, fungicide and antiseptic. The UV photolysis was ineffective in the removal of MG as only 12.35% degradation of MG (10 mg/L) was achieved after 60 min of irradiation. In contrast, 100.00% degradation of MG (10 mg/L) was observed after 60 min of treatment in the presence of 10 mM H2O2 by UV/H2O2 at pH 6.0. Similarly, complete removal (100.00%) of MG was found at 30 min of reaction time by UV/H2O2/Fe 2+ employing[MG]0 = 10 mg/L, [H2O2]0 = 10 mM, [Fe 2+ ]0 = 2.5 mg/L, and [pH]0 = 3.0. For the UV/H2O2 process, the degradation efficiency was higher at pH 6.0 compared to pH 3.0, as the kobs value was calculated to be 0.0873 and 0.0690 min -1 at pH 6.0 and 3.0, respectively. However, UV/H2O2/Fe 2+ showed higher reactivity at pH 3.0 than at pH 6.0. Chloride and nitrate ions slightly inhibited the removal efficiency of MG by both UV/H2O2 and UV/H2O2/Fe 2+ processes. Moreover, three degradation products (DPs) of MG, (i) 4-dimethylamino-benzophenone (DABP), (ii) 4-aminobenzophenone (ABP), and (iii) 4-dimethylamino-phenol (DAP), were identified by GC-MS during UV/H2O2 treatment. These DPs were found to have higher aquatic toxicity than the parent MG suggesting that researchers should focus on the removal of target pollutants as well as their DPs.Nevertheless, the results of this study indicate that both UV/H2O2 and UV/H2O2/Fe 2+ processes could be implemented to alleviate the harmful environmental impacts of dye and textile industries.

    Keywords: Malachite green, UV light, Hydrogen Peroxide, Photo-Fenton, Degradation mechanism, wastewater treatment

    Received: 19 Jul 2024; Accepted: 23 Sep 2024.

    Copyright: © 2024 Wilayat, Fazil, Khan, Zada, Shah, Al-Anazi, Shah, Han and Ateeq. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence: Javed A. Khan, Abdul Wali Khan University Mardan, Mardan, 23200, Khyber Pakhtunkhwa, Pakistan

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