Comparative study on 2,4-dichlorophenoxyacetic acid and 2,4-dichlorophenol removal from aqueous solutions via ozonation, photocatalysis and non-thermal plasma using a planar falling film reactor

Kosar Hikmat Hama Aziz; Hans Miessner; Siegfried Mueller; Ali Mahyar; Dieter Kalass; Detlev Moeller; Ibrahim Khorshid; Muhammad Amin M Rashid

doi:10.1016/j.jhazmat.2017.09.025

Comparative study on 2,4-dichlorophenoxyacetic acid and 2,4-dichlorophenol removal from aqueous solutions via ozonation, photocatalysis and non-thermal plasma using a planar falling film reactor

J Hazard Mater. 2018 Feb 5:343:107-115. doi: 10.1016/j.jhazmat.2017.09.025. Epub 2017 Sep 18.

Authors

Kosar Hikmat Hama Aziz¹, Hans Miessner², Siegfried Mueller², Ali Mahyar², Dieter Kalass², Detlev Moeller², Ibrahim Khorshid³, Muhammad Amin M Rashid³

Affiliations

¹ Laboratory of Atmospheric Chemistry and Air Quality, Brandenburg University of Technology (BTU Cottbus-Senftenberg), D-12489 Berlin, Germany; Department of Chemistry, College of Science, University of Sulaimani, Qlyasan Street, Kurdistan Region, Iraq. Electronic address: kosar.hamaaziz@univsul.edu.iq.
² Laboratory of Atmospheric Chemistry and Air Quality, Brandenburg University of Technology (BTU Cottbus-Senftenberg), D-12489 Berlin, Germany.
³ Department of Chemistry, College of Science, University of Sulaimani, Qlyasan Street, Kurdistan Region, Iraq.

PMID: 28942183
DOI: 10.1016/j.jhazmat.2017.09.025

Abstract

Ozonation and advanced oxidation processes based on photocatalysis (P.C.) and non-thermal plasma generated in a dielectric barrier discharge (DBD) in different gas atmospheres were compared for the degradation and mineralization of 2,4-dichlorophenoxy acetic acid (2,4-D) and 2,4-dichlorophenol (2,4-DCP) in aqueous solutions, using a planar falling film reactor with comparable design. The energetic yields (G₅₀) as measure of the efficiencies of the different methods are for 2,4-D in the order DBD/Ar-Fenton>ozonation>DBD/Ar>P.C.ozonation>DBD/Ar:O₂≫DBD/Air>P.C.oxidation. For 2,4-DCP the order is ozonation≫DBD/Ar-Fenton>P.C.ozonation>DBD/Ar>DBD/Ar:O₂≫P.C.oxidation>DBD/Air. The degradation by using ozone is very effective, but it should be noted that the mineralization measured by the total organic carbon (TOC) removal is low. The reason is the formation of stable towards ozone intermediates, especially low chain carboxylic acids. The fate of these intermediates during the degradation with the different methods has been followed and discussed.

Keywords: Advanced oxidation process; Dielectric barrier discharge; Energy yield; Falling film reactor; Mineralization.