Related Experiment Video
Updated: Jul 6, 2026

Sulfate Separation by Selective Crystallization with a Bis-iminoguanidinium Ligand
Published on: September 8, 2016
Fe(III) promoted LAS (linear alkylbenzenesulfonate) removal from waters
Nadra Debbache1, Kamel Djebbar, Bernadette Lavédrine
1Laboratoire de Photochimie Moléculaire et Macromoléculaire, UMR Université Blaise Pascal, CNRS 6505, F-63177 Aubière Cedex, France.
Abstract:
The mechanisms of the interactions between Fe(III) aquacomplexes and surfactants were investigated; three alkylbenzenzsulfonates, two surfactants (octylbenzenesulfonate (OBS) and dodecylbenzenesulfonate (DBS)), and a shorter derivative (ethylbenzenesulfonate (EBS)) were studied. The results with OBS show evidence for three different ways in which Fe(III) interferes with the surfactant: the widely described flocculation process, complexation of Fe(OH)2+ (aquacomplexes) by the surfactant, and a redox reaction. The formation of a weak complex is maximum for a ratio of three between the monomeric aquacomplex [FeOH(H2O)5]2+ and OBS. In the presence of oxygen, an intramolecular redox reaction occurs inside the complex. The interaction between commercial DBS and Fe(III) was also investigated. Immediate precipitation occurred, mainly involving derivatives of higher molecular weights that are contained in the DBS samples. The constituents with the shortest alkyl chain were not affected by the presence of Fe(III) as it was also observed with EBS.
Related Concept Videos
Electrophilic Aromatic Substitution: Sulfonation of Benzene
Radical Substitution: Hydrogenolysis of Alkyl Halides with Tributyltin Hydride
The bonds formed in this reaction are stronger than the bonds broken, making it energetically favorable. The reaction follows a radical chain mechanism similar to radical halogenation reactions,...
Ion Exchange
Hydroboration-Oxidation of Alkenes
Extraction: Advanced Methods
Precipitation and Co-precipitation

