Fe ²⁺ –Persulfate–Cetyltrimethylammonium Bromide Coupled System for the Removal of Crystal Violet in Environmental Samples

Abstract Cetyltrimethylammonium bromide (CTAB) and persulfate (S 2 O 8 2− ) coupled systems are used for the generation of SO 4 −• radicals. CTAB solubilized the S 2 O 8 2− and reduced the decomposition rate of crystal violet (CV). S 2 O 8 2− was not decomposed into reactive radical species by heat in the presence of CV at 40 °C. The ferrous ion (Fe 2+ ) activates the S 2 O 8 2− , which produces reactive radical species due to the cleavage of the peroxide linkage of S 2 O 8 2− . The degradation efficiency increased from 11.5% to 53.8% with Fe 2+ concentration increasing from 0.2 to 1.0 mM at fixed CV and S 2 O 8 2− . The k obs values decreased from 2.1 × 10 −3 to 0.9 × 10 −3 and 0.7 × 10 −3 min −1 for ethanol and tertiary butanol (TBA), respectively, in the S 2 O 8 2− –Fe 2+ –CTAB–CV system. The higher quench effect of ethanol than that of TBA might be due to the presence of α‐H, and SO 4 −• was the predominant radical species in activated S 2 O 8 2− at pH 6.5. The Fe 2+ ions activate the S 2 O 8 2− to produce SO 4 −• , which might provide a potentially useful technique for the degradation of toxic water contaminants. The presence of suitable surfactant is essential for the solubilization of aromatic hydrocarbons and their destruction with SO 4 −• radical‐based technologies.