Effect of additives on photodegradation of 1,3,5-trichlorobenzene in aqueous surfactant solutions.

Photolysis of 1,3,5-trichlorobenzene (TCB) in moderate concentration (0.5 mM) in the presence of several additives was examined in 10 mM of cationic and nonionic surfactant solutions. Additions of small amounts of hydrophobic additives, n-dodecanethiol (1 mM), n-dodecyldimethylamine (<2.5 mM), and N-(n-dodecyl)-N-methylaniline (C12An: <0.5 mM), were effective for photodechlorination of TCB, while the formation of by-products could not be inhibited perfectly. In contrast, exclusive and efficient dechlorination of TCB in cetyltrimethylammonium chloride solution was achieved in the presence of sodium borohydride (<5 mM), which was due to the enhanced local concentration of borohydride anions in cationic micelle surfaces.