The photodegradation of azo reactive dye (RR2) in the presence of acetone (ACE) or triethylamine (TEA) via indirect photolysis was investigated. Photolytic experiments were conducted in a merry-go-round photoreactor with 253.7-nm monochromatic UV lamps. The photodegradation of RR2 in aqueous ACE or TEA solution was found to be kinetically controlled by pseudo-first- and zero-order kinetics, respectively. Typically, the photodegradation reaction is more favorable at higher pH. In the presence of TEA, the rate enhancement primarily is a result of the electron transfer from TEA to RR2 and results in the photoreduction of dye chromophore. Photosensitization is likely the dominant mechanism in the presence of ACE. With respect to the decoloration rate, ACE proved to be a promising rate enhancer at elevated concentrations, and the solution color faded rapidly within 5 minutes of retention time. The photodecoloration of RR2 was found to co-occur with photodechlorination and was followed by photodesulfonation at a later stage in which the mineralized end products, including hydrogen, chloride, and sulphorate ions, were detected in approximately stoichiometric amounts.
|Number of pages||6|
|Journal||Water environment research : a research publication of the Water Environment Federation|
|Publication status||Published - 1 Sep 2002|
ASJC Scopus subject areas
- Environmental Chemistry
- Water Science and Technology