Photolysis of Dimethyl Phthalate via Microwave Discharge Electrodeless Iodine Lamp: Parameters, Feasibility and Mechanism

Abstract

This study reports, the photolysis of dimethyl phthalate using 206.2 nm UV light emitted from a locally made novel microwave discharge electrodeless iodine lamp (MDEIL). Optimal preparation parameters of MDEIL were determined as follows: iodine amount, 0.5 mg; krypton pressure, 2 torr and input power, 65 W. Removal efficiency of dimethyl phthalate reached 97.5 % at 20 min irradiation time and 20 mg L -1 initial dimethyl phthalate concentration. A possible mechanism of the dimethyl phthalate photolysis may involve electron transition reactions and reactions with hydroxyl radicals. The intermediates were identified as phthalic acid and 2-hydroxyl acid methyl esters. Results from this study may help promote further studies on the feasibility of MDEIL to decompose more aqueous organic contaminants, including other refractory contaminants.

Insights into the Titania (TiO2) Photocatalysis on the Removal of Phthalic Acid Esters (PAEs) in Water

“…Therefore, various techniques have been employed, including coagulation [97,98], adsorption [99], biodegradation [100,101], chlorination [102,103], photolysis [104], ozonation [105], Fenton process [106], and photocatalysis [107]. The coagulation and adsorption techniques, however, have shortcomings and constraints such as the generation of secondary pollutants, the sludge which requires filtration and will be eventually dumped in the waste area, while the used adsorbents that are no longer functional also create disposal problems.…”

Microwave catalytic activities of MFe2O4@CMT (M = Ni, Co) supported catalysts for the degradation of dimethyl phthalate

“…Dimethyl phthalate (DMP) ester is a common short-chained ester from the class of PAEs, which has been detected in the natural environment including water and sediments. 1 DMP is relatively recalcitrant to biodegradation in the natural environment because of its benzene carboxylic group and its hydrolysis half-life of about 3 years. 2 Moreover, DMP can be bioconcentrated and biomagnified in the aquatic food chain.…”