Abstract
The photodegradation of DDT in water was examined with a high-pressure mercury lamp. A total of 17 photodegradation products of DDT including DDD, DDE and DDMU were identified by gas chromatography-mass spectrometry (GC-MS). Mass spectrometric analyses were done with electron impact (EI), methane positive chemical ionization (PCI) and electron capture negative ion chemical ionization (ENCI). The degradation rate of DDT in the presence of acetone was measured against the irradiation time. After the irradiation for 10min, 80% of DDT was converted into a number of products, including DDD, DDE, DDMU and dichlorobenzophenone, through reductive dechlorination, oxidation, isomerization and chlorination. On the basis of the identified products, the photodegradation pathways of DDT are proposed.
