Photosensitized Degradation Of Chlorophenols In Heterogeneous System

The measurement and removal of chlorophenols are of great significant to reality since they are common environmental contaminations which have latent possibility to cause cancer, abnormality, and aberrance as well.Our laboratory had achieved rapid determination of chlorophenols based on the method of sensitized phototransformation-chemiluminescence detection. In this method, sensitized phototransformation was taken place in a homogenous system, and then the transformed products were analyzed on-line or off-line with NBS initiated chemiluminescence reaction. However, there were some disadvantages in this system such as the sensitizer in solution would affect the analysis of degradation products of chlorophenols, hence the investigation of the mechanism of the subsequent chemiluminescence reaction. In heterogeneous system, namely to bind sensitizers on carriers, it is hopeful to overcome these shortcomings. Based on this point, the current paper firstly discussed the phototransformation-chemiluminescence of chlorophenols by means of immobilized photosensitizer and secondly studied the sensitized photodegradation of chlorophenols in heterogeneous system, the main research contents were given as follows:(1) Firstly the sensitizer amino-fluorescence was synthesized,then amino-fluorescence and fluorescence were immobilized on carriers namely silica,glass and resin. Thereafter Their chemiluminescence phenomena were investigated.(2) Methylene blue was immobilized on cationic ion exchange resin by ion exchanging. 9, 10-diphenylanthracene (9, 10-DPA) was used to validate the produce of single oxygen in this system. The effect of the quantity of MB-R addition, the amount of MB loading, and the initial concentration of chlorophenols solution on the degradation of chlorophenols were investigated, and the reusability of MB-R was also valuated. The results showed that the efficiency of TCS degradation was satisfied: When the initial concentration of TCS was 1×10-4 mol/L, the optimal amount of MB-R addition was 8 g/L, in alkaline solution, the ratio of TCS degradation was up to 57.9 % after irradiation of 3h under visible light. However, the efficiency of DCP degradation was unsatisfied. The possible mechanism and degradation products were preliminarily investigated and it was found that the singlet molecular oxygen forming in the heterogeneous system played a major role for the photooxidation of chlorophenols.