A spiral photoreactor system(SPS) was developed for the degradation of 4-tert-octylphenol(4-t-OP) in aqueous phase.4-t-OP was previously considered as a endocrine disrupting compound frequently present in water.The direct photodegradation reaction caused by the SPS was found to accord with the characteristic of apparent first-order reaction with reaction rate constant k = 4.8 × 10-2 min-1.However,the direct photodegradation reaction could not make the 4-t-OP mineralized.The photodegradation efficiency increased from 88% to 91.2% in 45 min irradiation period after the internal surface of SPS was sintered with TiO2 thin film as catalyst.Catalyst concentration,number of catalyst coating layers and initial concentration of 4-t-OP were proven to be the factors affecting the photocatalytic degradation performance of the SPS on aqueous 4-t-OP.The degradation mechanism was investigated and the byproducts were analyzed using total organic carbon analyzer(TOC) and LC-MS.The possible chemical structures of the products were suggested.SPS with single layer of TiO2 prepared by sintering 13.6% of TiO2 precursor was proven to be more efficient than most of previous systems for removal of 4-t-OP from aqueous phase.28.3% of the 4-t-OP was mineralized in 45 min according to the decreased amount of TOC value.
