| The direct photolysis of chlorpyrifos in aqueous solution irradiated by high pressure lamb light(HPML), xenon light(XL), ultraviolet light(UV) and sunlight was investigated. Effect of water, temperature and pH on photodegradation of chlorpyrifos were studied under HPML. Effect of surfactants, fertilizers, ions and pigments on photolysis of chlorpyrifos, and photocatalysis degradation of chlorpyrifos were specifically studied. Bacterial strains which could degrade chlorpyrifos were separated from waste water dealing with sysetem of producing chlorpyrifos factory. Chlorpyrifos degradation dynamic was studied with separated strains. The single and combined degradation of chlorpyrifos was investigated in paddy water under simulated sunlight and sunlight. The main results were summarized as follows:1.The photolysis half life of chorpyrifos in aqueous solution under HMPL,UV,XL and sunlight was 0.62h,6.92h,19.74h,and 22.50h respectively.2.Under HMPL irradiation, photolysis rate constant of chlorpyrifos increased with solution temperature and half-life of chlorpyrifos at 20℃ and 35℃ was 2.55h and 1.75h respectively. The photolysis rate constant didn,t increase when temperature was more than 35℃. The photolysis rate constant of chlorpyrifos remained consistent from acid conditions to netrual condition and increased in alkaline conditions. The photolysis rate of chlorpyrifos in different types of water followed the sequence of distilled water>tap water>river water>lake water>paddy water.3.Under UV irradiation, anionic surfactant SDBS was no effect to chlorpyrifos with the concentration of slow dosage and the photosensitive effeiency of SDBS was 11.61% when the concentration of SDBS reached 5mg/L.When chlorpyrifos was mixed with nonionic surfactant Tween-80 at 1:0.1,1:1,1:2.5(dosage ratio), the photosensitive effeiency of Tween-80 was 7%, 24.79%, 90.20%.As to chlorpyrifos and the surfactant mixture of nonionic Span-20, when 1:1,1:5, Span-20 had a positive effect on the photolysis of chlorpyrifos. The photosensitive efficiency of 0201 and 2201 were 82.79% and 83.16% with two surfactants being fortified 50mg/L. Under HMPL irradiation, nongru500# had a weakly photosensitive efficiency on photolysis of chlorpyrifos. When chlorpyrifos was mixed with nongru404# at 1:0.5,1:1,1:2.5(dosage ratio), the photolysis constant rates were improved to1.26, 1.37, 1.73 times, and when 1:1and1:2.5,nongru603#, the photolysis constant rates were improved to1.17 and 1.58 times.Nongru601# acted as a photosensitizer in photolysis process of chlorpyrifos, and improved the relative constant rate to 1.28~2.22. The photosensitive efficiency of 0206B was 14.49%,14.49%,26.09% when the dosage ratio of chlorpyrifos and 0206B was 1:0.5, 1:1, 1:2.5.4.Under HPML irradiation, NH4HCO3 and Ca (H2PO4)2 had a photoquenching effect on photolysis of chlorpyrifos. KNO3 had a positive effect when the dosage ratio of chlorpyrifos and KNO3 was below 1:0.1 and had a negative effect when it was above 1:0.1. NH2CONH2 had a weakly photosensitive efficiency.5.Mn2+ and Zn2+ could accelerate photochemical degradation of chlorpyrifos and had a minor photosensitive efficiency. The photoquenching efficiency of Pb2+ and Cu2+ was 12.17% and 14.28% when the concentration of Pb2+ and Cu2+ respectively reached 50mg/L. The photosensitive effect of Fe2+ was 23.61%, 25.00%, 30.56% respectively when it was fortified 10mg/L, 25mg/L, 50mg/L.Cl- and Br- had no effect on photodegradation of chlorpyifos. As to the mixture of chlorpyrifos and I-, when their dosage ratio was 1:1, 1:2.5, 1:5, the photosensitive efficiency was 29.76%, 58.30%, 65.48%. The photoquenching efficiency of NO2- was 20.97% and 79.03% when the concentration of NO2- was 10mg/L.and 50mg/L.6.The chlorpyrifos homogeneous photodegradation was studied. Fe3+ has significant effect on chlorpyrifos photodegradation and the optional concentration was 1mmol/L.The half-life was 693min under 3 mmol/LH2O2, and it was 30.26min under HPML irradiation, and it was only 12.14min under 3 mmol/LH2O2 and HPML irradiation. The...
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