| In recent years,a variety of trace organic contaminants（TOr Cs）have been frequently detected in environmental water.Such pollutants may accumulate in organisms,leading to endocrine disorders,drug resistance or toxicity and other hazards.Sewage treatment plant is a key node for pollutants to enter the environment,and conventional treatment processes cannot effectively remove TOr Cs.Advanced oxidation processes（AOPs）,as a widely used Advanced water treatment technology,can effectively remove TOr Cs.However,the remaining organic matter in wastewater will capture a large number of strong oxidizing hydroxyl radicals（HO·）produced by AOPs,resulting in a reduced ability to remove TOr Cs.Therefore,ozone-ozone/ultraviolet（O3-O3/UV）process is proposed to solve this problem.The degradation pathway of O3-O3/UV process is mainly divided into two steps:1)O3 degrades a large number of organic matter and TOr Cs which is not resistant to O3;2)the residual O3 reacts with UV to generate HO·,which oxidizes and degrades the remaining TOr Cs which is resistant to O3.However,it is difficult to accurately control and measure the O3 contact time and UV irradiation dose in the commonly used O3/UV experimental equipment.This paper developed and built a new set of modular O3/UV experimental equipment for thin tube flow.Then,using pyruvate（PA）as an indicator,the compatibility of the new modularized fine tube flow O3/UV experimental device with O3-O3/UV process was investigated.The results showed that the device can accurately and conveniently adjust and measure the O3 contact time（0～2880s）,UV dose(0～900.0m J cm-2),O3 concentration(0～5.0mg L-1)and other process parameters,and at the same time,it could study the degradation effect and mechanism of different degradation pathways on TOr Cs in O3-O3/UV process.Based on the new modular tube flow O3/UV experiment device,this study was studied in different process,UV dose(0～300.0m J cm-2),initial concentration of pollutants(0.5～4.0mg L-1),O3 concentration(0～5.0mg L-1),p H（5.0、7.5、9.0）and water quality conditions（ultrapure water、artificial water distribution and the second pond water）,O3-O3/UV process of three kinds of different pollutants（sulfadimidine（SMN）,ibuprofen（IBP）and Ann honey（ACE-K））degradation effect and mechanism.The following conclusions was drawn:（1）Compared with individual O3 technology,individual UV technology and O3-O3/UV process,the experimental results showed that O3-O3/UV process had the best removal effect on TOr Cs.When the initial concentration of O3=1.0mg L-1,the UV dose=137.6 m J cm-2,the contact time of O3=60s,the p H=5.0,and ultrapure water,the removal rates of SMN,IBP and ACE-K by O3 alone were 86.3%,21.0%and 7.0%,respectively.The removal rates of O3-O3/UV were 87.3%,58.4%and 78.2%,respectively.（2）With the increase of O3 concentration,UV dose and p H,the removal rate of pollutants by O3-O3/UV process increased accordingly.The increase of the initial concentration of pollutants will lead to the decrease of the removal rate of pollutants.When the UV dose was 137.6 m J cm-2,0～5.0mg L-1 O3 could be completely decomposed by UV.（3）When the initial concentration of O3=5.0mg L-1,the contact time of O3=60s and the UV dose=138.1m J cm-2,the degradation rates of SMN,IBP and ACE-K by O3-O3/UV process could reach more than 90.0%.At the same time,DOM in sewage could also be effectively removed. |
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