Ozonation, photocatalysis and photocatalytic ozonation of diuron. Intermediates identification
Ozonation, photocatalysis and photocatalytic ozonation of diuron. Intermediates identification
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DOI：
10.1016/j.cej.2016.02.005
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发表时间：
2016-05
影响因子：
15.1
通讯作者：
R. R. Solís-R.;F. Rivas;A. B. Martínez-Piernas;A. Agüera
中科院分区：
文献类型：
--
作者：
R. R. Solís-R.;F. Rivas;A. B. Martínez-Piernas;A. Agüera
研究了臭氧氧化、光催化氧化和光催化氧化3-（3，4-二氯苯基）-1，1-二甲基脲（敌草隆）水溶液的效果。敌草隆的降解是通过自由基途径，通过羟基自由基在这些系统中涉及臭氧。光催化臭氧氧化对敌草隆的去除率与单一臭氧氧化相比没有明显提高，但TOC去除率有明显提高。光催化臭氧氧化在2 h内TOC去除率可达80%，而单次臭氧氧化仅能使TOC去除25%。光催化需要9小时，以达到25%的TOC减少。采用液相色谱-四极杆飞行时间质谱联用技术（LC-QTOF-MS/MS）初步鉴定了3种技术应用过程中产生的10种转化副产物。单一臭氧氧化和光催化臭氧氧化导致所有副产物的形成和完全消除。低重量羧酸的演变表明，在光催化臭氧化中的高TOC去除率与其氧化小的含氧化合物和释放无机氯化物和硝酸盐的能力有关。在光催化臭氧氧化过程中，对费氏弧菌的毒性演化表现出在反应初始阶段抑制作用增强（>90%的抑制作用），随后随着反应的进行，该参数降低。最终处理的样品显示出比初始样品更低的毒性（55%对20%）。
Aqueous 3-(3,4-dichlorophenyl)-1,1-dimethylurea (diuron) has been oxidized by ozonation, photocatalysis and photocatalytic ozonation. Diuron degradation takes place via radical pathway through hydroxyl radicals in those systems involving ozone. Diuron elimination in photocatalytic ozonation is not enhanced if compared to single ozonation; however, TOC removal was significantly improved. Specifically, 80% TOC removal in 2 h was reached in photocatalytic ozonation while single ozonation just led to 25% TOC reduction. Photocatalysis required 9 h to reach 25% TOC reduction. Ten transformation by-products generated during the application of the three technologies were tentatively identified by liquid chromatography–quadrupole time-of-flight mass spectrometry (LC–QTOF–MS/MS). Single ozonation and photocatalytic ozonation led to the formation and complete elimination of all by-products. Low weight carboxylic acids evolution suggests that high TOC removal in photocatalytic ozonation is linked to its capacity to oxidize small oxygenated compounds and release of inorganic chloride and nitrate. Toxicity evolution to Vibrio fischeri in photocatalytic ozonation displayed an increase in inhibition at the initial stages (>90% of inhibition), followed by a decrease of this parameter as the reaction progressed. The final treated sample shows a lower toxicity than the initial one (55% vs 20%).