Hybrid Treatment of Wastewater Containing Persistent Organic Compounds Using Photo-oxidation and Sonication

光催化-超声化法是一种新型的无氧化剂废水处理工艺。以酸性橙52(AO52)为模型染料，考察了无机离子、曝气量和双组分混合气体对其分解的影响，发现在AO52溶液中加入氯离子会降低总有机碳(TOC)的分解效率。在黑暗条件下的吸附实验结果表明，氯离子在光催化剂表面的吸附抑制了催化剂的活性，在双组分混合物的情况下，混合工艺的分解效率高于光催化和声解单独使用的工艺。混合工艺对多组分溶液的处理更为有效，其充气气体为Ar、氧气、氮气和空气。…的分解效率当使用氧气时，混合工艺的O52和TOC最高。这归因于氧对自由基反应的促进。因此，AO52及其中间产物得到了有效的降解。疏水性物质和亲水性物质分别主要通过自由基反应和热分解来分解，因此混合过程的分解效率高于光催化和声解过程。然而，根据工艺条件选择曝气是很重要的，因为有效气体的分解机理和物质的物理性质不同。硝酸根离子是通过超声波产生的。研究发现，除氮气外的气体鼓泡去除处理前溶解的氮气可以防止硝酸根离子的产生。利用斑马鱼生发泡的衰变活性，对处理后溶液的生物活性进行了检测。该溶液无生物活性。这表明，光催化-超声复合工艺是一种对环境安全、友好的工艺

Photo-catalysis with sonication (Hybrid) process is a new wastewater treatment process without oxidizing reagents. In this study, the effects of inorganic ions, kinds of aeration gas, and two-component mixture on the decomposition of acid orange 52 (AO52) used as a model dye have been investigated.When chloride ion used as inorganic ion was added into AO52 solution, the decomposition efficiency of total organic carbon (TOC) was decreased. From the result of the adsorption experiment under the dark condition, it was found that the adsorption of chloride ion on the surface of photocatalyst inhibits the catalyst activity.In the case of two-component mixture, the decomposition efficiency for the Hybrid process was higher than those for the processes Photocatalysis and Sonolysis processes were used separately. The Hybrid process is more effective for the treatment of multi-component solutions.Argon, oxygen, nitrogen, and air were used as the aeration gas. The decomposition efficiencies of A … More O52 and TOC for the Hybrid process were the highest when the oxygen gas was used. This is attributed to the promotion of radical reaction by oxygen. Therefore, AO52 and intermediate products were effectively decomposed. The hydrophobic and hydrophilic substance are mainly decomposed by radical reaction and thermal decomposition, respectively so that the decomposition efficiency in the Hybrid process become higher than those in the Photocatalysis and the Sonolysis processes. However, the selection of the aeration gas according to the processing conditions is important because the effective gas is different by the decomposition mechanism and the physical properties of the substanceThe nitrate ion is produced by using the ultrasound. It is found that the bubbling of gas except nitrogen in order to remove the dissolved nitrogen before the treatment prevent the nitrate ion production.The examination of bioactivity of the solution after the treatment using Hybrid process was conducted by using the decay activity of the germinal vesicle of zebrafish. The solution showed no bioactivity. This indicats that the Hybrid process, that is, Photo-catalysis with sonication process, is safe and friendly to the environment Less