Chakinala Anand G, Gogate Parag R, Chand Rashmi, Bremner David H, Molina Raúl, Burgess Arthur E
School of Contemporary Sciences, University of Abertay Dundee, DD1 1HG Dundee, United Kingdom.
Ultrason Sonochem. 2008 Mar;15(3):164-70. doi: 10.1016/j.ultsonch.2007.02.008. Epub 2007 Mar 20.
The effect of the presence and absence of the chloroalkanes, dichloromethane (CH(2)Cl(2)), chloroform (CHCl(3)) and carbon tetrachloride (CCl(4)) on the extent of oxidation of aqueous I(-) to I(3)(-) has been investigated in (a) a liquid whistle reactor (LWR) generating hydrodynamic cavitation and (b) an ultrasonic probe, which produces acoustic cavitation. The aim has been to examine the intensification achieved in the extent of oxidation due to the generation of additional free radicals/oxidants in the reactor as a result of the presence of chloroalkanes. It has been observed that the extent of increase in the oxidation reaction is strongly dependent on the applied pressure in the case of the LWR. Also, higher volumes of the chloroalkanes favour the intensification and the order of effectiveness is CCl(4)>CHCl(3)>CH(2)Cl(2). However, the results with the ultrasonic probe suggest that an optimum concentration of CH(2)Cl(2) or CHCl(3) exists beyond which there is little increase in the extent of observed intensification. For CCl(4), however, no such optimum concentration was observed and the extent of increase in the rates of oxidation reaction rose with the amount of CCl(4) added. Stage wise addition of the chloroalkanes was found to give marginally better results in the case of the ultrasonic probe as compared to bulk addition at the start of the run. Although CCl(4) is the most effective, its toxicity and carcinogenicity may mean that CH(2)Cl(2) and CHCl(3) offer a safer viable alternative and the present work should be useful in establishing the amount of chloroalkanes required for obtaining a suitable degree of intensification.
研究了氯代烷烃（二氯甲烷（CH₂Cl₂）、氯仿（CHCl₃）和四氯化碳（CCl₄））的存在与否对水溶液中I⁻氧化为I₃⁻程度的影响，实验分别在（a）产生水力空化的液体哨式反应器（LWR）和（b）产生声空化的超声探头中进行。目的是研究由于氯代烷烃的存在，反应器中产生额外的自由基/氧化剂而导致氧化程度的强化情况。观察到，在LWR的情况下，氧化反应的增加程度强烈依赖于所施加的压力。此外，较高体积的氯代烷烃有利于强化，其有效性顺序为CCl₄>CHCl₃>CH₂Cl₂。然而，超声探头的实验结果表明，CH₂Cl₂或CHCl₃存在一个最佳浓度，超过该浓度后观察到的强化程度几乎没有增加。然而，对于CCl₄，未观察到这样的最佳浓度，氧化反应速率的增加程度随CCl₄添加量的增加而升高。与在实验开始时一次性添加相比，在超声探头实验中，逐阶段添加氯代烷烃的效果略好。尽管CCl₄是最有效的，但它的毒性和致癌性可能意味着CH₂Cl₂和CHCl₃提供了更安全可行的替代方案，目前的工作对于确定获得适当强化程度所需的氯代烷烃量应该是有用的。
