高锰酸钾氧化嗅味物质β-环柠檬醛的动力学

摘要

The degradation and its kinetics of typical odorant β-cyclocitral of Microcystis aeruginosa by potassium permanganate were studied.In addition, the effect of oxidation on cell integrity and the release and degradation of β-cyclocitral were investigated.The results indicate that the reaction of potassium permanganate with β-cyclocitral follows the quasi secondary kinetics.The rate constant at pH=7 and 15 ℃ is 107.2 mol-1·L·s-1.The influence of pH on the process is not appreciable and the observed rate constant remains (0.078±0.016) min-1 with pH=2-9.After the oxidation of Microcystis-laden water, about 90％ cells are damaged and β-cyclocitral is released to the outside of the cell.The oxidative cleavage ofβ-carotene by potassium permanganate leads to the formation ofβ-cyclocitral, which results in the total concentration ofβ-cyclocitral increase firstly and then decrease during the process.%采用水处理常用氧化剂高锰酸钾对铜绿微囊藻产生的主要致嗅物质β-环柠檬醛(β-cyclocitral)进行氧化去除和动力学分析,并研究高锰酸钾对铜绿微囊藻细胞的破坏和β-环柠檬醛释出及其降解情况.研究结果表明:高锰酸钾与β-环柠檬醛反应符合准二级动力学模型,在溶液pH=7和温度15℃时其速率常数为107.2 mol-1·L·s-1;溶液pH对反应影响不大;当pH=2～9时,动力学表观速率常数kobs为(0.078±0.016)min-;高锰酸钾的加入造成藻细胞的破裂程度达到90%,使主要存在于胞内的β-环柠檬醛释出并降解;高锰酸钾能将铜绿微囊藻细胞内的β-胡萝卜素氧化成β-环柠檬醛,导致总β-环柠檬醛浓度在氧化过程中先升高后降低.