高锰酸钾氧化饮用水中醛类嗅味物质的效果及动力学研究
Study on the effect and kinetics of aldehydes oxidation by potassium permanganate in drinking water
张君枝 1刘方 1王齐 2李璐玮 1廖宇 1张慧鑫 1于建伟2
作者信息
- 1. 北京应对气候变化研究和人才培养基地,北京节能减排与城乡可持续发展省部共建国家协同创新中心,北京建筑大学,北京,102612
- 2. 中国科学院生态环境研究中心,北京,100085;中国科学院大学,北京,100049
- 折叠
摘要
我国北方呼和浩特市以黄河为水源的JH饮用水厂近年来冬季经常有醛类嗅味物质检出,常规处理工艺如混凝、沉淀等对其去除效果有限,需要对其进行其它处理工艺的探究.本文选择高锰酸钾对水厂检出频率和浓度均较高的反,反-2,4-庚二烯醛(tt24hept)、反-2-辛烯醛(t2oa)、反,反-2,4-辛二烯醛(tt24oda)、反,反-2,4-癸二烯醛(tt24dda)和β-环柠檬醛(β-cyclo)5种醛类嗅味物质进行氧化控制研究,探究其去除效果、氧化动力学和氧化机理.结果表明,20℃,pH=7时,2 mg·L-1高锰酸钾氧化5种醛类嗅味物质30 min后,去除率达75％以上.根据动力学分析可知,高锰酸钾氧化5种醛类嗅味物质属于伪二级动力学过程,其伪二级反应速率常数分别为5.25×104、2.66×104、4.50×104、2.71×104、5.37× 103L·mol-1·min-1,醛类嗅味物质结构中含碳碳双键数目越多、含亚甲基数目越少,反应速率常数越大.同时,氧化过程会产生新生态二氧化锰,促进高锰酸钾对嗅味物质的控制效果.最后,通过水厂原水加标实验效果验证,理论反应方程可为饮用水厂应对醛类物质嗅味问题提供相应的理论依据并指导生产.
Abstract
Aldehyde odor substances have always been detected in recent years in winter for JH drinking water treatment plant in Hohhot city of northern China,which with the resource water from Yellow River.Conventional treatment processes such as coagulation,sedimentation and other effects on its removal are limited to control the aldehyde odorants,other treatment processes need to explore.In this paper,potassium permanganate was selected for the oxidation of five aldehyde odorants,trans,trans-2,4-heptadienal(tt24hept),trans-2-octenal(t2oa),trans,trans-2,4-octadienal(tt24oda),trans,trans-2,4-decadienal(tt24dda)and β-cyclocitral(β-cyclo),which were detected with high frequency and concentration in JH plants.The oxidation removal,kinetics and mechanism were investigated.The results showed that at 20 ℃ and pH=7,the removal of the five aldehyde odorants was over 75％after 30 min of oxidation by 2 mg·L-1 potassium permanganate.According to the kinetic analysis,the oxidation of the five aldehyde odorants by potassium permanganate belongs to the pseudo-second-order dynamic process,and its pseudo-second-order rate constants were 5.25×104,2.66×104,4.50×104,2.71×104 and 5.37×103 L·mol-1·min-1,respectively.The higher number of carbon-carbon double bond and the lower amount of methylene presented in the structure of an aldehyde odor substance cause the higher reaction rate constant.At the same time,the oxidation process will produce new in-site manganese dioxide,which promoting the oxidation effect of potassium permanganate on the aldehyde odorants.Finally,through the spiked recovery experiments by the raw water of JH plant,it was verified that the theoretical reaction equation could provide the corresponding theoretical basis,and guide the production of the problem of aldehydes in drinking water treatment plants.
关键词
高锰酸钾/醛类嗅味物质/氧化动力学/二氧化锰Key words
potassium permanganate/aldehyde odorants/oxidation kinetics/manganese dioxide引用本文复制引用
基金项目
国家重点研发计划项目(2021YFC3200904)
国家自然科学基金(52070185)
国家自然科学基金(51408022)
中国科学院饮用水科学与技术重点实验室专项(20K03KLDWST)
出版年
2024
NETL
NSTL
万方数据