摘要
通过微波辅助羟胺降解方法,实现快速高效降解持久性有机物全氟辛酸(PFOA)。设置微波的功率为1200 W,在羟胺浓度为1.0 mM,微波加热温度为200ºC,pH=3.92的条件下,50 mg/L PFOA溶液在反应6分钟后的降解效率达到82.22%。微波透过反应器壁均匀加热反应体系,反应体系中的羟胺在微波条件下选择性地吸收微波能量,产生“火锅”效应,促进自由基的生成,提高降解效率。通过自由基淬灭实验,得到羟胺降解PFOA的主要活性物质为超氧阴离子自由基(O_(2)^(•–))。O_(2)^(•–)先攻击PFOA的羧基官能团(-COOH),导致C—O键断裂脱羟基(-OH),PFOA脱-OH后不稳定,继续断裂,逐步脱除CF2,最终降解为F-和CO_(2)。微波辅助羟胺降解PFOA可为开发新型持久性有机污染物的处理技术提供理论依据。
Microwave assisted hydroxylamine technology was used to achieve rapid and efficient degradation of perfluorooctanoic acid(PFOA).The degradation efficiency of PFOA(50 mg/L)reached 82.22%after 6 min of reaction when the microwave power,hydroxylamine concentration,reaction temperature and pH were 1200 W,1.0 mM,200℃ and 3.92,respectively.The reaction system was uniformly heated by microwave through the reactor wall,and the hydroxylamine in the reaction system selectively absorbed microwave energy under microwave conditions,resulting in“hot pot”effect,which promoted the generation of free radicals and improved the degradation efficiency.The free radical quenching experiments showed that superoxide radical(O_(2)^(•–))was the main active group for hydroxylamine to degrade PFOA.The O_(2)^(•–)first attacked the carboxyl functional group(-COOH)in PFOA,resulting in the fracture of C―O bond and loss of the hydroxyl group(-OH).After losing-OH,the remainder was unstable and continued to fracture and lose CF_(2) step by step,and was finally degraded into F-and CO_(2). Therefore, the PFOA degradation by microwave assisted hydroxylamine reduction provides a reference and theoretical basis for the treatment of emerging persistent organic pollutants.
作者
林芳
吕明
岳林霞
许楠
LIN Fang;LÜMing;YUE Linxia;XU Nan(Shenzhen Engineering Research Center for Nanoporous Water Treatment Materials,School of Environment and Energy,Peking University Shenzhen Graduate School,Shenzhen 518055)
出处
《北京大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2022年第3期546-552,共7页
Acta Scientiarum Naturalium Universitatis Pekinensis
基金
深圳市科技计划项目(JCYJ20200109140616774和GXWD20201231165807007-20200810165349001)资助。
作者简介
通信作者:许楠,E-mail:xunan@pkusz.edu.cn。
