摘要
一定浓度的亚硝酸盐溶液经太阳光模拟器照射一定时间后,观测溶液中亚硝酸盐的含量变化.改变溶液条件(介质、pH)和光照条件(时间、光强)等实验条件,同时进行黑暗对照实验,探求影响亚硝酸盐光解的因素和规律.结果表明,在光照的8 h内,时间越长亚硝酸盐的降解率越大,基本符合一级反应动力学曲线;光照强度越大亚硝酸盐的降解程度越大,光照强度分别为765、500、250 W.m-2的条件下,光化学降解一级动力学常数分别为0.0244 h-1、0.0102 h-1和0.0042 h-1;不同介质中亚硝酸盐降解程度为Milli-Q水、去离子水>人工海水,盐度对亚硝酸盐降解有显著的影响;pH越小越有利于亚硝酸盐光解.光降解产生的一氧化氮(NO)有随亚硝酸盐浓度的增加而增加的趋势.
The objective of this study was to investigate the photochemical reactions of nitrite in water.A nitrite solution was illuminated for a period of time under simulated sunlight,and the change of nitrite content in solution was observed.Different conditions of solution,such as concentration,temperature,medium and pH of medium,and conditions of illumination,such as duration,light intensity,and nitrite photodecomposition were discussed.Results showed that the longer illumination the higher the degradation rate of nitrite.First-order reaction kinetics model was found.The stronger light intensity the higher the degradation percentage of nitrite.The first-order kinetic constants for nitrite degradation were 0.0244 h-1,0.0102 h-1 and 0.0042 h-1 when the light intensity was 765,500 and 250 W · m-2,respectively.In different media,the degree of degradation exhibited the following sequence: Milli-Q,deionized water artificial seawater.Low pH promoted the degree of nitrite photodecomposition.The concentration of nitric oxide from nitrite photodecomposition showed an increasing trend with the concentration of nitrite.
出处
《环境化学》
CAS
CSCD
北大核心
2011年第11期1883-1888,共6页
Environmental Chemistry
基金
国家自然科学基金(40706040)
山东省中青年科学家科研奖励基金(2007BS08015)
山东省自然科学基金(Y2008E04)资助
关键词
亚硝酸盐
光降解
水溶液
模拟太阳光
一氧化氮
nitrite
photodecomposition
aqueous solution
simulate sunlight
nitric oxide(NO).