富里酸(FA)对微囊藻毒素-LR(MC-LR)的光降解作用及环境影响因素分析  

Photodegradation of microcystin-LR(MC-LR)by fulvic acid(FA)and effect of environmental factors

作　　者：汪艳昭 张静静 张达娟 戴伟 毕相东 WANG Yanzhao;ZHANG Jingjing;ZHANG Dajuan;DAI Wei;BI Xiangdong(Key Laboratory of Aqua-ecology and Aquaculture of Tianjin,College of Fisheries Sciences,Tianjin Agricultural University,Tianjin 300384,China)

机构地区：[1]天津农学院水产学院,天津市水产生态及养殖重点实验室,天津300384

出　　处：《大连海洋大学学报》2024年第2期281-288,共8页Journal of Dalian Ocean University

基　　金：国家自然科学基金面上项目(32172978);天津市科技计划项目(22JCYBJC00430,22ZYCGSN00050);甘肃省科技计划项目(21CX6NP223);天津市教委科研计划项目(2021KJ110)。

摘　　要：为研究自然水环境中溶解性有机质(DOM)对微囊藻毒素-LR(MC-LR)的光降解作用,选择DOM的主要光敏活性组分富里酸(FA)作为光敏剂,在模拟太阳光照射下,对比了不同质量浓度FA(2.5、5.0、7.5、10.0 mg/L)溶液中MC-LR的光降解规律和光降解产物,并探究了不同pH、光照度对FA光降解MC-LR的影响。结果表明:MC-LR能在去离子水中发生直接光降解反应,不同质量浓度的FA对MC-LR的光降解均有促进作用,其中,7.5 mg/L FA对MC-LR的光降解作用最强,180 min时降解率达52.65%;FA对MC-LR的光降解过程符合二级反应动力学方程,其光降解产物与在去离子水中直接光降解的产物相同;不同pH和光照度下,FA对MC-LR的光降解作用依次为pH 6>pH 7>pH 8>pH 9,39.8μmol/(s·m^(2))>56.9μmol/(s·m^(2))>22.8μmol/(s·m^(2))。研究表明,pH和光照度均会影响FA对MC-LR的光降解作用,其中,pH为6、光照度为39.8μmol/(s·m^(2))时,FA对MC-LR光降解作用最强。To investigate the photodegradation of microcystin-LR(MC-LR)by dissolved organic matter(DOM)in natural aquatic environments,the photolysis patterns and products of MC-LR in the main photosensitizer of DOM fulvic acid(FA)solutions with different concentrations of 2.5,5.0,7.5 and 10.0 mg/L were compared under simulated solar irradiation,and the effects of different pH values and light intensities on FA photodegradation of MC-LR were investigated.The results showed that the direct photolysis of MC-LR was found in deionized water.Different concentrations of FA led to promote the photolysis of MC-LR,with the best photodegradation at 7.5 mg/L of FA.There was degradation rate of 52.65%in 180 min.The photodegradation of MC-LR by FA was shown to be conformed to the second-order reaction kinetics,with the same photodegradation products as the direct photolysis products in deionized water.The descending order of photodegradation effects of FA on MC-LR were described as pH 6>pH 7>pH 8>pH 9 and 39.8μmol/(s·m^(2))>56.9μmol/(s·m^(2))>22.8μmol/(s·m^(2)),indicating that both pH value and light intensity affected the photodegradation of FA on MC-LR.The best promoting effect of FA on the MC-LR photodegradation was observed at pH 6 and light intensity of 39.8μmol/(s·m^(2)).

关 键 词：富里酸 微囊藻毒素 光降解 溶解性有机质(DOM) 

分 类 号：S964.3[农业科学—水产养殖]