硝酸根对有机磷光解释放磷酸根的影响  

Photo-induced phosphate released from organic phosphorus decomposition by nitrate

作　　者：刘广龙[1,2] 朱端卫[1] 周易勇[2] 曹秀云[2] 宋春雷[2] 华玉妹[1] 赵建伟[1] LIU Guang-long;ZHU Duan-wei;ZHOU Yi-yong;CAO Xiu-yun;SONG Chun-lei;HUA Yu-mei;ZHAO Jian-wei(College of Resources & Environment, Huazhong Agricultural University, Wuhan 430070, China;State key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China)

机构地区：[1]华中农业大学资源与环境学院,湖北武汉430070 [2]中国科学院水生生物研究所,淡水生态与生物技术国家重点实验室,湖北武汉430072

出　　处：《中国环境科学》2016年第12期3657-3664,共8页China Environmental Science

基　　金：国家自然科学基金项目(41230748;41401547);霍英东青年教师基金(151078);中央高校基本科研业务费资助(2662016PY061);中国博士后基金项目(2013M540619;2015T80855)

摘　　要：为了解硝酸根(NO_3^-)的光化学活性对水体中有机磷间接光解释放磷酸根过程的影响,采用室内模拟实验,研究了NO_3^-在草甘膦光解转化为磷酸根中的作用及NO_3^-浓度对该反应速度的影响,并以甲醇为羟基自由基(·OH)猝灭剂,印证了NO_3^-对富营养化湖泊水体中有机磷光解释放磷的作用.结果表明,在紫外光(UV)照射下,草甘膦可以直接光解转化为磷酸根,其磷酸根的释放量随着溶液初始p H和草甘膦浓度的增加而增大.加入NO3^-处理,光照60min后,磷酸根的释放量由空白处理的0.05mg/L增加到了0.43mg/L.添加Fe^(3+)可促进这一过程,而添加腐殖酸(HA)和碳酸氢根(HCO_3^-)则可以显著抑制磷酸根的释放.在湖泊水体中,添加草甘膦,磷酸根的释放量显著高于空白,而增加湖水中NO_3^-浓度时,磷酸根的释放量则进一步增大.在湖水/草甘膦/NO_3^-体系中添加·OH猝灭剂甲醇后,磷酸根的释放量显著降低.可见在紫外光条件下,NO_3^-的光化学作用对有机磷释放磷酸根过程具有重要影响.In order to understand the influence of nitrate(NO3-)photochemical activity on the phosphate released fromorganic phosphorus indirect photolysis degradation,the phosphate released from glyphosate photodegradation by NO3-wasinvestigated in deionised and natural water under UV irradiation.Meanwhile,the methanol was used as the?OH scavenger toconfirm the role of NO3-on the phosphate released from organic phosphorus degradation in the natural eutrophication lakes.The results showed that the phosphate could be released from glyphosate photolysis under UV irradiation and the releaseamount of phosphate increased with pH and initial concentration of glyphosate increasing under UV light irradiation indeionised water.NO3-adding enhanced the phosphate released from glyphosate photodegradation in comparison with directphotolysis and the concentration of phosphate increased from0.05mg/L to0.43mg/L with the20mg/L NO3-added to thesolution under UV irradiation for60min.The effect of environmental parameters including Fe3+,HCO3-and humic acid onthe phosphate released from glyphosate photodegradation by NO3-was also performed.In the presence of Fe3+,the amount ofphosphate released from glyphosate photodegradation increased significantly due to photosensitization by reactive speciessuch as hydroxyl radical.The presence of humic acid and HCO3-inhibited phosphate released through a radical scavengingeffect.The release amount of phosphate in the natural water with NO3-spiked is higher than that of control and the phosphatereleased was inhibited when the methanol was added to the reaction system.All these results reveal that NO3-plays animportant role in phosphate released from organic phosphorus photodegradation.

关 键 词：有机磷 磷酸根 硝酸根 光降解 自由基 

分 类 号：X703.5[环境科学与工程—环境工程]