硝酸根对有机磷光解释放磷酸根的影响

发布时间：2018-04-30 02:38

本文选题：有机磷 + 磷酸根　；参考：《中国环境科学》2016年12期

【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.
[Abstract]:In order to understand the effect of the photochemical activity of NO3-) on the process of indirect photolysis and release of phosphate from organophosphorus in water, laboratory simulation experiments were carried out. In this paper, the effect of no _ 3O _ 3 ~ (-) on the conversion of no _ 3 ~ + to phosphate radical and the effect of no _ 3N ~ (-) concentration on the reaction rate were studied. Methanol was used as hydroxyl radical (OH) quenching agent to confirm the effect of no _ 3- ~ (-) on the photolysis and release of phosphorus from eutrophic lake water by photolysis of organophosphorus. The results show that glyphosate can be photolysis to phosphate directly under UV irradiation, and the release of phosphates increases with the increase of initial pH and glyphosate concentration. After the addition of no _ 3 ~ +-treatment, the release of phosphate radical increased from 0.05mg/L of blank treatment to 0.43 mg / L 路L ~ (-1) after illumination with 60min. The addition of Fe~(3) promoted the process, but the addition of humic acid (HA) and bicarbonate (HCO3-) could significantly inhibit the release of phosphate. When glyphosate was added into the lake water, the release of phosphate was significantly higher than that of the blank, but the release of phosphate was further increased when the concentration of NO3- in the lake water was increased. When OH quencher methanol was added to the system of lake water / glyphosate / glyphosate / no _ 3- system, the release of phosphate radical decreased significantly. It can be seen that the photochemical action of NO3- has an important effect on the release of phosphate radical from organophosphorus under ultraviolet light.
【作者单位】：华中农业大学资源与环境学院;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;
【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)
【分类号】：X524

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