高等学校化学学报

高等学校化学学报 ›› 2005, Vol. 26 ›› Issue (8): 1527.

• 研究论文 • 上一篇    下一篇

海水中铁(Ⅲ)-二元有机酸盐配合物的光化学反应研究

杨桂朋1, 赵润德2   

  1. 1. 中国海洋大学化学化工学院;
    2. 青岛市环境保护局, 青岛266003
  • 收稿日期:2004-07-01 出版日期:2005-08-10 发布日期:2005-08-10
  • 通讯作者: 杨桂朋(1963年出生),男,博士,教授,博士生导师,主要从事海洋化学和环境化学研究.E-mail:gp yang@m ail.ouc.edu.cn E-mail:gp yang@m ail.ouc.edu.cn
  • 基金资助:

    国家自然科学基金(批准号:40176023)资助.

Photochemical Reaction of Fe(Ⅲ)-organic Acid Complex in Seawater

YANG Gui-Peng1, ZHAO Run-De2   

  1. 1. College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266003, China;
    2. Qingdao Environmental Protection Bureau, Qingdao 266003, China
  • Received:2004-07-01 Online:2005-08-10 Published:2005-08-10

PDF (PC)

摘要： 采用实验室模拟的方法研究了高压汞灯模拟日光照射下铁(Ⅲ)-二元有机酸盐配合物在天然海水中的光化学反应.结果发现,在二元有机酸盐配体的存在下,铁(Ⅲ)发生光化学反应生成还原态的铁(Ⅲ),铁(Ⅲ)会被溶液中的氧再氧化为铁(Ⅲ).铁(Ⅲ)的光还原反应速率受到配体浓度、pH、光强以及温度的影响.在二元有机酸与Fe(Ⅲ)浓度配比大于2的情况下,Fe(Ⅲ)-二元有机酸盐配合物的光还原反应初期铁(Ⅲ)浓度的增长符合一级动力学反应规律,100min后浓度趋于稳定,方程式为[Fe(Ⅲ)]t=kOA[OA]·[Fe(Ⅲ)]ini×[1-exp{-(kOA[OA]+kox)t}]/(kOA[OA]+kox).光强升高和pH降低都能加快光还原反应速率,而改变温度则基本上对光还原反应速率无影响,证明铁(Ⅲ)的光还原反应为自由基引发的电子转移过程.

关键词: 铁(Ⅲ), 二元酸盐配合物, 有机酸, 氧化还原, 自由基, 光化学反应, 海水

Abstract: The study on the photochemical reaction of Fe(Ⅲ)-organic acid complex in seawater was carried out by exposing the reaction solution to a high pressure lamp under different experimental conditions. The photo-reduction rate constants of Fe(Ⅲ) were affected by various factors including organic acid(OA) concentration, pH, light intensity and temperature. When the molar ratio of organic acid to Fe(Ⅲ) was above 2, the photo-reduction reaction of Fe(Ⅲ) exhibited a first-order reaction kinetic pattern at the initial stage, and remained nearly stable after 100 min, which could be described by the equation: [Fe(Ⅱ)]tkOA[OA][Fe(Ⅲ)]ini×[1-exp-(kOA[OA]+kox)t]/(kOA[OA]+kox).At near pH7, the activity of organic acids examined declined by the sequence below: tartaric acid>adipic acid>succinic acid>malic acid>malonic acid. Increase of irradiation intensity and decrease of pH value could enhance the photo-reduction rate of Fe(Ⅲ). On the contrary, when the temperature varied, the photo-reduction rate remained unchanged, which proved that the process of photo-reduction of Fe(Ⅲ) was a ligand-to-met al charge transfer process.

Key words: Fe(Ⅲ), Binary acid salt complex, Organic acid, Redox reaction, Free radical, Photochemical reaction, Seawater

中图分类号: 

TrendMD: