Mechanism for photochemical reaction of organically complexed iron

本研究的目的是建立天然水中有机络合铁在太阳辐射下的化学反应模型。首先，观察了模型有机物与Fe(II)形成的络合物的反应，估算了络合和解离的速率常数。然后，研究了有机质在辐射作用下的变化。激发波长越高，芳香族部分的光解率越高，即12h内光解率下降了50%。另一方面，类蛋白质含量增加了20%。但络合速率常数没有明显变化。虽然芳香族和类腐殖质部分被认为与铁的络合作用有关，但研究表明，它们的铁络合能力即使在部分光解后也不会有明显的变化。

The aim of this study was to develop chemical reaction model of organically complexed iron in natural water under solar radiation. At first, the reaction of complex composed of model organic matter and Fe(II) was observed, and rate constants of complexation and dissociation were estimated. Then, the changes of organic matter by radiation were examined. Photolysis of aromatic-like moiety with the higher excitation wavelength was especially high; i.e., it decreased by 50% in 12 hours radiation. On the other hand, protein-like moiety increased by 20%. However, the rate constant of complexation did not show significant change. Although aromatic and humic-like moieties are considered to be related to the complexation with iron, it was indicated that their ability for iron complexation would not change significantly even after partial photolysis.