【摘要】 本文应用穆斯堡尔谱学方法,研究了在不同pH条件下Fe⁺⁺⁺,Fe⁺⁺与胡敏酸结合的性质。计算机拟合的pH3.0⁵⁷Fe-胡敏酸络合物泥浆的穆斯堡尔谱和参数表明,三对四极双峰（图1,AA′,BB′,CC′）是合理的。在pH3.0 Fe（++）以高自旋态存在,它和胡敏酸的结合多于一种环境类型。在pH1.0的⁵⁷Fe-胡敏酸络合物中,观察到了Fe⁺⁺⁺的穆斯堡尔谱信号,但没有Fe⁺⁺的信号,在这个样品离心分离出的液体部分检测到了加入量的59.7%的铁,表明在pH1.0时相当数量的Fe⁺⁺⁺被胡敏酸还原成Fe⁺⁺,Fe⁺⁺并不与胡敏酸牢固结合。在30伏电析过的⁵⁷Fe-胡敏酸络合物样品中（pH2.8）出现了Fe⁺⁺⁺,Fe⁺⁺的穆斯堡尔谱,这一结果指示出,在电析过程中由于⁵⁷Fe⁺⁺⁺-胡敏酸络合物悬浮液pH的降低,一部分Fe⁺⁺⁺还原成Fe⁺⁺,在pH2.8相当数量的Fe⁺⁺与胡敏酸牢固结合。根据在80K记录的穆斯堡尔谱,在pH1—3的范围出现了磁有序成份,但在室温记录的穆斯堡尔谱没有磁分裂。更多还原

【Abstract】 The Mossbauer spectra at ambient temperature and 80 K of ⁵⁷Fe-humic acid complexes, of which were centrifuged or electrodialyzed, were recorded respectively, and the nature of Fe³⁺, Fe²⁺ bound with humic acid at different pH values was studied.The Mossbauer spectra and parameters of ⁵⁷Fe-humic acid slurry at pH 3 fitted by computer show that three doublets （Fig. 1 AA’, BB’, CC’） are reasonable. The Fe³⁺ in the humic acid at pH 3.0 occurs in more than one type of enviroment and high spin forms. The Mossbauer spectrum signal for Fe³⁺ was observed but not for Fe²⁺ in the ⁵⁷Fe-humic acid at pH 1.0. 59% of iron doped was detected in the decantate at pH 1.0. It showed that considerable proportion of Fe³⁺ was reduced to Fe²⁺ by humic acid at pH 1.0, but no Fe²⁺ bound with humic acid strongly. The Mossbauer spectra for Fe³⁺, Fe²⁺ were found in the ⁵⁷Fe-humic acid samples （pH 2.8） which were electrodialyzed at 30 V. This indicates that a part of Fe³⁺ is reduced to Fe²⁺. Owing to the decrease of pH of ⁵⁷Fe-humic acid complexes suspension in the process of electrodialysis, considerable proportion of Fe²⁺ was bound with humic acid at pH 2.8 strongly. According to Mossbauer spectra recorded at 80 K, there is evidence for magneticallyordered component in the range of the pH 1—3 but no evidence for that at ambient temperature.更多还原