黄腐酸对铁吸附行为的研究

A Study on the Adsorption Behavior of Fulvic Acid for Iron

采用振荡吸附法研究黄腐酸对铁的吸附行为，分别考察了时间、pH值，温度等对黄腐酸吸附Fe^3＋过程的影响．结果表明，pH=4．5～6．5，吸附量较大，且基本稳定，不随pH值的变化而变化；pH=5，200min达到吸附平衡；pH=3，Fe^3＋易从黄腐酸上解吸下来，180min可达到解吸平衡．从吸附等温线可看出，黄腐酸对Fe^3＋的吸附符合Langmiur和Freundlich吸附等温模型；吸附为吸热过程，吸附热△H为8．0091kJ·mol^-1．

The virbrating adsorption method is used to study the adsorption mechanism of Fe^3＋. Meanwhile, the effects of time, pH and temperature are also investigated. The result shows that, when pH = 4.5 - 6.5, adsorption is larger and stable and does not vary with the variable pH. When pH = 5, the amount of absorption becomes bigger with the longer time, and through about 200 minutes the adsorption balance can be obtained. When pH = 3, Fe^3＋ can be easily desorbed from FA, and through about 180 minutes the desorption balance can be obtained. From the isothermal adsorption curve, we can find that the adsorption of Fe^3＋ on fulvic acid is an endothermic process and also in coincidence with the Langmiur and Freundlich adsorption isotherms model. The adsorption caloric△H is 8.009 1 kJ · mol^-1.