土壤及铁氧化物对马尿酸的吸附解吸特性研究

Adsorption-desorption Characteristics of Hippuric Acid (HA) in Soil and Iron Oxide

为了探明土壤及针铁矿、水铁矿对马尿酸(HA)的吸附解吸特性,并为其在环境中的风险性评价提供理论依据。通过批平衡吸附试验,对HA在土壤、针铁矿、水铁矿中的吸附解吸行为进行了研究。结果表明,Langmuir模型可以对HA在物质上的吸附和解吸数据进行良好的非线性拟合,平均拟合系数为0.992,试验中HA在3种物质上的吸附和解吸不同程度地偏离线性模型;通过拟合得出的水铁矿和针铁矿对HA的最大吸附量分别为434.5 mg/kg和103.5 mg/kg,为土壤最大吸附量的20.89倍和5.22倍,而水铁矿是针铁矿的4.20倍;吸附容量lgKf顺序为水铁矿>针铁矿>土壤;HA在土壤、针铁矿、水铁矿中的解吸存在滞后现象。由此可见,水铁矿对HA吸附能力及吸附强度均最强。

The adsorption-desorption characteristics of hippuric acid（HA） in soils and iron oxide were investigated to provide the basic data on evaluating the safety in the environment.The characteristics of HA adsorption and desorption in the soil,goethite and ferrihydrite were investigated by using the equilibrium method.The Langmuir model was the best isotherm to describe all experimental data of adsorption and desorption,and the average fitting correlation coefficient was 0.992.The maximum adsorption capacity of HA in ferrihydrite and goethite was 434.5 mg/kg and 103.5 mg/kg,20.89 times and 5.22 times larger than those of the soil.The ferrihydrite was greater than the goethite 4.20 times.The adsorption capacity（lgKf） was in the order ferrihydrite goethite soil.The desorption of HA existed hysteresis in the soil,goethite and ferrihydrite.It was concluded that,the adsorption capacity and ability of HA in ferrihydrite were all the highest.