Hg在针铁矿上的吸附特性

Adsorption Properties of Hg on Goethite

汞(Hg)是一种具有高挥发性高毒性的重金属元素,针铁矿是一种主要的土壤铁矿物,根据大量的现场调查表明针铁矿是土壤截留汞的主要成分。通过一系列吸附实验探究表明大部分的汞在针铁矿上的吸附主要发生在前18 h内,而且吸附动力学符合Lagergren二级模型,这表明吸附速率主要受制于化学吸附过程。汞(Ⅱ)吸附等温线符合Langmuir方程,这表明该吸附过程为单分子层吸附。因此,针铁矿对汞有比较大的延阻容量。

Hg is a kind of heavy metal elements with high volatility and high toxicity and goethite is one of the mainsoil iron mineral. A large number of field investigations show that goethite is the main component of soil intercept Hg.Through a series of adsorption experiment exploration, it showed that most of the Hg adsorption on goethite mainlyoccurred in the first 18 h, and it was in line with the Lagergren secondary adsorption dynamics model, which showed thatthe adsorption rate was mainly subject to chemical adsorption process. The adsorption isotherm of Hg（Ⅱ） conformed tothe Langmuir equation, which indicated that the adsorption process was single-layer adsorption. Therefore, goethite had arelatively large ductile resistance capacity to Hg.