The Effects of Copper Coexistence on the Adsorption of Tetracycline onto Loess Soil

Ting Liu, Kun Wu



Tetracycline (TC) is a widely-used antibiotic, which can transport into aqueous and soil systems. The coexistence of copper (Cu) may change the characteristics of TC adsorption onto soils. This study investigated the effects of Cu existence on the adsorption of TC onto loess soil, which is ubiquitous in the northwest of China. The kinetic and isotherm experiments were carried out in the single and binary systems. The results showed that the kinetic data of TC could be well fitted by the pseudo-second-order model in the single or binary system. The coexistence of Cu could increase the adsorption rate of TC. On the other hand, the isotherm data were well fitted by the Langmuir model in the single or binary system, which indicated that the TC adsorption onto loess soil is mainly monolayer adsorption. The presence of Cu could enhance the adsorption of TC from pH 3.0 to 10.0. Hence, it is suggested that the migration of TC within loess soil may be slowed down because of the coexistence of Cu.


Keywords: Loess soil; tetracycline; copper; adsorption