Abstract:
The presence of antibiotics in soils is increasing drastically in last decades due to the intensive farming industry and excessive human consumption. Clay minerals are one of the soil components with great adsorption capacity for organic pollutants. The study of interactions between antibiotics and mineral surfaces will give us scientific knowledge of these pollutants through soils. In this work, we study the adsorption of the antibiotic ciprofloxacin in the clay mineral fraction of soils from the Argentinian zone of Santa Rosa (Corrientes), in a collaborative research of experiments and atomistic modelling calculations of the intercalation of ciprofloxacin in the interlayer space of montmorillonite. Adsorption and desorption isotherms were performed and compared with different isotherm models. Additionally, enthalpy, entropy, and free energy were determined from equilibrium constants at a function of temperature. All these experiments and calculations lead to the conclusions that two adsorption types of ciprofloxacin are found on clay minerals: one weakly sorbed that is released during the desorption experiments, and other one strongly joined that remains in the soil.
摘要:
在过去的几十年中,由于集约化的农业和过度的人类消费,土壤中抗生素的存在急剧增加。粘土矿物是对有机污染物具有较大吸附能力的土壤组分之一。抗生素与矿物表面相互作用的研究将为我们提供有关土壤中这些污染物的科学知识。在这项工作中,我们研究了抗生素环丙沙星在圣罗莎(Corrientes)阿根廷地区土壤的粘土矿物中的吸附,在蒙脱石层间空间中环丙沙星插层的实验和原子模型计算的协作研究中。进行了吸附和解吸等温线,并与不同的等温线模型进行了比较。此外,焓,熵,和自由能由温度函数下的平衡常数确定。所有这些实验和计算得出的结论是,在粘土矿物上发现了两种吸附类型的环丙沙星:一种在解吸实验期间释放的弱吸附类型。和另一个强烈加入,留在土壤中。