Soils are highly heterogeneous dynamic mixtures with unique properties. Each soil’s general properties affect its contaminants sorption; thus, obtaining sorption information about any regional soil may require actual sorption experiments. Hence, two soil types (alfisol–AFL and oxisol–OXL) were sampled and used for ivermectin sorption in order to obtain data on sub-Saharan soils for this new emerging contaminant from agriculture. Environmental parameters such as sorption time, ambient solution pH, ivermectin concentration, temperature and desorption were studied, while data were evaluated using two adsorption isotherm models, four kinetic models and the thermodynamics. The soils were neutral, typical of neutral West African soils and having slightly acidic pHpzc with similar particle size description and medium-to-low CEC_eff and SOM. Ivermectin sorption equilibrium was fast at 180 min for both soils. The rate constant k for sorption on AFL soil was slightly faster than for the OXL. Solution pH has some degree of influence on the sorption process which exhibited two sorption optimum peaks; one around pH 3 and the other around pH 9.5. Ivermectin sorption was concentration dependent; there was higher sorption as initial concentration increased, while sorption increased significantly with ambient temperature from 19.5 to 29.5 °C (≈55 %) but there was slight reduction on further temperature increase to 39.5 °C compared to sorption at 29.5 °C (≤1 %). The magnitude of the estimated energetics signaled a non-spontaneous and increasingly random process, with small size of the ΔH° values which were compatible with low energy interactive sorption forces and the overall process was exothermic. The ivermectin sorption process was controlled by external mass transfer (which was concentration dependent), with approximately 81.6 % of sorption occurring on the soil surfaces, while 18.4 % was within the pores or soil phases. The better fits of the sorption data to both the Freundlich adsorption isotherm model and the homogeneous fractal pseudo-second order model are complementary, and confirms that ivermectin sorption process on both soils involves complex interactions on heterogeneous sorption surfaces which include electrostatic interactions, multi–layer adsorption probably facilitated by π-π interactions between surface sorbed ivermectin molecules and those in solution, possibly trapping of ivermectin molecules within the soil pores, and various van der Waals attractive forces. Though ivermectin was rapidly dissipated on these soils, the hysteresis was high; irrespective of the soil, the amount of ivermectin leached per soil was small, in fact less than 6 % of the initial amount sorbed.

土壤是具有独特性质的高度异质的动态混合物。每种土壤的一般特性都会影响其污染物的吸附；因此，获得任何区域土壤的吸附信息可能需要实际的吸附实验。因此，对两种土壤类型（alfisol-AFL 和 oxisol-OXL）进行采样并用于伊维菌素吸附，以获得撒哈拉以南土壤中这种新出现的农业污染物的数据。研究了吸附时间、环境溶液 pH 值、伊维菌素浓度、温度和解吸等环境参数，同时使用两种吸附等温线模型、四种动力学模型和热力学评估数据。土壤是中性的，典型的中性西非土壤，具有微酸性 pHpzc，具有相似的粒度描述和中低 CEC_效果和 SOM。两种土壤的伊维菌素吸附平衡在 180 分钟时很快。速率常数k在 AFL 土壤上的吸附速度略快于 OXL。溶液 pH 对吸附过程有一定程度的影响，表现出两个最佳吸附峰；一个在 pH 3 左右，另一个在 pH 9.5 左右。伊维菌素吸附是浓度依赖性的；随着初始浓度的增加，吸附量增加，而吸附量随着环境温度从 19.5 °C 显着增加到 29.5 °C (≈55 %)，但与 29.5 °C (≤1 %）。估计的能量学的大小标志着一个非自发的和越来越随机的过程，ΔH° 值的小尺寸与低能量相互作用吸附力兼容，并且整个过程是放热的。伊维菌素吸附过程受外部传质控制（取决于浓度），大约 81.6% 的吸附发生在土壤表面，而 18.4% 发生在孔隙或土壤相内。吸附数据与 Freundlich 吸附等温线模型和均质分形伪二阶模型的更好拟合是互补的，并证实伊维菌素在两种土壤上的吸附过程涉及异质吸附表面上的复杂相互作用，包括静电相互作用、多层吸附可能是由表面吸附的伊维菌素分子和溶液中的那些之间的 π-π 相互作用促进的，可能是伊维菌素分子被困在土壤孔隙中，以及各种范德华吸引力。尽管伊维菌素在这些土壤上迅速消散，滞后很高；无论土壤如何，每个土壤浸出的伊维菌素量很小，实际上不到初始吸附量的 6%。