The adsorption of fluoride by soils influences its mobility and bioavailability. Therefore, the fluoride adsorption process in soils has garnered widespread attention. Yet research on assessing environmental risk based on the characteristics of fluoride adsorption in soil is still limited. Here, a suite of batch experiments were conducted using three soil types with distinct properties. The results demonstrate that soil organic matter (SOM) and pH are critical factors determining fluoride adsorption in soils. Paddy soil (PS) with its higher SOM content has a higher adsorption capacity compared with loessal soil (LS) and brown soil (BS). Under acidic conditions, BS and LS whose Ca²⁺ content is higher exhibited a higher adsorption capacity. The fluoride adsorption process in soils may involve electrostatic adsorption, complexation, and precipitation. The desorption results showed stronger fluoride binding to PS and LS than BS, while the fluoride adsorbed onto BS was almost completely desorbed. This research demonstrates that a deeper understanding of regional differences in soil properties is crucial for better studying the migration and accumulation characteristics of fluoride and its bioavailability in various soils. This study provides a theoretical basis for evaluating the bioavailability, exposure risk, and groundwater pollution risk of fluoride in different soils.

中文翻译：

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不同土壤类型中氟化物吸附的特点：潜在因素及其对环境风险评估的意义


土壤对氟化物的吸附会影响其流动性和生物利用度。因此，土壤中的氟化物吸附过程引起了广泛关注。然而，根据土壤中氟化物吸附特性评估环境风险的研究仍然有限。在这里，使用三种具有不同特性的土壤类型进行了一系列批量实验。结果表明，土壤有机质 （SOM） 和 pH 值是决定土壤中氟化物吸附的关键因素。与黄土 （LS） 和棕壤 （BS） 相比，SOM 含量较高的水稻土 （PS） 具有更高的吸附能力。在酸性条件下，Ca²⁺ 含量较高的 BS 和 LS 表现出较高的吸附能力。土壤中的氟化物吸附过程可能涉及静电吸附、络合和沉淀。解吸结果显示，氟化物与 PS 和 LS 的结合强度高于 BS，而吸附在 BS 上的氟化物几乎完全解吸。这项研究表明，更深入地了解土壤特性的区域差异对于更好地研究氟化物的迁移和积累特性及其在各种土壤中的生物利用度至关重要。本研究为评价不同土壤中氟化物的生物利用度、暴露风险和地下水污染风险提供了理论依据。