ABSTRACT

In groundwater, excess fluoride concentration (>1.5 mg/L) is a primary concern for various countries. Nanoadsorbents have been proven to possess higher adsorption capacity than conventional adsorbents. This review aims to provide insights into recent advancements in the adsorption of fluoride using various nanoadsorbents. Nanoparticles have very high specific surface area but are usually found unsuitable for real field applications as they tend to agglomerate. They are also difficult to recover after use and pose a significant threat to the environment through leaching. These limitations have given rise to the trend of the development of nanocomposites for defluoridation. Nanocomposites often involve a polymeric matrix that serves as a medium for their homogenous dispersion. This reduces agglomeration and leaching into the surroundings without altering the original activities of the nanoadsorbent. This review classifies the fluoride nanoadsorbents into three categories: bare nanoparticles, nanocomposites with nanoparticles inside the porous matrix, and nanocomposites with nanoparticles coated with or anchored on the matrix surface. Critical analyses of the importance and shortcomings of these classes have been presented. In general, bare nanocomposites show the best fluoride adsorption performance compared to other classes of nanoadsorbents.

摘要

在地下水中，氟化物浓度过高 (>1.5 mg/L) 是各国主要关注的问题。纳米吸附剂已被证明具有比传统吸附剂更高的吸附能力。本综述旨在深入了解使用各种纳米吸附剂吸附氟化物的最新进展。纳米颗粒具有非常高的比表面积，但通常被发现不适合实际应用，因为它们容易结块。它们在使用后也难以回收，并通过浸出对环境构成重大威胁。这些局限性导致了开发用于除氟的纳米复合材料的趋势。纳米复合材料通常包含聚合物基质，作为其均匀分散的介质。这减少了团聚和浸出到周围环境中，而不会改变纳米吸附剂的原始活性。该综述将氟化物纳米吸附剂分为三类：裸纳米粒子、纳米粒子在多孔基质内部的纳米复合材料，以及纳米粒子包覆或固定在基质表面的纳米复合材料。对这些课程的重要性和缺点进行了批判性分析。一般来说，与其他类别的纳米吸附剂相比，裸纳米复合材料表现出最好的氟化物吸附性能。和纳米复合材料，纳米颗粒涂有或固定在基质表面。对这些课程的重要性和缺点进行了批判性分析。一般来说，与其他类别的纳米吸附剂相比，裸纳米复合材料表现出最好的氟化物吸附性能。和纳米复合材料，纳米颗粒涂有或固定在基质表面。对这些课程的重要性和缺点进行了批判性分析。一般来说，与其他类别的纳米吸附剂相比，裸纳米复合材料表现出最好的氟化物吸附性能。