羟基磷灰石(HAP)是一种易于合成的,低成本矿物,已被认为是一种潜在的氟化物去除材料。HAP的一些合成方法非常简单且具有成本效益,而有些需要先进的实验室条件下复杂的合成技术。这篇综述评估了通过各种技术生产的HAP和HAP基复合材料的物理化学特性,他们最近在除氟方面的发展,最重要的是,除氟性能。第一次,根据分配系数(KD)而不是最大吸附容量(Qmax)比较了HAP和HAP复合材料的除氟性能,其受初始加载浓度的显著影响。新型HAP定制的复合材料表现出相对较高的KD值,表明其出色的氟化物去除能力以及高于120m2/g的比表面积。HAP掺杂铝配合物,HAP掺杂陶瓷珠,HAP-果胶纳米复合材料和HAP-stilbite纳米复合材料,HAP装饰纳米管,纳米线和纳米片表现出高Qmax和KD。HAP的秘密不是优异的除氟性能,而是在中性和接近中性的pH值下的最佳去除。大多数去氟材料都无法做到,使它们成为饮用水处理的理想吸附剂。多种机制,包括物理表面吸附,离子交换,和静电相互作用是脱氟的主要机制。进一步的研究工作必须集中在用于商业规模的脱氟的升级HAP基复合材料上。
Hydroxyapatite (HAP) is an easily synthesizable, low-cost mineral that has been recognized as a potential material for fluoride removal. Some of the synthesis methods of HAP are quite straightforward and cost-effective, while some require sophisticated synthesis techniques under advanced laboratory conditions. This
review assesses the physicochemical characteristics of HAP and HAP-based composites produced via various techniques, their recent development in
defluoridation and most importantly, the fluoride removal performances. For the first time, fluoride removal performances of HAP and HAP composites are compared based on partition coefficient (KD) instead of maximum adsorption capacity (Qmax), which is significantly influenced by initial loading concentrations. Novel HAP tailored composites exhibit comparatively high KD values indicating the excellent capability of fluoride removal along with specific surface areas above 120 m2/g. HAP doped with aluminium complexes, HAP doped ceramic beads, HAP-pectin nanocomposite and HAP-stilbite nanocomposite, HAP decorated nanotubes, nanowires and nanosheets demonstrated high Qmax and KD. The secret of HAP is not the excellent fluoride removal performances but best removal at neutral and near-neutral pH, which most of the
defluoridation materials are incapable of, making them ideal adsorbents for drinking water treatment. Multiple mechanisms including physical surface adsorption, ion-exchange, and electrostatic interactions are the main mechanisms involved in
defluoridation. Further research work must be focused on upscaling HAP-based composites for
defluoridation on a commercial scale.