童庆,徐慧,樊华,王希,象豫,李昆.Al13改性羟基磷灰石的除氟性能研究[J].环境科学学报,2021,41(7):2748-2757
Al13改性羟基磷灰石的除氟性能研究
- Study on the fluoride removal performance of Al13 modified hydroxyapatite
- 基金项目：国家科技重大专项（No.2017ZX07108-002）；国家科技重大专项（No.2017ZX07501-002）；国家自然科学基金面上项目（No.51778604）；宁夏回族自治区重大项目（No.2019BFG02032）
- 童庆
- 南昌大学资源环境与化工学院, 鄱阳湖环境与资源利用教育部重点实验室, 南昌 330031
- 徐慧
- 中国科学院生态环境研究中心, 环境水质学国家重点实验室, 北京 100085
- 樊华
- 南昌大学资源环境与化工学院, 鄱阳湖环境与资源利用教育部重点实验室, 南昌 330031
- 王希
- 中国科学院生态环境研究中心, 环境水质学国家重点实验室, 北京 100085
- 象豫
- 南昌大学资源环境与化工学院, 鄱阳湖环境与资源利用教育部重点实验室, 南昌 330031
- 李昆
- 南昌大学资源环境与化工学院, 鄱阳湖环境与资源利用教育部重点实验室, 南昌 330031
- 摘要：为了提高羟基磷灰石（HAP）的除氟效果，采用化学沉淀法合成3种不同Al/Ca值的Al13改性后的HAP吸附材料，并对其进行XRD、FTIR、SEM、BET等表征，考察吸附过程中pH的影响，同时通过吸附热力学、吸附动力学等探讨了其除氟性能.结果表明，Al13-HAP材料比HAP更加疏松多孔，当Al/Ca=0.7时，比表面积增大到了137.2 m2·g-1，孔容增大到0.8217 cm3·g-1.FTIR结果表明，Al13的掺入给吸附材料中带入了大量—OH.根据Al13-HAP吸附F-前后的表征，F-主要通过配体交换取代Al13-HAP中的—OH从环境中被去除.当Al/Ca=0.4时，Al13-HAP最大除氟效果达到5.03 mg·L-1；零电荷点pHPZC为8.46，大于HAP的pHPZC，具体表现为对天然水体pH值适用性较广.吸附过程与Langmuir吸附模型以及拟二级动力学模型契合度高，这也证实了化学吸附为主要作用，吸附热力学结果表明Al13-HAP吸附氟是自发的吸热过程.
- Abstract：To improve the fluoride removal efficiency using hydroxyapatite (HAP), three Al13 modified HAP materials with different Al/Ca values were applied, and the materials were characterized by XRD, FTIR, SEM, BET. The influence of pH on fluorine removal efficiency were investigated by calculation of adsorption thermodynamics and adsorption kinetics. The results showed that the Al13-HAP material was more porous than normal HAP. When the value of Al/Ca was 0.7, the specific surface area increased to 137.2 m2·g-1, and the pore volume was 0.8217 cm3·g-1. FTIR results indicated that the incorporation of Al13 brought lots of —OH groups. According to the characterization of materials before and after the adsorption, F- is mainly removed by replacing the —OH in Al13-HAP through ligand exchange. When the value of Al/Ca was 0.4, the maximum fluoride removal efficiency reached 5.03 mg·L-1; the pHPZC for modified material is 8.46, which is greater than the pHPZC of normal HAP, and the results showed that the materials could be applied in a wide pH range. The adsorption process fits well with the Langmuir adsorption model and the pseudo-second-order kinetic model, and the chemical adsorption is the main mechanism. The adsorption thermodynamics results showed that fluorine removal by Al13-HAP is a spontaneous endothermic process.
