桉树遗态结构HAP/C复合材料对水中Cd^(2+)的吸附性能

Adsorption of Cd(Ⅱ) from Aqueous Solution by the Porous Biomorph-Genetic HAP/C Composite of Eucalyptus Template

利用遗态转化工艺制备获得桉树遗态结构HAP/C复合材料(PBGC-HAP/C),将其用于含Cd(Ⅱ)模拟废水的吸附净化处理,研究了p H、初始含量、投加量、吸附剂粒径和吸附剂种类对Cd(Ⅱ)吸附的影响,并且进行了材料吸附前后进行X射线衍射仪、傅里叶变换红外光谱仪表征和吸附机理探讨。结果表明,对50 m L含Cd(Ⅱ)模拟废水,当pH为5、初始Cd(Ⅱ)质量浓度为5 mg/L、PBGC-HAP/C投加量为0.1 g时,吸附平衡时间为120 min,去除率可达97.88%。Langmuir等温模型和准2级动力学模型更适合描述该吸附过程;材料表面Cd^(2+)取代了部分钙离子位置,表面基团与Cd^(2+)发生络合反应,吸附过程主要以单分子层化学吸附为主,该反应为吸热反应,升高温度有利于吸附进行。

A porous biomorph-genetic composite of Hydroxyapatite/Carbon （PBGC-HAP/C） was prepared with eucalyptus template by morph-genetic process, the composite was used to adsorb Cd（Ⅱ） from simulated wastewater. Effects ofpH, initial concentration of the solution, dosage, adsorbent particle size and kinds on Cd（Ⅱ） adsorption were investigated. The X-ray diffractometer, Fourier transform infrared spectrometer were used to characterize the composite before and after adsorption, and removal mechanism was discussed. The results showed that, for 50 mL simulated wastewater containing Cd（Ⅱ）, when pH, initial mass concentration of Cd（Ⅱ）, PBGC-HAP/C dosage, adsorption time was 5, 5 mg/L, 0.1 g and 120 min respectively, the Cd（Ⅱ） removal rate could reach 97.88%. Langmuir isotherm and the pseudo second-order kinetic model were more suitable for the adsorption process. It is revealed that the calcium ion on the surface of the material was replaced by the cadmium ion, the functional groups on surface could form complex with cadmium ion. The adsorption process was mainly based on the monolayer chemical adsorption, and it was also the endothermal reaction, and raised temperature was conducive to the adsorption process.