摘要
以天然沸石为载体，采用FeCl3水解法制备用于磷吸附的载铁沸石（β-FeOOH-Z），优化β-FeOOH-Z的制备条件，包括FeCl，溶液浓度、负载pH值、负载时间、负载温度和烘干温度，并利用x射线衍射（XRD）和傅里叶变换红外光谱（FTIR）对β-FeOOH-Z及其磷吸附特性进行分析。结果表明，β-FeOOH-Z的优化制备条件为：FeCl3溶液浓度1mol／L、负载pH值6、负载时间24h、负载温度25℃和烘干温度60℃。优化制备条件下，100-120目沸石的载铁量为100．2mg／g，铁的负载率为18％，其磷吸附量为7．68mg／g，比天然沸石提高79．6％。XRD分析结果表明，β-FeOOH-Z中的杂质元素较天然沸石减少，并有效负载β-FeOOH；制备条件对β-FeOOH-Z的成分有较大影响，FeCl，溶液浓度较低、负载温度和烘干温度过高均使β-FeOOH-Z中含有α-Fe2O3，并导致其磷吸附效率降低。FTIR分析结果表明，β-FeOOH-Z的表面羟基在其吸附磷过程中起重要作用，羟基与磷酸根离子的配位交换是β-FeOOH-Z吸附磷的主要作用机制。
Zeolite loaded with β-FeOOH （β-FeOOH-Z） was prepared by hydrolysis of FeCl3 and coating on natural zeolite. Preparation conditions including FeCl3 concentration, pH, reaction time, reaction temperature and drying temperature were optimized. In addition, the β-FeOOH-Z was characterized with X-ray diffraction （XRD） and Fourier transform infrared spectroscopy （FTIR）. The results showed that the optimal preparation conditions were： FeCl3 concentration of l mol/L, pH of 6, reaction time of 24 h, reaction temperature of 25℃ and drying temperature of 60℃. Under the optimal preparation conditions, the obtained β-FeOOH-Z has particle size of 100 - 120 mesh, iron load amount of 100.2 mg/g and iron load ratio of 18%. Its adsorption capacity for phosphorus was 7.68 mg/g, which increased by 79.6% compared with that of the natural zeolite. XRD analysis showed that content of impurity elements in the β-FeOOH-Z was lower than that in natural zeolite, and theβ- FeOOH was effectively loaded on the natural zeolite. The composition of β-FeOOH-Z was greatly influenced by the preparation conditions, and low FeCl3 concentration, high reaction temperature and high drying temperature led to formation of α-Fe203, which reduced the efficiency of phosphorus adsorption. FTIR spectra of the β- FeOOH-Z suggested that surface hydroxies on the β-FeOOH-Z played an important role for phosphorus adsorption and ligand exchange between hydroxies and phosphate ions is the main adsorption mechanism.
出处
《环境工程学报》
CAS
CSCD
北大核心
2014年第2期499-504,共6页
Chinese Journal of Environmental Engineering
基金
国家自然科学基金资助项目(51178047)
