摘要
为探讨高炉渣去除水中铅的机理,采取等温吸附实验研究了高炉渣吸附铅的热力学特征,应用傅里叶红外光谱(FTIR)、X射线衍射(XRD)技术相结合的方法比较了吸附前后谱图的变化。实验结果表明,高炉渣吸附铅的平衡时间约为120 min;Freundlich方程可以很好地拟合不同温度下的吸附过程;平衡吸附量随温度升高有所减小,吉布斯自由能变化量为负值,吸附反应为一个自发放热过程。谱图分析显示,红外光谱980-1 100 cm^-1和515 cm^-1处波峰变化较为明显,X射线衍射谱在衍射角等于25°和35°附近出现了新峰;说明高炉渣内的Si—O—Si是主要吸附位点,参与反应的主要是炉渣内的硅氧键。
The adsorption mechanism of lead by blast-furnace slag(BFS) was studied,both the infrared spectroscopy and X-ray diffraction were used to analyse the changes of the patterns before and after adsorption,the thermodynamic characteristic was investigated using the adsorption isotherm experiment.The results showed that the time for equilibrium in the adsorption was 120 min and the Freundlich equation was optimal to simulate the adsorption of lead.The adsorption capacity at equilibrium decreased with the increased temperature and the Gibbs free angey changes (ΔG0) were negative,which indicated that the adsorption of lead by BFS was an exothermic and spontaneous process.Two adsorption bands appeared at 980-1 100 cm^-1 and around 515 cm^-1,some new diffraction peaks appeared at around 25° and 35° 2θ,which suggested that the adsorption of lead is mainly due to the site of Si—O—Si in the blast-furnace slag.
出处
《环境工程学报》
CAS
CSCD
北大核心
2010年第7期1473-1477,共5页
Chinese Journal of Environmental Engineering
基金
水体污染控制与治理科技重大专项子课题(2008ZX07425-004-02)
关键词
高炉渣
铅
吸附热力学
红外光谱
X-射线衍射
blast-furnace slag
Pb(Ⅱ)
adsorption thermodynamics
infrared spectroscopy
X-ray diffraction