Heavy metal removal using SiO2-TiO2 binary oxide:: experimental design approach
Heavy metal removal using SiO2-TiO2 binary oxide:: experimental design approach
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DOI：
10.1007/s10450-007-9042-4
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发表时间：
2008-02-01
影响因子：
3.3
通讯作者：
Matsunaga, Hideyuki
中科院分区：
文献类型：
--
作者：
Ismail, Adel A.;El-Midany, Ayman A.;Matsunaga, Hideyuki
研究了重金属离子Ni ~（2+）和Cd ~（2+）在TiO_2-SiO_2界面上的吸附行为。此外，测量了TiO 2-SiO2基质的物理性质，例如BET表面积、X射线衍射和零电荷点（pH（PZC））。统计设计的实验，以找到吸附的条件下，达到最大的重金属去除。二阶多项式函数用于关联自变量（pH值，金属离子浓度和振荡时间）和响应（重金属去除）。通过计算机程序Design expert（R）（Stat-Ease Inc.）确定回归参数值。多项式模型方程的拟合质量用回归系数R-2表示。结果表明，pH值是影响吸附的最显著因素。反过来，吸附百分比达到100%，在高的初始浓度和长的振荡时间，由于离子和TiO 2-SiO2矩阵之间的羟基化合物的形成。结果表明，存在残差的高斯（正态）分布（实验观察值和模型预测值之间的平方差），并且观察值和预测值之间的差异在+/-5%的范围内。这表明实验进行得很好，结果没有显著误差。
Sorption of Ni2+ and Cd2+ as heavy metals ions at the interface of the binary oxide TiO2-SiO2 was investigated. In addition, physical properties of TiO2-SiO2 matrices such as BET surface area, X-ray diffraction, and point of zero charge (pH(PZC)) were measured. Statistical design of experiments was applied to find the conditions of sorption at which the maximum heavy metal removal was achieved. A second order polynomial function was used to correlate the independent variables (pH, metal ion concentration, and shaking time) and response (heavy metal removal). Values of regression parameters were determined by the computer program, Design expert (R) (Stat-Ease Inc.). The quality of fit of the polynomial model equation was expressed by the regression coefficient R-2. The sorption results showed that the pH is the most significant factor. In turn, the sorbed percentage reached 100% at high initial concentration and long shaking times due to formation of hydroxyl compounds between the ions and TiO2-SiO2 matrices. The results show that there is a Gaussian (normal) distribution of residuals (squared differences between experimentally observed and predicted values from the model), and also that the differences between observed and predicted values are in the range of +/- 5%. These indicate that experiments were well-conducted and the results have no significant error.