Terzioğlu Pinar, Yücel Sevil, Öztürk Mehmet
Department of Chemistry, Faculty of Science, Muğla Sıtkı Koçman University, Kötekli 48000, Turkey E-mail:
Department of Bioengineering, Faculty of Chemistry and Metallurgy, Yildiz Technical University, Esenler, Istanbul 34210, Turkey.
Water Sci Technol. 2017 Jan;75(2):358-365. doi: 10.2166/wst.2016.526.
The main objective of the present study was to optimize lead adsorption onto zeolite NaA. For this purpose, to synthesize zeolite NaA under hydrothermal conditions, local wheat husk was precleaned with chemical treatment using hydrochloric acid solution. The unmodified (ZU) and NaCl-modified (ZN) zeolites were characterized by Brunauer-Emmett-Teller, scanning electron microscopy coupled with energy dispersive spectroscopy and X-ray diffraction. The optimization of adsorption process was examined using Box-Behnken Experimental Design in response surface methodology by Design Expert Version 7.0.0 (Stat-Ease, USA). The effects of initial lead (II) concentration, temperature, and time were selected as independent variables. Lack of fit test indicates that the quadratic regression model was significant with the high coefficients of determination values for both adsorbents. Optimum process conditions for lead (II) adsorption onto ZU and ZN were found to be 64.40°C and 64.80°C, respectively, and 90.80 min, and 350 mg L initial lead(II) concentration for both adsorbents. Under these conditions, maximum adsorption capacities of ZU and ZN for lead (II) were 293.38 mg g and 321.85 mg g, respectively.
本研究的主要目的是优化铅在沸石NaA上的吸附。为此，为了在水热条件下合成沸石NaA，使用盐酸溶液对当地麦壳进行化学预处理。通过布鲁诺尔-埃米特-泰勒法、扫描电子显微镜结合能谱和X射线衍射对未改性（ZU）和NaCl改性（ZN）的沸石进行了表征。使用Design Expert Version 7.0.0（美国Stat-Ease公司）的响应面方法中的Box-Behnken实验设计来研究吸附过程的优化。选择初始铅（II）浓度、温度和时间作为自变量。失拟检验表明，二次回归模型对于两种吸附剂均具有较高的决定系数值，具有显著性。发现铅（II）在ZU和ZN上吸附的最佳工艺条件分别为64.40°C和64.80°C，时间均为90.80分钟，两种吸附剂的初始铅（II）浓度均为350 mg/L。在这些条件下，ZU和ZN对铅（II）的最大吸附容量分别为293.38 mg/g和321.85 mg/g。
