纳米TiO_(2)/改性煤矸石复合材料的制备及性能研究

Synthesis and property of nano-TiO_(2)/modified coal gangue composite

以改性煤矸石为载体,以Ti(SO4)2为钛源,采用水热法制备纳米TiO_(2)/改性煤矸石复合材料,并以其为吸附剂,用于甲基橙模拟印染废水的吸附实验。研究了复合材料中TiO_(2)的质量分数、吸附剂用量、吸附时间、模拟废水浓度和pH对吸附性能的影响。正交试验结果表明,TiO_(2)质量分数为25%,吸附剂用量为3g,模拟废水浓度为5mg/L,pH为4,在25℃恒温条件下,震荡吸附210min,甲基橙的吸附去除率达到94.83%。吸附过程符合准二级动力学模型和Langmuir吸附等温线,属于单分子层吸附。用X射线衍射(XRD)、傅里叶变换红外光谱(FT-IR)和扫描电镜(SEM)对吸附剂进行表征,结果显示,TiO_(2)以锐钛矿型结构形式被成功负载于改性煤矸石表面,复合材料表面的羟基和钛氧键等官能团提高了对甲基橙的吸附脱色性能。

With the modified coal gangue as the carrier,Ti(SO4)2 as the titanium source,nano-TiO_(2)/modified coal gangue composites were prepared by hydrothermal method.The composites were used as the adsorbent,in the adsorption test of printing and dyeing wastewater simulated by methyl orange.The effects of TiO_(2) content,adsorbent dosage,adsorption time,simulated wastewater concentration and pH on the adsorption properties of the composites were studied.The results of orthogonal test showed that the mass fraction of TiO_(2) was 25%,the amount of adsorbent was 3 grams,the concentration of simulated wastewater was 5 mg/L,the pH was 4,and under the condition of constant temperature of 25℃for 210 min,the removal rate of methyl orange reached 94.83%.The adsorption process was in accordance with the quasi-second-order kinetic model and Langmuir adsorption isotherm,which belonged tomonolayer adsorption.The adsorbent was characterized by X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FT-IR)and scanning electron microscopy(SEM).The results showed that TiO_(2) was successfully loaded on the surface of modified gangue in the form of anatase structure,and the functional groups such as hydroxyl group and TiO_(2) bonded on the surface of composite material improved the adsorption and decolorization performance of methyl orange.