基于陶瓷废料的改性泡沫陶瓷对Cd^(2+)的吸附研究

Study on Adsorption of Cd^(2+) by Modified Foamed Ceramics Made by Ceramic Waste

利用有机泡沫浸渍法,以陶瓷废料为原料制备多孔泡沫陶瓷并对其密度、气孔率、抗压强度等电点以及物相进行表征。从红外光谱可以看出,利用γ-氨丙基三乙氧基硅烷(KH550)对泡沫陶瓷改性后,硅烷能很好地枝接在陶瓷表面,从而提高了其吸附Cd^(2+)的能力。用Langmuir吸附模型和Freundlich吸附模型对吸附等温线进行拟合后发现吸附过程比较复杂,但是受pH和温度的影响较大,整个吸附过程可以与准二级动力学很好的拟合,表明吸附过程既有静电吸附又有化学吸附。

The organic foam impregnation method was used to prepare porous foamed ceramics with ceramic waste as raw material. And its density, porosity, compressive strength, point of zero charge(pHpzc) and phase were characterized. It can be seen from the infrared spectrum that the silane is well grafted on the surface of the ceramics after the modification of foamed ceramics with γ-aminopropyl triethoxy silane(KH550). Thus the adsorption ability of Cd^(2+) is improving. The adsorption isotherm does not fit well with Langmuir adsorption model and Freundlich adsorption model. The adsorption process is relatively complex, but it is greatly affected by pH and temperature. The whole adsorption process can fit well with the pseudo-second-order kinetics, indicating that the adsorption process has both electrostatic adsorption and chemical adsorption.