废弃胶原纤维固化单宁吸附材料原位Fe_(2)O_(3)微波催化裂解减容研究

Microwave Assisted Pyrolysis of Collagen Fiber-Immobilized Tannins by the Catalysis of in situ Fe_(2)O_(3)

胶原纤维基吸附材料在核素吸附中表现出优异的性能,但同时产生放射性固废的处置问题。针对这一问题,利用原位Fe_(2)O_(3)对胶原纤维固化单宁(CFT)材料进行催化裂解,以实现废弃CFT的有效减容。通过热重分析技术对其热解过程进行研究,结果表明通过将Fe^(3+)负载至CFT(Fe-CFT)再进行裂解,能够使裂解温度降至约450℃,比CFT直接裂解温度降低了约150℃,残渣率降至9.5%。进一步以纳米Fe_(2)O_(3)为传热介质,在微波条件下对Fe-CFT进行裂解,Fe-CFT残渣率降至2.1%。利用傅里叶变换红外光谱仪、X射线衍射仪和元素分析仪对残渣进行表征,结果表明反应过程中Fe^(3+)原位生成的Fe_(2)O_(3)有效促进CFT的氧化裂解。综上,通过原位Fe_(2)O_(3)有效降低CFT的裂解温度,裂解后残渣率低,实现了废弃CFT的安全高效减容。

Collagen fiber based adsorbents have gradually received attention due to their exceptional performances in nuclide adsorption,but the final disposal of those adsorbents remains a concern.In this study,the pyrolysis of collagen fiberimmobilized tannins(CFT)was conducted by the catalysis of in situ Fe_(2)O_(3)for the purpose of safe and effective volume reduction.The pyrolysis process was first investigated through thermogravimetric analysis technique,and it was found that the Fe doped into CFT(Fe-CFT)could lower the pyrolysis temperature to approximately 450℃,which is 150 ℃ lower than that of direct pyrolysis without catalysts,while the residual rate was only 9.5%.Furthermore,the microwave-assisted pyrolysis of Fe-CFT was conducted using nano-Fe_(2)O_(3)as the heat transfer medium,the residual rate of Fe-CFT decreased further to 2.1%.The solid residue was then undertaken Fourier transform infrared spectroscopy,X-ray diffraction and elemental analyses,and it was found that the Fe^(3+)doped into CFT was converted into Fe_(2)O_(3),which effectively promoted the CFT pyrolysis process.In summary,this study innovatively utilizes microwave heating technology to effectively reduce the pyrolysis temperature of CFT through in situ Fe_(2)O_(3) catalysts,and the residual rate is very low,thereby achieving safe and efficient volume reduction of radioactive waste of collagen fiber-based adsorbents.