水热、热裂解制备稻秸炭的表征与吸附特性

以稻秸为原料,分别通过水热炭化和热裂解炭化制备稻秸炭(分别记为水热炭和热解炭),通过傅立叶红外线光谱(FT-IR)、X射线衍射(XRD)、扫描电子显微镜(SEM)和BET分析,比较两种稻秸炭的差异,通过亚甲基蓝、Cu²⁺的吸附实验,分析其对有机物与金属离子的吸附性能。结果表明:水热炭表面含有更丰富的含氧官能团,结构更加规整,但比表面积低于热解炭;水热炭对亚甲基蓝的吸附能力略低于热解炭,但对Cu²⁺的吸附能力显著高于热解炭;两种稻秸炭对亚甲基蓝的吸附及热解炭对Cu²⁺的吸附通过表面吸附及颗粒内扩散共同发挥作用,更符合Freundlich模型;水热炭通过表面含氧官能团与Cu²⁺相互作用,对吸附Cu²⁺具有显著优势,Langmuir模型更适合于对其吸附数据进行拟合。

Characterization and adsorption properties of rice straw carbon prepared by hydrothermal and pyrolytic treatment

Preparation of hydrothermal carbonization and pyrolytic carbonization products with rice straw as raw material,the characterization of the two carbon products,namely hydrothermal carbon(HC)and pyrolytic carbon(PC)was compared by Fourier transform infrared spectroscopy(FT-IR),X-ray diffraction(XRD),scanning electron microscope(SEM)and BET analysis,and the adsorption performance of organic compounds and metal ions were analyzed by methylene blue and Cu^2+adsorption test.The results showed that the HC contained a richer oxygen-containing functional group on the surface and its structure was more regular than PC,but its specific surface area was smaller.The adsorption capacity for methylene blue of HC was slightly lower,and the adsorption capacity for Cu^2+was significantly higher than that of PC.The adsorption of methylene blue on both carbon products and Cu^2+on PC mainly depended on the interaction of surface adsorption and particle diffusion,and the adsorption data more fit with Freundlich model.Through the interaction of oxygen-containing functional groups with Cu^2+,HC had remarkable advantages in the adsorption of metal ions,and Langmuir model was more suitable for the adsorption data fitting.