污泥基生物炭制备及其对亚甲基蓝吸附性能研究

Preparation of sludge biochar and its methylene blue adsorption properties

污泥作为放错地方的资源,可将其进行水热炭化生成生物炭对亚甲基蓝进行吸附。以剩余污泥为原材料,采用水热炭化法制备污泥基生物炭,通过正交实验,探索不同温度、固液比、水热时间、pH条件下制备污泥基生物炭的最佳条件及其对亚甲基蓝的吸附性能。结果表明,水热炭化法制备污泥基生物炭的最佳条件为:温度200℃,固液比1∶10,时间2 h,pH为7,最佳条件制得的污泥基生物炭吸附容量为111.11 mg/g。水热炭化后,污泥基生物炭的吸附位点明显增加,水热炭化后的污泥基生物炭具有较强的芳香性,吸附过程符合准二级动力学方程和Langmuir模型,为受化学吸附过程控制的单分子层吸附。剩余污泥在最佳条件水热炭化生成的生物炭对亚甲基蓝具有良好的吸附性能。

As a misplaced resource,sludge can be hydrothermally carbonized to produce biochar for methylene blue adsorption.Sludge-based biochar was prepared by hydrothermal carbonization of excess sludge,the optimal conditions for the preparation of sludge-based biochar at different temperatures,solid-liquid ratio,hydrothermal time and pH were investigated,as well as its adsorption properties for methylene blue.The results showed that the optimal conditions for the preparation of sludge-based biochar by hydrothermal carbonization were as follows:temperature 200℃,solid-liquid ratio 1∶10,time 2 h,pH 7,and adsorption capacity of sludge-based biochar was 111.11 mg/g.After hydrothermal carbonization,the adsorption sites of the sludge-based biochar increased obviously,and the sludge-based biochar after hydrothermal carbonization had strong aromaticity.The adsorption process accorded with the quasi-second-order kinetic equation and Langmuir model,it is a monolayer adsorption controlled by chemical adsorption process.The biochar formed by the hydrothermal carbonization of the excess sludge under the optimal conditions has good adsorption properties for methylene blue.