污泥活性炭的结构特征及表面分形分析

Structure Characterization and Surface Fractal Analysis of Sludge Activated Carbon

以城市污水厂污泥为主要原料添加适量添加剂,采用ZnCl2化学活化法制备的污泥活性炭,借助XRD,BET法,FT-IR,SEM等现代分析测试方法结合液相吸附法,表征结构特征和分析表面分形维数.结果表明:在适宜的活化温度、活化时间、ZnCl2浓度、原料粒度等工艺条件下,加入少量添加剂制备的污泥活性炭,最可几孔径分布在4.16nm左右,平均孔容0.4484～0.5122mL?g-1,比表面积为634.8～748m2?g-1,IR峰中出现C—OH,C—H,N=O,C=C功能组,孔结构是具有平行壁的狭缝状介孔结构.由液相吸附法得到的污泥活性炭分维近似为2,属于低分维二维表面.

Using municipal wastewater sludge as raw material, sludge activated carbon was prepared by ZnCl2 activation agent and addition of adequate additive. Its structure and absorption were characterized by means of adsorption isotherms, XRD, BET, FT-IR, SEM, etc., and its fractal dimension D value was determined by the method of adsorption from solution. The results show that the activated carbon produced under the condition of favourable pyrolyzation temperature, solution concentration of ZnCl2-immersed sludge, particle diameter of the raw material and adequate additive, exhibited BET surface area of 634.8-748 m^2.g^-1 and the most probable pore size of ca. 4.16 nm. Its IR peaks of C-OH, C-H, N=O and C=C confirmed existence of corresponding function groups. It has narrow mesoporous structure with parallel wall. The obtained fractal dimension D value of the sludge activated carbon derived by the method of adsorption from solution is close to 2. The sludge activated carbon can be characterized by low fractal dimension.