脱木素方法对木材吸附亚甲基蓝的影响

Effect of delignification methods on the methylene blue adsorption of wood

【目的】以巴沙木(Ochroma pyramidale)为原材料,使用不同试剂对其进行脱木素处理,探讨不同脱木素木材对亚甲基蓝(MB)的吸附性能。【方法】采用单因素分析方法,考察了初始质量浓度、接触时间、环境温度、初始pH值对3种脱木素木材吸附亚甲基性能的影响,并对其吸附动力学进行了研究。【结果】脱木素提高了木材的孔隙率和表面活性官能团含量。按照方法1得到的脱木素木材(DW1)和方法2得到的脱木素木材(DW2)对亚甲基蓝的吸附效果均明显优于方法3得到的脱木素木材(DW3),这说明脱木质素方法对木材吸附亚甲基蓝具有显著影响。在35℃、MB溶液质量浓度30 mg·L^(-1)、pH=10条件下,DW1对亚甲基蓝的吸附效果最好,最大吸附容量为12.47 mg·g^(-1)。脱木素木材对亚甲基蓝的吸附过程更符合准二级动力学模型和Langmuir吸附等温方程。【结论】与天然木材相比,脱木素木块可以提高对亚甲基蓝的吸附量,且不同脱木素方法得到的木块对亚甲基蓝的吸附效果有所不同。低价、简单处理的脱木素木块在水处理方面具有很大的潜在价值。

【Objective】Basha wood(Ochroma pyramidale)was used as raw material and delignified with different reagents to study the adsorption properties of different delignified wood for methylene blue(MB).【Method】The effects of initial concentration,contact time,ambient temperature and initial pH on the methylene adsorption of three kinds of delignified wood were investigated by single factor analysis,and their adsorption kinetics were studied.【Result】Delignification increased the porosity and the content of surface active functional groups of wood.The adsorption effect of the delignified wood by method 1(DW1)and Method 2(DW2)on methylene blue was significantly better than that of the delignified wood by method 3(DW3),which indicated that the method of delignification had a significant effect on the adsorption of methylene blue on wood.Under the condition of 35℃,the concentration of MB solution 30 mg·L^(-1) and pH 10,the adsorption effect of DW1 for methylene blue is the best,and the maximum adsorption capacity is 12.47 mg·g^(-1).The adsorption process of methylene blue on delignified wood is more consistent with the pseudo-second-order kinetic model and Langmuir adsorption isotherm equation.【Conclusion】Compared with natural wood,delignified wood blocks can increase the adsorption capacity of methylene blue,and the adsorption effects of wood blocks obtained by different delignification methods are different.The delignified wood blocks with low price and simple treatment have great potential value in water treatment.