油菜秸秆生物炭对水中亚甲基蓝的吸附性能研究  

Adsorption of Methylene Blue inWater by Rape Straw Biochar

作　　者：陈佼 李晓媛 李滨伶 孙解语 黄雯 陆一新[1,2] CHEN Jiao;LI Xiaoyuan;LI Binling;SUN Jieyu;HUANG Wen;LU Yixin(School of Materials and Environmental Engineering,Chengdu Technological University,611730;Faculty of Geosciences and Environmental Engineering,Southwest Jiaotong University,611756 Chengdu,China)

机构地区：[1]成都工业学院材料与环境工程学院,611730 [2]西南交通大学地球科学与环境工程学院,四川成都611756

出　　处：《水处理技术》2022年第12期37-42,47,共7页Technology of Water Treatment

基　　金：国家自然科学基金项目(21705133);四川省科技计划项目(2022YFG0307,2022NSFSC0393);四川省环境污染防治重点研发项目(2017SZ0179);国家级大学生创新训练计划项目(202211116025);成都工业学院校级科研项目(2022ZR001)。

摘　　要：以油菜秸秆为原料,采用限氧热解法在300℃、500℃、700℃条件下分别制备了油菜秸秆生物炭RSB300、RSB500、RSB700,对其元素组成、表面形貌、官能团分布等理化性质进行了表征,并研究了其对水中亚甲基蓝(MB)染料的吸附性能及机理。结果表明,随着热解温度的提高,RSB的碳化和芳香化程度有所提升,比表面积、总孔容和平均孔径也有所增大。当初始MB质量浓度为50 mg/L,pH为10.0,温度为25℃,RSB_(300)、RSB_(500)、RSB_(700)的投加量分别为0.6、0.4、0.3 g/L时,反应60 min左右达到吸附平衡,RSB700对MB的吸附量达到162.80 mg/g,分别比RSB_(300)、RSB_(500)提高了1.06、0.37倍。不同热解温度下制备的RSB对MB的吸附过程均更符合准二级动力学模型(R2>0.98),吸附等温线则更符合Freundlich模型和Temkin模型(R2>0.96),该吸附过程是自发、吸热、熵驱动的,以化学吸附为主,具体涉及静电引力、氢键、π-π键、离子交换等多重作用机制。RSB700的吸附性能优于RSB300、RSB500,可用作高效吸附水中MB的优选材料。The biochar RSB300,RSB500 and RSB700 were prepared by oxygen-limited pyrolysis at 300℃,500℃and 700℃,respectively,using rape straw as the raw material.The physical and chemical properties such as elemental composition,surface morphology and distribution of functional groups were characterized,and the adsorption performance and mechanism of methylene blue(MB)dye in water were investigated.The results showed that the carbonation and aromatization of RSB increased with the increase of pyrolysis temperature,and the specific surface area,total pore volume and average pore size also increased.When the initial MB mass concentration was 50 mg/L,pH was 10.0,temperature was 25℃,and the dosage of RSB300,RSB500 and RSB700 was 0.6,0.4 and 0.3 g/L respectively,the reaction reached adsorption equilibrium around 60 min,and the adsorption amount of MB by RSB700 reached 162.80 mg/g,which was 1.06 and 0.37 times higher than that of RSB300 and RSB500 respectively.The adsorption of MB by RSB prepared at different pyrolysis temperatures was more consistent with the quasi-secondary kinetic model(R2>0.98),and the adsorption isotherms were more consistent with the Freundlich and Temkin models(R2>0.96),which were spontaneous,heat-absorbing and entropy-driven,with chemisorption as the main mechanism,specifically involving electrostatic gravity,hydrogen bonding,π-πbonding and ion exchange.The adsorption performance of RSB700 is superior to that of RSB300 and RSB500 and can be used as a preferred material for efficient adsorption of MB in water.

关 键 词：油菜秸秆 生物炭 亚甲基蓝 热解温度 吸附机理 

分 类 号：TQ424[化学工程] X703.1[环境科学与工程—环境工程]