工业水处理 ›› 2023, Vol. 43 ›› Issue (3): 55-63. doi: 10.19965/j.cnki.iwt.2022-0425

• 试验研究 • 上一篇    下一篇

槟榔渣生物炭对水中亚甲基蓝的吸附特性及机制

陈佼1,2(), 李晓媛1, 刘钰洁2, 陆一新1,2,3()   

  1. 1.成都工业学院材料与环境工程学院, 四川 成都 611730
    2.西南交通大学地球科学与环境工程学院, 四川 成都 611756
    3.国家环境保护水土污染协同控制与联合修复重点实验室, 四川 成都 610059
  • 收稿日期:2023-01-05 出版日期:2023-03-20 发布日期:2023-03-21
  • 通讯作者: 陆一新 E-mail:401603414@qq.com;yxlu61@163.com
  • 作者简介:陈佼(1987— ),博士,副教授。E-mail:401603414@qq.com
    陆一新,博士,教授。E-mail:yxlu61@163.com
  • 基金资助:
    国家自然科学基金项目(21705133);国家环境保护水土污染协同控制与联合修复重点实验室开放基金项目(GHBK-2021-004);四川省科技计划项目(2022YFG0307);国家级大学生创新训练计划项目(202211116025)

Adsorption characteristics and mechanism of methylene blue in aqueous solution by areca residue biochar

Jiao CHEN1,2(), Xiaoyuan LI1, Yujie LIU2, Yixin LU1,2,3()   

  1. 1.School of Materials and Environmental Engineering,Chengdu Technological University,Chengdu 611730,China
    2.Faculty of Geosciences and Environmental Engineering,Southwest Jiaotong University,Chengdu 611756,China
    3.State Environmental Protection Key Laboratory of Synergetic Control and Joint Remediation for Soil & Water Pollution,Chengdu 610059,China
  • Received:2023-01-05 Online:2023-03-20 Published:2023-03-21
  • Contact: Yixin LU E-mail:401603414@qq.com;yxlu61@163.com

摘要:

分别在300、500、700 ℃条件下对废弃槟榔渣进行慢速热解180 min制得槟榔渣生物炭ARB300、ARB500、ARB700,探讨了其对水中亚甲基蓝(MB)的吸附性能及动力学、热力学特征,并通过电镜扫描、比表面积分析、红外光谱分析等手段对吸附机制进行了解析。结果表明,当溶液初始pH为9,ARB300、ARB500、ARB700投加质量浓度分别为1.0、0.7、0.5 g/L时,MB去除率均高于95%。准二级动力学模型和Langmuir等温吸附模型能更真实地反映MB在ARB上的吸附行为特征,该吸附行为符合单分子层化学吸附规律。热力学分析表明,吸附反应的ΔG<0,ΔH>0,ΔS>0,反映出ARB对MB的吸附是自发、吸热且熵驱动的过程。具体吸附机制涉及静电引力、孔隙填充、π-π作用、氢键作用等。ARB700对MB的理论最大吸附量达86.51~97.78 mg/g,分别比ARB300、ARB500相应的值提高了72.54%~85.37%、6.31%~8.30%,可作为废水中MB的高效吸附材料。

关键词: 生物炭, 槟榔渣, 热解温度, 亚甲基蓝, 吸附机制

Abstract:

Wasted areca residue biochars ARB300,ARB500 and ARB700 were produced by slow pyrolysis of waste areca residue at 300,500 and 700 ℃ for 180 min,respectively. Their adsorption properties,kinetics and thermodynamic characteristics for MB in aqueous solution were explored. The adsorption mechanism was discussed by SEM,BET and FTIR analysis. The results indicated that the MB removal rate was higher than 95% when the initial solution pH was 9 and the ARB300,ARB500 and ARB700 dosage were 1.0,0.7 and 0.5 g/L,respectively. The quasi second-order kinetic model and Langmuir isothermal adsorption model could more truly reflect the adsorption behavior characteristics of MB on ARB,which was in line with the law of monolayer chemical adsorption. Thermodynamic analysis showed that the adsorption reaction ΔG<0,ΔH>0,ΔS>0,reflecting that the adsorption of MB by ARB was a spontaneous,endothermic and entropy driven process. The specific adsorption mechanisms included electrostatic gravitation,pore filling,π-π bonding and hydrogen bonding,etc. The theoretical maximum MB adsorption capacity of ARB700 was up to 86.51-97.78 mg/g,which was 72.54%-85.37% and 6.31%-8.30% higher than that of ARB300 and ARB500 respectively. It could be considered as a high-performance adsorption material for eliminating MB from wastewater.

Key words: biochar, areca residue, pyrolysis temperature, methylene blue, adsorption mechanism

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