摘要
以1种商品腐殖酸(HA)为研究对象,以粉末活性炭(PAC)为吸附剂,测定了不同温度下HA在PAC上的吸附平衡。结果表明,在初始HA(以TOC表征)的质量浓度为10～65 mg/L时,较好的符合Langmuir模型,属于均质吸附。不同初始HA含量的分段吸附表明,在10～40 mg/L的低负载条件下,吸附质首先占据少量存在的非均质高活性点位,吸附平衡更好的符合Freundlich模型;在TOC的质量浓度为30～65 mg/L的较高负载条件下,高活性点位被占据,另一类大量存在于PAC表面的均质低活性点位则被利用,吸附平衡表现为均质吸附,模拟结果更符合Langmuir模型。热力学分析表明,PAC对HA的吸附是自发的放热熵减过程,吸附后液相体系中的混乱度变小。
Adsorption isotherms ofhumic acid （HA） on the powder activated carbon （PAC） at different temperature were determined and the results were simulated. It showed that in the whole range of HA concentration conducted in the experiments （10-65 mol/L of TOC）, the experiment data were better fitted with Langmuir model, indicating the sorption sites would be identical. When simulating the experiment data in the segmented HA concentration, it showed that in the low HA concentration range （10-40 mol/L of TOC）, the simulation result was more fitting to Freundlieh model, which involved very active and diverse but weakly present sites at the surface of PAC; whereas in the high HA concentration range （30-65 mol/L of TOC）, the very active sites were occupied, and the less active but strongly present and identical sites at the PAC surface reacted with HA, leading the better fitting for Langmuir model. Thermodynamic analysis results indicated that HA adsorbed by PAC was a spontaneous exothermic process with entropy reduction, and the chaotic degree of HA decreased after adsorption.
出处
《水处理技术》
CAS
CSCD
北大核心
2014年第1期29-32,36,共5页
Technology of Water Treatment
基金
陕西省重点科技创新团队计划(2013KCT-13)
陕西省教育厅专项基金资助(12JK0649)
关键词
腐殖酸
活性炭
等温吸附
分段模拟
热力学分析
humic acid
powder activated carbon
isothermal adsorption
segmented simulation
thermodynamic analysis
