摘要
采用紫外可见分光光度法，测量萘系减水剂（PNS）在粉煤灰颗粒表面的吸附量，研究温度、吸附时间和PNS初始质量浓度对吸附量的影响。结果表明：吸附量随吸附时间的变化关系符合准二级动力学方程，平衡吸附量随吸附平衡质量浓度的变化关系符合Langmuir等温吸附方程；随着温度的升高，吸附平衡质量浓度减小，平衡吸附量和饱和吸附量增大；饱和吸附量随温度的变化关系基本满足Clausius—Clapeyron方程，标准吸附焓为-7．8kJ／mol，在较低温度下，吸附以物理吸附为主，随着温度升高，化学吸附作用凸显。
The amount of PNS adsorbed on the surfaces of fly ash particles was measured via UV-visible spectrophotometry, and the effects of temperature, time and initial concentration of PNS on adsorption quantity were analyzed. The results showed that：the relationship between adsorption quantity and time fits the pseudo second-order adsorption kinetic equation, and the relationship between adsorption quantity at equilibrium and equilibrium concentration fits the Langmuir adsorption isotherm equation;when the temperature is elevated, the equilibrium concentration decreases, and the adsorption quantity at equilibrium and the maximum adsorption increased;the relationship between maximum adsorpt{on and temperature meets welt with Clausius-Clapeyron equation, and the standard adsorption enthalpy is -7.8kJ/mol. Physics adsorption dominates in the process when experiment temperature is relatively low, but chemical sorptions becomes apparent as the temperature increases.
基金
国家科技支撑计划（2011BAJ04B02）
关键词
萘系减水剂
粉煤灰
动力学
热力学
标准吸附焓
naphthalene-based superplasticizer
fly ash
kinetics
thermodynamics
standard adsorption enthalpy
