Study on the Adsorption Mechanism of Nonylphenol by Soil/Sediment in Lanzhou Section of the Yellow River

Abstract

In order to study the migration and transformation of pollutant on soil/sediment in Lanzhou section of the Yellow River, in this study, nonylphenol (NP) was selected as the target pollutant for an investigation of adsorption kinetic and adsorption isothermal experiments. The results show that the adsorption is described well by the pseudo-second-order kinetic model, occurring at two stages: fast adsorption and slow adsorption. The particle diffusion and surface adsorption were dominant in the sorption process. Adsorption thermodynamics was linear, fitting well with the Freundlich isothermal model. Thermodynamic parameter analysis showed that Gibbs free energy was less than zero, enthalpy and entropy were greater than zero, showing that it is spontaneous, endothermic, and chaos-increasing. The results have important implications regarding the mechanism of sorption and fate of NP in Yellow River.