影响γ-HCH在辽河沉积物表面上光化学降解行为因素

Photocatalytic degradation of γ-HCH affected by different components on surface of sediments in Liao River

γ-HCH在14种辽河(新民段)沉积物表面上的光化学降解行为符合准一级动力学.采用偏最小二乘(partialleastsquares,PLS)算法建立了沉积物组成与γ-HCH光解速率常数之间的定量关系模型,应用该模型可以预测γ-HCH在不同沉积物表面上的光解速率常数.该模型说明,沉积物中总碳、有机碳和无机碳质量分数的增多可抑制γ-HCH的光解,而Fe2O3和TiO2质量分数的增多对γ-HCH的光解有促进作用.

The photolysis of γHCH on the surface of fourteen different component sediments collected from the Xinmin section of the Liao River in China has been studied. The results of this research show that photodegradation of γHCH follows pseudo firstorder kinetics. Based on the different components, such as total carbon, organic carbon, inorganic carbon, Fe2O3 and TiO2 contents in sediments, a model which could be used to predict the photodegradation rate constant of γHCH in different surface sediments was developed by using partial leastsquares (PLS) analysis. It was concluded from the model that the main factors affecting photodegradation of γHCH in surface sediments using 365 nm UV as light source were total carbon, organic carbon, Fe2O3 contents in sediments. The photodegradation rate was inhibited by increasing total carbon, organic carbon, inorganic carbon contents, whereas the rate was accelerated by increasing selected oxides, such as Fe2O3 and TiO2 contents in the sediment samples.