| The lakes are more than freshwater resources in our country, which could be used for the regulation and storage of water, irrigation, supplying water, aquiculture, shipping, climate regulation and tourism development comprehensively. With the rapid development of urbanization, as well as more materialize living brought by modern industry, the natural environment is suffering serious damage, especially for the lakes. Up to now, the lakes are facing widespread problem of eutrophication, besides serious chemical pollution. Especially with applications of synthesis chemical in daily lives, industrial and agricultural production, various "emerging" pollutants is drawing more notice. Those pollutants present new challenges for the lake pollutant prevention in China. This study focuses on behavioral characteristics of lake sediments on adsorption of Benzotriazole, a nitrogen-containing toxic organic pollutant. Qualitative and quantitative methods are used to analysis physical and chemical properties of lake sediments, in order to represent the adsorption process. The conclusions are as follows:1.The adsorption kinetics experiment showed that adsorption equilibrium of benzotriazole on the lake sediments could be divided into three stages. Twenty minutes before the balance was a fast adsorption stage, which has a positive correlation with time until the maximum at3hours. Followed by the slow adsorption stage which lasted3-6hours. After6hours there was the equilibrium phase, in which benzotriazole had a balance between the two phases. This indicated that different adsorption mechanisms were involved in this process.2.The adsorption isotherm experiments showed that the adsorption isotherms of benzotriazole on sediment were fitted by linear and nonlinear models; with the correlation coefficients of more than0.99. According to the correlation coefficient, Langmuir adsorption model was better to describe the adsorption process than Freundlich one.3.Many factors, such as pH value, ionic strength, temperature, concentrations of anions, can affect the adsorption process of benzotriazole on sediment.â‘ The adsorption of benzotriazole on sediment surface was in positive correlation with pH,But the pH had little effect on the benzotriazole adsorption on Taihu sediments;â‘¡The surface sorption capacity of benzotriazole on sediment decreased with Ca2+concentration.â‘¢The increase of temperature resulted in a decrease of benzotriazole adsorption capacity on sediment;â‘£The effect of different anions on the adsorption capacity of benzotriazole on sediment was in the order of Cl"<NO3-<SO42-. |
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