长江万州段悬浮泥沙颗粒物对邻苯二甲酸酯的吸附特性

ADSORPTION OF PHTHALIC ACID ESTERS ON SUSPENDED PARTICULATES FROM THE WANZHOU REACH OF THE YANGTZE RIVER

研究了长江万州段悬浮泥沙对水中邻苯二甲酸酯(DMP,DEHP,DOP)的静态吸附特性。结果表明:DMP,DEHP,DOP3种邻苯二甲酸酯的吸附等温线呈现较为明显的"S"型。当PAEs的初始浓度低于500μg/L时,吸附等温线采用Freundlich等温式与Langmuir等温式拟合较好,当PAEs的初始浓度高于500μg/L,低于试验浓度1000μg/L时,用Linear等温式拟合效果较好,这表明当吸附质浓度较低时,表面吸附起主要作用,随着浓度升高,分配作用逐渐增强。经H2O2处理后的悬浮泥沙达到吸附平衡时,在试验浓度范围内邻苯二甲酸酯的吸附量均高于未处理悬浮泥沙平衡时的吸附量,且其吸附等温线用Freundlich等温式与Langmuir等温式拟合较好,表明处理后的泥沙的吸附作用主要是表面吸附;DMP,DEHP,DOP在开始的2h内,吸附速率较快,3种邻苯二甲酸酯在12h内均能达到吸附平衡。

In this study,PAEs(Phthalic Acid Esters)was selected to study their static adsorption characteristic on suspended particulates from the Wanzhou Reach of the Yangtze River.Several significant results were obtained from the study:the adsorption isotherms of DMP,DEHP,and DOP showed obvious'S' shape.Freundlich and Langmuir sorption isotherm could describe the sorption behaviors when the initial concentration of PAEs is bellow 500μg/L,while Linear sorption isotherm was better when the concentration of PAEs was between 500μg/L and 1 000μg/L.This indicated that the surface sorption played leading role when the adsorbate concentration was low and the partition strengthened gradually as the concentration grew.The adsorption quantity of suspended sediments treated by H2O2was higher than that of suspended sediments not treated by H2O2,when the adsorption equilibrium occured.And Freundlich equation and Langmuir equation fit this adsorption isotherm better,which showed that the absorption type of treated suspended sediments was the surface absorption.Experiments showed a rapid sorption of DMP,DEHP and DOP in the Yangtze River suspended particulates in 2hours,and the sorption equilibrium could be achieved in 12hours.