【作者】 董德明； 花修艺； 李鱼； 杨帆；

【Author】 De-Ming Dong*, Xiu-Yi Hua, Yu Li, Fan Yang College of Environment and Resources, Jilin University, 130012, Changchun

【机构】 吉林大学环境与资源学院；

【Abstract】 Natural freshwater surface coating (biofilm and associated minerals) was one of the most important solid matters that determined the behavior of pollutants such as heavy metals. Compared with particulate matter and sediment, more heavy metals were observed to be associated these films. Therefore, studies concerning heavy metals adsorption to natural surface coatings were of great significance. First, the device used to develop natural surface coatings was designed and manufactured, and the method to develop and collect these films was established. To study the effect of each component of these films, selective extraction method to remove different components from surface coatings selectively was established and improved, referring to that used in the extraction of soils and sediments. A surface coating batch selective extraction device was also designed. Then, the method of selective extraction followed by metal adsorption and statistical analysis was employed to study the heavy metal adsorption behavior of surface coatings and their components. For metal adsorption thermodynamics of surface coatings collected in different natural waters, the adsorption behavior of these films and components was affected by the characteristics of the waters. But for Pb, Cd, Zn and Co adsorption, major contributions were observed from Fe and Mn oxides, especially Mn oxides at low equilibrium concentration. While for Cu adsorption, organic matters contributed most. For metal adsorption kinetics, no significant differences were observed for Pb sorption to these surface coating components. For Cd adsorption, the adsorption rate followed this order: residues > organic matters > Fe oxides > Mn oxides, and Cd adsorption was faster than Pb adsorption. The effects of many factors, such as pH, ionic strength, concomitant organic ligands and heavy metals and even conditions to develop these films, on heavy metal adsorption to surface coatings were also studied. Metals adsorption increased with the increasing of pH, but for some metals such as Pb, adverse effect was observed at high pH range. Ionic strength reduced adsorption and lessened the effect of concomitant heavy metal. The effect of organic ligands was determined by the concentration ratio of ligand to metal, and also addition sequences. For concomitant heavy metals, the effect was determined by the adsorption abilities and concentrations of these heavy metals, and ionic strength. Develop conditions, including the water body, season, depth, size of coexisting particulate matter, pH and so forth. These conditions affected the adsorption by changing the amounts and properties of surface coating components.更多还原