太湖和洪泽湖天然有机质与重金属结合特性研究

Study on binding characteristics of natural organic matter and heavy metals in Taihu Lake and Hongze Lake

利用同步荧光光谱表征浅水湖泊太湖和洪泽湖中天然有机质(NOM)的组成,同时利用荧光淬灭滴定试验研究了NOM与Cu^2+和Cd^2+的结合特性.结果表明:两个湖泊的NOM中类蛋白质和类腐殖质组成比例存在显著的差异,太湖NOM主要由类蛋白质和类腐殖质组成,洪泽湖NOM则以类腐殖质为主;太湖和洪泽湖NOM与Cu^2+和Cd^2+的结合点位及结合能力存在显著差异,NOM中类腐殖质的结合点位要显著多于类蛋白质;太湖贡湖湾和梅梁湾NOM中类蛋白质与Cu^2+的结合能力以及梅梁湾NOM中类蛋白质与Cd^2+的结合能力强于类腐殖质,但贡湖湾NOM中类蛋白质与Cd^2+的结合能力则弱于类腐殖质,而洪泽湖NOM中类蛋白质与Cu^2+和Cd^2+的结合能力均强于类腐殖质;太湖NOM与重金属Cu^2+和Cd^2+的结合能力要显著高于洪泽湖NOM.

The composition of natural organic matter(NOM) in two different shallow lakes(Taihu Lake and Hongze Lake) was characterized by synchronous fluorescence spectroscopy. At the same time, the binding properties of NOM with Cu^2+ and Cd^2+ were studied by fluorescence quenching titration test. The results show there are significant differences in the proportion of protein-like and humus-like components in NOM between the two lakes. The NOM of Taihu Lake is mainly composed of protein-like and humus-like substances, while that of Hongze Lake is mainly humus-like substances. There were significant differences in binding sites and binding capacity of NOM with Cu^2+ and Cd^2+ between Taihu Lake and Hongze Lake. The binding sites of humus-like substances in NOM were significantly more than that of protein-like substances. The binding ability of proteins to Cu^2+ in NOM of Gonghu Bay and Meiliang Bay of Taihu Lake and the binding ability of proteins to Cd^2+ in NOM of Meiliang Bay are stronger than humus-like substances, but the binding ability of proteins to Cd2 + in NOM of Gonghu Bay is weaker than humus-like substances. The binding ability of proteins to Cu^2+ and Cd^2+ in NOM of Hongze Lake was stronger than that of humus-like substances, while that of heavy metals Cu2 + and Cd2 + in Taihu Lake was significantly higher than that of Hongze Lake.