摘要
针对白洋淀秋冬季节水生植物腐解释放大量溶解性有机物(DOM)的问题,利用紫外可见光谱(UV-Vis)和激发发射光谱(EEMs)结合平行因子分析法(PARAFAC)对DOM样品进行表征和分离。实验结果表明,PARAFAC共分离出4种组分(C1、C2、C3和C4),类腐殖酸组分C1和C2、类蛋白组分C3、含有类蛋白组分和类富里酸组分共同组成的C4。此外,对样品进行荧光淬灭滴定实验来研究DOM与重金属(Cu(Ⅱ)和Cd(Ⅱ))的相互作用,发现Cu(Ⅱ)对所有组分都存在明显的淬灭效果,并可以较好地拟合出络合常数(lg K),而Cd(Ⅱ)只与C4有较好的络合效果,这是由于C4中的类富里酸成分所造成的。研究进一步发现,样品U2中类蛋白组分C3和C4对重金属的淬灭效果比样品U0的类蛋白组分明显。这是由于样品U2中所添加的植物量较多,而植物腐解所释放的主要成分为类蛋白物质,有助于增强类蛋白组分的络合能力。研究结果可为科学评价水生植物腐解释放DOM对水体中重金属的迁移转化提供依据。
To investigate the characteristics of dissolved organic matter（ DOM） released by macrophyte decomposition at Lake Baiyangdian in autumn and winter,UV-vis spectra and excitation and emission matrix（ EEMs） analysis,combined with parallel factor（ PARAFAC） analysis,were used to separate and characterize DOM samples. The results indicated that 4 components（ i. e.,C1,C2,C3,C4） were separated from DOM samples by EEMs-PARAFAC analysis,C1 and C2 were classified into humic-like acids,C3 was assigned to protein-like substances,and C4 was consisted of fulvic-like acid and protein-like substances. In addition,fluorescence quenching titration（ FQT） experiment was conducted to study the interaction between DOM and heavy metals（ i. e.,Cu（ Ⅱ） and Cd（ Ⅱ））. Cu（ Ⅱ） had remarkable quenching effect on all DOM samples and the complexation constant（ lg K） could be properly modeled. However,Cd（ Ⅱ） had strong quenching effect only on C4 that may be due to the fulvic-like acid components in C4. Moreover,C3 and C4 were observed to have stronger quenching effects in U2 than U0. That may be explained by the higher plant density of sample U2. The protein-like substances were the main products released by plants decomposition,which could enhance the binding ability of protein-like components. The present study could provide an important basis to evaluate heavy metal migration and transportation affected by DOM derived from macrophyte decomposition.
出处
《环境工程学报》
CAS
CSCD
北大核心
2016年第5期2184-2192,共9页
Chinese Journal of Environmental Engineering
基金
国家自然科学基金资助项目(51209003)
国家科技支撑计划项目(2012BAJ21B08)
关键词
溶解性有机物
荧光光谱
平行因子
荧光淬灭
dissolved organic matter（DOM）
fluorescence spectra
parallel factor
fluorescence quenching titration
