园林植物水溶性有机物与Hg(Ⅱ)配位机理的三维荧光特性研究

Study on usage of three-dimensional fluorescence spectroscopy to the complexation between Hg(Ⅱ) and DOM extracting from the ornamental plant

为研究园林植物水溶性有机物(DOM)与Hg(Ⅱ)的配位机理以及检验修正型方程的优越性,研究采用三维荧光光谱技术对高温好氧堆肥后的园林植物水溶性有机物(DOM)与Hg(Ⅱ)结合的荧光特征进行研究。结果表明,园林植物DOM组成简单,主要成分为纤维木质素分解产生的类富里酸物质。可见区富里酸荧光峰(C)Ex/Em=330 nm/427 nm,紫外区富里酸荧光峰(A)Ex/Em=240 nm/430.5 nm。三维荧光光谱表明,在DOM与Hg(Ⅱ)络合过程中产生猝灭效应,随着Hg(Ⅱ)浓度的增加,园林植物可溶性有机物的荧光强度依次降低。修正型Sten-Volmer方程更能准确的计算出DOM与重金属Hg(Ⅱ)的配位能力以及配位稳定性。

To clarify the coordination mechanism between ornamental plant dissolved organic matter （DOM） and Hg（Ⅱ）, also and the superiority of modified Sten-Volmer equation, used three- dimensional fluorescence spectroscopy to study on the complexation between the Hg（Ⅱ） and dissolved organic matter （DOM） extracted from the high temperature good oxygen composting ornamental plant. The results showed that ornamental plant DOM was composed simply of fulvic substances producing by the decomposition of textile fiber lignin. Visible region of fulvic acid fluorescence （Ex/Em） was at the 330 nm/427 nm （C）, and UV fluorescence of fulvic acid （Ex/Em） was at the 240 nm/430.5 nm （A）. Three-dimensional fluorescence spectra exhibited that in the process of complexation between DOM and Hg（Ⅱ） could not only produce the quenching effect, but also with the increasing of Hg（Ⅱ） concentration, the fluorescence intensity of DOM of plants decreased. Modified Sten-Volmer equation can more accurately calculate coordination ability and stability between DOM and Hg（Ⅱ）.