热处理对沙漠边缘土壤腐殖酸荧光性质及其与Cu(Ⅱ)络合作用的影响

Effect of Heat Treatment on Fluorescence Properties of Humic Acids of Soil beside Desert and Their Cu(Ⅱ) Complexing Behavior

通过荧光光谱法研究了80℃处理下沙漠边缘土壤腐殖酸荧光性质及其与Cu(Ⅱ)络合行为的变化。热处理导致类富里酸的发射波长发生蓝移,类富里酸和类腐殖酸的荧光强度降低,它们与Cu(Ⅱ)络合的条件稳定常数(lg Ka)降低,结合常数(lg Kb)增加,腐殖酸中参与Cu(Ⅱ)络合的荧光基团和位点数增多。研究表明,干旱区高温环境会导致腐殖酸结构及组成发生变化,从而影响Cu(Ⅱ)在土壤中的迁移。

The changes in fluorescence properties of humic under 80 ℃ heat treatment and their Cu（ Ⅱ ） complexing spectroscopy. Results show that under heat treatment, a acids of soil from edge of the Taklimakan Desert behavior were investigated through fluorescence blue shift appears in the emission wavelength of fulvic-like substance; the fluorescence intensity and the Cu（ Ⅱ） complexing conditional stability constants （lgKa） of fulvic-like substance and humic-like substance decrease; the Cu（ Ⅱ ） complexing constants （lgKb） of fulvic-like substance and humic-like substance increase; and the fluorophore and site number of humic acids involved in Cu（ Ⅱ） complexing also increase. This study demonstrates that the structure and composition of humic acids might be modified by the high temperature in the arid desert zone and thus the transport behavior of Cu（ Ⅱ ） in soil is influenced.