The Effect Of Environmental Factors On Fluorescence Property Of Humic Acid

The humic acid is one of the most abundant organic matters in the nature. It will launch fluorescence by optical radiation and widely exist in the soil, the lake, the oceans, the rivers and the sediment. With the concentration of humic acid, the metal ions, pH value and the hydrostatic pressure in the water environment were changed, the fluorescence properties will change. The study of the effect of environmental factors on fluorescence property of humic acid will help us get better acquaintance of the complexation of humic acid and metal ions, provide useful information of function groups, and proclaim humic acid’s geochemical behaviour in the environment. The three-dimensional fluorescence spectrum was widely used to research the structure and the function group of humic acid because of its large amount of information, good selectivity and high sensitively.This thesis expounds the source and the domestic and overseas research status of the humic acid, and study the three-dimensional fluorescence spectrum of humic acid when the concentration of mental ions, the pH value, and the hydrostatic pressure were changed.The results show that fluorescence intensity was raised as the increased concentration of humic acid, but the fluorescence intensity increased when the concentration of humic acid was higher; The Cu+and Ni+can decrease the fluorescence intensity of humic acid because of the complexation of mental ion and humic acid, but K+and Mg2+cannot, and the complexation of Cu2+and humic acid was stronger than Ni2+; the complexation of Cu2+and humic acid was obvious when they under neutral and alkaline conditions, the complexation of Ni2+and humic acid become stronger when pH was higher; the fluorescence intensity of humic acid will increase when the hydrostatic pressure increased from0.1MPa to60MPa.These results will provide some valuable reference to the organic matter tracers, the deep-sea on-line inspection and understand the changes in the physical and chemical environment.