Recognizing dissolved organic matter with an improved fluorescence regional integral method

The aim of this paper was to study transformations of Dissolved Organic Matter (DOM) in marl rock groundwater. To achieve this, we carried out a series of soil column experiments, using a DOM solution as the water sample and marl rock as the testing rock sample. Three-Dimensional Excitation-Emission Matrix Spectra (3DEEMS) were generated for DOM solutions and the Analytic Hierarchy Process (AHP) was introduced to improve the traditional method of fluorescence regional integral (TMFRI). We termed this approach the Improved Method of Fluorescence Regional Integral (IMFRI) and used it to identify the type of DOM in the marl rock. The result shows that DOM recognition using TMFRI is only 50% accurate and consequently transformations are hard to recognize. In contrast, our results show that use of IFRIM has a DOM type recognition accuracy of 83.33% and so this method can be used with confidence to describe transformation characteristics. And we find that in the marl rock, the leaching test showed a new fluorescence peak at 312 h and the humic acid was degraded into soluble microbial products by microorganisms.