Enrichment Separation And Spectral Characterization Dissolved Organic Matter Occurrence In Lacustrine Sedimentary Aquifers

The dissolved organic matter in sediments(DOM)as an important factor affecting groundwater quality,meanwhile it have a major impact on the occurrence and migration of contaminants in the sediments.However,we face on many difficulties on research,due to the complex composition of sediments DOM,accurately characterize and the no easy to extraction,the method is not uniform.Based on previous research,we select the higher DOM content herein Jianghan Plain Quaternary aquifer as the study area,we using two different extract methods(dilute,concentrated salt extraction)extract DOM at different depths in the aquifer.The result of extraction is defined water soluble and exchangeable DOM.UV-Visible spectrophotometer and three-dimensional fluorescence spectra are used to characterize the result.The main conclusions are as follows:(1)As the different characterization of chemistry attack between dilute salt and concentrated salt,we extract the part of DOM by dilute salt,which is easy extracted,small particle,lack of stability.We defined it as WSOM(Water-solution DOM)the concentrated salt can extract macromolecule,stability DOM,we defined it as ESOM(Exchange-DOM).(2)Different DOM average enrich rate of around 60%by using PPL(styrene divinyl benzene polymer type sorbents).(3)DOM sediments mainly consist of humic A and proteins T peak,testing by EEMS indicating that the sediments DOM mainly made by humus and protein composition;silt sand layer,DOM contains humic,proteins organic ingredients,and contains a large number of small molecule organic components,have higher aromatic content and middle humification.Silt clay layer,DOM containing mainly humic fractions and a small amount of protein-like component,a certain amount of small molecule organic ingredients.Have higher humification and lowest aromatic content.Sand,DOM containing mainly protein-like organic ingredients,a small amount of humic organic ingredients and a lot of high molecules matter,the lowest humification,higher aromatic content.This paper has made a major innovation found that:(1)Two different forms of DOM isolated successfully from lacustrine sedimentary aquifers,analysis and characterize two different forms DOM.(2)combined with environmental factors analyze sedimentary aquifers DOM effect on the environment.