Research On Theory And Application Of Organic Pollutant Detection Based On LIF-CPTU Technology

With the accelerating process of urbanization in China,the pollution problem of construction sites has become a serious challenge facing China at this stage.In order to avoid the risk of traditional drilling sampling,indoor testing technology,and reduce testing costs and risks,the investigation and evaluation of contaminated sites based on in-situ testing has become an important topic in environmental geotechnical engineering practice.A large number of studies at home and abroad have shown that common organic pollutants can exhibit strong fluorescent characteristics.Therefore,the mechanism and application research of Laser-Induced Fluorescence incorporated with CPTU(LIF-CPTU)is of great theoretical and engineering value for the identification of pollutant types and concentration determination of organic pollution sites.In this context,this paper aims at the blank of domestic laser-excited fluorescence testing organic pollutant technology,using indoor fluorescence spectrometer to simulate the fluorescence effect of laser-excited organic contaminated soil,relying on organic contaminated sites as engineering support,combined with in-situ testing of field engineering.Through theoretical analysis,microscopic testing,and comparison with traditional organic contaminated soil testing methods,the feasibility and accuracy of LIF technology in practical applications are summarized.Through this research,the research and development of further LIF-CPTU probes is made.ready.The main research contents are as follows:(1)Based on the research and summary of laser excitation fluorescence technology at home and abroad,it mainly organizes the application of LIF technology in the environmental field,and clarifies the development trend and application prospect of fluorescent CPTU probe respectively.Through the analysis of the research status at home and abroad,the application of LIF-CPTU probe in geotechnical engineering and the reliability of the fluorescence effect of organic contaminated soil are studied.(2)Through the mechanism analysis of laser excitation fluorescence and the fluorescence effect in organic contaminated soil,the second chapter focuses on the combination of LIF and CPTU in in situ testing.Based on the Tufs University's LIF system,the study of the fluorescence excitation mechanism of organic contaminated soil can ensure the accuracy and real-time of fluorescence collection,and ensure the integrity of the soil in situ information,highlighting the advantages of the LIF-CPTU probe..(3)Perform indoor fluorescence spectrometer detection test to verify the fluorescence effect of organic contaminated soil.On this basis,by changing the mass ratio of organic contaminated soil,sample moisture content,particle size and other factors,the relationship between influencing factors and fluorescence spectral characteristics is analyzed,and the correlation between fluorescence intensity and pollutant concentration is established.To some extent,quantitative analysis of pollutants in organic contaminated soil is achieved.(4)Based on the in-situ test of an organic contaminated site in Nanjing,the results of indoor sampling analysis of organic pollutants by environmental research institutions are compared with the test results of the soil sample in the fluorescence spectrometer to obtain the types of organic pollutants present at the original site.At the same time,verify the accuracy and reliability of the fluorescence detection analysis method.Combined with the application of fluorescence detection technology in other related fields,the application prospect of LIF-CPTU probe is proposed.