| Benzenes and PAHs are the main parameters of typical organic pollutants in groundwater systems at In-production petrochemical sites,which are important indicators threatening the safety and quality of groundwater,and are also the main pollutants of organic pollution in groundwater bodies caused by petrochemical industries in recent years.To address the problems of low detection accuracy,long cycle time,low service life of the detection system,high maintenance cost,and large size of the equipment in the current methods of detecting groundwater systems,this paper designs a smart sensor based on fluorescence analysis method for detecting typical organic pollutants in groundwater systems in In-production petrochemical sites,based on benzene and benzo[b]fluoranthene as detection parameters and national standards,in order to meet the increasing high demand for groundwater system detection,and is dedicated to improving detection accuracy,realizing real-time online detection,extending service life,and reducing maintenance cost.The main studies are as follows.1.Based on Lambert-Beer law and the principle of fluorescence analysis method detection,proposed the use of fluorescence analysis method to detect typical organic pollutants in the groundwater system of In-production petrochemical sites at present,the molecular structure analysis of benzene in benzene series and benzo(b)fluoranthene in polycyclic aromatic hydrocarbons,to determine their molecular absorption in fluorescence analysis method,release energy characteristics and wavelength absorption range,and analysis of interference factors,put forward the corresponding elimination of interference countermeasures,based on this,a smart sensor was designed.2.Complete the overall sensor system design work,the overall is divided into mechanical structure design,hardware circuit design and software program design three modules;The mechanical structure design mainly includes the probe,connection joints,the main part and the selection of suitable filters,in which the probe and connection joints are designed with emphasis,compared with the traditional integrated sensor,the connection part is updated and iterated to achieve separate disassembly and maintenance of the target detection part in view of the inconvenience and high cost of later maintenance and repair;In the hardware circuit design part of the selection of the corresponding chip,complete the system circuit integration debugging;in the software design part,based on the STM32 embedded system to complete the μC/OS-III operating system transplant,write MCU program and display interface design,to achieve stand-alone control of real-time detection.3.The possible noise interference and homologue spectral overlap phenomenon in the detection process are analyzed.In terms of data pre-processing algorithm analysis,according to the characteristics of the testing experimental data,the combination of recursive average filtering algorithm and wavelet transform filtering algorithm is selected to achieve two filtering algorithm compensation and improve the accuracy of detection;To investigate the interference effects of benzenes and PAH congeners on two substances,benzene and benzo(b)fluoranthene,and propose solutions to provide ideas for subsequent improvement of detection accuracy.4.Finally,the designed sensor was experimentally validated by least squares method to establish the regression equation and verify the experimental data.After the analysis and comparison of the experimental data,it can be concluded that the performance of the smart sensor designed in this paper is excellent,and the ranges for the detection of benzene and benzo(b)fluoranthene are 0～20 ug/L,the correction coefficients are 0.9945 and 0.9982.The repeatability errors are ≤3.7% and ≤4.9%,and the indicated values are ≤2.2% and ≤ 2.9%.This paper is designed based on the fluorescence analysis method for the detection of typical organic pollutants in groundwater systems in In-production petrochemical sites,smart sensor can achieve rapid detection of benzene and benzo(b)fluoranthene parameters,while achieving rapid and convenient detection of water quality and intelligent remote monitoring,with good application value,can be widely used in a variety of detection scenarios. |
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