Seawater TOC Based On Multi-wavelength Bispectral Fusion Research On Detection System

Our country has a rich Marine resources,and it is becoming the main theme of our development of Marine resources to protect Marine water quality while developing ocean.With the development of industry,a large amount of organic matter has been discharged into the sea,which has seriously damaged the Marine ecological environment.Total organic carbon(TOC)represents the total carbon content of organic matter in the water body.The determination method of TOC concentration in seawater is defined as combustion oxidation nondispersive infrared absorption method in Chinese national standard,which is obviously higher than other methods in the detection accuracy.However,the operation process of this method is complicated,and the water sample needs to be taken back to the laboratory for testing.The spectral method can realize in situ detection and has the advantage of fast all-weather detection.Therefore,it is of great significance to study a seawater quality detection system based on spectral analysis technology that can realize TOC in situ detection.In this paper,on the basis of the establishment of the TOC detection model of seawater based on the combination of ultraviolet absorbance and fluorescence relative intensity,the TOC detection system of seawater based on the combination of multiple light sources is designed.The main contents of this paper are as follows:Firstly,the significance and research status of TOC in situ detection are expounded.The theory of ultraviolet absorption spectrum and fluorescence spectrum of organic matter was studied.Secondly,the collection system of ultraviolet absorption spectrum and fluorescence spectrum of the liquid to be tested was established in the laboratory,and the TOC detection model of single-wavelength ultraviolet absorbance,single-wavelength ultraviolet excited fluorescence and the TOC detection model of multi-wavelength ultraviolet absorption and fluorescence spectra were respectively established.The prediction effect of the established model is compared and analyzed.Thirdly,the TOC detection system(including optical path structure,hardware circuit,optical bracket and shell)that integrates ultraviolet absorption spectrum and fluorescence spectrum was designed,and the system debugging was completed.The optical support and shell of the detection system were designed with Solid Works software and manufactured with 3D printing technology.Finally,TOC test system was calibrated by using TOC reference material to configure standard liquid sample.And the TOC-L analyzer(the detection method is national standard method)and the seawater TOC detection system are used to compare the collected real seawater samples.The experimental results show that the detection results of the designed seawater TOC detection system are in good correlation with the detection results of the national standard method.