Research On Detection Technology And Device Of Dissolved Organic Matter In Deep Ultraviolet Water

Dissolved organic matter(DOM),which exists in natural water,is a highly complex mixture of chemical compositions.It is derived from the decomposition of biological residues or human activities,and it is widely present in various waterbodies.Excess DOM is an important contributing factor to water eutrophication or black-odor.It is difficult to be removed in a conventional water treatment process,but easy to be further converted to carcinogenic disinfection by-products(DBPs)or accumulated in the water supply network,bringing multiple potential health risks.Therefore,a simple,fast and accurate detection of DOM in water is the key to ensuring the safety of drinking water,healthy water environment and efficient use of water resources.In view of this,this subject deeply researched the detection technology of DOM in water based on deep ultraviolet,and developed the detection device on this basis.The specific research contents are as follows:1.First,a comparative analysis of the existing detection methods for DOM is conducted to demonstrate the correlation between the light with a wavelength of 280 nm generated by the deep ultraviolet LED and the concentration of DOM,and to verify its feasibility in theory.2.On this basis,the overall structure of the detection system is designed,including the fluid chamber,the photoelectric chamber,the optical detection section,the electronic circuit,and the light-transmitting quartz window.Through repeated optimization,the most suitable spatial layout for light source and detection circuit of the embedded device is determined.3.Put forward the overall design scheme of the hardware module circuit,including I / V conversion circuit,amplifying circuit,filter circuit,power supply circuit,main control circuit and digital transmission circuit.For each circuit unit,carefully compare parameters of different types of chips and different LED control circuits,and finally determine the most suitable circuit structure and core device for the project requirements.And analyze the functional logic of the entire system,and encode the firmware program of the single-chip microcomputer to control the operation of the entire system.4.Complete the printing and production of system modules,circuit board design,production and welding debugging,joint debugging of software and hardware,and optimization of the structural layout of the detection system.Finally,conduct an off-site test of the entire system,analyze the test results,and compare with existing instruments.The final test result shows that the fluorescence signal value detected by the device designed by this subject has a good linear relationship with the concentration of dissolved organic carbon,and has the advantages of fast response,high sensitivity and low power consumption.It can be used for water quality inspection of terminal water purification system or water pipeline network.Hence,this device has certain application prospects.