Detection Methods And Experimental Research On Malodorous Substances

Malodor is a gas with a pungent smells in our daily life,it is one of the severe of environmental pollution sources.Malodor monitoring has become an important part of environmental protection.In order to be able to effectively detect and analyze the stinky substances,we need to carry out in-depth study on the detection theory and detection method for malodorous substances.Through the study of malodor detection,we propose a complete set of testing theory and experimental methods to provide technical support and data accumulation for the development of malodor detection equipment.In this paper,the theory method and experimental method of odor detection are studied.The main work is as follows:(1)We studied the existing detection methods and summarized the main methods of odor detection based on current research status of odor detection available worldwide.This paper analyzes the shortcomings of the current malodor detection method.According to the malodor detection demand,a detection method based on gas chromatographic analysis method is proposed.(2)Based on the theory of gas chromatography separation,this paper studies the equilibrium theory,the Tray theory and the equilibrium theory in the chromatographic theory.The concentration model of the gas after column separation was established,and the separation experiment was carried out by using COMSOL Multiphysics simulation software.Based on the analysis of the simulation results,we propose a method for the analysis of malodorous substances using micro-gas chromatography as a separation device.(3)This paper presents a method for the detection of malodorous substances by means of micro preconcentrator.Through the study of gas adsorption theory,a micro preconcentrator for malodorous detection is developed using MEMS technology.With boron nitride and grapheme as adsorbent materials,a new adsorbent is developed.The experiment performance of new adsorbents and traditional adsorbents were compared with the pre-concentrator.The experimental results show that the detection limit of odorous substances can be improved by micro-concentrator.(4)Based on the characteristics of the malodorous substances,the Micro gas chromatography column is used as the separation device.The research on the materials,production technology,technical methods,the selection of the stationary phase materials in the column and the coating solution are studied in detail.Micro gas chromatographic column and packed micro gas chromatographic column are developed,and a new packed column with boron nitride as stationary phase was fabricated.(5)In this paper,the photoionization detector of the malodor detection system was researched and developed.Aiming at the requirements and characteristics of malodorous substance detection,a photoionization detector was selected as the detection unit of micro gas chromatographic system.The COMSOL Multiphysics software was used to simulate the photoionization rate.The simulation results show that the structure of photoionization detection is optimized.And the integration of photoionization detector and micro column is studied and analyzed.(6)A one-dimensional odor detection system,a multi-channel parallel odor detection system and a two-dimensional odor detection system were built by using micro gas chromatographic column,micro pre-concentrator and photoionization detector.In the one-dimensional detection system,the detoxification gas and the sulfur-containing malodorous gas were separated and experimented.The effects of different carrier gas on the separation were studied.The effects of flow and temperature on the measurement Value of the impact is studied in experiments.The selective separation experiment was carried out for a variety of mixed malodorous gases.The separation experiments of hydrocarbons odorous substances were completed by using a micro-packed column filled with a new material,boron nitride as stationary phase.The parallel multi-channel detection method and the two-dimensional chromatographic detection method are used to separate the odor gas;and the experimental results are analyzed.Based on the analysis of theoretical and experimental methods,it is proved that it is feasible to separate and detect malodorous gas based on Micro-gas chromatography column and Micro pre-concentrator.The research results provide a new technical method and experimental data for the miniaturization,portability and real-time on-line detection of malodorous gas detection equipment.