Research On Source Identification And Quantitative Assessment Of Odor Pollution From An Additive Project In Lanzhou

The issue of odor pollution has become increasingly prominent in environmental problems recently,which is widely recognized as hard to measure,evaluate and control.In order to figure out how to better evaluate odor pollution,this paper takes the exhaust gas emitted during the production process of antioxidant 1520 from an additive project in Lanzhou as the research subject.This paper conducts a study on the identification and quantitative evaluation of malodor pollution sources,which provides a new idea for quantitative evaluation of malodor pollution:(1)According to the odor-causing groups and molecular structure,the odor-causing substances involved in the production of the product are dimethylamine,o-cresol and n-octanethiol.By calculating odor activity values,it was determined that these three types of malodorous substances contribute significantly to the odor of the emitted exhaust gas.After screening,dimethylamine,o-cresol and n-octanethiol were selected as the malodor factors for this study.(2)Through the analysis of the product preparation reaction principle and production process,the nodes of odor production in the production plant are identified,and the source intensity of odor pollution at each node is determined by combining the process parameters and physical and chemical parameters calculation.(3)Around sensory perception and material properties,the quantitative evaluation of malodor pollution-ambient olfactory threshold mass concentration method was explored.The assessment system of "odor factor-olfactory threshold-odor concentration and intensity-ambient smell threshold mass concentration" is established to provide a brand new method for quantitative assessment of odor pollution.The ambient olfactory threshold mass concentrations obtained in this study were specifically showed as follow: At the factory boundary,dimethylamine≤1214 μg/m~3,o-cresol≤24.8 μg/m~3,n-octanethiol≤13.4 μg/m~3;Environmentally sensitive points and other areas,dimethylamine≤121.4 μg/m~3,o-cresol≤2.48 μg/m~3,n-octanethiol≤1.34μg/m~3(4)Prediction of each of the three malodor factors using the atmospheric dispersion estimation model AERMOD by applying atmospheric environmental impact prediction and evaluation techniques;The predicted results were evaluated against the corresponding ambient olfactory threshold mass concentrations,and the main source of malodor pollution was n-octanethiol.