Mass concentration level and distribution characteristics of air pollutants in coking plant area

In order to investigate the pollution characteristics of air pollutants in coking plant,the mass concentration and time distribution characteristics of total volatile organic compounds(TVOCs),NH3 and H2S in nonheating season and heating season were analyzed by online monitoring instruments in the ambient air of each section of the coking and chemical production areas in a typical coking plant in Shanxi. The SPSS software was used to analyze the correlation between air pollutants in different sections. The results show that the average mass concentrations of TVOCs,NH3,H2S are 96,376,176 μg/m3 in the coking plant,and the mass concentrations of pollutants in the chemical production section are higher than that in the coking section. In the different stages of chemical production,the mass concentrations of TVOCs from high to low are condensation and blast section(147 μg/m3)>independent tank farm(141 μg/m3)>ammonia water pump house(107 μg/m3)>crude benzol production section(77 μg/m3)>ammonium sulphate section(35 μg/m3). The NH3 mass concentrations are sorted as independent tank farm(542 μg/m3)>crude benzol production section(500 μg/m3)>ammonium sulphate section(401 μg/m3)>condensation and blast section(392 μg/m3)>ammonia water pump house(388 μg/m3). However,there is no significant difference in the H2S mass concentration among different sections. The mass concentrations of TVOCs and NH3 in the heating season are significantly higher than those in the nonheating season in the coking plant,and the H2S mass concentration is almost unchanged. In the heating season,the diurnal variation trend of each pollutant mass concentration is not obvious,but in the nonheating season,the significant diurnal variation characteristic is showed. The diurnal variation characteristics of air pollutants in the ambient air for chemical production and coking section are different. There is a high correlation between TVOCs,NH3,SO2,NOx,O3,PM2.5 and PM10 in the coking section,indicating that the main sources of pollutants are the same,and there are complex chemical reaction mechanisms between some compounds. There is a significant positive correlation between TVOCs and NH3 in the crude benzol production section. No correlation is found between TVOCs,NH3 and H2S in the vicinity of independent tank farm,condensation and blast section,ammonia water pump house and ammonium sulphate section,indicating that TVOCs and NH3 have similar generation and emission law in the crude benzol production section.