Quantifying Real-Time VOC Emissions of Typical Sources in the Chemical Industrial Park Using Multiplexed Online Mass Spectrometry

Chemical industrial parks are regions of high-intensity volatile organic compound (VOC) emissions, yet studies of their emission characteristics have been constrained by limited real-time data. Here, multiplexed online mass spectrometers were deployed to build a VOC monitoring network in a fine chemical industrial park in the Yangtze River Delta, retrieving hourly concentrations of 40 species from 38 stationary sources over two years using multiple linear regression with an iterative-calibration-matrix method. Toluene, acetone, ethyl acetate, methylene chloride, acrylonitrile, and 2-heptanol were identified as dominant pollutants, mainly associated with solvent use, drug intermediate production, and coating processes. Although total VOC concentrations typically remained below 2.5 ppm, short-term peaks of tens of parts per million were frequent. Emission rates and daily variation patterns from 17 companies across six industries were also evaluated. Dye manufacturing, printing and dyeing, and chemical fiber manufacturing show pronounced single peaks during working hours, whereas pesticide manufacturing, active pharmaceutical ingredient manufacturing, and biopharmaceuticals exhibit two peaks with moderate fluctuation, reflecting production schedules. Semiannual assessments indicated gradual emission declines in four integrated source areas. These results demonstrate that real-time VOC monitoring enables rapid identification of abnormal emissions and temporal trends, providing critical support for emission control and management in chemical industrial parks.