Chemical and stable isotopic characteristics of PM_(2.5) emitted from Chinese cooking

摘要

This study investigated the characteristics of air pollutants generated from preparing Chinese cuisine and analyzed the isotopic compositions of carbon and nitrogen in particulate matter with a diameter 2.5 gm (PM2.5) to source apportionment study. The CO and CO2 concentrations and temperatures were measured using suitable instruments in real time during cooking, including stir-fry, fry, deep-fry, hot-pot, and mixed cooking, and periods with non-cooking. Personal environmental monitoring instruments were used to collect PM2.5 for carbon and nitrogen elements and isotopes analysis. Our data indicated that the concentrations of CO and CO2 and the temperature were higher during periods of cooking, especially for the fry and stir-fry methods, than during periods with non-cooking. The concentrations of PM2.5, total carbon, and total nitrogen were also higher during cooking; the maximum concentrations were measured during fry. The values of delta C-13 were considerably lower during the periods of cooking (mean:-28.15 parts per thousand) than during non-cooking (-27.18 parts per thousand). The average values of delta N-15 were 8.63%0 and 11.74 parts per thousand during deep-fry and hot-pot cooking, respectively. The delta C-13 values can be used to distinguish between cooking and other non-cooking sources and further assess the effect of different cooking activities on PM2.5. The delta N-15 only can be used to investigate the effect of deep-fry on PM2.5. Moreover, the delta C-13 signature suggested that fry emits higher products of incomplete combustion than do other cooking activities. These findings can assist in pollution source identification of PM2.5, emission control, and the study of combustion characteristics. (c) 2020 Elsevier Ltd. All rights reserved.