深圳市餐饮源排放颗粒物的特征

Characteristics of particulate matters emitted from cooking in Shenzhen

采用在线监测和采样分析等手段对深圳市4家规模相当的餐厅(粤菜馆、茶餐厅、西餐厅、职工食堂)烹饪过程排放颗粒物的质量浓度、微观形貌、化学组分进行研究.结果表明,不同餐厅的烹饪方式、用油量、原材料及调料都会影响到餐厅排放颗粒物的理化性质.各餐厅午市烹饪时段排放的PM2.5/PM10约为7.5%—96.9%,说明餐饮源排放颗粒物在细颗粒和粗颗粒均有分布.餐饮源排放颗粒物主要包含6种形态:片状、块状、簇状、絮状、球状、不规则状,其中数量最多的为不规则状(30%)和块状颗粒物(21%).块状、片状、球状颗粒物粒径较小,处于小于2.5μm范围内;絮状和簇状颗粒物粒径普遍偏大,且大部分大于4.0μm;不规则状颗粒物在各个粒径段均有分布.Cu、Fe、Zn、Ca2+、Cl-、SO42-等6种物质在餐饮源排放颗粒物中均偏高,此外,粤菜馆和西餐厅的CH3COO-占比偏高.

Cooking emissions from four similar-scale restaurants(a cantonese restaurant, tea restaurant, western restaurant, and staff canteen) in Shenzhen were measured. Mass concentration, microscopic appearance and chemical compositions of particles were analyzed by online monitoring and sampling analysis. The results showed that the cooking methods, oil consumption, raw materials and spices of different restaurants affect the physical and chemical properties of cooking emission particulates. PM2.5 accounted for 7.5%—96.9% of PM10 in mass concentration, indicating that the cooking emission from four restaurants was distributed in both fine and coarse particles. The particles from the cooking emission occur mainly in six forms: flaky, massive, clustered, flocculent, spherical, and irregular shapes. The most abundant particles were irregular, and massive particles account for approximately 30% and 21% of the total particles. The particle sizes of massive, flaky and spherical particles were smaller than 2.5 μm;the particle sizes of flocculent and cluster particles were generally larger, and most of them were larger than 4.0 μm, while irregular particles were distributed in all sizes. The mass fractions of Cu, Fe, Zn, Ca2+, Cl-, and SO42- were high in cooking emissions. In addition, the proportion of CH3COO- in Cantonese and Western restaurants was high.