佛山市典型铝型材行业表面涂装VOCs排放组成

Source Profiles and Chemical Reactivity of Volatile Organic Compounds from Surface Coating of Aluminum Products in Foshan,China

选取佛山市典型铝型材行业不同表面涂装工艺(溶剂型涂料涂装、水性涂料涂装、电泳涂装、粉末喷涂)有组织废气VOCs进行了采样分析.结果表明,溶剂型涂料涂装废气VOCs浓度(63. 90~149. 67 mg·m^(-3))要远大于其他3种涂装工艺(2. 99~21. 93 mg·m^(-3)). VOCs组成来看,溶剂型涂料涂装废气VOCs以芳香烃为主,比例在52. 32%~71. 55%之间,主要污染物包括甲苯、乙苯、二甲苯等苯系物和乙酸乙酯等含氧挥发性有机物(OVOCs).水性涂料涂装废气以OVOCs为主,如乙酸乙酯(48. 59%)、四氢呋喃(8. 43%),芳香烃比例(11. 32%)远低于溶剂型涂料涂装废气.异丙醇是电泳涂装废气中最主要的VOCs化合物,贡献比例高达81. 19%.而粉末涂料涂装废气VOCs污染物主要是丙酮(30. 25%),以及丙烷(15. 48%)、乙烯(12. 15%)、乙烷(9. 35%)、正丁烷(5. 16%)等C2~C4的烷烃和烯烃.臭氧生成潜势(OFP)计算结果表明,溶剂型涂料涂装废气排放单位质量VOCs的臭氧生成潜势(OFP,以O3/VOCs计,下同)最高(3. 89 g·g^(-1)),其次是粉末喷涂(2. 53 g·g^(-1)),而水性涂料涂装和电泳涂装则较低(1. 31 g·g^(-1)和0. 85 g·g^(-1)).溶剂型涂料涂装废气中芳香烃对OFP贡献比例高达93. 28%,有9种C7~C10芳香烃位列OFP排名前10化合物;水性涂料涂装废气中乙酸乙酯、间/对-二甲苯和甲苯的臭氧生成潜势占比最高,分别为23. 24%、21. 76%和17. 07%;粉末涂料涂装废气中的关键活性组分则为乙烯、丙烯和1-丁烯等低碳烯烃,烯烃对其OFP贡献为71. 11%;电泳涂料涂装废气中异丙醇的OFP贡献(65. 08%)明显高于其他组分(<6%).

Volatile organic compounds（VOCs） samples were collected and analyzed for the surface coating processes of aluminum products in Foshan. The concentration levels of VOCs from solvent-based coating(63. 90-149. 67 mg·m-3) are much higher than that from water-based,electrophoretic,and powder coating(2. 99-21. 93 mg·m-3). With respect to the VOC composition,aromatics are the main VOC group of solvent-based coating emission, ranging from 52. 32%-71. 55%. Typical species include toluene,ethylbenzene,xylene,and ethyl acetate. The VOCs emitted from water-based coating are mainly oxygenated VOCs,such as ethyl acetate（48. 59%） and tetrahydrofuran（8. 43%）,while the percentage of aromatics（11. 32%） is lower than that of solvent-based coating. Isopropanol is the most abundant species of electrophoretic coating emissions,accounting for up to 81. 19% of the VOCs. The major VOC compounds of powder coating processes are acetone（30. 25%）,propane（15. 48%）,ethylene（12. 15%）,ethane（9. 35%）,and n-butane（5. 16%）. The calculation of the ozone formation potential（OFP） shows that the solvent-based coating has the highest OFP(3. 89 g·g-1),followed by powder coating(2. 53 g·g-1),while water-based and electrophoretic coating have lower OFPs(1. 31 and 0. 85 g·g-1,respectively). The most important contributor to OFP of solvent-based coating are aromatics,especially C7-C10 aromatics. The major contributors of water-based coating are ethyl acetate,m/p-xylenes,and toluene,with contributions of23. 24%,21. 76%,and 17. 07%,respectively. The key reactive components of powder coating are ethylene,propene,and 1-butene;the sum of alkenes accounts for 71. 11% of the OFP. With respect to the contribution of VOCs emitted from electrophoretic coating tothe OFP,the percentage of isopropanol（65. 08%） is significantly larger than that of other species（< 6%）.