电子制造业塑料件生产过程的挥发性有机物排放特征分析

选取珠三角地区典型电子制造企业,通过气袋采样及预浓缩-GC-MS/FID分析方法,获得塑料件生产过程的挥发性有机物(VOCs)浓度水平与组分特征.实验共检出包括烷烃、烯烃、芳香烃、醛类、卤代烃等在内的101种VOCs组分.其中,塑料件生产过程可分为注塑成型期和塑料件加工期,塑料件加工期包括喷涂工艺和非喷涂工艺.结果表明,注塑成型期总VOCs排放浓度较塑料件加工期低,含氧VOCs(OVOCs)、烷烃是最重要的组分;塑料件加工期的喷涂工艺VOCs排放浓度普遍高于非喷涂工艺,OVOCs、卤代烃是塑料件加工期主要的VOCs组分,其中,丙酮和三氯乙烯为主要成分.与其他研究相比,本研究中卤代烃排放比例明显提高,芳香烃排放比例下降.注塑成型期臭氧生成潜势标准化反应活性系数R值比塑料件加工期高24%,其中,丙烯醛是贡献最大的物种;在塑料件加工期,喷涂工艺的R值比非喷涂工艺高31%,正己醛是最主要的臭氧贡献物种.苯系物对二次有机气溶胶(SOA)生成潜势贡献起主导作用.在臭氧控制的背景下,不仅排放浓度高的喷涂工艺需受到控制,对于标准化反应活性大的其他工艺也需关注.

Emission characteristics of volatile organic compounds (VOCs)from the production processes of plastic parts in electronic manufacturing industry

Volatile organic compounds (VOCs)emitted from processes making plastic parts (i.e.injection molding and fabrication)in electronic manufacturing industry were measured at a typical factory in the Pearl River Delta by the bag sampling technique and subsequently the preconcentration-GC-MS/FID analysis at lab.In total,101 VOCs species were detected,including alkanes,alkenes,aromatic hydrocarbons,oxygenated VOCs (OVOCs),chlorinated hydrocarbons and others.Results showed that VOC emission concentrations were smaller during the injection molding than during the fabrication,with OVOCs and alkanes being the dominating species.In plastic parts fabrication,OVOCs and halogenated hydrocarbons dominated VOCs emission,particularly acetone and trichloroethylene,with surface coating process generally producing more VOCs than other processes.Compared with other studies,significantly more halogenated hydrocarbons emissions were observed in this study,with less aromatic hydrocarbon.Normalized reactivity for ozone formation potential of VOCs was 24% higher in plastic injection molding than in plastic fabrication.In fabrication process,the normalized reactivity for surface coating process was 31% higher than those non-coating processes.Hexanal,acrolein and propionaldehyde were the main contribution species for ozone formation potential in plastic parts production.Formation potentials of secondary organic aerosol (SOA)varied with different VOC emissions in different processes.In addition,benzenes from injection molding and cyclohexane from plastic fabrication had the largest potential contributions for each process (about 53.81% and 40.29%,respectively).Therefore,not only did the VOCs emissions from the surface coating process need to be controlled,but also the non-coating process with large ozone formation potential should be paid attention in future.