Faulkner William B, Goodrich L Barry, Botlaguduru Venkata S V, Capareda Sergio C, Parnell Calvin B
Department of Biological and Agricultural Engineering, Texas A&M University, College Station, TX 77843-2117, USA.
J Air Waste Manag Assoc. 2009 Aug;59(8):943-9. doi: 10.3155/1047-3289.59.8.943.
Almond harvest accounts for substantial particulate matter less than 10 microm in aerodynamic diameter (PM10) emissions in California each harvest season. This paper addresses the reduction of harvester ground speed from a standard 8 km/hr (5 mph) to 4 km/hr (2.5 mph) as a possible mitigation measure for reducing PM10 emissions. Ambient total suspended particulate (TSP) and PM10 sampling was conducted during harvest with alternating control (8 km/hr [5 mph]) and experimental (4 km/hr [2.5 mph]) treatments. On-site meteorological data were used in conjunction with both Industrial Source Complex-Short Term version 3 (ISCST3) and the American Meteorological Society/U.S. Environmental Protection Agency Regulatory Model (AERMOD) dispersion models to back-calculate emission rates from the measured concentrations. Baseline annual emission factors for nut pickup of 381 +/- 122 and 361 +/- 123 kg PM10/km2 x yr were determined using ISCST3 and AERMOD, respectively. Both of these values are substantially lower than the current PMIo emission factor for almond pickup of 4120 kg PM10/ km2 x yr. The particulate matter less than 2.5 microm in aerodynamic diameter (PM2.5) emission factors for nut pickup developed from this study were 25 +/- 8 kg PM2.5/km2 x yr and 24 +/- 8 kg PM10/km2 x yr were determined using ISCST3 and AERMOD, respectively. Reducing harvester speed resulted in an emissions reduction of 42% for TSP, but no differences were detected in emissions of PM10 and PM2.5. Differences detected in the emission factors developed using ISCST3 and AERMOD were not statistically significant, indicating that almond harvest emission factors previously developed using ISCST3 may be applied appropriately in AERMOD.
在加利福尼亚州，每个收获季节杏仁收获产生的空气动力学直径小于10微米的颗粒物（PM10）排放量相当可观。本文探讨了将收割机地面速度从标准的8公里/小时（5英里/小时）降至4公里/小时（2.5英里/小时），作为减少PM10排放的一种可能缓解措施。在收获期间进行了环境总悬浮颗粒物（TSP）和PM10采样，采用交替的对照（8公里/小时[5英里/小时]）和实验（4公里/小时[2.5英里/小时]）处理。现场气象数据与工业源复杂短期版本3（ISCST3）和美国气象学会/美国环境保护局监管模型（AERMOD）扩散模型一起用于根据测量浓度反推排放率。分别使用ISCST3和AERMOD确定了坚果捡拾的基线年排放因子，分别为381±122和361±123千克PM10/平方公里·年。这两个值均远低于目前杏仁捡拾的PM10排放因子4120千克PM10/平方公里·年。本研究得出的坚果捡拾的空气动力学直径小于2.5微米的颗粒物（PM2.5）排放因子分别为25±8千克PM2.5/平方公里·年和24±8千克PM10/平方公里·年，分别使用ISCST3和AERMOD确定。降低收割机速度使TSP排放量减少了42%，但在PM10和PM2.5的排放中未检测到差异。使用ISCST3和AERMOD得出的排放因子差异无统计学意义，表明先前使用ISCST3得出的杏仁收获排放因子可适用于AERMOD。
