School of Ecology and Environment, Beijing Technology and Business University, Beijing 100048, China; State Environmental Protection Key Laboratory of Food Chain Pollution Control, Beijing Technology and Business University, Beijing 100048, China.
School of Ecology and Environment, Beijing Technology and Business University, Beijing 100048, China.
Sci Total Environ. 2022 Dec 20;853:158601. doi: 10.1016/j.scitotenv.2022.158601. Epub 2022 Sep 8.
Non-road construction equipment (NRCE) has become a crucial contributor to urban air pollution. However, the current research on NRCE is still in its infancy, and the understanding of its pollutant emissions is not yet clear. In this study, multi-pollutant (CO, HC, NOx, PM, and BC) and CO emissions from 12 excavators and 9 loaders under real-world conditions are investigated by using a synchronous platform based on portable emission measurement system (SP-PEMS). We find the instantaneous emission rates of multi-pollutant present significant variability under different operation modes, and pollutant emissions are significantly high under cold start. Generally, multi-pollutant emission factors (EFs) have been all effectively reduced with the tightening of emission standards except for CO and NOx. The BC and PM emissions are significantly affected by engine types, and those emitted by electronically-controlled fuel injection (EI) engines are at lower concentration levels compared with mechanical fuel injection (MI) engines. The mass ratios of BC/PM for EI engines are 2.05 times that for MI engines on average. Through comparison, we find the multi-pollutant EFs of NRCE reported by different studies and the Guide vary greatly, and those recommended by the Guide may be overestimated or underestimated to varying degrees. Finally, we recommend the multi-pollutant EFs of NRCE under different emission standards by combining the results of various studies, and which will provide scientific support for the accurately establish of emission inventory.
非道路施工设备（NRCE）已成为城市空气污染的一个重要贡献者。然而，目前对 NRCE 的研究仍处于起步阶段，对其污染物排放的认识还不清楚。在这项研究中，使用基于便携式排放测量系统（SP-PEMS）的同步平台，对 12 台挖掘机和 9 台装载机在实际条件下的多污染物（CO、HC、NOx、PM 和 BC）和 CO 排放进行了研究。我们发现，在不同的操作模式下，多污染物的瞬时排放率存在显著的可变性，冷启动下的污染物排放显著较高。一般来说，除 CO 和 NOx 外，随着排放标准的收紧，多污染物排放因子（EFs）都得到了有效降低。BC 和 PM 的排放受到发动机类型的显著影响，电控燃油喷射（EI）发动机排放的 BC 和 PM 浓度比机械燃油喷射（MI）发动机低。EI 发动机的 BC/PM 质量比平均为 MI 发动机的 2.05 倍。通过比较，我们发现不同研究和指南中报告的 NRCE 多污染物 EF 差异很大，指南中推荐的 EF 可能会被高估或低估到不同程度。最后，我们结合各种研究的结果，为不同排放标准下的 NRCE 多污染物 EF 提出了建议，这将为准确建立排放清单提供科学支持。
