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; Key Laboratory of Cleaner Production and Integrated Resource Utilization of China National Light Industry, Beijing Technology and Business University, Beijing 100048, China.
School of Ecology and Environment, Beijing Technology and Business University, Beijing 100048, China.
Sci Total Environ. 2023 Feb 1;858(Pt 2):159970. doi: 10.1016/j.scitotenv.2022.159970. Epub 2022 Nov 5.
Detailed emission characterization of semivolatile/intermediate-volatility organic compounds (S/IVOCs) originating from nonroad construction machines (NRCMs) remains lacking in China. Twenty-one NRCMs were evaluated with a portable emission measurement system in the working process. Gas phase S/IVOCs were collected by Tenax TA tubes and analyzed via thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS). Particle phase S/IVOCs were collected by quartz filters and analyzed via GC-MS. The average emission factors (EFs) for fuel-based total (gas + particle phase) IVOCs and SVOCs of the assessed NRCMs were 221.45 ± 194.60 and 11.68 ± 10.67 mg/kg fuel, respectively. Compared to excavators, the average IVOC and SVOC EFs of loaders were 1.32 and 1.55 times higher, respectively. Compared to the working mode, the average IVOC EFs under the moving mode (only moving forward or backward) were 1.28 times higher. The IVOC and SVOC EFs for excavators decreased by 69.06% and 38.37%, respectively, from China II to China III. These results demonstrate the effectiveness of emission control regulations. In regard to individual NRCMs, excavators and loaders were affected differently by emission standards. The volatility distribution demonstrated that IVOCs and SVOCs were dominated by gas- and particle-phase compounds, respectively. The mode of operation also affected S/IVOC gas-particle partitioning. Combined with previous studies, the mechanical type significantly affected the volatility distribution of IVOCs. IVOCs from higher volatile fuels are more distributed in the high-volatility interval. The total secondary organic aerosol (SOA) production potential was 104.36 ± 79.67 mg/kg fuel, which originated from VOCs (19.98%), IVOCs (73.87%), and SVOCs (6.15%). IVOCs were a larger SOA precursor than VOCs and SVOCs. In addition, normal (n-) alkanes were suitably correlated with IVOCs, which may represent a backup solution to quantify IVOC EFs. This work provides experimental data support for the refinement of the emission characteristics and emission inventories of S/IVOCs originating from NRCMs.
非道路移动机械（NRCMs）排放的半挥发性/中等挥发性有机化合物（S/IVOCs）的详细排放特征在中国仍缺乏研究。本研究采用便携式排放测量系统对 21 台 NRCM 进行了工作过程评估。通过 Tenax TA 管收集气相 S/IVOCs，并通过热解吸-气相色谱-质谱法（TD-GC-MS）进行分析。通过石英滤膜收集颗粒相 S/IVOCs，并通过 GC-MS 进行分析。评估的 NRCMs 燃料基总（气相+颗粒相）IVOCs 和 SVOCs 的平均排放因子（EFs）分别为 221.45±194.60 和 11.68±10.67mg/kg 燃料。与挖掘机相比，装载机的 IVOC 和 SVOC EF 分别高 1.32 倍和 1.55 倍。与工作模式相比，在仅前进或后退的移动模式下，IVOC EF 高 1.28 倍。从中国 II 到中国 III，挖掘机的 IVOC 和 SVOC EFs 分别降低了 69.06%和 38.37%。这些结果表明排放控制法规是有效的。对于个别 NRCMs，挖掘机和装载机受到排放标准的影响不同。挥发性分布表明 IVOCs 和 SVOCs 分别由气相和颗粒相化合物主导。操作模式也影响 S/IVOC 的气粒分配。结合以往研究，机械类型显著影响 IVOCs 的挥发性分布。来自高挥发性燃料的 IVOCs 更分布在高挥发性区间。总二次有机气溶胶（SOA）生成潜力为 104.36±79.67mg/kg 燃料，主要来自 VOCs（19.98%）、IVOCs（73.87%）和 SVOCs（6.15%）。IVOCs 是比 VOCs 和 SVOCs 更大的 SOA 前体。此外，正构烷烃（n-alkanes）与 IVOCs 具有良好的相关性，这可能是量化 IVOC EF 的替代方法。本工作为 NRCMs 排放的 S/IVOC 排放特征和排放清单的精细化提供了实验数据支持。
