26 results on '"ZHILIANG YAO"'
Search Results
2. Contamination of per- and polyfluoroalkyl substances in the water source from a typical agricultural area in North China
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Xiaowei Wang, Hongwei Zhang, Xiaosong He, Jianfei Liu, Zhiliang Yao, Hongbin Zhao, Dayang Yu, Baosen Liu, Tianfu Liu, and Weilong Zhao
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General Environmental Science - Abstract
There is limited information on contaminations of per- and polyfluoroalkyl substances (PFASs) in the water source affected by agricultural activities. The contamination of PFASs was investigated in the sources of agricultural groundwater and nearby surface water from an important vegetable production base supply for Beijing and Tianjin, located in North China. Σ13PFAS concentrations ranged from 0.321 to 8.285 ng/L, with an average concentration of 2.022 ng/L in the groundwater and 19.673 ng/L in the surface water. With the increase in the carbon chain length, the mean concentrations of PFASs in groundwater generally showed a decreasing trend. The dominated congeners of short-chain perfluorobutanesulfonate and perfluorooctanoate acid (PFOA) were detected in all groundwater samples, with mean concentrations of 0.944 and 0.654 ng/L. The difference was that PFOA and perfluorooctanesulfonate (PFOS) were the dominant congeners in nearby surface water, with concentrations of 7.585 and 3.421 ng/L. Thus, the concentrations of PFOA and PFOS in the surface water were about 8.5 times higher than those in the groundwater, indicating that Σ13PFAS concentrations might decrease with the water migration from the overground to the underground. In addition, significant correlations were observed between PFASs and DOC/TN related to agricultural activities, suggesting a certain relationship existed between PFAS conger distributions and organic carbon/nutrients in water. Health risk assessment indicated that the PFAS exposure caused insignificantly immediate harm to residents in the studied area. This survey provided information on the sources, spatial distribution, and potential migration characteristics of PFASs in a typical agricultural area of North China.
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- 2023
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3. The effect of the active carbonyl groups and residual acid on the ammonia adsorption over the acid-modified activated carbon
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Changming Li, Shuying Zhao, Ming Li, Zhiliang Yao, Yang Li, Chuanqiang Zhu, Si-Min Xu, Junjie Li, and Jian Yu
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General Environmental Science - Published
- 2023
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4. Variation characteristics of fine particulate matter and its components in diesel vehicle emission plumes
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Jiateng Hao, Yiming Xu, Zhiliang Yao, Xinyue Cao, Bobo Wu, Kebin He, Yue Shi, Lei Kong, Xin Li, Xianbao Shen, and Jiacheng Shi
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Aerosols ,Environmental Engineering ,010504 meteorology & atmospheric sciences ,Nozzle ,chemistry.chemical_element ,Selective catalytic reduction ,General Medicine ,010501 environmental sciences ,Propelling nozzle ,01 natural sciences ,Carbon ,Plume ,Aerosol ,Diesel fuel ,chemistry ,Environmental chemistry ,Environmental Chemistry ,Environmental science ,Particle ,Computer Simulation ,Particulate Matter ,Vehicle Emissions ,0105 earth and related environmental sciences ,General Environmental Science - Abstract
A rapid reaction occurs near the exhaust nozzle when vehicle emissions contact the air. Twenty diesel vehicles were studied using a new multipoint sampling system that is suitable for studying the exhaust plume near the exhaust nozzle. The variation characteristics of fine particle matter (PM2.5) and its components in diesel vehicle exhaust plumes were analyzed. The PM2.5 emissions gradually increased with increasing distance from the nozzle in the plume. Elemental carbon emissions remained basically unchanged, organic carbon and total carbon (TC) increased with increasing distance. The concentrations of SO42-, NO3- and NH4+ (SNA) directly emitted by the vehicles were very low but increased rapidly in the exhaust plume. The selective catalytic reduction (SCR) reduced 42.7% TC, 40% NO3- emissions, but increased 104% SO42- and 36% NH4+ emissions, respectively. In summary, the SCR reduced 29% primary PM2.5 emissions for the tested diesel vehicles. The NH4NO3 particle formation maybe more important in the plume, and there maybe other forms of formation of NH4+ (eg. NH4Cl). The generation of secondary organic carbon (SOC) plays a leading role in the generation of secondary PM2.5. The SCR enhanced the formation of SOC and SNA in the plume, but comprehensive analysis shows that the SCR more enhanced the SNA formation in the plume, which is mainly new particles formation process. The inconsistency between secondary organic aerosol (SOA) and primary organic aerosol definitions is one of the important reasons for the difference between SOA simulation and observation.
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- 2021
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5. Real-world fuel-based and tillage area-based emission factors of agricultural machines during different tillage processes
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Xianbao Shen, Wenhan Yu, Zhiliang Yao, Lei Kong, Bobo Wu, Kaijie Xuan, Xinyue Cao, Xin Li, Hanyu Zhang, Xuewei Hao, and Qi Zhou
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General Environmental Science - Abstract
Emissions of agricultural machines during tillage processes played an important role in severe seasonal pollution events in agricultural areas in China and cannot be ignored. In this study, the CO, NOX, HC and PM2.5 emissions of agricultural machines during real-world tillage processes were tested using a portable emission measurement system (PEMS), and their fuel-based and tillage area-based emission factors were calculated. The CO, NOX, HC and PM2.5 emissions were influenced by emission standards, engine rated power, tillage processes and crops. Only the CO, HC and PM2.5 fuel-based emission factors were reduced from China 0 to China II. For China III agricultural machines, the fuel-based emission factors were higher during plowing and tilling than during harvesting. The tillage area-based CO, NOX, HC and PM2.5 emission factors of corn tillage process were 11.85 ± 8.30, 53.21 ± 48.80, 3.46 ± 3.14 and 1.64 ± 1.33 kg/km2, respectively. The tillage area-based CO, NOX, HC and PM2.5 emission factors of wheat tillage process were 19.69 ± 21.50, 79.98 ± 63.22, 3.90 ± 2.96 and 1.61 ± 2.43 kg/km2, respectively. The tillage area-based emission factors of China III agricultural machines during plowing and tilling were higher than those during harvesting. The fuel consumption per unit tillage area can be used to provide a reference for the interconversion of the two emission factors in future studies. By comparing the fuel-based emission factors in this study with those in the Guidelines and other studies, we observed that the CO, HC and PM2.5 emissions of agricultural machines with corresponding emission standards may be overestimated and the NOX emissions may be underestimated in areas where wheat and corn are mainly grown. Moreover, the pollutant emissions of agricultural machines were regionally different. These results could help elucidate the pollution contribution of agricultural machines in China.
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- 2022
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6. Emissions of PAHs From Crop Residues Burning in Domestic Stoves in Rural China
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Xuewei Hao, Qiangqiang Zhao, Xianbao Shen, Xinyue Cao, Sijie Feng, Xin Li, Xiaolong Yao, Pengrui Wang, and Zhiliang Yao
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General Environmental Science - Published
- 2022
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7. Digital soil mapping of soil total nitrogen based on Landsat 8, Sentinel 2, and WorldView-2 images in smallholder farms in Yellow River Basin, China
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Yiming, Xu, Bin, Li, Xianbao, Shen, Ke, Li, Xinyue, Cao, Guannan, Cui, and Zhiliang, Yao
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China ,Soil ,Farms ,Rivers ,Nitrogen ,Humans ,General Medicine ,Management, Monitoring, Policy and Law ,Pollution ,Environmental Monitoring ,General Environmental Science - Abstract
Predicting spatial explicit information of soil nutrients is critical for sustainable soil management and food security under climate change and human disturbance in agricultural land. Digital soil mapping (DSM) techniques can utilize soil-landscape information from remote sensing data to predict the spatial pattern of soil nutrients, and it is important to explore the effects of remote sensing data types on DSM. This research utilized Landsat 8 (LT), Sentinel 2 (ST), and WorldView-2 (WV) remote sensing data and employed partial least squares regression (PLSR), random forest (RF), and support vector machine (SVM) algorithms to characterize the spatial pattern of soil total nitrogen (TN) in smallholder farm settings in Yellow River Basin, China. The overall relationships between TN and spectral indices from LT and ST were stronger than those from WV. Multiple red edge band-based spectral indices from ST and WV were relevant variables for TN, while there were no red band-based spectral indices from ST and WV identified as relevant variables for TN. Soil moisture and vegetation were major driving forces of soil TN spatial distribution in this area. The research also concluded that farmlands of crop rotation had relatively higher TN concentration compared with farmlands of monoculture. The soil prediction models based on WV achieved relatively lower model performance compared with those based on ST and LT. The effects of remote sensing data spectral resolution and spectral range on enhancing soil prediction model performance are higher than the effects of remote sensing data spatial resolution. Soil prediction models based on ST can provide location-specific soil maps, achieve fair model performance, and have low cost. This research suggests DSM research utilizing ST has relatively high prediction accuracy, and can produce soil maps that are fit for the spatial explicit soil management for smallholder farms.
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- 2022
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8. Real-world emission characteristics of carbonyl compounds from agricultural machines based on a portable emission measurement system
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Wenhan Yu, Xianbao Shen, Bobo Wu, Lei Kong, Kaijie Xuan, Cheng Zhao, Xinyue Cao, Xuewei Hao, Xin Li, Hanyu Zhang, and Zhiliang Yao
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Aerosols ,Air Pollutants ,China ,Volatile Organic Compounds ,Environmental Engineering ,Smog ,General Medicine ,Acetaldehyde ,Ozone ,Formaldehyde ,Environmental Chemistry ,Acrolein ,Organic Chemicals ,General Environmental Science ,Environmental Monitoring ,Vehicle Emissions - Abstract
Emissions of carbonyl compounds from agricultural machines cannot be ignored. Carbonyl compounds can cause the formation of ozone (O
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- 2021
9. Source apportionment and ecological and health risk mapping of soil heavy metals based on PMF, SOM, and GIS methods in Hulan River Watershed, Northeastern China
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Yiming Xu, Xianxia Wang, Guannan Cui, Ke Li, Yanfeng Liu, Bin Li, and Zhiliang Yao
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Adult ,China ,General Medicine ,Management, Monitoring, Policy and Law ,Pollution ,Risk Assessment ,Soil ,Rivers ,Metals, Heavy ,Geographic Information Systems ,Humans ,Soil Pollutants ,Child ,General Environmental Science ,Environmental Monitoring - Abstract
Heavy metals in agricultural soils not only affect the food security and soil security, but also endanger the human health through the food chain. Based on the incorporation of index analysis, positive matrix factorization (PMF), self-organizing map (SOM), and geostatistical methods, this research performed the assessment of source apportionment and ecological and health risks of soil heavy metals in Hulan River Watershed, Northeastern China. According to the Pollution Load Index (PLI), 83.08% of the soil samples were slightly or mildly polluted, and 1.54% of the soil samples were severely polluted. The ecological risk index (EI) showed that about 80.77% and 60.77% of the soil samples were beyond the low risk level for Hg and Cd, respectively. In this research, the non-carcinogenic and carcinogenic risk indices for children were higher than adult males and adult females. Four potential sources were revealed based on the PMF and SOM analysis including atmospheric deposition and industrial emission; transportation source; agricultural source; and a combination of agricultural, industrial, and natural sources. Considerable and high ecological risk from Hg existed in the area close to the coal steam-electric plant, and considerable and high ecological risk from Cd existed in the Hulan River estuary area. The eastern part of the study area experienced higher non-carcinogenic and carcinogenic risks for adults and children than the western part of the study area. The source apportionment and ecological and health risk mapping provide important role in reducing pollution sources. Zonal pollution control and soil restoration measures should be performed in the areas with high ecological and health risks.
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- 2021
10. A state-of-the-art review of CO2 enhanced oil recovery as a promising technology to achieve carbon neutrality in China
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Shanxue Jiang, Yuening Li, Fang Wang, Haishu Sun, Huijiao Wang, and Zhiliang Yao
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Biochemistry ,General Environmental Science - Published
- 2022
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11. Real-world exhaust emissions and fuel consumption for diesel vehicles fueled by waste cooking oil biodiesel blends
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Jiacheng Shi, Xianbao Shen, Xinyue Cao, Hui Wu, Xin Zhang, Zhiliang Yao, and Wei Zhang
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Truck ,Atmospheric Science ,Biodiesel ,020209 energy ,02 engineering and technology ,Energy security ,010501 environmental sciences ,Pulp and paper industry ,01 natural sciences ,Diesel fuel ,Biofuel ,Greenhouse gas ,0202 electrical engineering, electronic engineering, information engineering ,Fuel efficiency ,Environmental science ,NOx ,0105 earth and related environmental sciences ,General Environmental Science - Abstract
The real-world exhaust emissions and fuel consumption of on-road diesel vehicles, fueled by waste cooking oil biodiesel blends, were measured using a portable emission measurement system (PEMS). Two light-duty diesel trucks (LDDTs) and two heavy-duty diesel trucks (HDDTs) filled with four mixed fuels with blend ratios of 0% (neat diesel), 5% (B5), 20% (B20), and 100% (B100) (biodiesel in traditional fossil diesel) were tested. The results show that the total fuel consumption (biodiesel + traditional fossil diesel) did not clearly decrease, but blending biodiesel into traditional fossil diesel could clearly decreased the consumption of traditional fossil diesel, reduce the countries' dependence on oil imports. Converting waste cooking oil into biofuel and blending with diesel is a three-win alternative, dealing simultaneously with greenhouse gas (GHG) emission, food security, and energy security. The CO, HC, NOX and PM2.5 emissions for all of the tested vehicles decreased with increasing biodiesel content in the blend, with the exception of PM2.5 and NOX for D3, the NOX emissions showed a decrease with increasing biodiesel content in the blend for most vehicles in this study. The effect of emission reduction for all biodiesel blending proportions under highway (HW) condition is better than that under Non-highway (NHW) condition. The degree of reduction in CO, HC, NOX, and PM2.5 emission increased with increasing biodiesel content in the blend under HW section. Under the NHW section, the emission factors for lower biodiesel blend proportions (below 12.5%) especially for B5 were higher than those for neat diesel. The biodiesel blend reduced CO, HC, NOX and PM2.5 emissions compared with neat diesel under different driving modes except for individual condition (especially for B5 under acceleration mode). Increasing the biodiesel content of the blend lowered the CO, HC, NOX, and PM2.5 emissions for acceleration and deceleration modes.
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- 2018
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12. Emission characteristics of polycyclic aromatic hydrocarbons and nitro-polycyclic aromatic hydrocarbons from diesel trucks based on on-road measurements
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Xinyue Cao, Zhiliang Yao, Xi Jiang, Xianbao Shen, Xuewei Hao, and Bobo Wu
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chemistry.chemical_classification ,Truck ,Atmospheric Science ,010504 meteorology & atmospheric sciences ,Environmental engineering ,Polycyclic aromatic hydrocarbon ,010501 environmental sciences ,01 natural sciences ,Diesel fuel ,chemistry ,Emission inventory ,Aromatic hydrocarbon ,0105 earth and related environmental sciences ,General Environmental Science - Abstract
Polycyclic aromatic hydrocarbon (PAH) and nitro-polycyclic aromatic hydrocarbon (NPAH) emissions from 18 diesel trucks of different sizes and with different emission standards were tested in Beijing using a portable emission measurement system (PEMS). Both the gaseous- and particulate-phase PAHs and NPAHs were quantified by high-performance liquid chromatography (HPLC) in the laboratory. The emission factors (EFs) of the total PAHs from light-duty diesel trucks (LDDTs), medium-duty diesel trucks (MDDTs) and heavy-duty diesel trucks (HDDTs) were 82229.11 ± 41906.06, 52867.43 ± 18946.47 and 93837.35 ± 32193.14 μg/km, respectively, much higher than the respective values of total NPAHs from their counterpart vehicles. The gaseous phase had an important contribution to the total PAHs and NPAHs, with a share rate of approximately 69% and 97% on average, respectively. The driving cycle had important impacts on the emissions of PAHs and NPAHs, especially for LDDTs and HDDTs. Higher emissions of PAHs and NPAHs were detected on non-highway roads compared to that on highways for these two types of vehicles. Compared to the results of different studies, the difference in the EFs of PAHs and NPAHs can reach several orders of magnitudes, which would introduce errors in the development of an emission inventory of PAHs and NPAHs.
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- 2017
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13. The effects of biodiesel blends on real-world carbonyl emissions from diesel trucks
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Xinyue Cao, Sijie Feng, Xiaolong Yao, Xianbao Shen, Zhiliang Yao, and Xin Li
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Atmospheric Science ,Biodiesel ,Ozone ,010504 meteorology & atmospheric sciences ,Portable emissions measurement system ,Formaldehyde ,Acetaldehyde ,Selective catalytic reduction ,010501 environmental sciences ,Pulp and paper industry ,complex mixtures ,01 natural sciences ,chemistry.chemical_compound ,Diesel fuel ,chemistry ,Butyraldehyde ,0105 earth and related environmental sciences ,General Environmental Science - Abstract
This work assessed the effects of biodiesel on carbonyl emissions from diesel trucks. Biodiesel converted from waste cooking oil was employed and mixed with commercial fossil diesel to produce four blends: B0 (pure conventional diesel fuel), B5 (5% v/v biodiesel), B20 (20% v/v biodiesel) and B100 (pure biodiesel). Four diesel trucks were tested under real-world conditions using a portable emissions measurement system, including one China III light-duty diesel truck (LDDT), one China IV LDDT, one China III heavy-duty diesel truck (HDDT) and one China IV HDDT. A driving cycle including highway (HW) and non-highway (NHW) driving conditions was employed and carbonyls were sampled using 2,4-dinitrophenylhydrazine cartridges and analyzed via high performance liquid chromatography. Seven carbonyl compounds were detected, and formaldehyde, acetaldehyde, acetone and butyraldehyde were the primary carbonyls. Total carbonyl emissions from the China III LDDT, China III HDDT and China IV HDDT vehicles with selective catalytic reduction decreased monotonically with increases in the biodiesel proportion, while the China IV LDDT with a particle oxidation catalyst system showed an increasing trend. With increases in the biodiesel proportions, complementary variations were observed in the proportions of formaldehyde and butyraldehyde obtained using the China III LDDT, China IV LDDT and China III HDDT vehicles. However, in the case of the China IV HDDT trials, the formaldehyde and acetaldehyde emissions exhibited complementary variations. Under different driving conditions, the effects of adding biodiesel on carbonyl emission factors were different. In China III LDDT trials, biodiesel reduced carbonyl emissions to a greater extent under HW conditions, but the opposite occurred in China III HDDT tests. Using the China IV LDDT vehicle, the emission factors did not increase as much during HW trials compared with NHW trials when the B5 and B20 fuels were used, but were significantly higher than the NHW values when pure biodiesel was employed. In China III LDDT data, the proportions of formaldehyde, acetaldehyde and butyraldehyde showed opposite variations under the two driving conditions. Using the China IV LDDT vehicle, a significant increase in formaldehyde and decrease in butyraldehyde were found during HW trials, but not NHW trials. Ozone formation potentials were obtained from carbonyls emission factors using the maximum incremental reactivity method and their variations were similar to those of the carbonyl emission factors.
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- 2020
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14. On-road emission characteristics of VOCs from light-duty gasoline vehicles in Beijing, China
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Xi Jiang, Zhiliang Yao, Yu Ye, Xinyue Cao, and Xianbao Shen
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Atmospheric Science ,Ozone ,010504 meteorology & atmospheric sciences ,Light duty ,Environmental engineering ,010501 environmental sciences ,01 natural sciences ,chemistry.chemical_compound ,chemistry ,Beijing ,Gas chromatography ,Gasoline ,0105 earth and related environmental sciences ,General Environmental Science - Abstract
This study is the third in a series of three papers aimed at characterizing the VOC emissions of vehicles in Beijing. In this study, 30 light-duty vehicles fueled with gasoline were evaluated using a portable emission measurement system (PEMS) as they were driven on a predesigned, fixed test route. All of the tested vehicles were rented from private vehicle owners and spanned regulatory compliance guidelines ranging from Pre-China I to China IV. Alkanes, alkenes, aromatics and some additional species in the exhaust were collected in Tedlar bags and analyzed using gas chromatography/mass spectrometry (GC–MS). Carbonyls were collected on 2,4-dinitrophenyhydrazine (DNPH) cartridges and analyzed using high-performance liquid chromatography (HPLC). Overall, 74 VOC species were detected from the tested vehicles, including 22 alkanes, 6 alkenes, 1 alkyne, 16 aromatics, 3 cyclanes, 10 halohydrocarbons, 12 carbonyls and 4 other compounds. Alkanes, aromatics and carbonyls were the dominant VOCs with weight percentages of approximately 36.4%, 33.1% and 17.4%, respectively. The average VOC emission factors and standard deviations of the Pre-China I, China I, China II, China III and China IV vehicles were 469.3 ± 200.1, 80.7 ± 46.1, 56.8 ± 37.4, 25.6 ± 11.7 and 14.9 ± 8.2 mg/km, respectively, which indicated that the VOC emissions significantly decreased under stricter vehicular emission standards. Driving cycles also influenced the VOC emissions from the tested vehicles. The average VOC emission factors based on the travel distances of the tested vehicles under urban driving cycles were greater than those under highway driving cycles. In addition, we calculated the ozone formation potential (OFP) using the maximum incremental reactivity (MIR) method. The results of this study will be helpful for understanding the true emission levels of light-duty gasoline vehicles and will provide information for controlling VOC emissions from vehicles in Beijing, China.
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- 2016
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15. Comparison of NOx emissions from China III and China IV in-use diesel trucks based on on-road measurements
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Xinyue Cao, Bobo Wu, Xi Jiang, Zhiliang Yao, and Yunong Wu
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Truck ,Atmospheric Science ,Engineering ,Waste management ,business.industry ,Environmental engineering ,Diesel fuel ,Beijing ,Fuel efficiency ,business ,China ,Nitrogen oxides ,NOx ,General Environmental Science - Abstract
To mitigate NOx and other emissions from diesel vehicles, China I, China II, China III and China IV emissions standards for new vehicles have been implemented nationwide. However, recent on-road measurements using a portable emission measurement system (PEMS) have revealed no significant reductions in the NOx emissions factors of diesel trucks due to the change from China II emissions standards to the more stringent China III standards. Thus, it is important to understand the effect of the China IV emissions standard on NOx emissions. In this study, nine China III and nine China IV diesel trucks of three sizes (light-duty diesel trucks (LDDTs), medium-duty diesel trucks (MDDTs) and heavy-duty diesel trucks (HDDTs)) were tested on real roads in Beijing using a PEMS. Compared to the tested China III diesel trucks, the China IV diesel trucks showed significant reductions of the average NOx emissions factors in terms of both distance travelled and fuel consumption. However, the driving conditions had an important impact on the reduction. Under non-highway driving (NHD), several of the tested China IV diesel trucks experienced no reduction or an increase in NOx emissions compared to their China III counterparts. The NOx emissions factors of the 18 tested diesel trucks under NHD were on average 1.5-times greater than those under highway driving (HD), and the effects on NOx emissions removal from China III to China IV diesel trucks were greater under HD than under NHD. In addition, no significant reduction of NOx based on fuel consumption for China IV diesel trucks was observed for MDDTs and HDDTs compared to the test results for similar China II vehicles reported in a previous study. To reduce NOx emissions in China, additional control measures of vehicular NOx emissions should be formulated.
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- 2015
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16. Chemical characterization of PM 2.5 emitted from on-road heavy-duty diesel trucks in China
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Yingzhi Zhang, Xianbao Shen, Kebin He, Huan Liu, and Zhiliang Yao
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Truck ,Atmospheric Science ,Diesel fuel ,chemistry ,Fine particulate ,Environmental engineering ,Fuel efficiency ,Sulfur content ,chemistry.chemical_element ,Heavy duty diesel ,Carbon ,NOx ,General Environmental Science - Abstract
Heavy-duty diesel trucks (HDDTs) are gaining more attention because of their contribution to NOX and PM2.5 emissions. To evaluate their contribution to ambient fine particulate matter (PM2.5), not only their emission factors, but also their source profile is required. We conducted on-road emissions tests to characterize the PM2.5 emission, documenting per second mass emission rates from in-use HDDTs in China, using portable emissions measurement systems. The average PM2.5 emission factors for pre-EURO and EURO 1 HDDTs were 1.104 g/km and 0.822 g/km, equivalent to 6.106 g/kg and 3.132 g/kg based on fuel consumption. Element carbon (EC) and organic carbon (OC) were the major components: EC accounted for 45–65% of PM2.5 for pre-EURO HDDTs and 36–69% for EURO 1 HDDTs, while the OC fraction for pre-EURO and EURO 1 HDDTs ranged from 20 to 31% and 19–31%, respectively. Thus, the average EC emission factors for pre-EURO and EURO 1 HDDTs were 0.667 g/km and 0.502 g/km, showing that implementation of tighter emission standards resulted in a 25% EC output reduction from pre-EURO to EURO 1 vehicles. Sulfate, comprising about 1% of PM2.5 mass, is still an abundant species in PM2.5 from HDDTs because of the high sulfur content in diesel fuel in China. Using these data, we updated national PM2.5 emission profiles for pre-EURO and EURO 1 HDDTs.
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- 2015
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17. Carbonaceous composition of PM2.5 emitted from on-road China III diesel trucks in Beijing, China
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Wei Zhang, Xinyue Cao, Hui Wu, Bobo Wu, Xianbao Shen, and Zhiliang Yao
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Truck ,Atmospheric Science ,Diesel fuel ,Beijing ,Portable emissions measurement system ,Fine particulate ,Environmental engineering ,Environmental science ,Composition (visual arts) ,Particulates ,Air quality index ,General Environmental Science - Abstract
Fine particulate matter (PM2.5) has attracted increasing attention due to its impacts on air quality and human health. As an important source of PM2.5, diesel vehicles are often the focus of research. In this study, we characterized the carbonaceous composition of PM2.5 that is emitted from on-road China III diesel trucks (DTs). Organic carbon (OC), elemental carbon (EC), and PM2.5 emission characteristics were determined for 17 China III DTs, including 6 light-duty diesel trucks (LDDTs), 5 medium-duty diesel trucks (MDDTs), and 6 heavy-duty diesel trucks (HDDTs), based on real-world measurements in Beijing, China, using a portable emissions measurement system (PEMS). The average distance-based PM2.5 emission factors (EFs) (g km−1) generally increased and the average CO2-based PM2.5 EFs (g (kg of CO2)−1) generally decreased with increased vehicle size from LDDTs to MDDTs to HDDTs. The effects of driving conditions on the EFs for carbonaceous PM2.5 were analyzed. The results show that distance-based and CO2-based EFs strongly depend on driving conditions. Generally, greater amounts of PM2.5 and OC are emitted from non-highway driving cycles, and greater amounts of EC are emitted from highway driving cycles for vehicles of the same size. For LDDTs, MDDTs, and HDDTs, no significant differences were observed between vehicles with different EC/OC ratios; therefore, the EC/OC ratio is not useful for distinguishing between the emissions generated by differently sized vehicles. The EC/OC, OC/PM2.5, and EC/PM2.5 mass ratios are strongly dependent on driving conditions for vehicles of the same size. The results of this study provide EFs for the carbonaceous composition of PM2.5 that are more appropriate for China; these results will be helpful for improving policies that are designed to control the carbonaceous composition of PM2.5 emitted from on-road DTs in China.
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- 2015
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18. Development of database of real-world diesel vehicle emission factors for China
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Kebin He, David Vance Wagner, Xianbao Shen, Qiang Zhang, Hong Huo, Yingzhi Zhang, Bo Zheng, and Zhiliang Yao
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Truck ,Pollutant ,Air Pollutants ,China ,Engineering ,Environmental Engineering ,Modeling software ,Databases, Factual ,Database ,business.industry ,General Medicine ,Particulates ,computer.software_genre ,Road transport ,Motor Vehicles ,Diesel fuel ,Environmental Chemistry ,Emission inventory ,business ,computer ,Vehicle Emissions ,General Environmental Science - Abstract
A database of real-world diesel vehicle emission factors, based on type and technology, has been developed following tests on more than 300 diesel vehicles in China using a portable emission measurement system. The database provides better understanding of diesel vehicle emissions under actual driving conditions. We found that although new regulations have reduced real-world emission levels of diesel trucks and buses significantly for most pollutants in China, NOx emissions have been inadequately controlled by the current standards, especially for diesel buses, because of bad driving conditions in the real world. We also compared the emission factors in the database with those calculated by emission factor models and used in inventory studies. The emission factors derived from COPERT (Computer Programmer to calculate Emissions from Road Transport) and MOBILE may both underestimate real emission factors, whereas the updated COPERT and PART5 (Highway Vehicle Particulate Emission Modeling Software) models may overestimate emission factors in China. Real-world measurement results and emission factors used in recent emission inventory studies are inconsistent, which has led to inaccurate estimates of emissions from diesel trucks and buses over recent years. This suggests that emission factors derived from European or US-based models will not truly represent real-world emissions in China. Therefore, it is useful and necessary to conduct systematic real-world measurements of vehicle emissions in China in order to obtain the optimum inputs for emission inventory models.
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- 2015
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19. On-road emission characteristics of VOCs from rural vehicles and their ozone formation potential in Beijing, China
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Xi Jiang, Xianbao Shen, Zhiliang Yao, Yu Ye, Bobo Wu, Xinyue Cao, and Kebin He
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chemistry.chemical_classification ,Atmospheric Science ,Ozone ,Portable emissions measurement system ,Environmental engineering ,Ethylbenzene ,chemistry.chemical_compound ,Diesel fuel ,chemistry ,Beijing ,Environmental chemistry ,Volatile organic compound ,Benzene ,General Environmental Science - Abstract
This paper is the second in a series of papers aimed at understanding volatile organic compound (VOC) emissions from motor vehicles in Beijing using on-board emission measurements, focusing specifically on rural vehicles (RVs). In this work, 13 RVs, including 6 different 3-wheel (3-W) RVs and 7 different 4-wheel (4-W) RVs, were examined using a portable emissions measurement system (PEMS) as the vehicles were driven on predesigned fixed test routes in rural areas of Beijing. Overall, 50 VOC species were quantified in this study, including 18 alkanes, 5 alkenes, 11 aromatics, 13 carbonyls and 3 other compounds. The average emission factor (EF) of the total VOCs for the 4-W RVs based on the distance traveled was 326.2 ± 129.3 mg/km, which is 2.5 times greater than that of the 3-W RVs. However, the VOC emissions for the 3-W RVs had higher EFs based on their CO2 emissions due to the different fuel economies of the two types of RVs. Formaldehyde, toluene, acetaldehyde, m-xylene, p-xylene, isopentane, benzene, ethylbenzene, n-pentane, 2-methoxy-2-methylpropane and butenal were the dominant VOC species from the RVs, accounting for an average of 68.6% of the total VOC emissions. Overall, the RVs had high proportions of aromatics and carbonyls. The ozone formation potentials (OFPs) were 670.6 ± 227.2 and 1454.1 ± 643.0 mg O3/km for the 3-W and 4-W RVs, respectively, and approximately 60%–70% of the OFP resulted from carbonyls. We estimated that the 3-W and 4-W RVs accounted for approximately 50% and 10%, respectively, of the total OFP caused by diesel vehicles (including diesel trucks and RVs) in Beijing in 2012. Thus, more attention should be given to VOC emissions and their impact on ozone formation.
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- 2015
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20. On-road emission characteristics of VOCs from diesel trucks in Beijing, China
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Xinyue Cao, Xi Jiang, Xianbao Shen, Yingzhi Zhang, Kebin He, Yu Ye, and Zhiliang Yao
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Truck ,chemistry.chemical_classification ,Atmospheric Science ,Engineering ,Ozone ,Portable emissions measurement system ,business.industry ,Environmental engineering ,chemistry.chemical_compound ,Diesel fuel ,chemistry ,Beijing ,Volatile organic compound ,business ,General Environmental Science - Abstract
This paper is the first in our series of papers aimed at understanding the volatile organic compound (VOC) emissions of vehicles in Beijing by conducting on-board emission measurements. This paper focuses on diesel vehicles. In this work, 18 China III diesel vehicles, including seven light-duty diesel trucks (LDDTs), four medium-duty diesel trucks (MDDTs) and seven heavy-duty diesel trucks (HDDTs), were examined when the vehicles were driven on predesigned fixed test routes in Beijing in China using a portable emissions measurement system (PEMS). Tedlar bag sampling and 2,4-dinitrophenyhydrazine (DNPH) cartridge sampling were used to collect VOC species, and gas chromatography-mass spectrometry (GC/MS) and high-performance liquid chromatography (HPLC) were used to analyze these samples. We obtained the VOC emission factors and relative compositions for diesel trucks of different sizes under different driving patterns. In total, 64 VOC species were quantified in this study, including 25 alkanes, four alkenes, 13 aromatics, 13 carbonyls and nine other compounds. The emission factors of the total VOCs based on mileage traveled for HDDTs were higher than those of LDDTs and MDDTs. Carbonyls, aromatics and alkanes were the dominant VOC species. Carbonyls accounted for 42.7%–69.2% of the total VOCs in the three types of tested diesel trucks. The total VOC emission factors of the tested vehicles that were driven on non-highway routes were 1.5–2.0 times higher than those of the vehicles driven on the highway. As for the OFP calculation results, with increased vehicle size, the ozone formation potential presented an increasing trend. Among the VOC components, carbonyls were the primary contributor to OFP. In addition, the OFPs under non-highway driving cycles were 1.3–1.7 times those under highway driving cycles. The results of this study will be helpful in improving our understanding of VOCs emitted from on-road diesel trucks in China.
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- 2015
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21. On-road emission characteristics of CNG-fueled bi-fuel taxis
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Xinyue Cao, Xianbao Shen, Xintong Wang, Yingzhi Zhang, Kebin He, and Zhiliang Yao
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Atmospheric Science ,Engineering ,business.industry ,Natural gas vehicle ,Air pollution ,Taxis ,Environmental engineering ,medicine.disease_cause ,Automotive engineering ,medicine ,Gasoline ,business ,Driving cycle ,NOx ,General Environmental Science - Abstract
To alleviate air pollution and lessen the petroleum demand from the motor vehicle sector in China, natural gas vehicles (NGVs) have been rapidly developed over the last several years. However, the understanding of the real-world emissions of NGVs is very limited. In this study, the emissions from 20 compressed-natural-gas-fueled bi-fuel taxis were measured using a portable emission measurement system (PEMS) under actual driving conditions in Yichang, China. The emission characteristics of the tested vehicles were analyzed, revealing that the average CO2, CO, HC and NOx emissions from the tested compressed-natural-gas (CNG) taxis under urban driving conditions were 1.6, 4.0, 2.0 and 0.98 times those under highway road conditions, respectively. The CO, HC and NOx emissions from Euro 3 CNG vehicles were approximately 40%, 55% and 44% lower than those from Euro 2 vehicles, respectively. Compared with the values for light-duty gasoline vehicles reported in the literature, the CO2 and CO emissions from the tested CNG taxis were clearly lower; however, significant increases in the HC and NOx emissions were observed. Finally, we normalized the emissions under the actual driving cycles of the entire test route to the New European Driving Cycle (NEDC)-based emissions using a VSP modes method developed by North Carolina State University. The simulated NEDC-based CO emissions from the tested CNG taxis were better than the corresponding emissions standards, whereas the simulated NEDC-based HC and NOx emissions greatly exceeded the standards. Thus, more attention should be paid to the emissions from CNG vehicles. As for the CNG-fueled bi-fuel taxis currently in use, the department of environmental protection should strengthen their inspection and supervision to reduce the emissions from these vehicles. The results of this study will be helpful in understanding and controlling emissions from CNG-fueled bi-fuel vehicles in China.
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- 2014
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22. Historical evaluation of vehicle emission control in Guangzhou based on a multi-year emission inventory
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Zhiliang Yao, Xiaomeng Wu, Huan Liu, Lixin Fu, Yu Zhou, Kebin He, Ye Wu, Shaojun Zhang, and Jiming Hao
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Toxicology ,Atmospheric Science ,Diesel fuel ,Asian games ,Fuel quality ,Gaseous pollutants ,Environmental engineering ,Environmental science ,Emission inventory ,National Ambient Air Quality Standards ,NOx ,General Environmental Science - Abstract
The Guangzhou government adopted many vehicle emission control policies and strategies during the five-year preparation (2005–2009) to host the 2010 Asian Games. This study established a multi-year emission inventory for vehicles in Guangzhou during 2005–2009 and estimated the uncertainty in total vehicle emissions by taking the assumed uncertainties in fleet-average emission factors and annual mileage into account. In 2009, the estimated total vehicle emissions in Guangzhou were 313 000 (242 000–387 000) tons of CO, 60 900 (54 000–70 200) tons of THC, 65 600 (56 800–74 100) tons of NOx and 2740 (2100–3400) tons of PM10. Vehicle emissions within the urban area of Guangzhou were estimated to be responsible for ∼40% of total gaseous pollutants and ∼25% of total PM10 in the entire city. Although vehicle use intensity increased rapidly in Guangzhou during 2005–2009, vehicle emissions were estimated to have been reduced by 12% for CO, 21% for THC and 20% for PM10 relative to those in 2005. NOx emissions were estimated to have remained almost constant during this period. Compared to the “without control” scenario, 19% (15%–23%) of CO, 20% (18%–23%) of THC, 9% (8%–10%) of NOx and 16% (12%–20%) of PM10 were estimated to have been mitigated from a combination of the implementation of Euro III standards for light-duty vehicles (LDVs) and heavy-duty diesel vehicles and improvement of fuel quality. This study also evaluated several enhanced vehicle emission control actions taken recently. For example, the enhanced I/M program for LDVs was estimated to reduce 11% (9%–14%) of CO, 9% (8%–10%) of THC and 2% (2%–3%) of NOx relative to total vehicle emissions in 2009. Total emission reductions by temporary traffic controls for the Asian Games were estimated equivalent to 9% (7%–11%) of CO, 9% (8%–10%) of THC, 5% (5%–6%) of NOx and 10% (8%–13%) of PM10 estimated total vehicle emissions in 2009. Those controls are essential to further vehicle emission mitigation in Guangzhou required by the new National Ambient Air Quality Standards.
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- 2013
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23. On-board measurements of emissions from diesel trucks in five cities in China
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Zhiliang Yao, Qiang Zhang, Hong Huo, Yingzhi Zhang, Xianbao Shen, and Kebin He
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Truck ,Atmospheric Science ,Engineering ,Diesel exhaust ,Waste management ,business.industry ,Environmental engineering ,Ambient air ,On board ,Diesel fuel ,Emission inventory ,China ,business ,NOx ,General Environmental Science - Abstract
This paper, which focuses on diesel trucks, is the third in a series of three papers published in Atmospheric Environment to understand vehicle emissions in China by conducting on-board emission measurements. Diesel trucks are a significant source of emissions in ambient air, especially for NOx. Recently, China announces an aggressive target to reduce national NOx emissions by 10% from 2010 to 2015 in the “Twelfth Five-Year Plan (2011–2015)” and diesel vehicles are identified as a key target for NOx control. However, the understanding of the real-world emissions of diesel trucks is limited. In this study, we measured HC, CO, NOx, and PM 2.5 emissions from 175 diesel trucks of different sizes and technologies in five Chinese cities during 2007 and 2011, and generated emission factors on the basis of the measurements. The results show that the HC, CO, and PM 2.5 emission factors have been reduced significantly as the emission standards become more stringent from Euro 0 to Euro IV, but the NOx emission factors change differently. Euro II trucks have 3–6% higher NOx emission levels than Euro I technologies and Euro III trucks fail to show a reduction as regulated by the standards. More stringent NOx requirements (e.g. Euro IV) for diesel vehicles need to be enforced. The comparison with the emission factors used in recent emission inventory studies shows that these inventories may have overestimated or underestimated diesel emissions for the years after 2006. This study emphasizes the importance of conducting local measurement research to improve the accuracy of the estimates of mobile emissions in China.
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- 2012
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24. On-board measurements of emissions from light-duty gasoline vehicles in three mega-cities of China
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Yan Ding, Xianbao Shen, Hong Huo, Qiang Zhang, Yingzhi Zhang, Kebin He, and Zhiliang Yao
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Atmospheric Science ,Engineering ,business.industry ,Light duty ,Taxis ,Environmental engineering ,Key issues ,On board ,Megacity ,Beijing ,Gasoline ,China ,business ,General Environmental Science - Abstract
This paper is the second in a series of three papers aimed at understanding the emissions of vehicles in China by conducting on-board emission measurements. This paper focuses on light-duty gasoline vehicles. In this study, we measured 57 light-duty gasoline vehicles (LDGVs) in three Chinese mega-cites (Beijing, Guangzhou, and Shenzhen), covering Euro 0 through Euro IV technologies, and generated CO, HC, and NOx emission factors and deterioration rates for each vehicle technology. The results show that the vehicle emission standards have played a significant role in reducing vehicle emission levels in China. The vehicle emission factors are reduced by 47–81%, 53–64%, 46–71%, and 78–82% for each phase from Euro I to Euro IV. Euro 0 vehicles have a considerably high emission level, which is hundreds of times larger than that of Euro IV vehicles. Three old taxis and four other Euro I and Euro II LDGVs are also identified as super emitters with equivalent emission levels to Euro 0 vehicles. Of the measured fleet, 23% super emitters were estimated to contribute 50–80% to total emissions. Besides vehicle emission standards, measures for restricting super emitters are equally important to reduce vehicle emissions. This study is intended to improve the understanding of the vehicle emission levels in China, but some key issues such as emission deterioration rates are yet to be addressed with the presence of a sufficient amount of vehicle emission measurements.
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- 2012
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25. Gaseous and particulate emissions from rural vehicles in China
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Zhiliang Yao, Qiang Zhang, Hong Huo, Kebin He, and David G. Streets
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Truck ,Atmospheric Science ,education.field_of_study ,Diesel fuel ,Policy making ,Pollutant emissions ,Population ,Environmental engineering ,Environmental science ,Particulates ,education ,NOx ,General Environmental Science - Abstract
Rural vehicles (RVs) could contribute significantly to air pollutant emissions throughout Asia due to their considerable population, extensive usage, and high emission rates, but their emissions have not been measured before and have become a major concern for the accuracy of regional and global emission inventories. In this study, we measured CO, HC, NOx and PM emissions of RVs using a combined on- board emission measurement system on real roads in China. We also compared the emission levels of the twenty RVs to those of nineteen Euro II light-duty diesel trucks (LDDTs) that we measured for previous studies. The results show that one-cylinder RVs have lower distance-based emission factors compared to LDDTs because of their smaller weight and engine power, but they have significantly higher fuel-based PM emission factors than LDDTs. Four-cylinder RVs have equivalent emission levels to LDDTs. Based on the emission factors and the activity data obtained, we estimate that the total emissions of RVs in China in 2006 were 1049 Gg of CO, 332 Gg of HC, 933 Gg of NOx, and 54 Gg of PM, contributing over 40% to national on-road diesel CO, NOx, and PM emissions. As RVs are a significant contributor to national emissions, further research work is needed to improve the accuracy of inventories at all levels, and the government should strengthen the management of RVs to facilitate both policy making and research work.
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- 2011
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26. Characterization of vehicle driving patterns and development of driving cycles in Chinese cities
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Hong Huo, Qidong Wang, Kebin He, Qinglin Zhang, and Zhiliang Yao
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Engineering ,Test procedures ,business.industry ,Poison control ,Transportation ,City size ,Vehicle driving ,Transport engineering ,Local road ,In vehicle ,Traffic speed ,business ,Driving cycle ,General Environmental Science ,Civil and Structural Engineering - Abstract
Current driving cycles used in China are not able to accurately assess vehicle emissions due to their inadequate representation of real-world driving. We in this study analyzed the driving characteristics and developed the driving cycles in Chinese cities, then compared them to the European test cycle and the American Federal Test Procedure. Eleven cities were selected, covering different city sizes and geographical locations. Car chasing technique was employed in each city to collect speed-time data on freeways, arterials, and residential roads during traffic peak and non-peak periods. The data collected were adjusted by the traffic adjustment factors to reflect the overall traffic. Eleven driving parameters were used to characterize driving characteristics and develop driving cycles. The results indicate that city size, local road infrastructure, and driving behavior are the most important factors that lead to the significant differences in vehicle driving patterns among the cities. The comparison with the European and US cycles suggests that the emission factors produced from the European or US cycles-based tests could be significantly different than those from the driving cycles in China.
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- 2008
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