Chengkang Gao

Heavy-duty diesel trucks (HDDTs) have caused serious environmental pollution in China. Accurate estimation of their pollutant emission characteristics is essential to reduce emissions and associated environmental and public health impacts. To achieve sustainable development for transport emissions in Northeast China, we developed localized emission factors and a high-resolution emission inventory of HDDTs, based on on-board test, Guidebook and international vehicle emission (IVE) model. The results show that the total emissions of CO, NO, NO₂, and PM from HDDTs in Northeast China in 2020 were 172.2 kt, 531.5 kt, 11.2 kt, and 921.4 t, respectively. In terms of spatial distribution, emissions decreased from the city center to the city fringe. Temporally, the NOx emission variation curves of different types of roads presented a “single-peak” emission characteristic, which was different from the peak of traffic flow. Three emission reduction scenarios are further developed in the paper. Scenario analysis shows that elimination of HDDTs that follow the old China III emission standard and installing tailpipe treatment devices are the most effective pollutant reduction measure. The reduction percentages for CO, NO, NO₂, and PM ranged from 62.9 to 83.89%. The results of our study could inform policymakers to devise feasible strategies to reduce vehicle pollution in Northeast China.

Heavy-duty diesel trucks (HDDTs) have caused serious environmental pollution in China. Accurate estimation of their pollutant emission characteristics is essential to reduce emissions and associated environmental and public health impacts. We developed localized emission factors and a high-resolution emission inventory of HDDTs in Northeast China, based on on-board test, Guidebook and international vehicle emission (IVE) model. The results show that the total emissions of CO, NO, NO₂ and PM from HDDTs in Northeast China in 2020 were 172.2 kt, 531.5 kt, 11.2 kt and 921.4 t, respectively. In terms of spatial distribution, emissions decreased from the city center to the city fringe. Temporally, the NOx emission variation curves of different types of roads presented a "single-peak" emission characteristic, which was different from the peak of traffic flow. We further developed three emission reduction scenarios to analyze the pollution reduction under different policies. Scenario analysis shows that elimination of HDDTs that follow the old China III emission standard and installing tailpipe treatment devices are the most effective pollutant reduction measure. The reduction percentages for CO, NO, NO₂ and PM ranged from 62.9–83.89%. The results of our study could inform policymakers to devise feasible strategies to reduce vehicle pollution in Northeast China.

To explore the emission characteristics of vehicle’s pollutants is of great significance to prevent and control the diffusion of pollutants. Limited by geographic location and economic condition, the model- and guideline-based studies on vehicle’s emission factor have become more concerned measures than the actual measurement. By analyzing the actual operating conditions of motor vehicles, this study obtains the emission factors of typical pollutants from different motor vehicles by adopting international vehicle emission (IVE) model and guideline method, respectively. Furthermore, the resulting emission factors by the above methods were compared and analyzed with on-road method. The results show that: (1) the emission factors of vehicle pollutants change regularly with velocity, emission standard, and accumulated mileage. Taking CO as an example, its emission factor shows a downward trend with the increase of velocity and emission standard and an upward trend with the increase of accumulated mileage; (2) compared with the actual measurement, the vehicle emission factor obtained by the guideline method has a large error, while the IVE model is close to the actual.

To explore the emission characteristics of vehicle’s pollutants is of great significance to prevent and control the diffusion of pollutants. Limited by geographic location and economic condition, the models- and guidelines-based studies on vehicle’s emission factor have become more concerned measures than the actual measurement. By analyzing the actual operating conditions of motor vehicles, this study obtain the emission factors of typical pollutants from different motor vehicles by adopting international vehicle emission (IVE) model and guideline method, respectively. Furthermore, the resulting emission factors by the above methods were compared and analyzed with on-road method. The results show that: (1) the emission factors of vehicle pollutants change regularly with velocity, emission standard and accumulated mileage. Taking CO as an example, its emission factor shows a downward trend with the increase of velocity and emission standard, and an upward trend with the increase of accumulated mileage; (2) Compared with the actual measurement, the vehicle emission factor obtained by the guideline method has a large error, while the IVE model is close to the actual.

To date there have been many studies of water system optimization which were focused on the water use performance of industrial, regional, and urban areas from a macro-perspective. However, water system optimization colleges and universities are rare, though the amount of water consumption is huge in higher education institutions. We applied a water extended input–output model to investigate and analyze the water system of Northeastern University. Results showed that the water consumption at Northeastern University is 106.72 m3/year per capita; 74.44% of the total water consumption at Northeastern University takes place in dormitories and other school buildings. In contrast with industrial and agricultural sewage, the pollutants in campus sewage are simple and are easy to render harmless or eliminate. Analyzed results showed that the rate of water recycling is low. In this paper, we present an optimization project for improving water efficiency at Northeastern University. Through measures such as dormitory toilets that reuse washroom sewage, our proposed plan will reduce water consumption per capita by 2.13 m3/year. If our proposed plan is adopted at other higher education institutions whose size is the same as Northeastern University all over the country, 7,842.77 × 105 m3/year of water will be saved, which is equivalent to 3.45 × 106 yuan.