Regulations for the control of air-pollutant emissions from ships within pollutant emission control areas (ECAs) have been issued for several years, but the lack of practical technologies and fundamental theory in the implementation process remains a challenge. In this study, we designed a model to calculate the nitrogen-oxide-emission intensity of ships and the sulfur content of ship fuels using theoretical deduction from the law of the conservation of mass. The reliability and availability of the derived results were empirically evaluated using measurement data for NO_x, SO_2, and CO₂ in the exhaust gas of a demonstration ship in practice. By examining the model and the measured or registered fuel-oil-consumption rates of ships, a compliance-determination workflow for NO_x-emission intensity and fuel-sulfur-content monitoring and supervision in on-voyage ships were proposed. The results showed that the ship fuel’s NOx-emission intensity and sulfur content can be evaluated by monitoring the exhaust-gas composition online and used to assist in maritime monitoring and the supervision of pollutant emissions from ships. It is recommended that uncertainties regarding sulfur content should be considered within 15% during monitoring and supervision. The established model and workflow can assist in maritime monitoring. Meanwhile, all related governments and industry-management departments are advised to actively lead the development of monitoring and supervision technology for ship-air-pollutant control in ECAs, as well as strengthening the quality management of ships’ static data.

The transportation industry is a forerunner of social and economic development and has always been an active green and ecological development practitioner. Jiangsu Province is a major port province. In 2023, the cumulative cargo throughput of Jiangsu ports has reached 3.51 billion tons, accounting for 20.67% of the total port throughput of the country. The overall development of China’s port volatile organic compounds (VOCs) governance industry is still in the early stage, and most port enterprises in Jiangsu Province have not established a sound VOCs monitoring and regulatory system. Therefore, it is of great importance to carry out research on the regulatory countermeasures of VOCs emission in Jiangsu port for the green development of transportation in China and Jiangsu Province. The research results show that there are some problems in Jiangsu oil and gas chemical terminals, such as insufficient supporting policies for oil and gas recovery, non-standard operation mode of oil and gas recovery, high investment in oil and gas recovery construction, low enthusiasm of port and shipping enterprises in construction, low utilization rate of oil and gas recovery facilities, insufficient front space of built terminals, and oil and gas recovery technology maturity and safety need to be improved. Therefore, it is proposed to strengthen the management of the whole process of oil and gas recovery construction in new terminals, strictly implement the management measures of oil and gas recovery in terminals, and strengthen the regular detection of VOC emission concentration.

In this study, the PM_2.5 pollution transport budget in the atmospheric boundary layer (ABL) of Beijing–Tianjin–Hebei (BTH) and Chengdu–Chongqing (CY) was quantitatively evaluated from the perspective of horizontal and vertical exchange. Based on the aircraft meteorological data relay (AMDAR) observation data, the study found that the vertical exchange process of pollutants is mainly influenced by the combined effects of meteorological conditions and topographical factors. Meteorological factors determine the direction and intensity of the vertical exchange, while the complexity of the terrain affects the exchange pattern through local circulation and air flow convergence. The characteristics of the pollution transport budget between the BTH and CY regions show that the BTH region has a net output of pollutants throughout the year, while the CY region has a net input of pollutants. The total transport budget of the four typical representative seasons in BTH is negative. It indicated that BTH, as the region with the highest intensity of air pollution emission in China, is dominated by outward transport of air pollutants to surrounding regions. Due to the influence of topographic and meteorological conditions in the CY region, the air pollutants tend to accumulate in the basin rather than diffuse. The transport budget relationship of the four seasons is positive and the input of air pollutants can be obviously simulated. Combined with the results of the vertical wind profile, Beijing is more vulnerable to the prevailing cold air sinking in the northwest in winter, which is characterized by the inflow of the free troposphere (FT) into the ABL. As for Chongqing, it is blocked by mountains so that the gas convection at the top of the ABL is obvious. This horizontal convergence phenomenon induces upward vertical movement, which makes Chongqing show a strong characteristic of the ABL transport to the FT.