Estimation of gross emissions from commercial leisure boats and single-deck passenger vessels

The study addresses atmospheric air pollution caused by small vessels and single-deck passenger vessels operating on the inland waterways of the Russian Federation, including St. Petersburg, in accordance with federal air protection legislation. For the first time, annual gross emissions from commercial small vessels and singledeck passenger vessels are assessed using St. Petersburg as a case study. The assessment is based on a new approach that combines national and international ship emission inventory methodologies with measurement data on emissions from two-stroke and four-stroke boat engines and marine diesel engines. The proposed approach takes into account the composition of the commercial pleasure fleet, including approximately 450 small vessels and 140 single-deck passenger vessels actively operated in St. Petersburg, as well as engine technical characteristics, weighted average specific emissions of NOx, CxHy and CO, engine load factors, and operating time. According to the results obtained, annual gross emissions from commercial small vessels may reach 248488 t, including 207–466 t of CO, 15–24 t of CxHy, and 7–17 t of NOx. Emissions from single-deck passenger vessels may reach 32–70 t, including 15–21 t of CO, 1–9 t of CxHy, and 10–46 t of NOx. Together, these emissions account for 0.2160.429 % of the total gross emissions from the transport sector. Further research should focus on experimental studies of pollutant emissions from the recreational fleet, refinement of operating modes, fuel consumption and operating time through shipowner surveys, and a more detailed assessment of the entire recreational fleet in St. Petersburg, not only its commercial segment.