Since 1 January 2017, ships berthed at the core ports of three designated “domestic emission control
areas” (DECAs) in China should be using fuel with a sulfur content less than
or equal to 0.5 %. In order to evaluate the impacts of fuel switching, a
measurement campaign (SEISO-Bohai) was conducted from 28 December 2016 to
15 January 2017 at Jingtang Harbor, an area within the seventh busiest port
in the world. This campaign included meteorological monitoring, pollutant
monitoring, aerosol sampling and fuel sampling. During the campaign, 16 ship
plumes were captured by the on-shore measurement site, and 4 plumes indicated
the usage of high-S
Maritime transport is an important source of pollutants globally; thus, it is
one of the well-established culprits regarding the adverse effects of ship
emissions on air quality (Eyring et al., 2005, 2010; Endresen et al., 2003;
Fridell et al., 2008; Jalkanen et al., 2009; Liu et al., 2016; Viana et al.,
2014), climate (Lauer et al., 2007; Tronstad Lund et al., 2012; Liu et al.,
2016) and human health (Campling et al., 2013; Corbett et al., 2007;
Winebrake et al., 2009). Estimations show that ships contribute 15 % of
the global
These situations have drawn a lot of attention regarding coastal air
pollution and related emission control strategies, such as scrubbers.
However, recent research has also reported the potential pollution of surface
waters by ship emissions due to certain methods of treating ship exhausts
(Hassellöv et al., 2013; Stips et al., 2016; Turner et al., 2017, 2018),
indicating that the exhaust aftertreatment may not be the best choice of ship emission reduction.
The International Maritime Organization (IMO), the European Union and the US have implemented
regulations in an effort to reduce ship emissions, among which fuel quality
regulation has proven potent in many countries for addressing the issue of
sulfur oxides (
Based on the abovementioned widely acclaimed fuel quality regulations, China promulgated
the implementation of the ship emission control area in the Pearl River
Delta, the Yangtze River Delta and the Bohai Rim (Beijing–Tianjin–Hebei
area) (MOT, 2015) in 2015, designing three DECAs with phased S
In order to explore the methods used to capture fuel-related emission change and the impact on the air quality due to fuel switching, we selected the Bohai Rim (Beijing–Tianjin–Hebei area) as the study site and conducted in situ measurements of meteorological parameters and pollutants along with chemical analyses of sampled fuels and aerosols, which are all typical methods utilized within the field of air quality measurement. The campaign ran from 27 December 2016 to 15 January 2017, covering the primary implementation period of the new regulation. By comparing ship emissions and air quality before and after fuel switching, this paper sheds light on the potential emission reduction effects of the enforced regulation. Meanwhile, certain features in ship plumes were found to be related to fuel type, providing another angle for supervising ship fuels in practice. This may be helpful in the actual implementation and management of the new regulation.
The measurement station (39.204576
A small meteorological monitoring station was placed on the roof of the
container and obtained temperature (
Continuous concentrations of six gases (NO,
The campaign resulted in the collection of 14 valid particle samples: 2 parallel samples were collected per day before 31 December 2016 and 1 sample was collected per day after that. The filters were exposed for 23 h (normally from 16:30 to 15:30 LST, local standard time, the next day and were labeled according to the end date) on 80 mm (diameter) preferred quartz microfiber filters (CHM QF1 grade) using a Laoying Model 2030 TSP sampler. All samples were immediately put into their original polyethylene plastic boxes, wrapped in two layers of prebacked tinfoil, and then subsequently housed in a refrigerator. In order to avoid any possible contamination of the samples, all of the abovementioned procedures were strictly quality-controlled.
A 0.55 cm
A 50 cm
A 20 cm
Observations of trace gases (ppb) and molar
Identifying a “ship plume event” using direct and simultaneous measurements of trace
gases with in situ instruments aims at the surveillance of emissions and
fuel types utilized by passing ships. As the measurement site is in the
vicinity of the channel and the berths, when wind directions are favorable
for measurements ship plumes passing the instrument cause a distinctive
change in the measured components against background concentrations; these changes are
defined as a ship plume event. Several studies have confirmed that synchronic variation
in pollutant concentrations can be used to identify the occurrence of ship
plume events from observation made near the harbor (Alföldy et al., 2013;
Ault et al., 2010; Contini et al., 2015; Gao et al., 2016; Lu et al., 2006;
Kattner et al., 2015):
Marine vessel plume number 9 showing the
Nitrogen compounds were abundant in the atmosphere in JT due to the heavy
traffic, whereas the source of high
The
Intermediate fuel oil (IFO), also known as heavy fuel oil, is typically used by
marine vessels. IFO is the petroleum product left after all of the
other fractions from crude oil have been distilled. This product has a high density, carbon/hydrogen
ratio and sulfur content (varying from 2 % to 5 %) compared with gas
and oil products used by other means of transportation. In addition, IFO
contains high concentrations of organics and metals from the original crude oil.
IFOs are categorized into IFO380, IFO180 and IFO60
by their maximum viscosity measured at 50
Components of intermediate fuel oil (IFO), hybrid fuels, and marine gas oils (MGOs) and marine diesel oils (MDOs).
BD refers to “below the detection limit”. “–” refers to “not reported”
Research has shown that ships in sulfur emission control areas (SECAs) switch
to marine diesel fuel (MDO), a cleaner fuel typically used to meet the
requirement of many fuel quality regulations and emission limits. Compared
with IFOs, MDOs have a lower density, a lower carbon/hydrogen ratio, and a
lower nitrogen (
In order to establish the fuel type ships were using after the implementation of fuel restrictions in JT, three fuel samples were taken from three respective vessels berthed in JT on 14 January 2017, and the fuel properties and chemical composition of the fuels were analyzed according to the petroleum industry standard (SH) and the national standard (GB) of China.
Back trajectories were used to identify the origin and potential influences of different source regions on the vanadium (V) concentrations during each sampling day. The 24 h back trajectories of the air mass during each sampling day were computed at 500 m a.g.l. (above ground level) using the HYSPLIT 4 model (NOAA, 2013). The Global Data Assimilation System (GDAS) meteorological data were used as input. Trajectories began at 08:00 UTC (16:00 LST, consistent with the sampling period) and were calculated every 6 h.
The enrichment factor (EF) was used for the general evaluation of influences of
anthropogenic sources on the elemental contents of particles (Zhao et
al., 2013) and is calculated following Eq. (1):
The sulfur oxidation ratio (SOR) and the nitrogen oxidation ratio (NOR) are used to
elucidate the
The climate of JT is strongly influenced by the sea breeze. The mean
relative humidity during campaign was 69.4 % (ranging from 21.8 % to
99.9 %), while the mean temperature was
Hourly
During the campaign, the day-to-day variation in emission was large due to
variation in both the complicated sources and removal in JT; however, the
data generally exhibited a heavily polluted environment in JT. As the primary
pollutant at site, PM
The
Variations in carbonaceous and ionic species are depicted in Fig. 6. The mean
(range of) concentrations of carbonaceous species determined in PM
Distribution of differences in the
As the major long-range transported aerosol components,
The high humidity in JT promotes secondary aerosol formation from local
emissions (Yu et al., 2018). As the chemical composition of atmospheric particulate matter is largely
affected by prevailing weather conditions, the samples were categorized as
“polluted days” or “clean days” based on the corresponding
PM
Variation of
Sulfur oxidation rate (SOR) and the nitrogen oxidation rate (NOR) of particles collected in this study and in the city areas of Tangshan (Zhang et al., 2017) and Beijing (X. Li et al., 2018).
Enrichment factor of elements in PM
The ranges and mean concentrations of all measured elements are shown in
Fig. 8. Overall, the mass concentrations of Al, Ti, Mg, Fe, Na, K, Mn, V,
Ni, Zn and Pb were abundant and they varied largely with the sample time.
Samples were categorized into three batches based on the PM
The enrichment factor (EF) was used to normalize the observed concentrations
of elements and to evaluate the influences of crustal and anthropogenic
sources. Generally, elements from Ca to K in Fig. 8 are mainly from
geological sources and are thus classified as “crustal elements”. Ca was
mostly from stable crustal sources which had the lowest EF values. With EF
values around 10, and no evident temporal variation, the elements from Ti to
U in Fig. 8 may have a major local crustal origin such as dust. Regression
analysis comparing the EF values of Na and K revealed a strong correlation
(
The establishment of a marker to deduce variations in ship emissions is
crucial. There has been a particular focus on Ni and V in PM
The chemical composition of MDOs/MGOs indicates that V is below the detection limit,
but PM
In this study, ship plume events were used for the surveillance of emissions
and the fuel types utilized by passing ships (see Sect. 2.3). In total, 16 ship
plume events were measured during this campaign, for which the molar
Previous inventories, measurements and ship plume studies have proven a
direct correlation between S
Molar
Considering all of the abovementioned aspects, we concluded that a ratio over
7.5 was a suggestion of fuel with a S
Test showed that the three ships we sampled from in 14 January 2017 burned MDOs (Table 2), which was in conformity with the implementation of the fuel regulation in JT. There would be obvious benefits such as significant improvements in emissions and air quality once all vessels comply and switch to MDOs or other alternative distillate fuels. Nevertheless, to enforce this, it is crucial to ensure the compliance of ships, which requires a more convenient and timely method of indicating fuel quality which does not involve analyzing fuel samples.
After identifying low-S
Field measurements were conducted at a measurement station in JT, including continued monitoring of meteorological conditions and gas
and particle concentrations, from 28 December 2016 to 15 January 2017.
Samples of PM
Pollutant profiles showed a heavy polluted environment in JT in wintertime.
On over 50 % of days, the PM
After the implementation of low-sulfur fuel, fuel
samples were collected from three vessels and were all found to be compliant with the
fuel switching regulation. Based on previous studies and background at the measuring site,
ship plume events were identified to be convenient for the surveillance of fuel
quality. The
Despite the fact that carbonaceous species in particles were not significantly
influenced by fuel switching, the gas and particle pollutants in the ambient air
exhibited clear and effective improvements from the implementation of low-sulfur fuel.
A comparison with the prevailing atmospheric conditions suggest
a prompt 70 %
Data are available upon request.
YZ, FD, and HM contributed equally. YZ primarily participated in the chemical analyses and wrote the article. FD and HM mainly participated in the design and conducted the field measurements, which was considered to be an equal contribution to this work. MF helped design the experiments and was responsible for the pilot preparations. ZL and QX helped conduct the field measurements. XJ and SL contributed to setting instruments. KH provided constructive comments on this research. HL conceived this study and provided guidance on the whole research process as well revising the paper.
The authors declare that they have no conflict of interest.
This article is part of the special issue “Shipping and the Environment – From Regional to Global Perspectives (ACP/OS inter-journal SI)”. It is a result of the Shipping and the Environment – From Regional to Global Perspectives, Gothenburg, Sweden, 23–24 October 2017.
This work was supported by the National Science Fund for Excellent Young Scholars (grant no. 41822505), the National Natural Science Found of China (grant nos. 91544110 and 41571447), Beijing Nova Program (grant no. Z181100006218077), the National Key R&D Program (grant no. 2016YFC0201504), the Special Fund of State Key Joint Laboratory of Environment Simulation and Pollution Control (grant no. 16Y02ESPCT), the National Research Program for Key Issues in Air Pollution Control (grant no. DQGG0201&0207), and the National Program on Key Basic Research Project (grant no. 2014CB441301). We appreciate that Hebei Sailhero Environmental Protection High-tech Co., Ltd. and Guangzhou Hexin Instrument Co., Ltd. provided the instruments used for our observations. We are also grateful for all of the help from the Sino-Japan Friendship Centre for Environmental Protection and Sinopec Research Institute of Petroleum Processing.
This paper was edited by Markus Quante and reviewed by two anonymous referees.