Jialiang Feng

Measurements of emission factors for primary carbonaceous particles from residential raw‐coal combustion in China

The emission factors (EFs) of particles and their carbonaceous fractions, including black carbon (BC) and organic carbon (OC), are measured for residential burning of coal-chunks. Nine types of coals with wide-ranged thermal maturities were used. Particulate emissions from coal-stove are collected on quartz fiber filters through a dilution sampling system and analyzed for BC and OC by thermal-optical method. The EFs of particulate matter, OC, and BC from bituminous coal burning are 16.77, 8.29, and 3.32 g/kg, respectively, on the basis of burned dry and ash-free (daf) coal mass. They were much higher than those of anthracites, which are 0.78, 0.04, and 0.004 g/kg, respectively. Annual emission inventories of particles, OC, and BC from household coal burning are also estimated based on the EFs and coal consumption. The results of the calculations are 917.8, 477.7, and 128.4 gigagrams (Gg) for total particles, OC, and BC emitted in China during the year 2000.

Concentrations and seasonal variations of polybrominated diphenyl ethers (PBDEs) in in- and out-house dust and human daily intake via dust ingestion corrected with bioaccessibility of PBDEs

The objective of this study was to investigate the concentrations, seasonal variations, bioaccessibility, and associated human daily intake of polybrominated diphenyl ethers (PBDEs) in in- and out-house dust collected in Shanghai, China. The PBDE concentrations varied from 131.6 to 3,886.7 ng g(-1) (with an average of 948.2 ng g(-1)) in in-house dust and from 8.7 to 3,116.3 ng g(-1) (with an average of 290.8 ng g(-1)) in out-house dust during four seasons. The PBDE concentrations in the autumn were the lowest for both in- and out-house dust. Among the detected PBDEs, BDE209 was the predominant congener, accounting for more than 80% of the total PBDE amounts. The bioaccessibility of PBDEs, measured using a simulation system of human gastrointestinal tract, was determined as 14.2-66.4% depending on individual PBDE congeners and showed significant negative correlations with organic matter in dust. After corrected with the bioaccessibility of PBDEs, the human daily intake of PBDEs via dust ingestion was calculated to be 0.4-21.4 and 4.3-40.6 ng day(-1) for an average adult and child in Shanghai, respectively. The values were much lower than most estimates in the literature, in which the bioaccessibility of PBDEs were not taken into account, suggesting that the intake of PBDEs may have been overestimated.

Diurnal variations of polycyclic aromatic hydrocarbons associated with PM2.5 in Shanghai, China

Forty-eight daily time interval PM2.5 samples were collected from December 2006 to January 2008 in an urban site in Shanghai, China. Concentrations and compositions of polycyclic aromatic hydrocarbons (PAHs) were analyzed with GC-MS to study the diurnal and seasonal variations and to identify the main emitting sources. The diurnal variation of the PAHs concentrations was greater in the late autumn and winter sampling days, and was greatly influenced by meteorological conditions such as wind speed and ambient temperature. The concentration of PAHs in the mornings (6:30-10:00) increased distinctly, and was high in the late autumn and winter sampling days, indicating the contribution from vehicle emissions during rush hours. The diurnal variation of the high molecular weight PAHs did not seem to be controlled by the shift of gas-particle partitioning due to temperature variation, instead, it could be indicative of the variation in the source. Statistical analyses showed that the concentrations of PAHs were negatively correlated with temperature and wind speed, and positively correlated with relative humidity. Diagnostic ratios of PAHs suggested mixed emission sources of petroleum and coal/biomass combustion for PAHs in the PM2.5 in Shanghai.

Polychlorinated biphenyls in the atmosphere of Taizhou, a major e-waste dismantling area in China

PM2.5, total suspended particles (TSP) and gas phase samples were collected at two sites of Taizhou, a major e-waste dismantling area in China. Concentrations, seasonal variations, congener profiles, gas-particle partitioning and size distribution of the atmospheric polychlorinated biphenyls (PCBs) were studied to assess the current state of atmospheric PCBs after the phase out of massive historical dismantling of PCBs containing e-wastes. The average sigma38PCBs concentration in the ambient air (TSP plus gas phase) near the e-waste dismantling area was (12,407 +/- 9592) pg/m3 in winter, which was substantially lower than that found one decade ago. However, the atmospheric PCBs level near the e-waste dismantling area was 54 times of the reference urban site, indicating that the impact of the historical dismantling of PCBs containing e-wastes was still significant. Tri-Penta-CBs were dominant homologues, consisting with their dominant global production. Size distribution of particle-bound PCBs showed that higher chlorinated CBs tended to partition more to the fine particles, facilitating its long range air transportation.

Characteristics of organic matter in PM2.5 from an e-waste dismantling area in Taizhou, China

Solvent extractable organic compounds in PM(2.5) samples collected in Taizhou, a city famous for its electrical and electronic waste (e-waste) recycling industry in Zhejiang province of China, were analyzed to identify the main emission sources based on molecular markers. Two types of plastics which were most frequently contained in the e-wastes, wires/cables and plastic blocks, were burned in the lab and the particles emitted analyzed. The concentrations of PAHs and phthalate esters at the e-waste dismantling area during our sampling periods were about two times of that at the reference urban site, indicating the high pollution level there. The high concentrations of quaterphenyl found at the dismantling area indicated that burning of plastics or polymers was an important emission source of the PAHs in the fine particles. The diagnostic analysis based on the compositions of alkanes, hopanes and other molecular markers showed that engine exhaust, biomass burning and kitchen emissions were also important emission sources at the e-waste dismantling area. Our results suggested that more effort should be paid to control the correlative emission sources such as transportation and kitchen to achieve better air quality at the e-waste dismantling area besides regulating the recycling activities.

Composition, source, mass closure of PM2.5 aerosols for four forests in eastern China.

PM2.5 aerosols were collected in forests along north latitude in boreal-temperate, temperate, subtropical and tropical climatic zones in eastern China, i.e., Changbai Mountain Nature Reserve (CB), Dongping National Forest Park in Chongming Island (CM), Dinghu Mountain Nature Reserve (DH), Jianfengling Nature Reserve in Hainan Island (HN). The mass concentrations of PM2.5, organic carbon (OC), elemental carbon (EC), water soluble organic carbon (WSOC) as well as concentrations of ten inorganic ions (F-, Cl-, NO3-, SO4(2-), C2O4(2-), NH4+, Na+, K+, Ca2+, Mg2+) were determined. Aerosol chemical mass closures were achieved. The 24-hr average concentrations of PM2.5 were 38.8, 89.2, 30.4, 18 Cig/m3 at CB, CM, DH and HN, respectively. Organic matter and EC accounted for 21%-33% and 1.3%-2.3% of PM2.5 mass, respectively. The sum of three dominant secondary ions (SO4(2-), NO3-, NH4+) accounted for 44%, 50%, 45% and 16% of local PM2.5 mass at CB, CM, DH and HN, respectively. WSOC comprised 35%-65% of OC. The sources of PM2.5 include especially important regional anthropogenic pollutions at Chinese forest areas.

Spatial and temporal variations of nitro-polycyclic aromatic hydrocarbons in PM2.5 aerosols in Yangtze River Delta Region, China

Nitrated polycyclic aromatic hydrocarbons (nitro-PAHs) are of great interest because of their high potential mutagenicity and carcinogenicity. PM2.5 aerosol campaigns were carried out for four seasons from December 2007 to January 2009 in Xujiahui, Baoshan and Lin’an in Yangtze River Delta Region, China. Nine nitro-PAHs were detected, the average seasonal concentrations for three sampling sites ranging between 0.17–879 pg m−3. 2-Nitrofluoranthene was the most abundant nitro-PAH, accounting for 54% of the total nitro-PAH concentration, followed by 9-nitroanthracene, 3-nitrophenanthrene and 7-nitrobenz(a)anthracene, about 15%, 16% and 10%, respectively. There were good correlation between mass concentrations of PM2.5 and the total concentrations of nitro-PAHs from samples in Xujiahui, R2 = 0.76, and Baoshan, R2 = 0.60; yet, a poor correlation in Lin’an, R2 = 0.44.

Laser ablation single particle aerosol mass spectrometry for the direct analysis of raw coal samples

A new solid material analysis method using laser ablation single particle aerosol mass spectrometry (LA-SPAMS) has been developed. The instrument has been designed to be compact with a high-energy pulse laser system to generate the particles, a closed chamber to settle the samples and also to prevent particle interference from the air, and a single particle aerosol mass spectrometer to measure the aerodynamic size and the chemical composition of the particles precisely and simultaneously. LA-SPAMS focuses on the on-line measurement of the size and chemical composition of individual particles ablated from solid materials and was used to analyze five raw coal samples from different locations in China. In total, more than 100 000 particles were sized ranging from 200 to 2000 nm. Furthermore, around 20–40% of the particles were chemically analyzed to produce both positive and negative mass spectra. The particle size distributions for the five coal samples differ significantly, having peaks of various sizes and different profiles. Mass spectral signatures of the five samples were studied by analyzing the average mass spectrum of each sample and each particle cluster was extracted using the ART-2a method. The main compositions observed in the average mass spectra of the samples include metallic and nonmetallic elements, elemental carbon, organic carbon, and other compounds, and the differences between the samples are the chemical compositions in each group. The particles ablated from the five raw coal samples were divided into nine classes according to their primary chemical composition, and the particle class compositions for the coal samples are very specific allowing them to be used as the particle markers to characterize the coal samples. LA-SPAMS avoids tedious and time-consuming chemical digestion processes, allows the direct analysis of solid materials and the simultaneous determination of all detectable components based on single particle analysis, and realizes real-time online analysis. It is particularly suited to the analysis of heterogeneous materials such as coals and mineral ores and has applications in fields such as geology and metallurgy.

Intermediate Volatility Organic Compound Emissions from a Large Cargo Vessel Operated under Real-world Conditions

Intermediate volatility organic compound (IVOC) emissions from a large cargo vessel were characterized under real-world operating conditions using an on-board measurement system. Test ship fuel-based emission factors (EFs) of total IVOCs were determined for two fuel types and seven operating conditions. The average total IVOC EF was 1003 ± 581 mg·kg-fuel-1, approximately 0.76 and 0.29 times the EFs of primary organic aerosol (POA) emissions from low-sulfur fuel (LSF, 0.38 wt % S) and high-sulfur fuel (HSF, 1.12 wt % S), respectively. The average total IVOC EF from LSF was 2.4 times that from HSF. The average IVOC EF under low engine load (15%) was 0.5-1.6 times higher than those under 36%-74% loads. An unresolved complex mixture (UCM) contributed 86.1 ± 1.9% of the total IVOC emissions. Ship secondary organic aerosol (SOA) production was estimated to be 546.5 ± 284.1 mg·kg-fuel-1; IVOCs contributed 98.9 ± 0.9% of the produced SOA on average. Fuel type was the dominant determinant of ship IVOC emissions, IVOC volatility distributions, and SOA production. The ship emitted more IVOC mass, produced higher proportions of volatile organic components, and produced more SOA mass when fueled with LSF than when fueled with HSF. When reducing ship POA emissions, more attention should be paid to commensurate control of ship SOA formation potential.

An Integrated Source Apportionment Methodology and Its Application over the Yangtze River Delta Region, China

An integrated source apportionment methodology is developed by amalgamating the receptor-oriented model (ROM) and source-oriented numerical simulations (SOM) together to eliminate the weaknesses of individual SA methods. This approach attempts to apportion and dissect the PM2.5 sources in the Yangtze River Delta region during winter. First, three ROM models (CMB, PMF, ME2) are applied and compared for the preliminary SA results, with information from PM2.5 sampling and lab analysis during the winter seasons. The detailed source category contribution of SOM to PM2.5 is further simulated using the WRF-CAMx model. The two pieces of information from both ROM and SOM are then stitched together to give a comprehensive information on the PM2.5 sources over the region. With the integrated approach, the detailed contributing sources of the ambient PM2.5 at different receptors including rural and urban, coastal and in-land, northern and southern receptors are analyzed. The results are compared with previous data and shows good agreement. This integrative approach is more comprehensive and is able to produce a more profound and detailed understanding between the sources and receptors, compared with single models.