[Emission Inventory and Pollution Characteristics of Industrial VOCs in Hangzhou, China].

For the 2022 Asian Games, a series of major events were held in Hangzhou City in 2016 at the international summit, where research on VOC emission inventories, especially on industrial VOCs, has attracted the attention of local residents and management departments. By taking a bottom-up approach, 3518 enterprises in more than 30 industries in Hangzhou were investigated and an industrial VOCs emission inventory for Hangzhou was established. Based on the data on regional emissions, emissions intensity, and spatial distribution, the industrial VOCs emissions in Hangzhou were systematically analyzed. The VOC emissions from industrial sources in Hangzhou amounted to 36839.5 tons in 2015. Printing and reproduction of recorded media; chemical raw materials and chemical products manufacturing; and the metal, textile, rubber, and plastics products industries were the most important sources of industrial VOC emissions in Hangzhou. The largest industrial VOC emissions were measured in Xiaoshan District, followed by Fuyang District and Dajiangdong Industrial Agglomeration Area. The highest VOC emissions intensity was detected in Fuyang District, Jiande City, and Lin'an City. Industrial VOC emissions were mainly concentrated in more intensive industrial areas in Xiaoshan, Fuyang, Yuhang, and Dajiangdong Districts.

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.

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.

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.

Polybrominated diphenyl ethers in the atmosphere of Taizhou, a major e-waste dismantling area in China.

Concentrations, congener profiles, gas-particle partitioning and size distributions of polybrominated diphenyl ethers (PBDEs) in the atmosphere of Taizhou were studied to evaluate the impact of e-waste recycling on the environment. Total concentration of 13 PBDEs near the e-waste dismantling area was 506 pg m(-3) in summer and 1,662 pg m(-3) in winter, about 7 times higher than that of the reference urban site, but much lower than that of Guiyu, another major e-waste dismantling area in China. This should be attributable to the centralized management measures taken in recent years in Taizhou. BDE-209 was the major congener and mainly in coarse particles.