Chia-Kuan Liu

Dry deposition of Mn, Zn, Cr, Cu and Pb in particles of sizes of 3 μm, 5.6 μm and 10 μm in central Taiwan

This investigates the concentrations of Mn, Zn, Cr, Cu, and Pb ambient air in total suspended particulates (TSPs) and dry deposition. The ratios of the calculated to measured dry deposition fluxes of ambient-air Mn, Zn, Cr, Cu and Pb at five characteristic sampling sites from 2009 to 2010 were determined using two dry deposition models. Experimental results demonstrate that the mean concentrations of metallic elements in TSPs and dry deposition were highest at the Quan-xing (industrial) sampling site, which is surrounded by various industrial factories and is in a severely polluted area. The mean seasonal concentrations of metallic elements in TSPs were highest in the winter and fall at all five sites. The analytical concentrations of metallic elements in fall and winter at these five sites were elevated in low winds. The Baklanov model yielded more accurate predictions concerning the dry deposition of metallic elements in ambient air when the sizes of the deposited particles were <5.6 μm, and the Noll and Fang model yielded better predictions when the sizes of the particles were >5.6 μm.

Atmospheric mercury pollution at an urban site in central Taiwan: Mercury emission sources at ground level

Total gaseous mercury (Hg) (TGM), gaseous oxidized Hg (GOM), and particulate-bound Hg (PBM) concentrations and dry depositions were measured at an urban site in central Taiwan. The concentrations were 6.14±3.91 ng m(-3), 332±153, and 71.1±46.1 pg m(-3), respectively. These results demonstrate high Hg pollution at the ground level in Taiwan. A back trajectory plot shows the sources of the high TGM concentration were in the low atmosphere (<500 m) and approximately 50% of the air masses coming from upper troposphere (>500 m) were associated with low TGM concentrations. This finding implies that Hg is trapped in the low atmosphere and comes from local Hg emission sources. The conditional probability function (CPF) reveals that the plumes of high TGM concentrations come from the south and northwest of the site. The plume from the south comes from two municipal solid waste incinerators (MSWIs). However, no significant Hg point source is located to the northwest of the site; therefore, the plumes from the northwest are hypothesized to be related to the combustion of agricultural waste. Dry deposition fluxes of Hg measured at this site considerably exceeded those measured in North America. Overall, this area is regarded as a highly Hg contaminated area because of local Hg emission sources.

Seasonal Variations (Autumn, Winter, and Spring) of Atmospheric Particulate and Particulate-Bound Mercury Hg(p) at a Suburban/Coastal Area

From September 3, 2009, to March 5, 2010, the dry deposition, total suspended particulate (TSP) matter, coarse and fine particulates, and bound mercury (Hg[p]) in the atmosphere were investigated at Bei-Shi sampling site in central Taiwan. When using projection film as collection medium, the average ambient air particulates for day dry deposition fluxes and TSPs were 162.09 ± 97.69 (μg/(min/cm2)) and 78.71 ± 34.42 (μg/m3), respectively. The average fine particulate matter (PM2.5) and coarse particulate matter (PM2.5–10) were 20.5 ± 6.30 μgm−3 and 11.2 ± 4.44 μg m−3, respectively. Average atmospheric particulates Hg(p) in dry depositions, TSPs, PM2.5−10, and PM2.5were 0.156 ± 0.082 ng/m2*min, 0.07 ± 0.036 ng/m3, 0.011 ± 0.006 ng/m3,and 0.007 ± 0.005, respectively. The average compositions of atmospheric bound Hg Hg(p) in dry depositions, TSPs, PM2.5−10 and PM2.5 were 1.02, 36.8, 4.16 and 2.821, respectively. Also, the highest composition for particulate Hg(p) in TSP was observed in spring (50.74 ng/g), and the highest composition for particulate Hg(p) in PM2.5 occurred in autumn (3.11 ng/g). However, the highest composition for particulate Hg(p) in PM2.5−10 occurred in winter (4.67 ng/g). In what concerns particulate Hg(p) in TSP, the values were all less than those from previous studies (Wang et al., 2006). Related to Hg(p) in PM2.5, the values were also all less than those from previous studies (Tsai et al. 2003; Marsik et al. 2007). In what concerns Hg(p) in PM2.5−10, the values were all less than those of previous studies (Marsik et al. 2007). The data presented in this communication provides information that may be useful in forensic investigations of Hg environmental releases.

Atmospheric total arsenic (As), (As3+) and (As5+) pollutants study in central Taiwan

This investigation measures the concentrations of arsenic (As), (As3+), (As5+) in total suspended particles (TSP) and dry deposits at five characteristic sampling sites in central Taiwan during the years 2009–2010, and identifies their seasonal variations. The investigation was performed in region in which a science park, transportation, waste incineration facility, fossil fuel combusting steel factory, electronics factory, plastic factory, chemical factory and Taichung Thermal Power Plant (TTPP) are located. The Bei-shi sampling station and He-mei town sampling station were located in, an area of heavy transportation. The Quan-xing sampling station was close to an electronics factory and a fossil fuel combusting steel factory. The As for Chang-Hua sampling station was located at the chemical factory. Finally, the Gao-Mei wetland sampling station was close to a waste incineration; they were characterized as a waste incineration plant and TTPP. The highest average concentrations of arsenic in TSP were found at Quan-xing (industrial) and the lowest were found at He-mei (residential). The average amounts of dry deposited arsenic (As), (As3+) and (As5+) were highest at the Quan-xing (industrial) site and lowest at the Gao-mei (wetland) site. The average seasonal concentrations of (As), (As3+) and (As5+) in TSP and the average dry deposited amounts were highest in the autumn and lowest in the summer at five sampling sites.

Ambient suspended particulate matter and ionic speciation in Asian countries during 1998—2007

Atmospheric acid precursor emissions in Asia are increasing at a significant rate. This is expected to continue for the next several years. This main purpose for this study is to observe the concentration variations of PM2.5, PM2.5-10 , PM10, total suspended particulates (TSP), atmospheric particulates, and dry deposition fluxes of ionic species in Asian countries during the years 1998—2007. The results show that the average ionic species concentration order for chloride ions (Cl—) in PM 10 was China > Taiwan > Korea. The average ionic species concentration order for nitrate ions (NO3 —) species in PM 10 was China > Taiwan > Korea for Asian countries. In addition, the average ionic species sulfate ion (SO4 2— ) concentrations in PM10 were 13.248 and 18.497 (μg/m 3) in Taiwan and China, respectively, during the years 1998—2006. However, the average ionic species concentrations order for ammonium ions (NH4 +) in PM10 was Taiwan > China > Korea the years 2000—2006. Moreover, the average ionic species concentration order for chloride ions (Cl—) in PM2.5 was Japan> Taiwan> Korea> China in the years 1998—2006. And the average ionic species concentration order for nitrate ions (NO3 —) in PM2.5 was Korea > China > Japan > Taiwan for Asian countries during 1998—2006. Moreover, the average ionic species concentration order for sulfate ions (SO4 2—) in PM 2.5 was China > Korea > Taiwan > Japan in the years 1998—2006. As for the average ionic species concentration order for ammonium ion (NH 4 +) in PM2.5, China > Taiwan > Japan > Korea in the years 1999—2006. Finally, the mean ionic species of nitrate ions (NO3 —), sulfate ions (SO4 2 —) and ammonium ions (NH4+) were found highest in China compared with the rest of the other Asian countries during the years 1998—2006.

Atmospheric Particle Bound Mercury Hg(p) Concentrations and Amounts in Total Suspended Particulates and Dry Deposition at an Industrial and Wetland Sampling Sites in Taiwan

The focus of this study is to observe the seasonal variations of particulate bound mercury Hg(p) concentration and amount of Hg(p) (ng/g) in total suspended particulates (TSP) and dry deposition at two (industrial and wetland) characteristic sampling sites in Taiwan, during the years 2009–2010. Concentrations of Hg(p) from each sample (quartz filter, overhead projection film) were analyzed by a direct Hg(p) analyzer DMA-80. Approximately 30 mg of the filter sample was loaded directly into the DMA-80 and analyzed. The results indicated that the mean highest Hg(p) in TSP (expressed in ng/m3) and dry deposition (expressed in ng/m2/min) both occurred at the industrial site (Quan-xing) while the corresponding mean lowest Hg(p) concentrations occurred at the wetland site (Gao-mei). Also, the mean highest amount of Hg(p) (expressed in ng/g) in TSP and dry deposition occurred at the industrial site (Quan-xing), while the mean lowest amount of Hg(p) occurred at the wetland site (Gao-mei). Metal products manufacturing and heavily loaded traffic during weekdays were possible sources responsible for the high concentrations of Hg(p) observed at Quan-xing (industrial) sampling site.