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Biomedical subjects

Guor-Cheng Fang

Publications and source records attributed to Guor-Cheng Fang.

At least 37 records · Page 2Linked to original sources

Characteristic study of polycyclic aromatic hydrocarbons for fine and coarse particulates at Pastureland near Industrial Park sampling site of central Taiwan.

The concentrations of ambient air polycyclic aromatic hydrocarbons were measured in a farm area (Tunghai University Pastureland) between August 2001 and April 2002 in central Taiwan, Taichung. Particle-bound polycyclic aromatic hydrocarbons (PAHs) were collected on quartz filters, the collected sample was extracted with a dichloromethane (DCM)/n-hexane mixture (50/50, v/v) for 24 h, and then the extracts were subjected to gas chromatography-mass spectrometric analysis. The PM2.5 (fine particulate) and PM2.5-10 (coarse particulate) total PAHs concentrations at the Tunghai University Pastureland sampling site were found to be 180.62 ngm(-3) and 164.98 ngm(-3), respectively. In general, the concentrations of polycyclic aromatic hydrocarbons were higher in spring and winter than those of summer and autumn for either PM2.5 or PM2.5-10 in Pastureland in central Taiwan. Moreover, coarse particulates are the dominant species during the dust storm season (March and April) in central Taiwan.

Air↗

The determination and fate of disinfection by-products from ozonation of polluted raw water.

The major disinfection by-products (DBPs) resulting from ozone treatment of polluted surface water were investigated. By-products of either health concern or which may contribute to biological instability of treated drinking water were investigated. The major DBPs were analyzed in two fractions: carbonyl compounds and brominated organic compounds. The natural organic matter (NOM) was also isolated and fractionated from polluted water for subsequent ozonation and DBPs identification under conditions of typical drinking treatment. The main identified carbonyl compounds were low molecular weight carboxylic acids, benzoic compounds, aliphatic aldehydes and odorous aldehydes, respectively. Brominated organics were also found in ozonated water, including bromoform (CHBr3), monobromoacetic acid (MBAA), dibromoacetic acid (DBAA), 2,4-dibromophenol (2,4-DBP) and dibromoacetonitrile (DBAN), respectively. It was also found that the characteristic of organic precursors have significant influences on brominated organic by-products formation. Humic acid demonstrated the highest CHBr3, DBAA and 2,4-DBP formations, whereas hydrophilic neutral produced less CHBr3 and 2,4-DBP than the rest of the organic fractions but produced the highest amount of DBAN. In addition to the other target compounds, a total of 59 different organic compounds were detected by means of gas chromatograph/high-resolution electron-impact mass spectrometry (GC/EI-MS) detection and tentatively identified using mass spectral library searching, mainly aromatics, acids/esters, alcohols, aldehydes, phthalates and amines/amino acids were analyzed. The percentage of elimination or formation levels reached during ozonation is also discussed in this study.

Carboxylic Acids↗

Removal of carbon dioxide by a spray dryer.

With the global warming due to greenhouse effects becoming serious, many efforts are carried out to decrease the emissions of CO2 from the combustion of carbonaceous materials. In Taiwan, there are 19 large-scale municipal solid waste incinerators running and their total emission of CO2 is about 16,950 kton y-1. Spray dryer is the most prevailing air pollution control devise for removing acid gas in waste incineration; however, the performance of spray dryer on the removal of CO2 is seldom studied. This study employs a laboratory-scale spray dryer to investigate the removal efficiency of CO2 under different operating conditions. The evaluated parameters include different absorbents mixed with CaOH2, operating temperature, the concentration of absorbent, and the inlet concentration of CO2. Experimental results show that the best removal efficiency of CO2 by a spray dryer is 48% as the absorbent is 10%NaOH+5%CaOH2 and the operating temperature is 150 degrees C. Comparing this result with previous study shows that the performance of spray dryer is better than traditional NaOH wet scrubber. For NaOH+CaOH2 spray dryer, the removal efficiency of CO2 is decreased with the inlet concentration of CO2 increased and the optimum operating temperature is 150 degrees C. Except NaOH+CaOH2, absorbents DEA+CaOH2, TEA+CaOH2, and single CaOH2 are not effective in removing CO2 by a spray dryer.

Absorption↗

Ambient air particulate dry deposition, concentrations and ionic species study at Taichung Harbor near Taiwan Strait.

The characterization for watersoluble species of dry deposition flux, total suspended particulate (TSP), fine particle (particle matter with aerodynamical diameter 2.5 microm, PM2.5), coarse particle (particle matter with aerodynamical diameter 2.5-10 microm, PM(2.5-10)), and dry deposition velocity were studied at Taichung Harbor sampling sites of central Taiwan during February-August 2004. The average downward dry deposition flux, TSP, PM10 concentrations obtained in Taichung Harbor were about 0.51, 0.3, and 3.4 times more than those values obtained by traffic sampling site in central Taiwan. Average dry deposition velocity for mass, Cl-, NO3-, SO4(2-), Na+, NH4+, Mg2+, and Ca2+ were 9, 3.8, 0.3, 0.25, 0.46, 0.18, 0.51 and 2.28 cm respectively at the harbor sampling site. In general, average particle mass dry deposition velocity was about 1.8 times more than those values obtained at the traffic sampling site. Chemical analysis, also indicated that three major soluble inorganic species concentrations (sulfate+nitrate+ammonium) accounted for 59.8% and 80.6% of the PM2.5 and PM(2.5-10) mass concentrations, respectively at the Taichung Harbor sampling site.

Air Pollutants↗

Review of atmospheric water-soluble ionic species in Asia during 1998-2001.

Anthropogenic acid precursor emissions in Asia are increasing at a significant rate and this is expected to continue for the next several years. This paper comprises of studies that included sulfate, nitrate and ammonium around Asian countries (China, Korea, Japan and Taiwan) in recent years. The paper also provides the water-soluble ionic fine and coarse particulate concentrations in these Asian countries in recent years. Fine and coarse particulates in Taiwan (Kaohsiung and Talchung) and China (Nanjing and Shanghai) were found to have higher sulfate (average 18.68 and 15.75 microg/m3) and nitrate (average 12.77 and 7.71 microg/m3) concentrations than any other Asian country. The average sulfate concentrations for Japan and Korea were 7.31 and 5.84 microg/m3, respectively. The average nitrate concentrations for Japan and Korea were 6.73 and 4.65 microg/m3, respectively during the years 1998-2001. The different sample collection devices, analysis methods and pollutant concentrations are discussed in this study. The purpose of this study is to arrange the atmospheric water-soluble ionic species (SO4(2-) and NO3) investigations in the Asian region. The data obtained here can also help to understand the sources, concentrations, phase distribution and health impact of atmospheric water-soluble ionic species (SO4(2-) and NO3-) in other Asian regions.

Asia↗

Concentrations of nano and related ambient air pollutants at a traffic sampling site.

A micro-orifice uniform deposit impactor (MOUDI) and a nano-MOUDI were used to measure the atmospheric coarse (PM2.5 -10), fine (PM2.5), ultrafine (PM0.056-1) and nano (<0.056 microm) particle concentrations and size distributions at a traffic sampling site in winter in central Taiwan, from November 2004 to January 2005. Concentrations of metallic elements (Fe, Mg, Cr, Zn, Pb, Cu) and major ion (SO4(2-), NO3(-), NH4(+)) in particles of various sizes (nano, ultrafine, fine and coarse) were measured. Ambient air particulates generally exhibited a bimodal size distribution in the range 0.056-10 microm. The results show that the concentrations followed the order, Fe>Mg>Cr>Zn>Pb> Cu in PM10, fine, ultrafine and nano-sized particles. Moreover, the data showed that the average metallic elements Fe and Zn have similar concentration distributions: the concentration decreased as the particle size fell in the nano size range.

Air Pollutants↗

Metallic elements study on fine and coarse particulates during daytime and nighttime periods at a traffic sampling site.

Fine (PM2.5) and coarse (PM(2.5-10)) particulates were collected simultaneously by using a versatile air pollutant system at a traffic sampling site during daytime and nighttime sampling periods during August 2003 to March 2004. A flame atomic absorption spectrophotometer coupled with hollow cathode lamps were used for chemical analysis. Enrichment factor and principal component analysis were used to compare chemical components and to find the possible emission sources at this traffic sampling site. The variation of metallic element concentrations on fine and coarse particulates during daytime and nighttime was also discussed in this study. Soil dust, traffic exhaust, marine salt and anthropogenic activities were the major pollutant sources at the traffic sampling site in central Taiwan.

Air↗

Characterization, identification of ambient air and road dust polycyclic aromatic hydrocarbons in central Taiwan, Taichung.

The concentrations of ambient air polycyclic aromatic hydrocarbons (PAHs) were measured simultaneously in an industrial area (Taichung Industrial Park, TIP) and suburban area (Tunghai University, THU) in central Taiwan, Taichung. A total of samples were collected simultaneously at the two sites between August 2002 and March 2003. Particle-bound PAHs (p-PAHs) were collected on quartz filters and gas-phase PAHs (g-PAHs) on glass cartridges using polyurethane foam sampler, respectively. Both types of samples were extracted with dichloromethane/n-hexane mixture (50/50, v/v) for 24 h, then the extracts were subjected to gas chromatography/mass spectrometric analysis. Moreover, the roadside dust particle PAHs composition were also collected and analyzed at TIP, THU and traffic road sampling sites. The five main road lines in Taichung City were selected as traffic road sampling sites. Correlation studies between PAHs concentrations and meteorological parameters were revealed that temperature has greater effects (P>0.6) than other meteorological parameters such as wind speed, relative humidity and atmospheric pressure on g-PAHs and p-PAHs. PAHs sources were resolved by using principal component analysis and diagnostic ratios. The major sources of PAHs were combustion, traffic vehicle exhaust (diesel and gasoline engine), incinerator and industrial stationary sources at both sampling sites in central Taiwan.

Air Pollutants↗

Estimation of PAHs dry deposition and BaP toxic equivalency factors (TEFs) study at Urban, Industry Park and rural sampling sites in central Taiwan, Taichung.

The concentrations of polycyclic aromatic hydrocarbons (PAHs) in gas phase and particle bound were measured simultaneously at industrial (INDUSTRY), urban (URBAN), and rural areas (RURAL) in Taichung, Taiwan. And the PAH concentrations, size distributions, estimated PAHs dry deposition fluxes and health risk study of PAHs in the ambient air of central Taiwan were discussed in this study. Total PAH concentrations at INDUSTRY, URBAN, and RURAL sampling sites were found to be 1650 +/- 1240, 1220 +/- 520, and 831 +/- 427 ng/m3, respectively. The results indicated that PAH concentrations were higher at INDUSTRY and URBAN sampling sites than the RURAL sampling sites because of the more industrial processes, traffic exhausts and human activities. The estimation dry deposition and size distribution of PAHs were also studied. The results indicated that the estimated dry deposition fluxes of total PAHs were 58.5, 48.8, and 38.6 microg/m2/day at INDUSTRY, URBAN, and RURAL, respectively. The BaP equivalency results indicated that the health risk of gas phase PAHs were higher than the particle phase at three sampling sites of central Taiwan. However, compared with the BaP equivalency results to other studies conducted in factory, this study indicated the health risk of PAHs was acceptable in the ambient air of central Taiwan.

Air Pollutants↗

Decolorizing of lignin wastewater using the photochemical UV/TiO2 process.

Studies on applying the photochemical UV/TiO2 oxidation process to treat the lignin-containing wastewater for dissolved organic carbon (DOC), color and reducing A254 (the absorption at the wavelength of 254 nm) have been carried out. The data obtained in this study demonstrate that the UV/TiO2 process is effective in oxidizing the lignin thus reducing the color and DOC of the wastewater treated. The combined UV/TiO2 treatment can achieve better removal of DOC and color than the UV treatment alone. Color removal, based on American Dye Manufacture Index (ADMI) measurement, is greater than 99% if the pH is maintained at 3.0 with the addition of 1 g l(-1) TiO2. When 10 g l(-1) TiO2 is applied, the oxidation reduction potential (ORP) value is reached to result in an 88% removal of both DOC and color. A model was developed based on the variation of ORP during the photochemical reaction to simulate the decoloring process. The proposed model can be used to predict the color removal efficiency of the UV/TiO2 process.

Color↗

Dry deposition (downward, upward) concentration study of particulates and heavy metals during daytime, nighttime period at the traffic sampling site of Sha-Lu, Taiwan.

Downward, upward dry deposition fluxes and total suspended particulate of particulate heavy metals (Fe, Pb, Zn, Cu, Mg and Mn) were measured in daytime and nighttime period in Sha-Lu, a small city in the central Taiwan during summer period of 2003. The results showed that the total suspended particulate concentrations of particulate mass in the daytime period (averaged 996.2 g/m3) were higher than in nighttime period (averaged 560.7 g/m3). And the downward dry deposition fluxes (averaged 54.07 g/m2s) were about two times as that of upward dry deposition fluxes (averaged 26.48 g/m2s) in the daytime period. Furthermore, the average downward dry deposition fluxes (averaged 26.22 g/m2s) were also about two times as that of upward dry deposition fluxes (averaged 12.11 g/m2s) in the nighttime period. In addition, the average downward dry deposition fluxes are greater than the upward dry deposition fluxes for all the heavy metals in either daytime or nighttime period. The proposed reasons are that the wind speed and concentration difference for daytime and nighttime period lead to these results at the traffic sampling site of central Taiwan. In addition, the deposition velocity for mass, heavy metals (Fe, Pb, Zn, Cu, Mg and Mn) during daytime and nighttime period were also calculated. The average daytime dry deposition velocity for downward particulate mass, upward particulate mass, Fe, Pb, Zn, Cu, Mg and Mn were 5.56, 2.66, 1.71, 0.18, 1.06, 0.24, 0.47 and 0.11 (cm/s), respectively. And the average nighttime dry deposition velocity for downward particulate mass, upward particulate mass, Fe, Pb, Zn, Cu, Mg and Mn were 4.70, 2.11, 1.66, 0.18, 0.86, 0.23, 0.32 and 0.07 (cm/s), respectively at traffic sampling site of central Taiwan.

Air Pollutants↗

Polycyclic aromatic hydrocarbons in the ambient air of suburban and industrial regions of central Taiwan.

The concentrations of gas-phase and particle-bound polycyclic aromatic hydrocarbons (PAHs) were measured simultaneously at an industrial area (Taichung Industrial Park) and a suburban area (Tunghai University Campus) in Taichung, Taiwan. Twenty-four hours samplings for two consecutive days were performed between August and December 2002 at both sampling sites. Ambient air particle-bound PAHs were collected on quartz filters and gas-phase PAHs were collected on glass cartridges using a PUF Sampler, respectively. Both types of samples were extracted with a DCM/n-hexane mixture (50/50, v/v) for 24 h, then the extracts were subjected to gas chromatography-mass spectrometric (GC-MS) analysis. Total PAHs concentrations at the Taichung Industrial Park (TIP) sampling site and the Tunghai University Campus (THUC) sampling site were found to be 1232.3+/-963.6 and 609.8+/-356.3 ng/m(3), respectively. Stationary combustion processes were mainly responsible for PAHs sources at the TIP sampling site, while traffic vehicle exhaust was the largest contributor for PAHs sources at the THUC sampling site.

Air Pollutants↗

Characterization of particulate, metallic elements of TSP, PM(2.5) and PM(2.5-10) aerosols at a farm sampling site in Taiwan, Taichung.

Atmospheric aerosol particles and metallic concentrations were monitored at the Experimental Farm of Tunghai University (EFTU) sampling site in this study. Total suspended particulate matter (TSP) was collected by using a PS-1 sampler at the farm-sampling site, in central Taiwan, from July 2001 to April 2002. At the same time, PM(2.5) and PM(2.5-10) were also measured with a Universal sampler from January 2002 to April 2002. Only subjects with the most complete data records on TSP sampling (N=43) and PM(10) sampling (N=23) were used in this analysis. Taichung Industrial Park, Taichung Kang Road (traffic) and a Hospital Incinerator surround the Experimental Farm of Tunghai University. Atmospheric concentrations of metallic elements were analyzed by a flame atomic absorption spectrophotometer (AA-680/G). The results indicated that the metallic elements Mg, Cu and Mn were the largest components in the TSP fraction; the metallic elements Fe and Cd were the largest composition in the PM(2.5-10) fraction; however, the metallic elements Pb, Zn, Cr and Ni were the largest abundance in the PM(2.5) fraction. The atmospheric metallic elements in the TSP, PM(2.5) and PM(2.5-10) fractions came different emission sources, such as soil, traffic, industry and resuspended particles.

Aerosols↗

Fine (PM2.5), coarse (PM2.5-10), and metallic elements of suspended particulates for incense burning at Tzu Yun Yen temple in central Taiwan.

Ambient suspended particulate concentrations were measured at Tzu Yun Yen temple (120 degrees, 34('), 10(") E; 24 degrees, 16('), 12(") N) in this study. This is representative of incense burning and semi-open sampling sites. The Universal-sampler collected fine and coarse particle material was used to measure suspended particulate concentrations, and sampling periods were from 16/08/2001 to 2/1/2002 at Tzu Yun Yen temple. In addition, metallic element concentrations, compositions of PM(2.5) and PM(2.5-10) for incense burning at Tzu Yun Yen temple were also analyzed in this study. The PM(2.5)/PM(10) ratios ranged between 31% and 87% and averaged 70+/-11% during incense the burning period, respectively. The median metallic element concentration order for these elements is Fe>Zn>Cr>Cd>Pb>Mn>Ni>Cu in fine particles (PM(2.5)) at the Tzu Yun Yen temple sampling site. The median metallic element concentration order for these elements is Fe>Zn>Cr>Pb>Cd>Ni>Mn>Cu in coarse particle (PM(2.5-10)) at the Tzu Yun Yen temple sampling site. Fine particulates (PM(2.5)) are the main portion of PM(10) at Tzu Yun Yen temple in this study. From the point of view of PM(10), these data reflect that the elements Fe, Zn, and Cr were the major elements distributed at Tzu Yun Yen temple in this study.

Air Pollution, Indoor↗

Characterization of atmospheric PM10 and related chemical species in southern Taiwan during the episode days.

The concentrations of atmospheric PM10 on days with episodes of pollution were examined at four different sampling sites (CC, DL, LY, and HK) in southern Taiwan. The related to particulates water-soluble ionic species (Na+, K+, Mg2+, Ca2+, NH4+, Cl-, NO3-, SO4(2-)), carbonaceous species (EC and OC) and metallic species (Zn, Ni, Pb, Fe, Mn, Al, Si, V) were also analyzed. On the episode days of this study, the PM10 mass concentration ranged from 155 to 210 microgm(-3), from 150 to 208 microgm(-3), from 182 to 249 microgm(-3), and from 166 to 228 microgm(-3) at CC, DL, LY, and HK, respectively. The results indicate that the dominant water-soluble species were SO4(2-), NO3-, NH4+, and Cl- at the four sampling sites on these days. Moreover, the high sulfate and nitrate conversion values (SOR and NOR) presented herein suggest that secondary formations from SO2 to SO4(2-) and from NO2 to NO3- are present in significant quantities in the atmosphere of southern Taiwan on episode days. In particular, high SOR and NOR verified that both SO4(2-) and NO3- dominated the increase of atmospheric PM10 concentration in southern Taiwan on episode days.

Air Pollutants↗

Deodorization of dimethyl sulfide using a discharge approach at room temperature.

The traditional technologies for odor removal of thiol usually create either secondary pollution for scrubbing, adsorption, and absorption processes, or sulfur (S) poisoning for catalytic incineration. This study applied a laboratory-scale radio-frequency plasma reactor to destructive percentage-grade concentrations of odorous dimethyl sulfide (CH3SCH3, or DMS). Odor was diminished effectively via reforming DMS into mainly carbon disulfide (CS2) or sulfur dioxide (SO2). The removal efficiencies of DMS elevated significantly with a lower feeding concentration of DMS or a higher applied rf power. A greater inlet oxygen (O2)/DMS molar ratio slightly improved the removal efficiency. In an O2-free environment, DMS was converted primarily to CS2, methane (CH4), acetylene (C2H2), ethylene (C2H4), and hydrogen (H2), with traces of hydrogen sulfide (H2S), methyl mercaptan (CH3SH), and dimethyl disulfide. In an O2-containing environment, the species detected were SO2, CS2, carbonyl sulfide, carbon dioxide (CO2), CH4, C2H4, C2H2, H2, formaldehyde, and methanol. Differences in yield of products were functions of the amounts of added O2 and the applied power. This study provided useful information for gaining insight into the reaction pathways for the DMS dissociation and the formation of products in the plasmolysis and conversion processes.

Absorption↗

The concentration, dry deposition, composition study of ambient air particulate and metallic pollutants at a traffic sampling site.

Aerosol samples were collected by total suspended particulate (TSP) and dry deposition plate (downward, upward) from August to November in 2003 in central Taiwan. The particulate metallic elements (Fe, Pb, Zn, Cu, Mg and Mn) were also measured in this study during the summer and autumn periods of 2003. The results obtained in this study indicated that the ambient air particulate mass concentrations in the daytime period (averaged 975.4 microg/m3) were higher than the night-time period (averaged 542.1 microg/m3). And the downward dry deposition fluxes (averaged 58.12 microg/m2-sec) were about 2.2 times that of upward dry deposition fluxes (averaged 26.37 microg/m2-sec) in the daytime period. Furthermore, the average downward dry deposition fluxes (averaged 26.54 microg/m2-sec) were also about 2.3 times that of upward dry deposition fluxes (averaged 11.52 microg/m2-sec) in the night-time period. Moreover, the average downward dry deposition fluxes are greater than the upward dry deposition fluxes for all the heavy metals in either daytime or night-time period. In addition, the deposition velocity for mass, metallic elements (Fe, Pb, Zn, Cu, Mg and Mn) during daytime and night-time period were also calculated. In addition, the average TSP composition (mg/g) in the daytime period of the metallic elements (Fe, Pb, Zn, Cu, Mg and Mn) is 1.73, 0.26, 1.16, 0.28, 0.43 and 0.12 mg/g, respectively. And the average TSP composition in the night-time period of the metallic elements (Fe, Pb, Zn, Cu, Mg and Mn) is 3.02, 0.33, 1.57, 0.41, 0.58 and 0.13 mg/g, respectively at traffic sampling site of central Taiwan.

Aerosols↗

Suspended particulate variations and mass size distributions of incense burning at Tzu Yun Yen temple in Taiwan, Taichung.

Ambient suspended particulate concentrations were measured at Tzu Yun Yen temple in this study. This is characteristic place of incense burning and indoor air pollution sampling site. A universal sampler, micro-orifice uniform deposited impactor (MOUDI) sampler and dry deposition plate were used to measure particulate concentrations. Tzu Yun Yen temple is a typical famous Buddhist-Taoist combined temple, where many pilgrims come from different areas and various belief systems indicating the eclecticism of the temple. The average number of people visiting this temple is above 5000 per day. The PM2.5/PM10 ratios ranged between 31.2 and 87.4% and averaged 69.6+/-12.3% during the incense-burning period, respectively. The results also demonstrated that the fine particulates concentrations (PM2.5) constituted the majority of indoor-suspended particulates at Tzu Yun Yen temple. PM10 concentration was 110.1 microg m(-3) for Zhong Yuan Jie (A festival on the seventh full moon in a lunar year, otherwise known as a summer lantern festival and (or) the commemoration of the dead. Almost all temples have maximum pilgrims for the commemoration of the dead on this day.) and the 1st or 15th of nong li (Nong li is a Chinese lunar calendar system in which 1 year is divided into fixed periods, and the beginning and end of a year is determined. The new moon and full moon are the 1st and 15th, respectively of each month in the Chinese lunar calendar. Many pilgrims appeared at each temple for blessing and good luck for themselves on the 1st and 15th of each Chinese lunar month.) with numbers higher than non-Zhong Yuan Jie and non-1st or -15th day of nong li (average = 85.5 microg m(-3)). In general, the average dry deposition flux (49.4 mg m(-2) day(-1)) in the indoor environment is lower than those measured in the outdoor environment (184.0 mg m(-2) day(-1)) in this study. The mean dry deposition flux of indoor/outdoor ratio was 46.2%. The average mass size distributions were bimodal with the major peaks within 0.56-1 microm and 5.6-10 microm, respectively during non-Zhong Yuan Jie and non-1st or -15th days of each month (Chinese lunar calendar). The average mass size distributions were bimodal with the major peaks within 0.18-0.32 microm and 5.6-10 microm, respectively during Zhong Yuan Jie and the 1st or 15th of nong li of each month (Chinese lunar calendar) at Tzu Yun Yen temple.

Air Pollution, Indoor↗