東華大學圖書館 |

Language: English

Help

回圖書館首頁

手機版館藏查詢

Back to Search results for [ null ]

Switch To: Labeled | MARC Mode | ISBD

Analyses of atmospheric pollutants i...

Yuan, Zibing.

Linked to FindBook

Google Book

Amazon

博客來

Analyses of atmospheric pollutants in Hong Kong and the Pearl River Delta by observation-based methods.

Record Type:	Language materials, printed : Monograph/item
Title/Author:	Analyses of atmospheric pollutants in Hong Kong and the Pearl River Delta by observation-based methods./
Author:	Yuan, Zibing.
Description:	161 p.
Notes:	Adviser: Alexis Lau.
Contained By:	Dissertation Abstracts International67-12B.
Subject:	Atmospheric Sciences. -
Online resource:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3245376

Analyses of atmospheric pollutants in Hong Kong and the Pearl River Delta by observation-based methods.
Yuan, Zibing.

Analyses of atmospheric pollutants in Hong Kong and the Pearl River Delta by observation-based methods. - 161 p.

Adviser: Alexis Lau.

Thesis (Ph.D.)--Hong Kong University of Science and Technology (Hong Kong), 2006.

Despite continuous efforts paid on pollution control by the Hong Kong (HK) environmental authorities in the past decade, the air pollution in HK has been deteriorating in recent years. In this thesis work a variety of observation-based approaches were applied to analyze the air pollutant monitoring data in HK and the Pearl River Delta (PRD) area. The two major pollutants of interest are ozone and respirable suspended particulate (RSP, or PM10), which exceed the Air Quality Objective more frequently. Receptor models serve as powerful tools for source identification, estimation of source contributions, and source localization when incorporated with wind profiles. This thesis work presents the first-ever application of two advanced receptor-models, positive matrix factorization (PMT) and Unmix, on the PM10 and VOCs speciation data in HK.Subjects--Topical Terms:

1019179
Atmospheric Sciences.

Analyses of atmospheric pollutants in Hong Kong and the Pearl River Delta by observation-based methods.
LDR:05940nam 2200301 a 45 001 950093
005 20110525
008 110525s2006 ||||||||||||||||| ||eng d
035 $a (UMI)AAI3245376
035 $a AAI3245376
040 $a UMI $c UMI
100 1 $a Yuan, Zibing. $3 1273490
245 1 0 $a Analyses of atmospheric pollutants in Hong Kong and the Pearl River Delta by observation-based methods.
300 $a 161 p.
500 $a Adviser: Alexis Lau.
500 $a Source: Dissertation Abstracts International, Volume: 67-12, Section: B, page: 6958.
502 $a Thesis (Ph.D.)--Hong Kong University of Science and Technology (Hong Kong), 2006.
520 $a Despite continuous efforts paid on pollution control by the Hong Kong (HK) environmental authorities in the past decade, the air pollution in HK has been deteriorating in recent years. In this thesis work a variety of observation-based approaches were applied to analyze the air pollutant monitoring data in HK and the Pearl River Delta (PRD) area. The two major pollutants of interest are ozone and respirable suspended particulate (RSP, or PM10), which exceed the Air Quality Objective more frequently. Receptor models serve as powerful tools for source identification, estimation of source contributions, and source localization when incorporated with wind profiles. This thesis work presents the first-ever application of two advanced receptor-models, positive matrix factorization (PMT) and Unmix, on the PM10 and VOCs speciation data in HK.
520 $a Speciated PM10 data were collected from a monitoring network in HK between July-1998 and Dec-2005. Seven and nine sources were identified by Unmix and PMF10, respectively. Overall, secondary sulfate and vehicle emissions gave the largest contribution to PM10 (27% each), followed by biomass burning/waste incineration (13%) and secondary nitrate (11%). Sources were classified as local and regional based on its seasonal and spatial variations as well as source directional analysis. Regional sources accounted for about 56% of the ambient PM10 mass on an annual basis, and even higher (67%) during winter. Regional contributions also showed an increasing trend, with their annual averaged fraction rising from 53% in 1999 to 64% in 2005. The particulate pollution in HK is therefore sensitive to the regional influence and regional air quality management strategies are crucial in reducing PM level in HK. On the other hand, many species with significant adverse health impacts were produced locally. Local control measures should be strengthened for better protection of public health.
520 $a Secondary organic carbon (SOC) could be a significant portion of OC in particles. SOC was examined by using PMF-derived source apportionment results and estimated to be sum of OC present in the secondary sources. The annual average SOC in HK was estimated to be 4.1 mugC/m3 while summertime average was 1.8 RgC/m3 and wintertime average was 6.9 ggC/m 3. In comparison with the SOC estimates by the PMF method, the method that uses elemental carbon (EC) as the tracer for primary OC to derive at SOC overestimates by 78-210% for the summer samples and by 9-49% for the winter samples. The overestimation by the EC tracer method was a result of incapability of obtaining a single OC/EC ratio that represented a mixture of primary sources varying in time and space. It was found that SOC and secondary sulfate had their seasonal variation in sync, suggesting common factors that control their formation. The close tracking of SOC and sulfate appears to suggest that in-cloud pathway is also important for SOC formation.
520 $a Speciated VOCs were obtained in four air quality monitoring stations (AQMSs) in HK from August-2002 to August-2003. Both Unmix and PMF identified five stable sources. Mixed solvents gave the largest contributions ranging from 34% at rural Tap Mun to 52% at urban Central/Western. The wind directional analysis indicates the main source location at the central PRD area. Regional transport accounts for about 19% of the total VOC, while the two local and vehicle-related sources are responsible for 27%. By weighing the abundance and reactivity of each VOC species, mixed solvent use is estimated to be the largest contributor of local ozone, with the contributions ranging from 42% at Tung Chung to 57% at Tap Mun. The next largest is the vehicle exhaust, accounting for about 28% in Yuen Long. Biogenic emission is responsible for nearly 20% of the ozone generation at Tap Mun but this figure is likely underestimated.
520 $a Distinct secondary inorganic aerosol (SIA) responses are expected to the reduction of different precursors as a result of non-linear chemical reactions involved in its formation. The last part of this thesis work concerns developing a chemical box model to determine the sensitivity of SIA to changes to the emissions of their precursors. The model is composed of three parts. The first part is a time-dependent module to estimate the temporal variation of all species, before and after the emission has been disturbed. The second part is a gas-particle conversion module that partitions the semi-volatile species into the two phases. The last module would then calculate the aerosol forming potential for the entire simulation period. It is estimated that SIA shows the largest response to the reduction of SO2 emission in YL, followed by NH3 and NOx. Significant regional transport of SIA is discovered in YL, limiting the indication of relative effectiveness for controlling different precursors. At the end, future research directions are proposed to better refine and validate the OBM performance for SIA simulation.
590 $a School code: 1223.
650 4 $a Atmospheric Sciences. $3 1019179
690 $a 0725
710 2 $a Hong Kong University of Science and Technology (Hong Kong). $3 1022235
773 0 $t Dissertation Abstracts International $g 67-12B.
790 $a 1223
790 1 0 $a Lau, Alexis, $e advisor
791 $a Ph.D.
792 $a 2006
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3245376