A Conceptual Model and Remediation Strategy for Volatile Organic Compounds in Groundwater in Unconsolidated Sediments: A Lawrence Livermore National Laboratory Case Study

2003 ◽  
Vol 9 (1) ◽  
pp. 83-94 ◽  
Author(s):  
F. HOFFMAN
Keyword(s):  
Volatile Organic Compounds ◽  
Conceptual Model ◽  
Organic Compounds ◽  
Lawrence Livermore National Laboratory ◽  
National Laboratory ◽  
Unconsolidated Sediments ◽  
Remediation Strategy ◽  
Volatile Organic

scholarly journals An Integrated Method for Factor Number Selection of PMF Model: Case Study on Source Apportionment of Ambient Volatile Organic Compounds in Wuhan

Atmosphere ◽  
2018 ◽  
Vol 9 (10) ◽  
pp. 390 ◽  
Author(s):  
Fenjuan Wang ◽  
Zhenyi Zhang ◽  
Costanza Acciai ◽  
Zhangxiong Zhong ◽  
Zhaokai Huang ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Source Apportionment ◽  
Correlation Coefficient ◽  
Organic Compounds ◽  
Industrial Emissions ◽  
Integrated Method ◽  
Pmf Model ◽  
Volatile Organic ◽  
Measurement Period

The positive matrix factorization (PMF) model is widely used for source apportionment of volatile organic compounds (VOCs). The question about how to select the proper number of factors, however, is rarely studied. In this study, an integrated method to determine the most appropriate number of sources was developed and its application was demonstrated by case study in Wuhan. The concentrations of 103 ambient volatile organic compounds (VOCs) were measured intensively using online gas chromatography/mass spectrometry (GC/MS) during spring 2014 in an urban residential area of Wuhan, China. During the measurement period, the average temperature was approximately 25 °C with very little domestic heating and cooling. The concentrations of the most abundant VOCs (ethane, ethylene, propane, acetylene, n-butane, benzene, and toluene) in Wuhan were comparable to other studies in urban areas in China and other countries. The newly developed integrated method to determine the most appropriate number of sources is in combination of a fixed minimum threshold value for the correlation coefficient, the average weighted correlation coefficient of each species, and the normalized minimum error. Seven sources were identified by using the integrated method, and they were vehicular emissions (45.4%), industrial emissions (22.5%), combustion of coal (14.7%), liquefied petroleum gas (LPG) (9.7%), industrial solvents (4.4%), and pesticides (3.3%) and refrigerants. The orientations of emission sources have been characterized taking into account the frequency of wind directions and contributions of sources in each wind direction for the measurement period. It has been concluded that the vehicle exhaust contribution is greater than 40% distributed in all directions, whereas industrial emissions are mainly attributed to the west southwest and south southwest.

Characteristics of roadside volatile organic compounds in an urban area dominated by gasoline vehicles, a case study in Hanoi

Chemosphere ◽  
2020 ◽  
Vol 254 ◽  
pp. 126749 ◽  
Author(s):  
Bich-Thuy Ly ◽  
Yoshizumi Kajii ◽  
Thi-Yen-Lien Nguyen ◽  
Koki Shoji ◽  
Dieu-Anh Van ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Urban Area ◽  
Organic Compounds ◽  
Gasoline Vehicles ◽  
Volatile Organic
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