TY - JOUR TI - Using positive matrix factorization to investigate microbial dechlorination of contaminants in groundwater DO - https://doi.org/doi:10.7282/T3C53P4F PY - 2016 AB - Monitoring data regarding aqueous groundwater concentrations of chlorinated benzenes, chlorinated ethenes and halomethanes as well as ancillary parameters (such as geochemical, nutrient and field data) have been collected from various wells at the Chambers Works site for over two decades. In effort to make use of this investment we applied a sophisticated statistical analysis to the data to elucidate evidence of potential degradation processes that these chemicals may undergo in the subsurface. Halogenated organic compounds are subject to various chemical, physical and biological forces and can undergo chemical reactions and transformations. Positive matrix factorization (PMF) was applied to the monitoring data onsite and has proven useful in characterizing different locations and revealing microbial degradation processes resulting, in distinct fingerprints for each organohalide family explored in this work. PMF resolved three factors in the chlorinated benzenes (Chapter 2), chlorinated ethenes (Chapter 3), and halomethanes (Chapter 4) groundwater datasets. In Chapter 2, for the chlorinated benzene dataset, one factor represents a source of 1,2-dichlorobenzene and the other two factors represent dechlorination, where one factor represents a more advanced dechlorination regime than the other. In Chapter 3, for the chlorinated ethenes dataset, one factor represents a source of tetrachloroethene and trichloroethene. Of the three resolved factors in the chloroethenes dataset, two factors represent stages of dechlorination in which one factor represents a more advanced dechlorination regime than the next. Finally, in Chapter 4, PMF resolved three factors in the halomethane dataset where two factors represent sources of carbon tetrachloride and chloroform and one factor represents dechlorination. KW - Environmental Sciences KW - Groundwater--Pollution KW - Water--Purification LA - eng ER -