
Vincent DiPietri
Ph.D. Student in Civil and Environmental Engineering, admitted Autumn 2024
Education & Certifications
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PhD, Stanford University, Civil and Environmental Engineering
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M. S., Towson University, Environmental Science (2024)
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B. S., Towson University, Chemistry (2022)
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B. S., Towson University, Molecular Biology, Biochemistry, and Bioinformatics (2022)
All Publications
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Chloride Enhances DNA Reactivity with Chlorine under Conditions Relevant to Water Treatment.
Environmental science & technology
2022; 56 (18): 13347-13356
Abstract
Free available chlorine (FAC) is widely used to inactivate viruses by oxidizing viral components, including genomes. It is commonly assumed that hypochlorous acid (HOCl) is the chlorinating agent responsible for virus inactivation; however, recent studies have underscored that minor constituents of FAC existing in equilibrium with HOCl, such as molecular chlorine (Cl2), can influence FAC reactivity toward select organic compounds. This study measures the FAC reaction kinetics with dsDNA and ssDNA extracted from representative bacteriophages (T3 and ϕX174) in samples augmented with chloride. Herein, chloride enhances FAC reactivity toward dsDNA and, to a lesser extent, toward ssDNA, especially at pH < 7.5. The enhanced reactivity can be attributed to the formation of Cl2. Second-order rate constants were determined for reactions of ssDNA and dsDNA with HOCl and Cl2. DNA chlorination kinetics followed the reactivity-selectivity principle, where the more-reactive nucleophilic species (ssDNA, ∼100× more reactive than dsDNA) reacted less selectively with electrophilic FAC species. The addition of chloride was also shown to enhance the inactivation of bacteriophage T3 (dsDNA genome) by FAC but did not enhance the inactivation of bacteriophage ϕX174 (ssDNA genome). Overall, the results suggest that Cl2 is an important chlorinating agent of nucleic acids and viruses.
View details for DOI 10.1021/acs.est.2c03267
View details for PubMedID 36027047
View details for PubMedCentralID PMC9494735