Comparative OH radical oxidation using UV-Cl2 and UV-H2O2 processes

Research Article| December 01 2007 Comparative OH radical oxidation using UV-Cl2 and UV-H2O2 processes Michael J. Watts; Michael J. Watts 1Department of Civil and Environmental Engineering, Duke University, 121 Hudson Hall, Box 90287, Durham, NC 27708-0287, USA Search for other works by this author on: This Site PubMed Google Scholar Erik J. Rosenfeldt; Erik J. Rosenfeldt 2Department of Civil and Environmental Engineering, University of Massachusetts, Amherst, MA 01003, USA Search for other works by this author on: This Site PubMed Google Scholar Karl G. Linden Karl G. Linden 3Department of Civil, Environmental and Architechtural Engineering, University of Colorado-Boulder, 428 UCB, Boulder, CO 80309, USA Tel.: 303-492-4798 Fax: 303-492-7317; E-mail: karl.linden@colorado.edu Search for other works by this author on: This Site PubMed Google Scholar Journal of Water Supply: Research and Technology-Aqua (2007) 56 (8): 469–477. https://doi.org/10.2166/aqua.2007.028 Article history Received: February 24 2007 Accepted: June 09 2007 Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Cite Icon Cite Permissions Search Site Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAll JournalsThis Journal Search Advanced Search Citation Michael J. Watts, Erik J. Rosenfeldt, Karl G. Linden; Comparative OH radical oxidation using UV-Cl2 and UV-H2O2 processes. Journal of Water Supply: Research and Technology-Aqua 1 December 2007; 56 (8): 469–477. doi: https://doi.org/10.2166/aqua.2007.028 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex Hydroxyl radicals (•OH) are a direct photolysis product of both aqueous free chlorine and hydrogen peroxide under UV irradiation. The photooxidation rates of an OH-radical probe compound, nitrobenzene, were compared in aqueous solutions of free chlorine, and H2O2, exposed to monochromatic UV irradiation (254 nm). Acidic (< pH 6) free chlorine solutions had the highest observed rates of nitrobenzene decay. In deionized water, with initial oxidant concentrations < 0.15 mM, the first order nitrobenzene decay rates increased in the following order of treatments: UV-Cl2(pH 7) < UV-H2O2 < UV-Cl2 (pH 6) < UV-Cl2 (pH 5). However, water quality had a significant impact; background photon and radical scavengers led to reduced rates of nitrobenzene decay in natural waters. Analysis of the necessary energy input required to achieve 90% nitrobenzene degradation showed UV-Cl2 at pH 5 to be the most efficient oxidation process whereas at neutral pH, process efficiency was a function of the initial concentration of the oxidant; at 0.05 or 0.06 mM initial oxidant, UV-Cl2 was the most efficient oxidation process, while at >0.15 mM initial oxidant, UV-H2O2 was most efficient. advanced oxidation process, fluence rate, free chlorine, hydrogen peroxide, nitrobenzene, ultraviolet This content is only available as a PDF. © IWA Publishing 2007 You do not currently have access to this content.