title: Pilot study on bromate reduction in ozonation of water with low carbonate alkalinities by carbon dioxide.
abstract: A pilot study was carried out to explore the application of carbon dioxide for pH depression in a bubble column and its ability to inhibit bromate formation for water with a low alkalinity. Results showed that in the absence of ammonia, CO2 was capable of reducing bromate 38.0%-65.4% with one-unit pH depression. CO2 caused a slightly lower bromate reduction (4.2%) than did H2SO4 when the pH was depressed to 7.4, and a more a pronounced lower reduction (8.8%) when the pH was depressed to 6.9. In the presence of 0.20 mg/L-N ammonia, bromate was largely inhibited with 73.9% reduction. When the pH was depressed to 7.4, CO2 and H2SO4 showed an 11.3% and 23.5% bromate reduction respectively, demonstrating that the joint use of CO2 and ammonia might be a plausible strategy of blocking all three bromate formation pathways. CO2 could be applied through the aeration diffuser together with ozone gas, resulting in a similar bromate reduction compared with the premixing method through Venturi mixer.
authors.affiliation: Harbin Institute of Technology Shenzhen Graduate School, Shenzhen 518055, China. liji98@tsinghua.org.cn
authors.forename: Ji
authors.initials: J
authors.lastname: Li
authors.forename: Li
authors.initials: L
authors.lastname: Zou
authors.forename: Lulu
authors.initials: L
authors.lastname: Guo
authors.forename: Jialin
authors.initials: J
authors.lastname: Ji
mesh_terms: D000641:Ammonia / Q000737:chemistry; D001959:Bromates / Q000737:chemistry*; D002245:Carbon Dioxide / Q000737:chemistry*; D002254:Carbonates / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D010084:Oxidation-Reduction; D010126:Ozone / Q000737:chemistry*; D010865:Pilot Projects; D014867:Water / Q000737:chemistry*
chemical_list: D001959:Bromates; D002254:Carbonates; D014867:Water; D002245:Carbon Dioxide; D010126:Ozone; D000641:Ammonia