Reaction kinetics of selected micropollutants in ozonation and advanced oxidation processes.
Second-order reaction rate constants of micropollutants with ozone (k(O3)) and hydroxyl radicals (k(OH)) are essential for evaluating their removal efficiencies from water during ozonation and advanced oxidation processes. Kinetic data are unavailable for many of the emerging micropollutants. Twenty-four micropollutants with very diverse structures and applications including endocrine disrupting compounds, pharmaceuticals, and personal care products were selected, and their k(O3) and k(OH) values were determined using bench-scale reactors (at pH 7 and T = 20 °C). Reactions with molecular ozone are highly selective as indicated by their k(O3) values ranging from 10(-2)-10(7) M(-1) s(-1). The general trend of ozone reactivity can be explained by micropollutant structures in conjunction with the electrophilic nature of ozone reactions. All of the studied compounds are highly reactive with hydroxyl radicals as shown by their high k(OH) values (10(8)-10(10) M(-1) s(-1)) even though they are structurally very diverse. For compounds with a low reactivity toward ozone, hydroxyl radical based treatment such as O(3)/H(2)O(2) or UV/H(2)O(2) is a viable alternative. This study contributed to filling the data gap pertaining kinetic data of organic micropollutants while confirming results reported in the literature where available.
Department of Civil and Environmental Engineering, University of Waterloo, Waterloo, Ontario, Canada. x3jin@engmail.uwaterloo.ca
Xiaohui
X
Jin
Sigrid
S
Peldszus
Peter M
PM
Huck
D000588:Amines / Q000737:chemistry; D000814:Aniline Compounds / Q000737:chemistry; D000840:Anisoles / Q000737:chemistry; D052244:Endocrine Disruptors / Q000737:chemistry; D006795:Household Products; D006861:Hydrogen Peroxide / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D017665:Hydroxyl Radical / Q000737:chemistry; D007700:Kinetics; D010084:Oxidation-Reduction; D010126:Ozone / Q000737:chemistry*; D004364:Pharmaceutical Preparations / Q000737:chemistry; D010636:Phenols / Q000737:chemistry; D010795:Phthalic Acids / Q000737:chemistry; D011084:Polycyclic Aromatic Hydrocarbons / Q000737:chemistry; D014865:Waste Disposal, Fluid / Q000379:methods; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification / Q000379:methods
D000588:Amines; D000814:Aniline Compounds; D000840:Anisoles; D052244:Endocrine Disruptors; D004364:Pharmaceutical Preparations; D010636:Phenols; D010795:Phthalic Acids; D011084:Polycyclic Aromatic Hydrocarbons; D014874:Water Pollutants, Chemical; D017665:Hydroxyl Radical; D010126:Ozone; C060998:anisole; D006861:Hydrogen Peroxide; C023650:aniline