title: Natural solar photolysis of total organic chlorine, bromine and iodine in water.
abstract: Municipal wastewater has been increasingly used to augment drinking water supplies due to the growing water scarcity. Wastewater-derived disinfection byproducts (DBPs) may negatively affect the aquatic ecosystems and human health of downstream communities during water reuse. The objective of this research was to determine the degradation kinetics of total organic chlorine (TOCl), bromine (TOBr) and iodine (TOI) in water by natural sunlight irradiation. Outdoor solar photolysis experiments were performed to investigate photolytic degradation of the total organic halogen (TOX) formed by fulvic acid and real water and wastewater samples. The results showed that TOX degradation by sunlight irradiation followed the first-order kinetics with half-lives in the range of 2.6-10.7 h for different TOX compounds produced by fulvic acid. The TOX degradation rates were generally in the order of TOI > TOBr ≅ TOCl(NH2Cl) > TOCl(Cl2). High molecular weight TOX was more susceptible to solar photolysis than corresponding low molecular weight halogenated compounds. The nitrate and sulfite induced indirect TOX photolysis rates were less than 50% of the direct photolysis rates under the conditions of this study. Fulvic acid and turbidity in water reduced TOX photodegradation. These results contribute to a better understanding of the fate of chlorinated, brominated and iodinated DBPs in surface waters.
authors: Department of Civil and Environmental Engineering, South Dakota State University, Brookings, SD 57007, USA.
authors: Ibrahim
authors: I
authors: Abusallout
authors: Department of Civil and Environmental Engineering, South Dakota State University, Brookings, SD 57007, USA. Electronic address: guanghui.hua@sdstate.edu.
authors: Guanghui
authors: G
authors: Hua
mesh_terms: D001578:Benzopyrans / Q000737:chemistry; D001966:Bromine / Q000528:radiation effects*; D002713:Chlorine / Q000528:radiation effects*; D054879:Halogenation / Q000528:radiation effects; D006863:Hydrogen-Ion Concentration; D007455:Iodine / Q000528:radiation effects*; D007700:Kinetics; D008970:Molecular Weight; D009566:Nitrates / Q000032:analysis; D010782:Photolysis / Q000528:radiation effects*; D045483:Rivers / Q000737:chemistry; D013447:Sulfites / Q000032:analysis; D013472:Sunlight; D014867:Water / Q000737:chemistry*; D060753:Water Quality
chemical_list: D001578:Benzopyrans; D009566:Nitrates; D013447:Sulfites; D014867:Water; D002713:Chlorine; D007455:Iodine; D001966:Bromine; C005023:fulvic acid
keywords: Disinfection byproducts; Solar photolysis; Total organic bromine; Total organic chlorine; Total organic iodine