Degradation Kinetics of Atrazine and Its Degradation Products with Ozone and OH Radicals: A Predictive Tool for Drinking Water Treatment

Citations Over TimeTop 1% of 2000 papers

Abstract

The present study investigates the degradation of atrazine (2-chloro-4-(ethylamino)-6-isopropylamino-s-triazine) by ozone and OH radicals during ozonation and advanced oxidation processes, with the identification of the main degradation products. Besides the dealkylated and amide degradation products (6-amino-2-chloro-4-isopropylamino-s-triazine, 6-amino-2-chloro-4-(ethylamino)-s-triazine, 4-acetamido-2-chloro-6-isopropylamino-s-triazine, 4-acetamido-6-amino-2-chloro-s-triazine, and chlorodiamino-s-triazine), two new degradation products with an imine group were identified (2-chloro-4-ethylimino-6-isopropylamino-s-triazine and 6-amino-2-chloro-4-ethylimino-s-triazine). The contribution of the different pathways (direct ozone and OH radical reaction) to the overall degradation process has been quantified, and the rate constants of the reactions of atrazine and its main degradation products with both oxidants have been measured. The ethyl group is more reactive than the isopropyl group (i.e. 19 times during ozonation and four times during OH radical attack). The ethyl group reacts in higher proportion through oxidation to acetamide or imine derivates than to dealkylation. In contrast, the isopropyl group reacts mainly through dealkylation to the free amino group. Acetamido and imino groups are found to be resistant to chemical oxidation. These reactivities were corroborated by the measured values of the rate constants with both oxidants. A combination of product distribution and the kinetic parameters together with ozone and OH radical concentrations allowed us to calculate the evolution of the concentration of the degradation products for a given ozonation process.

Related Papers

• Sorption, Transport and Transformation of Atrazine in Soils, Minerals and Composts： A Review(2011)
• → Differential Responses to Preemergence and Postemergence Atrazine in Two Atrazine‐Resistant Waterhemp Populations(2016)33 cited
• → Enhanced Degradation of Atrazine by Corn (Zea mays)(1981)31 cited
• → Συμπεριφορά των ζιζανιοκτόνων atrazine και metolachlor και των μεταβολιτών τους στο έδαφος(2005)
• Enhanced toxicity of atrazine to Daphnia magna in the presence of nano-CeO_2(2012)