Efficiency And Mechanism Of Atrazine Degradation By Ozonation/Hydroxylamine/Ferrous System

As a green,efficient and non-secondary pollution oxidant,ozone has been widely used in the treatment of drinking water and sewage.However,a single ozone molecule can only oxidize most organic pollutants containing electric-rich groups,and its oxidation effect on refractory organic pollutants is very limited.Therefore,the reasonable construction of ozone oxidation system that can effectively produce active species is of great significance for the removal of refractory organic matter.This paper is to hard to degrade the pesticide atrazine as reaction substrate,based on ferrous ion and hydroxylamine can effectively activate the characteristics of ozone,built can effectively produce hydroxyl radicals,singlet oxygen,tetravalent iron ion active substances such as ozone/hydroxylamine/ferrous oxidation system,and the system of the influence factors of degradation of atrazine and reaction conditions were studied and optimized,and the reaction system of the reaction path of the active substance and concluded that the degradation products of the target and degradation path for the study of theory.First,using atrazine as the target pollutant,the effect of different reaction systems on the degradation efficiency of atrazine was studied.The results show that the ozone/hydroxylamine/ferrous system has a significant advantage in the degradation of atrazine,and then the reaction conditions were optimized.The results showed that under the condition of atrazine concentration of 1 ?M,ozone concentration was 28 ?M,ferrous ion concentration was 5 ?M,hydroxylamine concentration was 4 ?M,p H was 3.0,and reaction temperature was 20 ?.The removal rate of atrazine reached a maximum of 90%.At the same time,the effect of terminator concentration,alkalinity in water,common anions and cations on the oxidative degradation of atrazine in ozone/hydroxylamine/ferrous iron system wasstudied.The results show that when the concentration of the terminator is 1250 times the concentration of atrazine,the effect on the determination of the concentration of atrazine is the smallest,and the relative experimental deviation is0.5%.The 1 m M bicarbonate alkalinity in the water and 2 m M chloride and phosphate ions can significantly inhibit the degradation of atrazine by the ozone/hydroxylamine/ferrous system.The possible active species in the ozone/hydroxylamine/ferrous reaction system were further investigated,and the hydroxyl radical and iron tetravalent ions in the system were qualitatively determined and analyzed.The degradation of the target was inhibited by bicarbonate ion as an inhibitor,and the pathway and mechanism of the active species were determined by comparing the existing studies.Based on the previous studies,the intermediates of atrazine degradation by ozone/hydroxylamine/ferrous system and the reaction path of atrazine degradation by this reaction system were speculated.