No abstract

Elsevier; IWA Publishing Caregnato, Paula; Rosso, Janina A.; Soler, Juan M.; et ál.. (2013). Chloride anion effect on the advanced oxidation process of methidathion and dimethoate: role of Cl2(center dot-) radical. Water Order of Authors: Monica Cristina Gonzalez, PhD.Abstract: The reaction of phosphor-containing pesticides such as methidathion (MT) and dimethoate (DM) with dichloride radical anions (Cl2.-) was investigated. The second order rate constants (1.3 ± -1 s-1, were determined for the reaction of Cl2.-with MT and DM, respectively. A reaction mechanism involving an initial charge transfer from the sulfide groups of the insecticides to Cl2.-is proposed and supported by the identified transient intermediates and stable reaction products. The formation of chlorinated by-products was determined. The unexpected consequences of an efficient Cl2.-reactivity towards MT and DM on the degradation capacity by Advanced Oxidation Procedures applied to polluted waters containing the insecticides and Cl-anions is discussed.

The reaction of three chloronicotinoid insecticides, namely Imidacloprid (IMD), Thiacloprid (THIA) and Acetamiprid (ACT), with carbonate radicals (CO3*-) was investigated. The second order rate constants (4 ± 1)×106, (2.8 ± 0.5)×105, and (1.5 ± 1)×105 M-1s-1 were determined for IMD, THIA and ACT, respectively. The absorption spectra of the organic intermediates formed after CO3*-attack -aminoalkyl radicals. A reaction mechanism involving an initial charge transfer from the amidine nitrogen of the insecticides to CO3*-is proposed and further supported by the identified reaction products. The pyridine moiety of the insecticides remains unaffected until nicotinic acid is formed. CO3*-radical reactivity towards IMD, ACT, and THIA is low compared to that of HO* radicals, excited triplet states, and 1O2, and is therefore little effective in depleting neonicotinoid insecticides. Dear Editor, Please find enclosed the manuscript entitled: "Removal of neonicotinoid insecticides by carbonate radicals". The present manuscript gives an insight into the reaction mechanisms and kinetics of carbonate radicals with neonicotinoid insecticides, namely imidacloprid, thiacloprid and acetamiprid. We thank you in advance for your kind cooperation. Cover Letter, For Editor only Highlights:Cloronicotinoid insecticides show low reactivity towards carbonate radicals.The reaction involves an initial charge transfer from the insecticide to CO 3 -.After prolonged irradiation chloronicotinic acid is formed.Hydroxyl and sulfate radicals are among the most effective in degrading the insecticides. 23The pyridine moiety of the insecticides remains unaffected until nicotinic acid is formed. 27

No abstract

No abstract

No abstract

No abstract

No abstract