TY - JOUR
T1 - Percarbonate mediated advanced oxidation completely degrades recalcitrant pesticide imidacloprid
T2 - Role of reactive oxygen species and transformation products
AU - Sablas, Michael M.
AU - de Luna, Mark Daniel G.
AU - Garcia-Segura, Sergi
AU - Chen, Chiu Wen
AU - Chen, Chih Feng
AU - Dong, Cheng Di
N1 - Funding Information:
The authors thank the Ministry of Science and Technology, Taiwan (Contract Nos. MOST 106-2221-E-022-002-MY3 and 106-2221-E-022-003-MY3) and the Department of Science and Technology, Philippines for financially supporting this study. The authors declare no competing financial interest.
Funding Information:
The authors thank the Ministry of Science and Technology, Taiwan (Contract Nos. MOST 106-2221-E-022-002-MY3 and 106-2221-E-022-003-MY3 ) and the Department of Science and Technology, Philippines for financially supporting this study.
Publisher Copyright:
© 2020 Elsevier B.V.
Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2020/11/1
Y1 - 2020/11/1
N2 - Pesticides are vital and indispensable especially in agricultural production. However, pesticide contamination is also a serious threat to human health and the environment. Imidacloprid (IMD), an archetypal neonicotinoid insecticide, is commonly used to protect a variety of crops worldwide. This study examined the destruction of IMD contaminant in wastewater via catalytic oxidation with sodium percarbonate (SPC). The process exemplified 100% removal at optimum condition. Rates of reaction were expressed in terms of the apparent rate constants (kapp) and were observed to satisfactorily follow pseudo-first-order kinetics. Inhibitory effects of humic acid and various coexisting ions on IMD degradation were examined and the trend was observed as follows: NO2− > PO43− > NH4+ > Cl− > NO3−. In addition, we elucidated the participation of [rad]OH (hydroxyl), [rad]O2− (superoxyl), and HO2[rad] (perhydroxyl) radicals in the process by performing scavenging experiments for these reactive oxygen species. A likely IMD degradation pathway was proposed based on the intermediate species identified via gas chromatography/mass spectroscopy electron ionization procedure. Overall, the present study established SPC as a cleaner alternative to other oxidants for pesticide degradation as it is non-toxic, safe to handle, and produces by-products that inherently exist in the natural water matrix.
AB - Pesticides are vital and indispensable especially in agricultural production. However, pesticide contamination is also a serious threat to human health and the environment. Imidacloprid (IMD), an archetypal neonicotinoid insecticide, is commonly used to protect a variety of crops worldwide. This study examined the destruction of IMD contaminant in wastewater via catalytic oxidation with sodium percarbonate (SPC). The process exemplified 100% removal at optimum condition. Rates of reaction were expressed in terms of the apparent rate constants (kapp) and were observed to satisfactorily follow pseudo-first-order kinetics. Inhibitory effects of humic acid and various coexisting ions on IMD degradation were examined and the trend was observed as follows: NO2− > PO43− > NH4+ > Cl− > NO3−. In addition, we elucidated the participation of [rad]OH (hydroxyl), [rad]O2− (superoxyl), and HO2[rad] (perhydroxyl) radicals in the process by performing scavenging experiments for these reactive oxygen species. A likely IMD degradation pathway was proposed based on the intermediate species identified via gas chromatography/mass spectroscopy electron ionization procedure. Overall, the present study established SPC as a cleaner alternative to other oxidants for pesticide degradation as it is non-toxic, safe to handle, and produces by-products that inherently exist in the natural water matrix.
KW - Advanced oxidation processes
KW - Imidacloprid
KW - Inorganic ions
KW - Natural organic matter
KW - Reactive oxygen species
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U2 - 10.1016/j.seppur.2020.117269
DO - 10.1016/j.seppur.2020.117269
M3 - Article
AN - SCOPUS:85086833748
SN - 1383-5866
VL - 250
JO - Separation and Purification Technology
JF - Separation and Purification Technology
M1 - 117269
ER -