TY - JOUR
T1 - Degradation of neonicotinoids and caffeine from surface water by photolysis
AU - Raschitor, Alexandra
AU - Romero, Alberto
AU - Sanches, Sandra
AU - Pereira, Vanessa J.
AU - Crespo, João G.
AU - Llanos, Javier
N1 - Funding Information:
Publicly available datasets were analyzed in this study. This data can be obtained by contacting the corresponding author of the work at: [email protected] Acknowledgments: Financial support from Fundação para a Ciência e a Tecnologia through the project PTDC/EAM-AMB/30989/2017 is gratefully acknowledged. iNOVA4Health— UID/Multi/04462/2013, a program financially supported by Fundação para a Ciência e Tecnolo-gia/Ministério da Educação e Ciência through national funds and co-funded by FEDER under the PT2020 Partnership Agreement is gratefully acknowledged. This work is also supported by the Associate Laboratory for Green Chemistry—LAQV, which is financed by national funds from FCT/MCTES (UIDB/50006/2020). Funding from the INTERFACE Programme, through the Innovation, Technology and Circular Economy Fund (FITEC), is gratefully acknowledged.
PY - 2021/12/1
Y1 - 2021/12/1
N2 - Along with rapid social development, the use of insecticides and caffeine-containing products increases, a trend that is also reflected in the composition of surface waters. This study is focused on the phototreatment of a surface water containing three neonicotinoids (imidacloprid, thi-amethoxam, and clothianidin) and caffeine. Firstly, the radiation absorption of the target pollutants and the effect of the water matrix components were evaluated. It was observed that the maximum absorption peaks appear at wavelengths ranging from 246 to 274 nm, and that the water matrix did not affect the efficiency of the removal of the target pollutants. It was found that the insecticides were efficiently removed after a very short exposure to UV irradiation, while the addition of hydrogen peroxide was needed for an efficient caffeine depletion. The electrical energy per order was estimated, being the lowest energy required (9.5 kWh m−3 order−1) for the depletion of thiamethoxan by indirect photolysis, and a concentration of hydrogen peroxide of 5 mg dm−3. Finally, a prelimi-nary evaluation on the formation of by-products reveals that these compounds play a key role in the evolution of the ecotoxicity of the samples, and that the application of direct photolysis reduces the concentration of these intermediates.
AB - Along with rapid social development, the use of insecticides and caffeine-containing products increases, a trend that is also reflected in the composition of surface waters. This study is focused on the phototreatment of a surface water containing three neonicotinoids (imidacloprid, thi-amethoxam, and clothianidin) and caffeine. Firstly, the radiation absorption of the target pollutants and the effect of the water matrix components were evaluated. It was observed that the maximum absorption peaks appear at wavelengths ranging from 246 to 274 nm, and that the water matrix did not affect the efficiency of the removal of the target pollutants. It was found that the insecticides were efficiently removed after a very short exposure to UV irradiation, while the addition of hydrogen peroxide was needed for an efficient caffeine depletion. The electrical energy per order was estimated, being the lowest energy required (9.5 kWh m−3 order−1) for the depletion of thiamethoxan by indirect photolysis, and a concentration of hydrogen peroxide of 5 mg dm−3. Finally, a prelimi-nary evaluation on the formation of by-products reveals that these compounds play a key role in the evolution of the ecotoxicity of the samples, and that the application of direct photolysis reduces the concentration of these intermediates.
KW - Advanced oxidation process
KW - Caffeine
KW - Direct photolysis
KW - Drinking water treatment
KW - Ecotoxicity
KW - Neonicotinoids
UR - http://www.scopus.com/inward/record.url?scp=85120337378&partnerID=8YFLogxK
U2 - 10.3390/molecules26237277
DO - 10.3390/molecules26237277
M3 - Article
C2 - 34885852
AN - SCOPUS:85120337378
SN - 1420-3049
VL - 26
JO - Molecules
JF - Molecules
IS - 23
M1 - 7277
ER -