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Photodegradation and ecotoxicology of acyclovir in water under UV254 and UV254/H2O2 processes

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journal contribution
posted on 25.07.2017, 10:47 by Danilo Russo, A. Siciliano, M. Guida, Emilia Galdiero, Angela Amoresano, Roberto Andreozzi, Nuno M. Reis, Gianluca Li-PumaGianluca Li-Puma, Raffaele Marotta
The photochemical and ecotoxicological fate of acyclovir (ACY) through UV254 direct photolysis and in the presence of hydroxyl radicals (UV254/H2O2 process) were investigated in a microcapillary film (MCF) array photoreactor, which provided ultrarapid and accurate photochemical reaction kinetics. The UVC phototransformation of ACY was found to be unaffected by pH in the range from 4.5 to 8.0 and resembled an apparent autocatalytic reaction. The proposed mechanism included the formation of a photochemical intermediate (ϕACY = (1.62 ± 0.07)·10−3 mol ein−1) that further reacted with ACY to form by-products (k’ = (5.64 ± 0.03)·10−3 M−1 s−1). The photolysis of ACY in the presence of hydrogen peroxide accelerated the removal of ACY as a result of formation of hydroxyl radicals. The kinetic constant for the reaction of OH radicals with ACY (kOH/ACY) determined with the kinetic modeling method was (1.23 ± 0.07)·109 M−1 s−1 and with the competition kinetics method was (2.30 ± 0.11)·109 M−1 s−1 with competition kinetics. The acute and chronic effects of the treated aqueous mixtures on different living organisms (Vibrio fischeri, Raphidocelis subcapitata, D. magna) revealed significantly lower toxicity for the samples treated with UV254/H2O2 in comparison to those collected during UV254 treatment. This result suggests that the addition of moderate quantity of hydrogen peroxide (30–150 mg L−1) might be a useful strategy to reduce the ecotoxicity of UV254 based sanitary engineered systems for water reclamation.

History

School

  • Aeronautical, Automotive, Chemical and Materials Engineering

Department

  • Chemical Engineering

Published in

Water Research

Volume

122

Pages

591 - 602

Citation

RUSSO, D. ...et al., 2017. Photodegradation and ecotoxicology of acyclovir in water under UV254 and UV254/H2O2 processes. Water Research, 122, pp. 591-602.

Publisher

© Elsevier

Version

AM (Accepted Manuscript)

Publisher statement

This work is made available according to the conditions of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) licence. Full details of this licence are available at: https://creativecommons.org/licenses/by-nc-nd/4.0/

Acceptance date

07/06/2017

Publication date

2017

Notes

This paper was accepted for publication in the journal Water Research and the definitive published version is available at http://dx.doi.org/10.1016/j.watres.2017.06.020

ISSN

0043-1354

eISSN

1879-2448

Language

en