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

Abstract

The photochemical and ecotoxicological fate of acyclovir (ACY) through UV direct photolysis and in the presence of hydroxyl radicals (UV/HO 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 (ϕ = (1.62 ± 0.07)·10 mol ein) that further reacted with ACY to form by-products (k' = (5.64 ± 0.03)·10 M s). 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 (k) determined with the kinetic modeling method was (1.23 ± 0.07)·10 M s and with the competition kinetics method was (2.30 ± 0.11)·10 M s 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 UV/HO in comparison to those collected during UV treatment. This result suggests that the addition of moderate quantity of hydrogen peroxide (30-150 mg L) might be a useful strategy to reduce the ecotoxicity of UV based sanitary engineered systems for water reclamation.

A chronicle of SARS-CoV-2: Seasonality, environmental fate, transport, inactivation, and antiviral drug resistance

“…Furthermore, subjection to efavirenz (20.6 ng L -1 ) elicited hepatocyte cell damage and even caused death in O. mossambicus ( Robson et al, 2017 ) . Ecotoxicity assay for acyclovir revealed that toxicity on V. fischeri, Raphidocelis subcapitata , D. magna can be reduced upon treatment with UV 254 (1.62 ×10 −3 mol ein −1 )/H 2 O 2 (30-150 mg L -1 ) ( Russo et al, 2017 ) . Emtricitabine and Nevirapine are reported by Ngumba et al (2016), to show toxicity for water flea, algae and fish.…”

Microwave assisted green synthesis of Fe2O3/biochar for ultrasonic removal of nonsteroidal anti-inflammatory pharmaceuticals

“…7 Accordingly, some alternative approaches have already been explored for the removal or degradation of NSAIDs, 8 as well as adsorption, electrochemical oxidation, photo-degradation, ultrasonic irradiation, and advanced oxidation process. [9][10][11][12][13][14][15][16][17] However, adsorption has been found to be the most appropriate technology due to its low-cost, exactitude, feasibility, the simplicity, and safety of the treatment process. [18][19][20][21][22][23][24][25] Moreover, a number of adsorbents such as functionalized carbon nanotubes (FCN), graphene, polystyrene-divinylbenzene resin, activated carbon, and etc.…”

Current emerging SARS-CoV-2 pandemic: Potential direct/indirect negative impacts of virus persistence and related therapeutic drugs on the aquatic compartments

“…This could consequently entail more adverse effects to human health than other classes of drugs (Jain et al, 2013). Moreover, further drawbacks are represented by AVs low biodegradability and their increasing use during pandemic outbreaks (Funke et al, 2016;Hill et al, 2014;Russo et al, 2017).…”