Solar photocatalytic treatment of trimethoprim in four environmental matrices at a pilot scale: Transformation products and ecotoxicity evaluation

Abstract

The pilot-scale solar degradation of trimethoprim (TMP) in different water matrices (demineralized water: DW, simulated natural freshwater: SW; simulated wastewater: SWW; and real effluent: RE) was investigated in this study. DOC removal was lower in the case of SW compared to DW, which can be attributed to the presence of inorganic anions which may act as scavengers of the HO·. Furthermore, the presence of organic carbon and higher salt content in SWW and RE led to lower mineralization per dose of hydrogen peroxide compared to DW and SW. Toxicity assays in SWW and RE were also performed indicating that toxicity is attributed to the compounds present in RE and their by-products formed during solar Fenton treatment and not to the intermediates formed by the oxidation of TMP. A large number of compounds generated by the photocatalytic transformation of TMP were identified by UPLC-QToF/MS. The degradation pathway revealed differences among the four matrices; however hydroxylation, demethylation and cleavage reactions were observed in all matrices. To the best of our knowledge this is the first time that TMP degradation products have been identified by adopting a solar Fenton process at a pilot-scale set-up, using four different aqueous matrices.

New insights into the transformation of trimethoprim during biological wastewater treatment

“…2b), no further TPs could be identified. DAPC was also previously found as a photodegradation product of TMP (Michael et al., 2012). …”

Electrochemical Degradation of Piroxicam on a Boron‐Doped Diamond Anode: Investigation of Operating Parameters and Ultrasound Synergy

“…Further experiments were conducted in different water matrices like surface water (SW), bottled water (BW), and secondary‐treated wastewater (WW) and the results are also presented in Figure . It was observed that working with real matrices increased the removal of PIR, which is contrary to other studies that applied AOPs, such as photocatalysis Fenton or ultrasounds for the destruction of pharmaceuticals. The apparent kinetic constants were 0.138, 0.288, 0.94 and 1.46 min −1 for UP, SW, BW and WW, respectively.…”

Antimicrobial lubricant formulations containing poly(hydroxybenzene)-trimethoprim conjugates synthesized by tyrosinase

“…The well-described oxidation, biodegradation, and metabolism of trimethoprim (Michael et al 2012) allowed to conclude that, in the presence of trimethoprim, the methylparaben oxidation by tyrosinase yields poly(hydroxybenzene)-trimethoprim conjugates. During this process, demethylation and/or hydroxylation of trimethoprim can promote compounds which maintain the two-ring trimethoprim structure such as the 5-((2,4-diaminopyridimidin-5-yl)methyl)-2,3-dimethoxyphenol.…”

“…The enzymatic oxidation of methylparaben by tyrosinase was also tested in the presence of trimethoprim with the concomitant conjugation of the last at the reactive sites of oxidized methylparaben. The oxidation, biodegradation, and metabolism of trimethoprim are well described in literature (Michael et al 2012). The major transformation steps include three pathways, namely cleavage, hydroxylation, and demethylation reactions.…”