This paper studies the degradation mechanism, the reaction kinetics and the toxicity of photolysis products of naproxen in waters under UV irradiation (120 W mercury lamp) by quenching experiments of reactive oxygen species (ROS), oxygen concentration experiment and toxicity evaluation using Vibrio fischeri bacteria. The results demonstrated that NPX could be degraded effectively by UV irradiation and the photolysis pathways was the sum of the degradation by direct photolysis and self-sensitization via ROS, and the contribution rates of self-sensitized photodegradation were 0.1%, 80.2%, 35.7% via *OH, (1)O2, O2*-, respectively. The effect of oxygen concentration illustrated that dissolved oxygen had an inhibitory effect on the direct photodegradation of NPX, and the higher the oxygen content, the more obvious the inhibitory effect. The toxicity evaluation illustrated the formation of some intermediate products that were more toxic than NPX during the photodegradation of NPX. The process of NPX degradation in all cases could be fitted by the pseudo first-order kinetics model.
Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), Departamento de Química, Facultad de Ciencias Exactas, Universidad Nacional de La Plata (UNLP), CCT La Plata-CONICET, La Plata, Argentina.
Phototoxicity of skin due to the application of skincare products or fragrances is increasing from day to day, since a lot of natural extracts, with low or no toxicity in the dark, are being used in the skin exposed to solar radiation. In particular, the use of 4-hydroxy-3-methoxy benzaldehyde, known as vanillin, in the pharmaceutical, food, and cosmetic industries has increased in the last years. This compound is generally considered as safe for humans, and it has been used in a wide range of applications.
This work focused on the transformation behavior of the emerging beaytlmethodeyammonium chbride (BAC-12) disinfectant existed in the treatment of medical sewage during its disinfection treatment. The degradation ability of ozone (O) to BAC-12 was the best, followed by UV/NaOCl, UV, and NaOCl. The enhancement of BAC-12 in UV/NaOCl system is caused by the combined effect of UV photolysis, reactive chlorine species (RCS), and •OH.
The reduction of Cr(VI) to Cr(III) is key to lowering environmental toxicity and mobility, but the reverse process remains less understood. We investigated Cr(III) oxidation mechanisms across various pH levels and light wavelengths (185, 254, and 358 nm) in the presence of Fe(III). At pH 3.
Carbon monoxide (CO), along with nitric oxide and hydrogen sulfide, is one of a trinity of known gasotransmitters, or endogenously produced gaseous molecules that signal and regulate a panoply of physiological functions. CO releasing molecules (CORMs) are chemical tools that enable the study and application of this ephemeral gas, that, ideally, release CO on-demand when externally stimulated. Surveying the available triggers, photolysis is potentially advantageous: It is contactless and grants practitioners unparalleled spatial and temporal control.
- The presence of trace antibiotic residues in the environment can lead to antibiotic resistance and the formation of harmful antibiotic-metal complexes (AMCs), which raise concerns for ecosystems.
- This study focuses on the behavior of the carbapenem antibiotic IMP in environmental waters, examining its interactions with humic acids and metals, and finding that light and temperature significantly degrade the drug.
- Results showed that higher concentrations of humic acid accelerated the degradation of IMP through photochemical reactions, particularly involving reactive oxygen species generated by copper, highlighting the importance of understanding these interactions for assessing ecological risks.
