Use of scavenger agents in heterogeneous photocatalysis: truths, half-truths, and misinterpretations.

Even though a gap exists in understanding the behavior of radical scavengers and interfering species, they have been extensively employed to elucidate degradation mechanisms or to improve the degradation efficiency in heterogeneous photocatalysis. Focusing on the influence of different species, such as scavengers (t-butanol, formic acid, methanol, p-benzoquinone, oxalate, superoxide dismutase, and azide), interfering species (sulfite, dichromate, bromate, carbonate, chloride, and iodide) and inorganic ions (nitrate, sulfate, and phosphate), this work investigated the production of hydroxyl radicals and singlet oxygen during TiO/UVA reactions. Electron paramagnetic resonance spectroscopy (EPR) was applied to investigate radicals formed in the presence of each interfering/scavenger species.

Visible-light reduced silver nanoparticles' toxicity in Allium cepa test system.

Silver nanoparticles (AgNPs) are widely used in consumer products due to their antibacterial property; however, their potential toxicity and release into the environment raises concern. Based on the limited understanding of AgNPs aggregation behavior, this study aimed to investigate the toxicity of uncoated (uc-AgNP) and coated with polyvinylpyrrolidone (PVP-AgNP), at low concentrations (0.5-100 ng/mL), under dark and visible-light exposure, using a plant test system.

Evaluation of the Fenton process effectiveness in the remediation of soils contaminated by gasoline: Effect of soil physicochemical properties.

The remediation of four different soils contaminated by gasoline was performed using Fenton processes. Herein, the effect of the main physicochemical characteristics of the soils in the Fenton performance is emphasized. Fenton processes were applied in a column system, with and without addition of soluble iron (II), using undisturbed soil samples collected in four regions of the Paraná State (Brazil).