Sonochemical degradation of diclofenac: byproduct assessment, reaction mechanisms and environmental considerations.

The study covers a thorough assessment of the overall degradation of diclofenac-Na (DCF) by high-frequency ultrasound, focusing particularly on identification, interpretation, and characterization of the oxidation byproducts and their reaction mechanisms. It was found that sonication of 5 mg L(-1) DCF at near neutral pH rendered complete conversion of the compound, 45 % carbon, 30 % chlorine, and 25 % nitrogen mineralization. Density functional theory (DFT) calculations confirmed the experimentally detected major byproduct 2,6-dichloroaniline, the formation of which was explained by OH• addition to the ipso-position of the amino group.

More on sonolytic and sonocatalytic decomposition of Diclofenac using zero-valent iron.

The study is an extension of our previous work on sonolytic and sonocatalytic decomposition of Diclofenac-Na (DCF) to depict and highlight further operation parameters of significance, and to assess the effect of a novel home-made catalyst made of magnetic nanoparticles of zero-valent iron (ZVI). It was found that high-frequency was more effective than power ultrasound (20 kHz), and the efficiency was a maximum at 861 kHz, acetate-buffered pH 3.0 and air bubbling provided that samples were prepared from a pre-heated stock solution to enhance solubility of the compound.

Impact of dilution on the transport of poly(acrylic acid) supported magnetite nanoparticles in porous media.

This paper investigates the impact of dilution on the mobility of magnetite nanoparticles surface coated with poly(acrylic acid) (PAA). Transport experiments were conducted in a water-saturated sand-packed column for input nanoparticle solutions with total Fe concentrations ranging from 100 to 600mg/L. Particle size analysis of the synthesized nanoparticle solutions showed that PAA provides good size stability for Fe concentrations as low as about 1mg/L.

The occurrence and fate of anti-inflammatory and analgesic pharmaceuticals in sewage and fresh water: treatability by conventional and non-conventional processes.

The presence of pharmaceutical (PhAC) residues in the environment is an emerging issue due to their continuous and uncontrolled release (via excretion from medical care) to the water environment and detrimental effects on aquatic organisms at low concentrations. A large fraction of PhAC pollution in water is composed of anti-inflammatory (AI) and analgesic (AN) drugs, which are rapidly excreted in urine. The present review is aimed to emphasize the occurrence of AI/AN wastes in sewage and fresh water bodies, their impacts on non-target organisms, and conversion or elimination by chemical, biochemical and physical treatment methods.