Temperature and nitrogen-induced modification of activated carbons for efficient catalytic ozonation of salicylic acid as a model emerging pollutant.

The occurrence of emerging pollutants on effluents of wastewater treatment plants makes unfeasible their reutilization and consequently to comply with the sixth goal of 2030 Agenda for sustainable development. Thus, it is extremely important to find ways to remove these pollutants without compromising the quality of reclaimed water. Ozonation has been successfully explored for this purpose, but it still presents limitations towards some oxidant-resistant pollutants. To surpass this, the conversion of ozone (O3) into more reactive species is required, which can be accomplished by using catalysts. Carbon catalysts, such as activated carbons (ACs), represent a more environmentally attractive option than traditional metal-based catalysts, with the advantage of being easily modified to tune their textural and surface properties to the reaction chemistry. In this study, two different sources of ACs were tested in the catalytic ozonation of a frequently detected emerging pollutant: salicylic acid (SalAc). These ACs were submitted to thermal treatment under H2 and functionalization with N precursors, such as melamine and poly(ethyleneimine), to induce changes in the surface properties, especially in the nitrogen content. Although no correlation was found between the N-content and catalytic activity, the thermal treatment under H2 increased the mesopores surface area (Smeso), which reflected in greater catalytic activity. As that, the best-performing AC was the one with the highest Smeso, which revealed also to be resistant to O3 and able to convert O3 into more reactive species, evidenced by the capacity of oxalic acid, a well-known ozone-resistant by-product. The same AC was then submitted to three consecutive reutilization cycles and a more significant activity loss was observed in terms of SalAc degradation rate (⁓ 40%) then total organic carbon removal (⁓ 25%), from the first to the third cycle. This decline in efficiency was ascribed to the presence of by-products adhered to the catalyst surface, which impede its ability to react effectively with O3.

1997 William J. Stickel Silver Award. The anti-inflammatory action of locally injected ketorolac.

Locally injected steroids are used to treat inflammatory conditions, in spite of the complications associated with their use. Ketorolac tromethamine, an injectable nonsteroidal anti-inflammatory drug, has not previously been evaluated for treatment of musculoskeletal inflammatory conditions via local administration. Eighty Achilles tendons of rabbits were traumatized in a controlled fashion. At the time of trauma, a single dose of ketorolac (1, 3, or 5 mg/kg) or normal saline was administered peritendinously. Three days later, the tendons were harvested and examined histologically to evaluate the degree of inflammation present in the tissue. No statistically significant difference was found between the experimental and control groups. The authors conclude that locally injected ketorolac does not prevent the onset of an inflammatory process.