The corrosion inhibition features of a new eco-friendly coumarin derivative, namely, 4-((4-((4-hydroxy-3-methoxybenzylidene)amino)-5-thioxo-4,5-dihydro-1H-1,2,4-triazol-3-yl)methyl)coumarin (HATC), for corrosion of the mild steel surface in an acidic environment was studied using gravimetric techniques and quantum chemical calculations. It was concluded that the tested coumarin derivative is an excellent corrosion inhibitor with high inhibition efficiency. The inhibition performance increases with increasing concentration of the investigated coumarin (HATC) and decreases with increasing temperature. The mechanism of adsorption includes a physical adsorption mechanism. Theoretical studies done on the new coumarin molecule using the density functional theory (DFT) have shown that the most likely entities in coumarin molecules to bond to the metal surface are nitrogen, sulfur and oxygen atoms.

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After upgrading the Pakistan Research Reactor-1 from 5 MW (Th) to 10 MW (Th), increased inventory of 100m Ag and 124 Sb in the waste stream demanded some sort of treatment to bring the radioactivity levels within the disposal limits. A chemical treatment, making use of scavenging precipitation of the radionuclides with hydrous oxides of iron, was studied. Fe(II) hydrous oxide coprecipitation by using green vitriol provided complete removal of silver activity and an acceptable decontamination factor (DF) for antimony. Coagulant doses and other parameters for decontamination of the bulk of the waste were studied and ORDER REPRINTS optimized. Various parameters and results of the process are presented. High DFs for silver and antimony radionuclides have been achieved.