Heterogeneous catalytic ozonation has been increasingly studied for the degradation and mineralization of refractory organic water pollutants in recent years. Compared with homogeneous catalysts, an important advantage of heterogeneous catalysts is that they can be easily separated from the treated water, making the process economically viable. While many studies have focused on the development and evaluation of metal oxide-based catalytic ozonation, possible leaching of metal ions and the subsequent effect on the contaminants' degradation are sometimes overlooked. Here, we examined metal leaching from several solid catalysts and further investigated the influence of the leached metal ions on the mineralization of two model compounds (oxalate and nitrobenzene) during continuous ozonation. Metallic ion leaching was observed from both commercially-available catalysts and catalysts prepared via wet-chemistry methods in the lab. The water matrix has been demonstrated to play an important role in metal leaching. The homogeneous catalytic effect resulting from the leached metal ions was found to be significant. A mechanism involving the formation of an unstable Cu(III)/oxalate complex through the reaction between ˙OH and Cu(II)/oxalate was proposed to explain the experimental observations. Our results indicate that the stability of the solid catalysts and the effects of the leached ions must be carefully examined during the catalytic ozonation of organic contaminants. Through this study we highlight the importance of rigorous, accepted protocols for evaluating and reporting heterogeneous catalyst performance in water/wastewater treatment within the research community.

Four essential oils from the leaf (P23) and rhizomes (P19, P22, P24) of Acorus calamus L., collected from various parts of Nepal, were obtained by hydrodistillation and analyzed by GC-MS. From a total of 61 peaks, 57 compounds were identified among the four essential oils accounting for 94.3%, 96.2%, 97.6%, and 94.1% of the oils, respectively. All of the essential oils were dominated by ( Z)-asarone (78.1%–86.9%). The essential oils also contained ( E)-asarone (1.9%–9.9%) and small amounts of γ-asarone (2.0–2.3%), ( Z)-methyl isoeugenol (1.5–2.0%), and linalool (0.2–4.3%). Allelopathic testing of the rhizome oil showed inhibition of seed germination of Lactuca sativa and Lolium perenne with IC₅₀ values of 450 and 737 μg/mL, respectively. The rhizome essential oil demonstrated stronger seedling growth inhibition of L. perenne than of L. sativa, however. The rhizome oil also showed notable brine shrimp lethality ( LC₅₀ = 9.48 μg/mL), cytotoxic activity (92.2% kill on MCF-7 cells at 100 μg/mL), and antifungal activity against Aspergillus niger (MIC = 19.5 μg/mL).

Starting with (R)-(–)-cryptone, prepared in 42% overall yield from (+)-nopinone in five steps, the first synthesis of noroxopenlanfuran was accomplished, confirming its absolute configuration.

Elimination of meropenem from environmental matrices using a novel Co/Bi/TiO₂ NTA electrode with high anode stability and ROS generation capability.