Sparfloxacin

This study aimed to investigate the differences in the mechanisms of microscopic hepatotoxicity, developmental toxicity, and neurotoxicity in aquatic organisms co-exposed to styrene-butadiene rubber tire microplastics (SBR TMPs) and fluoroquinolone antibiotics (FQs). We found that hepatotoxicity in zebrafish induced by SBR TMPs and FQs was significantly higher than developmental toxicity and neurotoxicity. Furthermore, the main effects of the FQs primarily manifested as synergistic toxicity, whereas the low- and high-order interactions of the FQs mainly exhibited synergistic and antagonistic effects, respectively. Factorial analysis and the mixture toxicity index revealed that the synergistic effects of lomefloxacin × moxifloxacin and ciprofloxacin × lomefloxacin × enrofloxacin interactions significantly contributed to hepatotoxicity in zebrafish exposed to SBR TMP. SBR TMPs and antibiotics primarily induced hepatotoxicity, developmental toxicity, and neurotoxicity in zebrafish by affecting the activities of Cyp1a, Acox1, TRα, and mAChR. The observed toxicities were closely linked to the hydrophilic/hydrophobic groups, electronegativity, group mass, and structural complexity of the FQ molecules. This study provides new insights regarding the toxicological risks to aquatic organisms from co-exposure to SBR TMPs and FQs from a microscopic perspective. Future studies should include a broader range of antibiotics and tire microplastics and consider their long-term adverse effects on aquatic life.

Research on transition metal-triggered advanced oxidation processes (TM-AOPs) has primarily focused on the regulation of catalysts and oxidants, but the alternative route that involves utilizing pollutant-derived electrons to enhance TM-AOPs has been largely overlooked. This study presents a case of selective degradation using fluoroquinolone antibiotics, with ofloxacin (OFX) selected as the model pollutant. Under the presence of PDS and trace Cu(II) (10 μM or 0.64 mg/L, below the limit of US drinking water standard), the OFX degradation rate was enhanced by 12.1 times compared to sole PDS oxidation. Notably, the system exhibited high pollutant selectivity and efficient oxidant utilization. Through various experimental methods, Cu(I) was confirmed as a crucial intermediate, while Cu(III) and •OH was identified as the predominant and secondary reactive oxidative species, respectively. The critical role of OFX was proved to be chelating with Cu(II) and facilitating the production of Cu(I). The degradation selectivity of OFX was attributed to the synergy of the chelating and oxidation sites in its chemical structure. Intramolecular single electron transfer occurred between the chelated OFX and Cu(III), leading to the Cu(III) reduction and OFX oxidation on the piperazine nitrogen atom. This study serves as a representative example of a greener pollutant-induced catalytic process based on the utilization of pollutant's electron bank, and offers novel insights into the correlation between a pollutant's chemical structure and its degradation selectivity.