The adsorption behaviors of ciprofloxacin(CIP),a fluoroquinolone antibiotic,onto goethite(Gt)in the presence of silver and titanium dioxide nanoparticles(AgNPs and TiO_(2)NPs)were investigated.Results showed that CIP ...The adsorption behaviors of ciprofloxacin(CIP),a fluoroquinolone antibiotic,onto goethite(Gt)in the presence of silver and titanium dioxide nanoparticles(AgNPs and TiO_(2)NPs)were investigated.Results showed that CIP adsorption kinetics in Gt with or without NPs both followed the pseudo-second-order kinetic model.The presence of AgNPs or TiO_(2)NPs inhibited the adsorption of CIP by Gt.The amount of inhibition of CIP sorption due to AgNPs was decreased with an increase of solution pH from 5.0 to 9.0.In contrast,in the presence of TiO_(2)NPs,CIP adsorption by Gt was almost unchanged at pHs of 5.0∼6.5 but was decreased with an increase of pH from 6.5 to 9.0.The mechanisms of AgNPs and TiO_(2)NPs in inhibiting CIP adsorption by Gt were different,which was attributed to citrate coating of AgNPs resulting in competition with CIP for adsorption sites on Gt,while TiO_(2)NPs could compete with Gt for CIP adsorption.Additionally,CIP was adsorbed by Gt or TiO_(2)NPs through a tridentate complex involving the bidentate inner-sphere coordination of the deprotonated carboxylic group and hydrogen bonding through the adjacent carbonyl group on the quinoline ring.These findings advance our understanding of the environmental behavior and fate of fluoroquinolone antibiotics in the presence of NPs.展开更多
基金supported by the National Key Research and Development Program of China (No. 2020YFC1808300)the Fundamental Research Fund for the Central Universities (No. 2652019115)+1 种基金Guangxi Key Research Project (Guike AB18050026)the Natural Science Foundation of China (No. 41731282)。
文摘The adsorption behaviors of ciprofloxacin(CIP),a fluoroquinolone antibiotic,onto goethite(Gt)in the presence of silver and titanium dioxide nanoparticles(AgNPs and TiO_(2)NPs)were investigated.Results showed that CIP adsorption kinetics in Gt with or without NPs both followed the pseudo-second-order kinetic model.The presence of AgNPs or TiO_(2)NPs inhibited the adsorption of CIP by Gt.The amount of inhibition of CIP sorption due to AgNPs was decreased with an increase of solution pH from 5.0 to 9.0.In contrast,in the presence of TiO_(2)NPs,CIP adsorption by Gt was almost unchanged at pHs of 5.0∼6.5 but was decreased with an increase of pH from 6.5 to 9.0.The mechanisms of AgNPs and TiO_(2)NPs in inhibiting CIP adsorption by Gt were different,which was attributed to citrate coating of AgNPs resulting in competition with CIP for adsorption sites on Gt,while TiO_(2)NPs could compete with Gt for CIP adsorption.Additionally,CIP was adsorbed by Gt or TiO_(2)NPs through a tridentate complex involving the bidentate inner-sphere coordination of the deprotonated carboxylic group and hydrogen bonding through the adjacent carbonyl group on the quinoline ring.These findings advance our understanding of the environmental behavior and fate of fluoroquinolone antibiotics in the presence of NPs.
