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The rapid evolution of antimicrobial resistant genes (AMRs) in water resources is well correlated to the persistent occurrence of ciprofloxacin in water. For the first time, encapsulated nanoscale zerovalent iron (nZVI) with a shell of magnesium hydroxide (Mg/Fe0) was used to adsorb ciprofloxacin from water. Optimization of the removal conditions exhibited that 5% was the optimum mass ratio between magnesium hydroxide and nZVI [Mg(OH)2/nZVI)] as more than 96% of 100 mg L−1 of ciprofloxacin was removed. In addition, 0.5 g L−1 of Mg/Fe0 showed an extraordinary performance in removing ciprofloxacin over a wide range of pH (3–11) with removal efficiencies exceeded 90%. Kinetic analysis displayed that the kinetic data was well described by both Pseudo first-order and second-order models. Also, the equilibrium data was well fitted by Freundlich isotherm model. In addition, thermodynamic analysis evidenced that the removal of ciprofloxacin by Mg/Fe0 was exothermic, and spontaneous. The experiments also revealed that physisorption and chemisorption were the responsible mechanisms for ciprofloxacin removal. The proposed treatment system remediated 10 litters of 100 mg L−1 of ciprofloxacin solution with 100% overall removal efficiency. This treatment system could be a promising and practical solution to decrease ciprofloxacin concentration in different water bodies.

Removal of cesium from waters is an emerging issue after the accident at Fukushima Daiichi Nuclear Power Plant. In this work, new nanoscale zero valent iron–zeolite (nZVI–Z) and nano-Fe/Cu–zeolite (nFe/Cu–Z) composites for cesium removal were fabricated through ion exchange process followed by liquid-phase reduction. The characterization by XRD and SEM-EDS demonstrated that nZVI and nano-Fe/Cu particles were successfully loaded onto zeolite. The performance of the composites for the removal of cesium from aqueous solutions with the ability to separate the adsorbent magnetically was investigated. Batch sorption experiments were systematically carried out to assess the effect of different parameters such as pH, initial concentration, contact time, adsorbent dosage and temperature. The removal kinetics of cesium was adequately described by the pseudo-second-order kinetic model, which indicates that the uptake mechanism was chemisorption. The rate constant values for adsorption by nFe/Cu–Z were greater than the values obtained for nZVI–Z, meaning that nFe/Cu–Z had faster adsorption kinetics towards cesium solutions. The equilibrium adsorption data gave better mathematical fitting towards Langmuir and Freundlich isotherm models, where the maximum adsorption capacity of nFe/Cu–Z (77.51 mg/g) was found to be higher than that for nZVI–Z (71.12 mg/g). The observed thermodynamic parameters showed that the adsorption of cesium was endothermic process and spontaneous in nature. The composites were efficiently recovered from solution after the adsorption experiments by an easy, simple and rapid magnetic separation. The obtained results suggested that both composites could be used as a promising technique for the treatment of waters containing cesium.

Following the accident at the Fukushima Daiichi Nuclear Power Plant in 2011, radioactive cesium was released into the environment in large amounts and heavily contaminated drinking water in Fukushima and neighboring prefectures. In this research, the capability of nanoscale zero valent iron (nZVI) and bimetallic nano-Fe/Cu particles for cesium removal from aqueous solutions was evaluated for the first time. The nanoparticles were characterized by TEM, XRD, SEM-EDS and BET-N2 adsorption. The effect of several variables such as initial cesium concentration, contact time, pH, temperature, competing cations and dosage of the nanoparticles on the sorption behavior of cesium was studied using a batch technique. The obtained results showed that nZVI and nano-Fe/Cu particles displayed effective performance for removal of cesium. For both nanoparticles, the removal efficiency exceeded 99% at initial cesium concentration of 1 mg/L and 1 g/L doses. The experimental data were well fitted to the pseudo-second-order kinetic model, which means that the overall rate constant of cesium sorption process was controlled by chemisorption. The rate constant of nano-Fe/Cu particles was larger than that of nZVI, indicating a faster kinetic sorption by nano-Fe/Cu particles. The thermodynamic parameters indicated exothermic and spontaneous nature of the sorption process. The Langmuir, Freundlich and Redlich-Peterson isotherm models were also used to fit the equilibrium data. nZVI and nano-Fe/Cu particles exhibited excellent selective sorption toward cesium in the simulated contaminated water after Fukushima accident. The current work demonstrated that nZVI and nano-Fe/Cu particles can be considered as promising materials for cesium removal from contaminated waters.

Iridium-catalyzed hydrosilylation of amides with 1,1,3,3-tetramethyldisiloxane (TMDS) allows access to silylhemiaminals, which are often spontaneously converted to aldenamines. Iridium(I) phosphine species generated from IrCl(CO)(PPh3)2, IrCl(PPh3)3, or a mixture of [IrCl(COD)]2 and phosphorous ligands showed high catalytic activity for this reaction protocol, which demonstrated remarkable compatibility toward other reducible functional groups such as ketone and ester groups. This reaction enables the synthesis of π-conjugate enamines having hole-transport properties by appropriate selection of the iridium catalyst. Easy access to silyl hemiaminals and enamined stimulated other research groups to discover new reductive C–C bond-forming reactions to transform amides to amine derivatives, which can be applied to the synthesis of complex alkaloid molecules.

Efficient separation of strontium ions (Sr2+) from waters has become a critical technological requirement after the nuclear accident at Fukushima Daiichi power station. In the present investigation, new nanocomposites of zero valent iron nanoparticles–zeolite (nZVI–Z) and nano-Fe/Cu–zeolite (nFe/Cu–Z) were synthesized via a simple liquid-phase reduction approach and tested to determine their effectiveness in the sorptive removal of Sr2+ from aqueous solutions. The sorption of Sr2+ on both nanocomposites was studied in a batch sorption mode as a function of various environmental conditions such as initial Sr2+ concentration, contact time, pH, temperature, dosage of sorbent and competing cations (Na+, K+, Mg2+ and Ca2+). The results indicated that initial pH and temperature were significant for Sr2+ sorption on both nanocomposites. The Sr2+ sorption efficiency increases with the increase in nanocomposite dosage and decreases with the Sr+2 concentration. It was also found that although the sorption of Sr2+ was decreased by the presence of coexisting cations, the nanocomposites still exhibited high uptake capacity of Sr2+ ions. The Sr2+ sorption kinetics can be satisfactorily fitted by a pseudo-second-order kinetic model. The sorption isotherm data were well predicted using the Langmuir model. The maximum sorption capacity for nFe/Cu–Z was found to be 88.74 mg/g, which was greater than that for nZVI–Z (84.12 mg/g). In addition to the high sorption capacity, the nanocomposites could be easily separated from aqueous media after Sr2+ sorption using an external magnetic field. The calculated thermodynamic parameters such as ∆H°, ∆S° and ∆G° revealed the endothermic and spontaneous nature of the sorption process. The nanocomposites were also applied in a real seawater medium. The present study confirmed that the prepared nZVI–Z and nFe/Cu–Z nanocomposites could be employed as promising methods for the removal of Sr2+ from wastewater streams.