Ciprofloxacin Adsorption Capacity Research Articles

Preparation of a Three-Dimensional Porous Graphene Oxide-Kaolinite-Poly(vinyl alcohol) Composite for Efficient Adsorption and Removal of Ciprofloxacin.

Because of the widespread presence of antibiotics in water, soil, and other environments, they pose great potential risks to the environment, threatening human and animal health. In this study, graphene oxide-kaolinite homogeneous dispersion was prepared by simple liquid phase exfoliation. The three-dimensional (3D) porous graphene oxide-kaolinite-poly(vinyl alcohol) composites were prepared by the cross-linking of poly(vinyl alcohol) and the formation of ice crystals during the freezing-drying process. Three influencing factors [adsorbent dosage, ciprofloxacin (CIP) initial concentration, and time] of CIP adsorption and removal were systematically analyzed by the response surface method. The order of significance for response values (CIP removal rate) was adsorbent dosage > CIP initial concentration > time. The 3D porous material showed good adsorption capacity of CIP, the theoretical maximum adsorption capacity was 408.16 mg/g, and it had good recyclability. By Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy analysis, it was found the composite adsorbs CIP by hydrogen bonding and π-π interaction. In conclusion, the graphene oxide-kaolinite-poly(vinyl alcohol) porous composite is a good candidate for efficient antibiotic wastewater treatment.

Adsorption characteristic of ciprofloxacin antibiotic onto synthesized alpha alumina nanoparticles with surface modification by polyanion

In the present study, we reported the first adsorption characteristic of Ciprofloxacin (CFX) antibiotic onto synthesized alumina nanoparticles with surface modification by a polyanion. Strong polyanion poly(styrenesulfonate) (PSS), was used for surface modification of synthesized alumina nanoparticles. The alumina which was structural alpha phase, was confirmed by X-ray diffraction (XRD). The functional vibration groups of AlO and OH was characterized by Fourier transform infrared spectroscopy (FT-IR). The sphere morphology and particle size of about 40 nm was evaluated by Transmission electron microscopy (TEM), while the specific surface area of 6.08 m2/g was determined by Brunauer–Emmett–Teller (BET) method. Surface modification of nanoalumina with PSS enhanced a significant increase in CFX removal from aqueous solution. Some important parameters which influenced to the CFX removal including pH, contact time and adsorbent dosage, were systematically optimized. Under experimentally selected parameters, the removal efficiency and adsorption capacity of CFX using PSS-modified nanoalumina (PMNA) reached maximum of 97.8% and 34.5 mg/g, respectively. Adsorption isotherms of CFX onto PMNA were fitted well by the two-step adsorption model while adsorption kinetics of CFX followed the pseudo-second order. Based on the change in surface charge monitored by zeta potential, surface modification by FT-IR and adsorption isotherms, we suggest that CFX adsorption onto PMNA was induced by both electrostatic and non-electrostatic interactions but electrostatic attraction was dominant. The PMNA were reusable with high removal efficiency for CFX >96%. Removal efficiency for CFX in an actual hospital wastewater sample using PMNA achieved over 75%. Our results indicate that PMNA is a new and excellent adsorbent for antibiotic removal in wastewater treatment.

Adsorption characteristics of ciprofloxacin onto g-MoS2 coated biochar nanocomposites

The g-MoS2 coated biochar (g-MoS2-BC) composites were synthesized by coating original biochar with g-MoS2 nanosheets at 300°C(BC300)/700°C (BC700). The adsorption properties of the g-MoS2-BC composites for ciprofloxacin (CIP) were investigated with an aim to exploit its high efficiency toward soil amendment. The specific surface area and the pore structures of biochar coated g-MoS2 nanosheets were significantly increased. The g-MoS2-BC composites provided more it electrons, which was favorable in enhancing the it-it electron donor-acceptor (EDA) interactions between CIP and biochar. As a result, the g-MoS2-BC composites showed faster adsorption rate and greater adsorption capacity for CIP than the original biochar. The coated g-MoS2 nanosheets contributed more to CIP adsorption on the g-MoS2-BC composites due to their greater CIP adsorption capacity than the original biochar. Moreover, the synergistic effect was observed for CIP adsorption on g-MoS2-BC700, and suppression effect on g-MoS2-BC300. In addition, the adsorption of CIP onto g-MoS2-BC composites also exhibited strong dependence on the solution pH, since it can affect both the adsorbent surface charge and the speciation of contaminants. It was reasonably suggested that the mechanisms of CIP adsorption on g-MoS2-BC composites involved pore-filling effects, it-it EDA interaction, electrostatic interaction, and ion exchange interaction. These results are useful for the modification of biochar in exploiting the novel amendment for contaminated soils.

Engineering magnetic N-doped porous carbon with super-high ciprofloxacin adsorption capacity and wide pH adaptability

We report a high performance magnetic N-doped nanoporous carbon (MNPC) adsorbent synthesized by a simple single-step pyrolysis protocol. Grinding the mixture of ZnO nanoparticles, cobalt hydroxide and 2-methylimidazole produced Zn/Co-ZIFs that were converted into MNPC following subsequent pyrolysis in N2 atmosphere. The optimized MNPC-700-0.4 adsorbent, obtained at 700 °C with Co/(Zn + Co) molar ratio of 0.4, is featured with super-high ciprofloxacin (CIP) adsorption capacity of 1563.7 mg g−1 at 25 °C, fast adsorption dynamics (1.5 h of adsorption equilibrium time), wide pH adaptability (almost unchanged CIP adsorption capacity in pH 4–10), and good magnetic property. The magnetic property and CIP adsorption performance can be easily regulated by modulating the molar ratio of Co/(Zn + Co) and the pyrolysis temperature. The optimal MNPC-700-0.4 was chosen to explore adsorption kinetics and isotherm. The effects of pH, ionic strength and humic acid on CIP adsorption were investigated. CIP adsorption obeyed pseudo-second-order kinetics and well fitted the Langmuir adsorption model. The favorable textural properties (high surface area and pore volume), riched nitrogen structure and large amounts of defects endow the MNPC-700-0.4 lots of sites for CIP adsorption. The CIP adsorption onto MNPC-700-0.4 was mainly controlled by the electrostatic interaction, hydrophobic interaction, π-π stacking and hydrogen bond.

Porous three-component hybrid hydrogen-bonded covalent organic polymers: Design, synthesis and ciprofloxacin adsorption

Since the great risks posed by fluoroquinolones arise much concerns, it is required a prompt action to establish efficient adsorbents with excellent behaviors for adsorptive removal in remediation management. Herein, three porous three-component hybrid hydrogen-bonded covalent organic polymers were reasonably designed and successfully prepared via orthogonal reactions based on Schiff-base chemistry and hydrogen-bonding. The resulting polymers were used to remove a model fluoroquinolone antibiotic, ciprofloxacin (CIP), from wastewater. The benzene-1,3,5-tricarbohydrazide (BTCH) and 1,3-di(4-pyridyl)propane (BPP) reacted with 4,4′-biphenyldicarboxaldehyde (BPDA) (JLUE-HCOP-7) and exhibited the profound highest adsorption capacity for CIP as 84.03 mg/g, followed by the reaction of BTCH, BPP and terephthalaldehyde (TPA) (JLUE-HCOP-6), and the reaction of BTCH, 4,4′-bipyridine (BPY) and TPA (JLUE-HCOP-5). The adsorption processes were systematically investigated through batch adsorption experiments. Most of the CIP were removed within 12 h; moreover, the kinetic data and isothermal data were well fit with the pseudo 2nd order model and Langmuir model, respectively. In addition, the high adsorption affinity may be attributed to porousness advantage, electrostatic interactions, hydrophobic effect, electron donor–acceptor (EDA) interactions and hydrogen bonding.

Structural design of magnetic biosorbents for the removal of ciprofloxacin from water

Magnetic biosorbents with specific morphological and molecular structure (PMCCs) were designed for the removal of ciprofloxacin (CIP) from water. Radical polymerization method was applied to immobilize the designed polymer brushes onto core-shell shaped magnetic microspheres to fabricate PMCCs. PMCCs exhibited a maximum adsorption capacity of 527.93 mg·g−1, which is much higher than reported adsorbents, owing to the complete stretch of polymer brushes and increased active sites as well as enhanced interaction. The investigation on the adsorption behavior of PMCCs for CIP manifested that CIP adsorption well fitted the Langmuir isotherm model and pseudo-second-order kinetic model. The calculated thermodynamic parameters suggested that CIP adsorption onto PMCCs was spontaneous and exothermic. Further recycling experiments showed a loss of less than 20% in the CIP adsorption capacity after five times, demonstrating the reusability of the as-designed biosorbents.

Efficiently removal of ciprofloxacin from aqueous solution by MIL-101(Cr)-HSO3: the enhanced electrostatic interaction

Metal–organic frameworks (MOFs) have been widely used to remove organic/toxic compounds from waste water. Ciprofloxacin (CIP) has been detected in surface and waste water, which is harmful to aquatic organisms and human body. Herein, MIL-101(Cr)-HSO3 was synthesized by solvothermal method and its structural features were characterized by XRD, SEM, FTIR, N2 adsorption–desorption analysis at 77 K and zeta potential. Then, the CIP adsorption performance of MIL-101(Cr)-HSO3 was investigated, in which the effect of adsorbent dosage, contact time, pH and ionic strength were explored. MIL-101(Cr)-HSO3 showed the highest adsorption capacity when the adsorbent dosage was 0.1 g/L and the pH was 8.0. The observation from the effects of pH and ionic strength suggested a stronger electrostatic interactions between CIP and MIL-101(Cr)-HSO3. The pseudo-second-order model fitted the adsorption kinetics data of MIL-101(Cr)-HSO3 well. Moreover, the equilibrium adsorption data of MIL-101(Cr)-HSO3 followed the Langmuir model, indicating a mono-layer adsorption of CIP onto surface of MIL-101(Cr)-HSO3. The calculated maximum CIP adsorption capacity from Langmuir model was 564.9 mg/g, which was higher than the reported materials. Besides, the equilibrium adsorption data were fitted to the Tempkin model with r2 = 0.9880, which also suggested a stronger electrostatic interaction between CIP and MIL-101(Cr)-HSO3. Finally, the introduced sulfonic acid group made the material more negatively charged on the surface, which benefited the adoption of CIP via stronger electrostatic interactions resulting the enhanced adsorption capacity of CIP. The results show that the MIL-101(Cr)-HSO3 is a promising candidate for removal of CIP and introducing proper functional groups on organic linker is a convenient way to obtain MOFs with better performance for a specific application.

A novel Fe3O4/graphene oxide/citrus peel-derived bio-char based nanocomposite with enhanced adsorption affinity and sensitivity of ciprofloxacin and sparfloxacin

To create more active adsorption sites on biochar, the Fe3O4/GO/citrus peel-derived magnetic bio-nanocomposite (mGOCP) with hierarchically porous architectures was synthesized by a facile one-pot hydrothermal approach for efficient removal of fluoroquinolone antibiotics ciprofloxacin (CIP) and sparfloxacin (SPA). The characterization analysis of bio-nanocomposites showed that the incorporation of GO could ensure relatively higher surface area (1556 cm2 g−1), more abundant pore structure, and higher thermal stability within mGOCP bio-nanocomposites than Fe3O4/citrus peel-derived magnetic bio-nanocomposites (mCP). And the mGOCP-1% attained outstanding adsorption capacity for CIP (283.44 mg g−1) and SPA (502.37 mg g−1), respectively. The primary adsorption mechanisms for CIP and SPA included π-π electron donor-acceptor interaction, H-bonding, hydrophobic interaction and electrostatic interaction. Overall, the surface morphology and structural composition of biochars could be regulated with GO to facilitate the adsorption capacity. Moreover, the developed mGOCP could be extended as a potential adsorbent for removal of other emerging organic pollutants in water.

Ciprofloxacin desorption from gel type ion exchange resin: Desorption modeling in batch system and fixed bed column

The aim of this paper was to assess the desorption of ciprofloxacin (CIP) from the Supergel™ SGC650H resin and to evaluate the possibility of future reuse of the adsorbent by applying adsorption cycles. Preliminary desorption tests by using different aqueous HCl concentrations as eluent agents and adsorption experiments with the previously treated resin with these same solutions were carried out in batch system to determine the best eluent condition. Physico-chemical characterization tests were performed for virgin and HCl-treated resin, evidencing changes on the resin’s structure and functional groups caused by the eluents. The preliminary results showed that the HCl concentration of 2 mol L−1 provided both the CIP-desorption efficiency from the resin and the improvement of CIP adsorption capacity. Therefore, this eluent concentration was applied for the further equilibrium experiments in batch system. Mathematical modeling was applied to the kinetic and equilibrium desorption data obtained in batch system, evidencing that internal diffusion model showed a good agreement with the experimental data. Based on the estimated parameters from the independent batch experiments, the model was able to adequately predict the desorption kinetic behavior in fixed bed column. Overall, the results showed that the HCl aqueous solution of 2 mol L−1 could be efficiently applied to assess adsorption cycles, due to the high desorption efficiency combined with the enhancement of the resin’s capacity. Furthermore, the present work provided a robust and predictive mathematical model, which could support the design and the scale up of industrial level equipment.

Coating magnetic biochar with humic acid for high efficient removal of fluoroquinolone antibiotics in water

As antibiotics are widely consumed, fluoroquinolones (FQs) behave to have huge hidden danger to human health. Various agricultural residues have potential to produce biochar rich in porous structure for adsorption of contaminants. In this study, potato leaves and stems were pyrolyzed at 500 °C under anoxic condition for biochar (BC) preparation. At the same conditions, magnetic biochar (MBC) and humic acid (HA) coated magnetic biochar (HAB) were also prepared. In particular, characterizations of HAB showed the extensive coating of HA on MBC surface and introducing more oxygen-containing groups, which may promote the adsorption capacity of biochar. Three typical FQs (ciprofloxacin (CIP), norfloxacin (NOR) and enrofloxacin (ENR)) were used as target contaminants to further investigate the adsorption property of HAB. Compared with BC and MBC, novel adsorbent HAB due to introduction of HA exhibited better FQs adsorption ability, and its maximum adsorption capacity for CIP, NOR and ENR were 1.80, 1.67 and 1.70 times higher than those of MBC and were 3.40, 2.88, 2.96 times higher than those of raw BC, respectively. Pseudo-second-order kinetic model and Langmuir isotherm model could describe the process of FQs adsorbed on HAB more appropriately, and thermodynamic results illustrated that the sorption process was spontaneous and endothermic. In addition, FQs adsorption by HAB was increased with initial solution pH from 3.0 to 10.0, while it was slightly decreased with ionic strength rising (0.001–0.1 M CaCl2). Combined with FTIR results, high FQs removal efficiency could be attributed to electrostatic, hydrophobic, H-bond and π-π EDA interactions.

Graphene oxide & reduced graphene oxide polysulfone nanocomposite pellets: An alternative adsorbent of antibiotic pollutant-ciprofloxacin

ABSTRACTEfficient nanocomposites, GO-Psf and RGO-Psf has been synthesised from polysulfone and graphene oxide. The synthesised nanomaterials were characterised using contact angle measurements, SEM, TEM, XRD, TGA, DSC, Raman and FT-IR analytical techniques. The reported polymeric nanomaterials are attractive due to their high surface area and thermal stability. The maximum adsorption capacity for ciprofloxacin is 82.781 mg/g and 21.486 mg/g on GO-Psf and RGO-Psf, respectively. The kinetic and adsorption analysis identifies the nanomaterials as attractive adsorbents for removal of antibiotic pollutant, ciprofloxacin from aqueous solution.

ZIF-67 derived hollow cobalt sulfide as superior adsorbent for effective adsorption removal of ciprofloxacin antibiotics

The hollow nanostructures receive increasing attention in recent years. In particular, the confined cavity in the hollow nanostructures can function as a carrier for loading target molecules, whereas the porous walls are beneficial for shortening the transport distance of target molecules from solution to surface of adsorbent, making it possible to achieve high adsorption capacity with short adsorption time. Here, the hollow Co3S4 was synthesized by using ZIF-67 as template and thioacetamide as sulfide reagent through a simple solvothermal method, and characterized by SEM, TEM, HRTEM, XRD, FT-IR, zeta potential measurement, TG, N2 adsorption-desorption and XPS analysis. The adsorption performance of hollow Co3S4 for ciprofloxacin (CIP) antibiotics was evaluated in neutral aqueous solution. The equilibrium adsorption data were well fitted by Langmuir model, and a high maximum CIP adsorption capacity of 471.7 mg g−1 was obtained. The relatively high correlation coefficient of Tempkin model (r2 = 0.960) indicated a stronger electrostatic interaction between CIP and hollow Co3S4, which was consistent with the observation from the effects of pH and ionic strength. Result of adsorption kinetic investigation indicated fast CIP adsorption by hollow Co3S4. The adsorption kinetics follows the pseudo-second-order kinetic model and liquid-film diffusion model. CIP adsorption by hollow Co3S4 was hardly affected by humic acid. Further, the hollow Co3S4 exhibited no obvious loss in CIP removal after recycling for five times. The result displays an important environmental significance of hollow Co3S4 for CIP sequestration, in particular in wastewater, where CIP antibiotics are only slightly transformed or even unchanged.

Preparation of C@silica core/shell nanoparticles from ZIF-8 for efficient ciprofloxacin adsorption

Ciprofloxacin (CIP) in water is harmful to fish, human body and potentially harmful to ecological system, thus it needs to be removed. Adsorption is a simple treatment method, but the reported adsorbents rarely showed high adsorption performance. Herein, we present the preparation of a C@silica core/shell nanoparticles material for removal of CIP from aqueous solution. The nanoparticles were prepared by first coating a layer of silica gel on ZIF-8 nanoparticles via hydrolysis of tetraethoxysilane (TEOS), followed by carbonization. XRD, FT-IR, TEM, and N2 adsorption–desorption analysis were employed to examine the obtained products. TEM images clearly show the core/shell structures with a thickness of the silica layer of 13–28 nm. N2 adsorption–desorption results exhibit the textural properties of the products with both micro- and meso-pores and a high surface area of 594.4 m2/g. More CIP amount can be adsorbed from water with higher surface area. The equilibrium adsorption amount reaches a climax at pH 6. The maximum CIP adsorption amount of the C@silica core/shell nanoparticles is 516.8 mg/g, much higher than the parental carbon. In addition, the maximum CIP adsorption amount is significantly increased to 1575 mg/g with the presence of Cu(II) in the aqueous solution. We investigated the mechanism for the increased adsorption capacity of the C@silica core/shell nanoparticles materials, indicating that the silica coating makes these nanoparticles more negatively charged and thus benefits the adsorption of CIP via stronger electrostatic interaction. The C@silica nanoparticles can be easily prepared and their CIP adsorption capacity is very high. The results show that the C@silica nanoparticles are promising candidates for removal of CIP from water.

Cu(II)-influenced adsorption of ciprofloxacin from aqueous solutions by magnetic graphene oxide/nitrilotriacetic acid nanocomposite: Competition and enhancement mechanisms

Nitrilotriacetic acid-functionalized magnetic graphene oxide (NDMGO) was developed for the removal of ciprofloxacin (CIP) with and without the presence of Cu(II). The physicochemical properties of NDMGO were characterized using SEM, TEM, XRD, FI-IR, XPS and zeta potential measurements. The CIP adsorption process could be better simulated by the pseudo-second-order kinetics and Freundlich isotherm model. Effects of Cu(II) concentrations on CIP uptake, as well as the influence of pH, ionic strength, background electrolyte and the addition sequences of CIP/Cu(II) were investigated. Adsorption results exhibited that the presence of Cu(II) obviously enhanced the CIP adsorption capability through Cu(II) bridging effect. The adsorption capacity for CIP was stronger in the (CIP-Cu(II))-NDMGO system than in the (NDMGO-Cu(II))-CIP and (NDMGO-CIP)-Cu(II) systems. Meanwhile, this nanomaterial showed high performance for Cu(II) adsorption. In addition to Cu(II) bridge enhancement, the mechanism could also be explained by hydrogen bonds, amidation reaction, electrostatic and π-π interaction. These results provided valuable information for the removal of CIP and improved our understanding on reaction mechanism of antibiotics by NDMGO in the presence of metal ions, demonstrated that NDMGO could be developed as an effective adsorbent to simultaneously removal metal ions and organic substances.

Study of ciprofloxacin adsorption and regeneration of activated carbon prepared from Enteromorpha prolifera impregnated with H3PO4 and sodium benzenesulfonate

Activated carbons were derived from Enteromorpha prolifera immersed in H3PO4 solution or the H3PO4 solution mixed with sodium benzenesulfonate (SBS), producing AC and AC-SBS. NaOH solution was employed in regeneration of ciprofloxacin (CIP)-loaded AC and AC-SBS to obtain RAC and RAC-SBS. The properties of the original and regenerated activated carbons were characterized by thermo-gravimetric analysis (TGA), scanning electron microscopy (SEM), N2 adsorption/desorption isotherms and Fourier transform infrared spectroscopy (FTIR). Batched adsorption studies were carried out to compare CIP adsorption behaviors of the four carbons. The results suggested that the four samples exhibited higher proportions of mesopores and similar functional groups. Although AC displayed much higher specific surface area (SBET) (1045.79m2/g) than AC-SBS (738.03m2/g), its CIP adsorption capacity was much less than AC-SBS. The maximum adsorption capacity for AC, AC-SBS, RAC and RAC-SBS were found to be 250mg/g, 286mg/g, 233mg/g and 256mg/g, respectively, with the isotherms adhering to Langmuir isotherm model. The electrostatic attraction and cation exchange between CIP and the four carbons were the dominant adsorption mechanisms. Moreover, the thermodynamic parameters represented that the adsorption process had been confirmed to be a spontaneous and endothermic reaction.

Zeolitic imidazolate framework-8 derived nanoporous carbon as an effective and recyclable adsorbent for removal of ciprofloxacin antibiotics from water

The nanoporous carbons (NPC) derived from a one-step carbonization of zeolitic imidazolate framework-8 (ZIF-8) were synthesized and used for ciprofloxacin (CIP) removal from water. The resultant products were characterized by SEM, TEM, FT-IR, Raman, N2 adsorption-desorption analysis, XRD, TGA and Zeta potential. The optimized NPC-700 (carbonized at 700°C for 2h) exhibited an optimal performance in CIP adsorption removal. CIP adsorption on NPC-700 as a function of contact time, initial CIP concentration, adsorbent dosage, pH, ionic strength and humic acid concentration were investigated. Kinetics of CIP removal was found to follow pseudo-second-order rate equation. Both Langmuir and Freundlich models fitted the adsorption data well and gave similar correlation coefficients (>0.96). However, Freundlich isotherm gave a better fit (r2=0.9969), suggesting a multilayer adsorption of CIP onto surface of NPC-700 adsorbent. The maximum adsorption capacity for CIP based on Langmuir model was 416.7mg/g, which was higher than those of other adsorbents. The NPC-700 material showed no apparent loss in CIP adsorption after seven cycles. These features reveal that the metal-organic framework (MOF) derived NPC may be a promising adsorbent for CIP removal from water.

Enhanced adsorptive removal of selected pharmaceutical antibiotics from aqueous solution by activated graphene.

Activated graphene adsorbents (G-KOH) were synthesized by a one-step alkali-activated method, with a high specific surface area (SSA) and a large number of micropores. As a result, the SSA of the final product greatly increases to ∼512.6m(2)/g from ∼138.20m(2)/g. The resulting G-KOH was used firstly as an adsorbent for the removal of ciprofloxacin (CIP) in aqueous solutions. Experimental results indicated that G-KOH has excellent adsorption capacity (∼194.6mg/g). The alkali-activation treatment introduced oxygen-containing functional groups on the surface of G-KOH, which would be beneficial to improving the adsorption affinity of G-KOH for the removal of CIP. Kinetic regression results showed that the adsorption kinetic was more accurately represented by a pseudo-second-order model. The overall adsorption process was jointly controlled by external mass transfer and intra-particle diffusion, and intra-particle diffusion played a dominant role. A Langmuir isotherm model showed a better fit with adsorption data than a Freundlich isotherm model for the adsorption of CIP on G-KOH. The remarkable adsorption capacity of CIP onto G-KOH can be attributed to the multiple adsorption interaction mechanisms (hydrogen bonding, π-π electron donor-acceptor interactions, and electrostatic interactions). Results of this work are of great significance for environmental applications of activated graphene with higher SSA as a promising adsorbent for organic pollutants from aqueous solutions.

Surface molecularly imprinted polymers based on yeast prepared by atom transfer radical emulsion polymerization for selective recognition of ciprofloxacin from aqueous medium

ABSTRACTTo achieve selective recognition of water‐soluble ciprofloxacin (CIP), an effective method was developed for the preparation of surface molecularly imprinted polymers based on the yeast particles (yeast@MIPs) via atom transfer radical emulsion polymerization (ATREP). The reactions were carried out in the nontoxic and green emulsion system at room temperature, which was environment friendly with low energy consumption. In this study, the yeast, for the advantages of low cost, easily available source and abundant active groups on the cell wall, was selected as an ideal biological support substrate. The prepared yeast@MIPs was characterized by FT‐IR, SEM, TEM, EDS, and elemental analysis techniques. Batch mode adsorption studies were carried out to investigate the specific adsorption equilibrium, kinetics, selective recognition, and reuse ability of yeast@MIPs. The experimental static adsorption data of CIP on to yeast@MIPs were well‐described by Langmuir, Freundlich, and pseudo‐second‐order models. The maximum static adsorption capacity for CIP of yeast@MIPs was 18.48 mg g−1, and the adsorption equilibrium could be reached in 60 min. The selectivity coefficients for CIP relative to enrofloxacin, tetracycline, and sulfadiazine were 1.212, 2.002, and 10.65, which demonstrated CIP of high affinity and selectivity over three competitive antibiotics. In addition, the reusability of the material without obvious deterioration (8.52% loss) in performance was observed at least four repeated cycles. And the yeast@MIPs was used to determine CIP from spiked shrimp samples by HPLC analysis. These results showed that yeast was a well‐defined substrate and ATREP was a promising technique for the preparation of surface molecularly imprinted polymers targeting templates. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40310.

Adsorption of ciprofloxacin on surface functionalized superparamagnetic porous silicas

The effect of surface functional groups 3-aminopropyltriethoxy- and 4-(triethoxysilyl)-butyronitrile-, 3-mercaptopropyltriethoxy-, phenyltrimethoxy-, and n-octyl-dimethoxychloro- grafted superparamagnetic particles coated with hexagonal mesoporous silicas (HMS-SPs) on the adsorption of ciprofloxacin (CIP) was evaluated. CIP adsorption followed the pseudo-second-order kinetic model, and intraparticle diffusion was suggested to be the rate-controlling step. Higher CIP adsorption capacities revealed on the hydrophobicity of the adsorbents, however, the phenyltrimethoxy group had the highest adsorption capacity due to the interaction of ¶–¶ electron-donor acceptors. The adsorption capacities strongly depended on an electrostatic interaction, with the exception of the phenytrimethoxy group. The presence of tannic acid (TA) could increase the adsorption capacity of CIP on adsorbent surfaces by multilayer adsorption between a positively charged amine group of CIP and negatively charged TA.

Comparison of activated carbons from Arundo donax Linn with H4P2O7 activation by conventional and microwave heating methods

The pore structure, chemical properties and adsorption behavior of activated carbons (ACs) derived from Arundo donax Linn using H4P2O7 activation by conventional (AAC) and microwave heating methods (MAAC) were compared. AAC was produced by carbonizing/activating at 600°C for 1h in a muffle furnace. MAAC was prepared with radiation power of 700W and radiation time of 15min. N2 adsorption/desorption isotherms, Boehm titration, Fourier-transform infrared spectroscopy (FTIR) and adsorption capacity of ciprofloxacin (CIP) were used for this purpose. MAAC exhibited larger surface area (1567m2/g) and larger micropore surface area (631m2/g). Results from Boehm’s titration and Fourier-transform infrared spectra suggested that AAC was characteristic of more acidic functionalities than MAAC. It was shown that AAC presented better performance for CIP adsorption per unit surface area. The influence of the textural and surface properties of the adsorbents on the CIP adsorption was discussed.