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The structural and electronic properties, such as adsorption energy, magnetic property, and charge-transferring process of Nin (n = 1-6) clusters interacting with pristine, strained and defective graphene were investigated by using the density functional theory calculations with the Perdew-Burke-Ernzerhof exchange-correlation energy functional. By introducing strain and defects, the stability of the cluster-graphene system was improved significantly. The magnetic moments increased monotonically for Nin clusters on pristine and strained graphene while exhibited an oscillating behaviour for defective graphene. On the other hand, more charges being transferred from Nin clusters to defective graphene were observed compared with pristine and strained graphene. [ABSTRACT FROM AUTHOR]

[Display omitted] • In-situ cellulose mineralization in homogeneous system improves dispersion of TiO 2. • The excellent and pH-sensitive adsorption capacity of microsphere is obtained. • The microsphere exhibits an auto-accelerating degradation on Rhodamine B. • The intermediate-adsorbed microsphere obtains visible light responsive property. It is a daunting task to balance the catalyst stability and exposure of active site of highly efficient immobilizing photocatalyst system for wastewater treatment. In this study, an in-situ mineralization method based on homogeneous system was proposed to directly construct amorphous TiO 2 into cellulose hydrogel network as the crosslinker for efficiently and safely processing wastewater. This unique structure not only endowed TiO 2 /cellulose microsphere (TMS) with an adsorption capacity of 91.7 mg/g on methylene blue, which was approximately 14 times to cellulose microsphere containing commercial TiO 2 nanoparticles, but also made TMS reusable due to its pH sensitive adsorption capacity. More interestingly, TMS exhibited an auto-accelerating process in decomposing Rhodamine B where the degradation intermediate could act as the receptor of photo-regenerated holes to improve photocatalytical activity. In further cyclic test, the degradation rate constant of intermediate-adsorbed TMS was up to 0.02 mg−1min−1. Moreover, the intermediate-adsorbed TMS obtained visible light responsive property, including a removal ratio of 86.3 % against tetracycline (c 0 = 20 mg/L) in 120 min. This in-situ cellulose mineralization provides a new sight into the design of hydrogel immobilized catalyst system with high dispersion and active site exposure for efficient and safe water treatment. [ABSTRACT FROM AUTHOR]

Abstract: Titania film imprinted by bilirubin molecule at the surface of quartz crystal was prepared using molecular imprinting and surface sol–gel process. The molecularly imprinted titania film was characterized by FTIR spectra, and the interaction between bilirubin and imprinted film was investigated using quartz crystal microbalance (QCM) technique. Compared with pure titania film, the molecularly imprinted titania film exhibits a much higher adsorption capacity for the target molecule, and the adsorption kinetic parameter estimated from the in situ frequency measurement is about 1.6×108 M−1, which is ten times higher than that obtained on pure titania film. The photocatalytic measurements indicate that the bilirubin adsorbed on molecularly imprinted titania film can be completely removed under UV illumination. Moreover, our study indicates that the molecularly imprinted titania film possesses a better stability and reusability. [Copyright &y& Elsevier]

The effects of pH, initial concentration and temperature on the adsorption of phenol by chitosan are investigated in this paper. The isothermal data was applied to Langmuir linear and the Freundlich linear isotherm equation, and the thermodynamic parameters (ΔH, ΔG, ΔS) were calculated according to the values of binding Langmuir constant, KL. Results indicated that the adsorption between chitosan and phenol was significantly physical in nature, the negative ΔH constant at lower temperature confirmed that more phenol was adsorbed by chitosan at lower temperature. The kinetics of the sorption process of phenol on chitosan was investigated using the pseudo-first order and pseudo-second order kinetics, and results showed that the second order equation model provided the best correlation with the experimental results. [ABSTRACT FROM AUTHOR]

The adsorption behaviors of 1-naphthol, 1-naphthylamine and 1-naphthol/1-naphthylamine mixtures in water over two macroreticular adsorbents were investigated in single or binary batch systems at 293 K, 303 K and 313 K respectively. All the adsorption isotherms in the studied systems can be adequately fitted by Langmuir model. In the case of aminated macroreticular adsorbent NDA103, 1-naphthol is adsorbed to a larger extent than 1-naphthylamine; while, the opposite trend is found for nonpolar macroreticular adsorbent NDA100. It is noteworthy that at higher temperature (303 K and 313 K), the total uptake amounts of 1-naphthol and 1-naphthylamine in all binary-component systems are obvious larger than the pure uptake amounts in single-component systems, which is presumably due to the cooperative effect primarily arisen from the hydrogen-bonding interaction between the loaded 1-naphthol and 1-naphthylamine molecules. The simultaneous adsorption systems were confirmed to be helpful to the selective adsorption towards 1-naphthol according to the larger selective index. [ABSTRACT FROM AUTHOR]

The adsorption behaviors of 2-naphthalenesulfonic acid and aniline on a conventional macroporous resin Amberlite XAD4 and the other two newly-developed hypercrosslinked resins NDA101 and NDA100 were investigated in a single or binary batch system at 293 K and 313 K, respectively. All the adsorption isotherms of 2-naphthalenesulfonic acid and aniline on the test resins in both systems can fit well with the Langmuir equation, indicating that the adsorption is a favorable process. At the identical equilibrium concentration, the amount of aniline adsorbed on polymeric resins in the single system is higher than that in the binary system because of the competitive adsorption between 2-naphthalenesulfonic acid and aniline on the resin surface. However, the uptake amount of 2-naphthalenesulfonic acid in the binary system is markedly larger than that in the single system, which is presumably due to the cooperative effect arisen from the electrostatic interaction between 2-naphthalenesulfonic acid and aniline adsorbed on the resin surface. The simultaneous adsorption system was proven to be helpful for the selective adsorption toward 2-naphthalenesulfonic acid due to its larger selective index. [ABSTRACT FROM AUTHOR]

The adsorption behaviors of phenol and aniline on nonpolar macroreticular adsorbents (NDA100 and Amberlite XAD4) were investigated in single or binary batch system at 293K and 313K respectively in this study. The results indicated that the adsorption isotherms of phenol and aniline on both adsorbents in both systems fitted well Langmuir equation, which indicated a favourable and exothermic process. At the lower equilibrium concentrations, the individual amount adsorbed of phenol or aniline or macroreticular adsorbents in single-component systems was higher than those in binary-component systems because of the competition between phenol and aniline towards the adsorption sites. It is noteworthy, on the contrast, that at higher concentrations, the total uptake amounts of phenol and aniline in binary-component systems were obviously larger than that in single-component systems, and a large excess was noted on the adsorbent surface at saturation, which is presumably due to the cooperative effect primarily arisen from the hydrogen bonding or weak acidbase interaction between phenol and aniline. [ABSTRACT FROM AUTHOR]

Single and binary adsorption behaviors of salicylic acid and 5-sulfosalicylic acid onto hypercrosslinked polymeric adsorbents, i.e. NDA-101 and NDA-99 were investigated. The Freundlich model can successfully describe all the adsorption isotherms tested, which indicates a favorable and exothermic adsorption process. The adsorption of salicylic acid relies on π-π interaction, while the electrostatic interaction further influences the adsorption of 5-sulfosalicylic acid onto NDA-99. The adsorptive capacity of salicylic acid on NDA-99 decreases but increases on NDA-101 with 5-sulfosalicylic acid as the background component in a binary solute system. The amount of 5-sulfosalicylic acid adsorbed was decreased with the increase in initial concentration of salicylic acid on both adsorbents. The competition for the adsorption sites is considered to be predominant in the solid-to-liquid interaction process. The adsorption selectivity of salicylic acid onto NDA-101 is higher than onto NDA-99 by more than an order of magnitude. Thus, combination technique involving NDA-101 followed by NDA-99 can be effectively applied to separate and recover salicylic acid and 5-sulfosalicylic acid from wastewater. [ABSTRACT FROM AUTHOR]

The adsorption behavior of pesticide 2,4-dichlorophenoxyacetic acid (2,4-D) in aqueous solution has been investigated using a hypercrosslinked polystyrene adsorbent (NDA-99) modified by dimethylamine group as well as a nonionic macroporous adsorbent (XAD-4). The Langmuir and Freundlich isotherm models were employed to fit the experimental data to describe adsorption mechanism. It shows that NDA-99 resin exhibits an adsorption affinity for 2,4-D higher than XAD-4 resin owing to its exceptional micropore structure and the amine group of the hypercrosslinked matrix. Further studies indicate that the hydrogen bonding interaction and the stronger π-π conjugation play a significant role in the course of the adsorption of 2,4-D on NDA-99 resin, which is in agreement with the IR spectroscopic results and the ΔE values of HOMO (the highest occupied molecular orbit) of adsorbent and LUMO (the lowest unoccupied molecular orbit) of adsorbate calculated from the MINDO/3 model. [ABSTRACT FROM AUTHOR]

In this paper, the adsorption behaviors of phenol on polymeric adsorbents (Amberlite XAD4, NDA101, and D301) were investigated in batch system at 293, 303, and 313 K, respectively. As the results shown, the adsorption isotherms of phenol on all adsorbents can be well fitted by Langmuir and Freundlich equations, which indicate a favorable and exothermic process. The adsorption capacity on a newly developed aminated adsorbent, NDA101, on which adsorption could be achieved by both hydrogen bonding interaction and π-π interaction, are higher than that on a weak base adsorbent, D301, on which adsorption could be achieved by hydrogen bonding interaction only, and on a nonpolar adsorbent, XAD4, on which adsorption could be achieved by π-π interaction only. The results of this paper indicate that the synergistic effect of some weak interactions, which occur simultaneously would contribute more to the adsorption than that occur individually. [ABSTRACT FROM AUTHOR]

Adsorption of catechol from aqueous solution with the hypercrosslinked polymeric adsorbent NDA-100 and its derivatives AH-1, AH-2 and AH-3 aminated by dimethylamine, the commercial resin Amberlite XAD-4 and weakly basic anion exchanger resin D301 was compared. It was found that the aminated hypercrosslinked resins had the highest adsorption capacities among the tested polymers. The empirical Freundlich equation was successfully employed to describe the adsorption process. Specific surface area and micropore structure of the adsorbent, in company with tertiary amino groups on matrix affected the adsorption performance towards catechol. In addition, thermodynamic study was carried out to interpret the adsorption mechanism. Kinetic study testified that the tertiary amino groups on the polymer matrix could decrease the adsorption rate and increase the adsorption apparent activation energy. [ABSTRACT FROM AUTHOR]

An experimental comparison of the adsorption properties of hypercrosslinked resin AM-l modified by phenolic hydroxyl group with Amberlite XAD-4 toward 2.4-dichlorobenzoxyacetic acid was performed. This paper focuses on the static equilibrium adsorption behaviors and the adsorption thermodynamics. Two isotherm models were used to explain the results. It is seen that the Langmuir equation can give a perfect fit. The adsorption capacities from the different ranges of temperature, the adsorption enthalpy change value and the comparison of desorption conditions lead to the same conclusion that the adsorption of 2,4-dichlorobenzoxyacetic acid from water onto AM-l is a type of physical and chemical transition. [ABSTRACT FROM AUTHOR]

In this paper two newly developed hypercrosslinked resins were used to treat micropolluted drinking water and their static and kinetic adsorption were investigated at 293 K. The results show that these two adsorbents are superior to Amberlite XAD-4 for removing chloroform and trichioroethylene in aqueous solutions. The breakthrough capacity and the total capacities from mini-column adsorption studies for chloroform and triclitoroethylene on XAD-4, ZH-01 and ZH-00 are calculated respectively under experimental conditions. [ABSTRACT FROM AUTHOR]

An aminated hype rcrosslinked macroporous polymeric adsorbent was synthesized and characterized. Adsorption isotherms for 1-amino-2-naphthol-4-sulfonic acid (1, 2, 4-acid) and 2-naphthol obtained from various binary adsorption environments can be well fitted by Freundlich equation, which indicated a favorable adsorption process in the studied range. Adsorption for 1, 2, 4-acid was an endothermic process in comparison with that for 2- naphthol of an exothermic process. 2-naphthol molecules put a little influence on the adsorption capacity for 1, 2, 4- acid. However, the adsorption to 1, 2, 4-acid depressed that to 2-naphthol in a large extent for the stronger electrostatic interaction between 1, 2, 4-acid and adsorbent. The predominant mechanism can be contributed to the competition for adsorption sites. And the simultaneous environment was confirmed to be helpful to the selective adsorption towards 1,2,4-acid based on the larger selectivity index. [ABSTRACT FROM AUTHOR]

Studies properties and thermodynamics of adsorption of benzoic acid onto XAD-4 and a water-compatible hypercrosslinked adsorbent. Comparison of adsorbing capacity for benzoic acid and Amberlite XAD-4; Enthalpy and free energy changes of adsoprtion manifesting physical sorption process; Demonstration of adsorbing capacity of hypercrosslinked polymeric adsorbent to benzoic acid as compared to that of Amberlite XAD-4.

Abstract: Adsorption equilibrium isotherms of phenolic compounds, phenol, p-cresol, p-chlorophenol and p-nitrophenol, from aqueous solutions by Amberlite XAD-4 polymeric adsorbent and its acetylized derivative MX-4 within temperature range of 283-323K were obtained and fitted to the Freundlich isotherms. The capacities of equilibrium adsorption for all four phenolic compounds from their aqueous solutions increased around 20% on the acetylized resin, which may be contributed to the specific surface area and the partial polarity on the network. Estimations of the isosteric enthalpy, free energy, and entropy for the adsorption process were reported. [ABSTRACT FROM AUTHOR]

The cellulase produced by Trichoderma sp. was characterized by investigating the adsorption and enrichment of U and the physiological response to U exposure. The effects of U exposure (0 and 400 μM) on the growth, morphological characteristics, cellulase production, U adsorption, and U enrichment capacity of the Trichoderma strain were assessed. The effects of U exposure on the basic metabolism of this fungus were also analyzed by non-targeted metabolomics. Exposure to U (400 μM) for 24 h resulted in OD 600 turbidity of 0.278, and activities of carboxymethyl cellulase (CMC), filter paper enzyme (FPA), and β-glucosidase of 12834 U·mL−1, 9285 U·mL−1, and 12574 U·mL−1, respectively. The measurement of the background α and β radioactivity showed an α activity concentration of 3.35 × 106 Bq·kg−1 in the fungus, a β activity concentration of 6.28 × 105 Bq·kg−1, and a U enrichment rate of 70.4 ± 4.5%. GC-MS metabolomics analysis identified a total of 319 metabolites (34 up-regulated and 30 down-regulated), which mainly caused the metabolic imbalance of organic acids and derivatives. The alanine, aspartate, and glutamate metabolic pathways were the most significantly enriched. Trichoderma sp. therefore has a strong ability to tolerate/accumulate U and continues to produce cellulase under U (400 μM) exposure. However, U interferes with the basic metabolism of this fungus. • Trichoderma sp. has a strong ability to tolerate/accumulate U and continues to produce cellulase under U (400 μM) exposure. • U exposure mainly leads to an imbalance in the metabolism of organic acids and derivatives in cells. • U exposure leads to a significant imbalance in the enrichment pathways of alanine, aspartate and glutamate metabolism. [ABSTRACT FROM AUTHOR]

Abstract: The adsorption behavior of p-aminobenzoic acid and o-aminobenzoic acid onto the different polymeric adsorbents was systematically investigated as a function of the solution concentration and temperature. Experimental results indicated that the equilibrium adsorption data of the four polymeric adsorbents fitted well in the Freundlich isotherm. The adsorption capacity of multi-functional polymeric adsorbent NJ-99 was the highest, which might be attributed to the strong hydrogen-bonding interaction between the amino groups on the resin and the carboxyl group of aminobenzoic acid. The adsorption capacity of o-aminobenzoic acid onto any adsorbent was higher than p-aminobenzoic acid. Thermodynamic studies suggested the exothermic, spontaneous physical adsorption process. Adsorption kinetics results showed that the adsorption followed the pseudo-second-order kinetics model and the intraparticle mass transfer process was the rate-controlling step. [Copyright &y& Elsevier]

Abstract: Phenol and cresol (o-, m-, and p-) were selected as the adsorbates with different dipole moment (cresol>phenol, methyl being electron-drawing group) and solubility (phenol>cresol, methyl being hydrophobic group). Macropore polymers (NDA-1800 and XAD-4), hypercrosslinked polymers (NDA-100), and chemically modified adsorbents (NDA-150 and NDA-99), were comparatively used to investigate the adsorption properties including equilibria, thermodynamics and kinetics. First, all of the results about equilibria show that the adsorption data fit well to the Freundlich model. The adsorption capacity of NDA-99 and NDA-150 especially for phenol is larger in a certain extent than other three types of polymers. The hydrophobic interaction from large specific surface was mainly occurred, while the polar groups containing oxygen and amine markedly enhance the adsorption process via hydrogen interaction. Furthermore, the adsorption amount for NDA-99 and XAD-4 decrease linearly with the solubility of solutes tested. Then, the negative values of enthalpy demonstrate the predominantly exothermic and physical solid-extraction processes. Finally, the relatively more rapid adsorption process could be found onto NDA-150 than NDA-99, with the reason of the double larger pore size of the former. In conclusion, solubility of solute, together with surface area, pore size and modified groups, extremely exerts influences to the adsorption performances. [Copyright &y& Elsevier]

The adsorption equilibrium isotherms of three aromatic sulfonic acid compounds, 2-naphthalenesulfonic acid, p-toluenesulfonic acid and p-chlorobenzenesulfonic acid, from aqueous solutions by maeroporous weak base anion exchanger within the temperature range of 293 K-313 K were obtained. Several isotherm equations were correlated with the equilibrium data, and the experimental data was found to fit the three-parameter Redlich-Peterson equation best within the entire range of concentrations. The study showed that the hydrophobicity of solute has distinct influence on adsorption capacity of the anion exchanger for the aromatic sulfonic acid. Moreover, estimations of the isosteric enthalpy, free energy, and entropy change of adsorption were also reported. The positive isosteric enthalpy and entropy change for adsorption indicate an endothermic and entropy driven process in the present study. [ABSTRACT FROM AUTHOR]

Equilibrium data for the adsorption of phenolic compounds, i.e., phenol p-cresol p-chlorophenol and p- nitrophenol from aqueous solutions by a water-compatible hypercrosslinked polymeric adsorbent (N J-8) within temperature range of 283–323 K were obtained and correlated with a Freundlich-type of isotherm equation, so that equilibrium constants KF and n were obtained. The capacities of equilibrium adsorption for all the four phenolic compounds on the NJ-8 from aqueous solutions are around 2 times as high as those of Amberlite XAD-4, which may be attributed to the unusual micropore structure and the partial polarity on the network The values of the enthalpy (always negative) are indicative of an exothermic process, which manifests the adsorption of all the four phenolic compounds on the two polymeric adsorbents to be a process of physical adsorption. The negative values of free energy change show that the solute is more concentrated on the adsorbent than in the bulk solution. The absolute free energy values of adsorption tot NJ-8 are always higher than those for Amberlite XAD-4, which indicates that phenolic compounds are preferentially adsorbed on NJ-8. The negative values of the adsorption entropy arc consistent with the restricted mobilities of adsorbed molecules of phenolic compounds ms compared with the molecules in solution. The adsorption entropy values of phenolic compounds for NJ-8 are lower than those for Amberlite XAD-4, which means the micropores of NJ-8 require more orderly arranged adsorbate. [ABSTRACT FROM AUTHOR]