A novel holmium-based porous metal-porphyrin framework, {(H3 O+ )[Ho(H2 TPPS)]- ⋅ 4H2 O}n (denoted as UPJS-17), was synthesised by hydrothermal reaction. Structural analysis reveals, that UPJS-17 has a three-dimensional open framework. The framework is negatively charged and the negative charge is compensated by hydronium cation. The compound showed no N2 adsorption but the Ar, CO2 and H2 . From the argon adsorption, the surface area of ~150 m2 g-1 was determined. Carbon dioxide adsorption was measured at various temperatures (0, 10, 20, 30 and 40 °C) and the compound showed the highest adsorption capacity (at 0 °C) of 7.0 wt % of CO2 . From the carbon dioxide adsorption isotherms the isosteric heat of 56,5 kJ mol-1 was determined. Hydrogen adsorption was studied at -196 °C with hydrogen uptake of 2.1 wt % at 1 bar.

• Klíčová slova
• carbon dioxide adsorption, hydrogen adsorption, isosteric heats, metal-organic frameworks, metal-porphyrin frameworks,
• Publikační typ
• časopisecké články MeSH

From the beginning of molecular theory, the interplay of chirality and magnetism has intrigued scientists. There is still the question if enantiospecific adsorption of chiral molecules occurs on magnetic surfaces. Enantiomer discrimination was conjectured to arise from chirality-induced spin separation within the molecules and exchange interaction with the substrate's magnetization. Here, it is shown that single helical aromatic hydrocarbons undergo enantioselective adsorption on ferromagnetic cobalt surfaces. Spin and chirality sensitive scanning tunneling microscopy reveals that molecules of opposite handedness prefer adsorption onto cobalt islands with opposite out-of-plane magnetization. As mobility ceases in the final chemisorbed state, it is concluded that enantioselection must occur in a physisorbed transient precursor state. State-of-the-art spin-resolved ab initio simulations support this scenario by refuting enantio-dependent chemisorption energies. These findings demonstrate that van der Waals interaction should also include spin-fluctuations which are crucial for molecular magnetochiral processes.

• Klíčová slova
• CISS, chirality, enantiospecific adsorption, magnetic surfaces, van der Waals interactions,
• Publikační typ
• časopisecké články MeSH

Two selected waste building sludges (WBS) were used in this study: (i) sludge from the production and processing of prestressed concrete pillars (B) and (ii) sludge from the production of technical stone (TS). The materials were used in their original and Fe-modified forms (BFe/TSFe) for the adsorption of NH4+ and PO43- from contaminated waters. The experiments were performed on a model solution simulating real wastewater with a concentration of 1.7 mmol·L-1 (NH4+) and 0.2 mmol·L-1 (PO43-). The adsorption of PO43- had a high efficiency (>99%) on B, BFe and TSFe, while for TS, the adsorption of PO43- was futile due to the high content of available P in the raw TS. The adsorption of NH4+ on all sorbents (B/BFe, TS/TSFe) had a lower efficiency (<60%), while TS proved to be the most effective. Leaching tests were performed according to the CSN EN 12457 standard for B/BFe and TS/TSFe before and after NH4+ and PO43- sorption when the contents of these ions in the leachates were affected by adsorption experiments in the cases of B and TS. For BFe and TSFe, the ion content in the leachates before and after the adsorption experiments was similar.

• Klíčová slova
• Fe-modification, adsorption, waste building sludge,
• Publikační typ
• časopisecké články MeSH

Protein adsorption behavior was examined on poly(N-isopropylacrylamide-co-sodium methacrylate)-based hydrogels at different temperatures: 5, 20, and 37 °C, and pH: 4.5, 7, and 9.2. The hydrogels, whose covalent skeleton contains pendant anionic units due to the presence of the sodium methacrylate co-monomer, exhibited both thermo- and pH-sensitivity with different extents, which depended on the content of ionizable moieties and the cross-linker density. The hydrogel composition, temperature, and pH influenced the zeta potential of the hydrogels and their swelling properties. The proteins selected for the study, i.e., bovine serum albumin (BSA), ovalbumin (OVA), lysozyme (LYZ), and a monoclonal antibody (mAb2), differed in their aminoacidic composition and conformation, thus in isoelectric point, molecular weight, electrostatic charge, and hydrophobicity. Therefore, the response of their adsorption behavior to changes in the solution properties and the hydrogel composition was different. LYZ exhibited the strongest adsorption of all proteins with a maximum at pH 7 (189.5 mg ggel-1); adsorption of BSA and OVA reached maximum at pH 4.5 (24.4 and 23.5 mg ggel-1), whereas mAb2 was strongly adsorbed at 9.2 (21.7 mg ggel-1). This indicated the possibility of using the hydrogels for pH-mediated separation of proteins differing in charge under mild conditions in a water-rich environment of both the liquid solution and the adsorbed phase. The adsorption affinity of all proteins increased with temperature, which was attributed to the synergistic effects of attractive electrostatic and hydrophobic interactions. That effect was particularly marked for mAb2, for which the temperature change from 5 to 37 °C caused a twentyfold increase in adsorption. In all cases, the proteins could be released from the hydrogel surface by a reduction in temperature, an increase in pH, or a combination of both. This allows for the elimination of the use of salt solution as a desorbing agent, whose presence renders the recycling of buffering solutions difficult.

• Klíčová slova
• hydrogels, pH sensitivity, protein adsorption, protein release, temperature-sensitivity,
• MeSH
• adsorpce MeSH
• hydrofobní a hydrofilní interakce MeSH
• hydrogely * chemie   MeSH
• koncentrace vodíkových iontů MeSH
• monoklonální protilátky chemie   MeSH
• muramidasa chemie   MeSH
• ovalbumin chemie   MeSH
• proteiny chemie   MeSH
• sérový albumin hovězí * chemie   MeSH
• teplota * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• hydrogely * MeSH
• monoklonální protilátky MeSH
• muramidasa MeSH
• ovalbumin MeSH
• proteiny MeSH
• sérový albumin hovězí * MeSH

We present a combined experimental and theoretical quantification of the adsorption enthalpies of seven organic molecules (acetone, acetonitrile, dichloromethane, ethanol, ethyl acetate, hexane, and toluene) on graphene. Adsorption enthalpies were measured by inverse gas chromatography and ranged from -5.9 kcal/mol for dichloromethane to -13.5 kcal/mol for toluene. The strength of interaction between graphene and the organic molecules was estimated by density functional theory (PBE, B97D, M06-2X, and optB88-vdW), wave function theory (MP2, SCS(MI)-MP2, MP2.5, MP2.X, and CCSD(T)), and empirical calculations (OPLS-AA) using two graphene models: coronene and infinite graphene. Symmetry-adapted perturbation theory calculations indicated that the interactions were governed by London dispersive forces (amounting to ∼60% of attractive interactions), even for the polar molecules. The results also showed that the adsorption enthalpies were largely controlled by the interaction energy. Adsorption enthalpies obtained from ab initio molecular dynamics employing non-local optB88-vdW functional were in excellent agreement with the experimental data, indicating that the functional can cover physical phenomena behind adsorption of organic molecules on graphene sufficiently well.

• MeSH
• adsorpce MeSH
• chemické modely MeSH
• chromatografie plynová MeSH
• grafit chemie   MeSH
• mikroskopie elektronová rastrovací MeSH
• molekulární modely MeSH
• organické látky MeSH
• statická elektřina MeSH
• termodynamika MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• grafit MeSH
• organické látky MeSH

Per- and polyfluoroalkyl substances (PFASs) are a class of persistent organic pollutants widely distributed in aquatic environments. The adsorption and photocatalytic methods have been widely used to remove PFASs in water because of their respective advantages. Still, they have apparent defects when used alone. Therefore, the adsorption and photocatalytic technologies are combined through suitable preparation methods, and the excellent properties of the two are used to synergize the treatment of organic pollutants. This strategy of "concentrating" pollutants and then degrading them in a centralized manner plays an essential role in removing trace PFASs. Nevertheless, a review focusing on this kind of adsorption photocatalyst system is lacking. This review will fill this gap and provide a reference for developing a carbon-based composite photocatalyst. Firstly, different carbon-based composite photocatalysts are reviewed in detail, focusing on the differences in various composite materials' excellent adsorption and catalytic properties. Secondly, the factors influencing the removal effect of carbon-based composite photocatalysts are discussed. Thirdly, the removal mechanism of carbon-based composite photocatalysts is summarized in detail. The removal process involves two steps: adsorption and photodegradation. The adsorption process involves multiple cooperative adsorption mechanisms, and photocatalytic degradation includes oxidative and reductive degradation. Fourthly, the comparison of adsorption-photocatalysis with common treatment techniques (including removal rate, range of adaptation, cost, and the possibility of expanding application) is summarized. Finally, the prospects of carbon-based composite photocatalysts for repairing PFASs are given by evaluating the performance of different composites.

• Klíčová slova
• Adsorption, Carbon materials, Composites, PFASs, Photocatalysis,
• MeSH
• adsorpce MeSH
• chemické látky znečišťující vodu * analýza   MeSH
• fluorokarbony * analýza   MeSH
• látky znečišťující životní prostředí * MeSH
• uhlík MeSH
• voda MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• chemické látky znečišťující vodu * MeSH
• fluorokarbony * MeSH
• látky znečišťující životní prostředí * MeSH
• uhlík MeSH
• voda MeSH

Nitrogen discharges from decentralized wastewater treatment (DWT) systems contribute to surface and groundwater contamination. However, the high variability in loading rates, long idle periods and lack of regular maintenance presents a challenge for biological nitrogen removal in DWT. A Tire-Sulfur Hybrid Adsorption Denitrification (T-SHAD) process was developed that combines nitrate (NO3(-)) adsorption to scrap tire chips with sulfur-oxidizing denitrification. This allows the tire chips to adsorb NO3(-) when the influent loading exceeds the denitrification capacity of the biofilm and release it when NO3(-) loading rates are low (e.g. at night). Three waste products, scrap tire chips, elemental sulfur pellets and crushed oyster shells, were used as a medium in adsorption, leaching, microcosm and up-flow packed bed bioreactor studies of NO3(-) removal from synthetic nitrified DWT wastewater. Adsorption isotherms showed that scrap tire chips have an adsorption capacity of 0.66 g NO3(-)-N kg(-1) of scrap tires. Leaching and microcosm studies showed that scrap tires leach bioavailable organic carbon that can support mixotrophic metabolism, resulting in lower effluent SO4(2-) concentrations than sulfur oxidizing denitrification alone. In column studies, the T-SHAD process achieved high NO3(-)-N removal efficiencies under steady state (90%), variable flow (89%) and variable concentration (94%) conditions.

• Klíčová slova
• Decentralized wastewater systems, Denitrification, Nitrate adsorption, Scrap tire chips, Sulfur oxidation,
• MeSH
• adsorpce MeSH
• bioreaktory MeSH
• chemické látky znečišťující vodu chemie   MeSH
• denitrifikace * MeSH
• dusičnany chemie   MeSH
• dusík chemie   MeSH
• odpad tekutý - odstraňování ekonomika   metody   MeSH
• odpadní voda chemie   MeSH
• síra chemie   MeSH
• tuhý odpad MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH
• Názvy látek
• chemické látky znečišťující vodu MeSH
• dusičnany MeSH
• dusík MeSH
• odpadní voda MeSH
• síra MeSH
• tuhý odpad MeSH

Substances such as drugs, as well as special ligands with expressive biospecific properties, all with different affinities, interact with proteins which can be characterized by dissociation constants. The method for estimation of the dissociation constant on the basis of adsorption kinetics was verified for two typical cases: adsorption of lactate dehydrogenase onto bead cellulose derivatized by reactive dyes C.I.2. or C.I.19, and adsorption of different drugs (neuroleptics and local anesthetics) onto calmodulin immobilized on agarose gel. The real equilibrium values obtained by using the complete time-concentration model of adsorption were fitted according to the respective adsorption isotherms by non-linear regression.

• MeSH
• adsorpce MeSH
• celulosa MeSH
• fenothiaziny metabolismus   MeSH
• kalmodulin MeSH
• kinetika MeSH
• L-laktátdehydrogenasa metabolismus   MeSH
• rozpustnost MeSH
• Publikační typ
• časopisecké články MeSH
• srovnávací studie MeSH
• Názvy látek
• celulosa MeSH
• fenothiaziny MeSH
• kalmodulin MeSH
• L-laktátdehydrogenasa MeSH
• phenothiazine MeSH Prohlížeč

Growing concern over the hazardous effect of radionuclides on the environment is driving research on mitigation and deposition strategies for radioactive waste management. Currently, there are many techniques used for radionuclides separation from the environment such as ion exchange, solvent extraction, chemical precipitation and adsorption. Adsorbents are the leading area of research and many useful materials are being discovered in this category of radionuclide ion separation. The adsorption technologies lack the ability of selective removal of metal ions from solution. This drawback is eliminated by the use of ion-imprinted polymers, these materials having targeted binding sites for specific ions in the media. In this review article, we present recently published literature about the use of ion-imprinted polymers for the adsorption of 10 important hazardous radionuclides-U, Th, Cs, Sr, Ce, Tc, La, Cr, Ni, Co-found in the nuclear fuel cycle.

• Klíčová slova
• adsorption, ion-imprinted polymers, radioactive waste, radionuclides, separation,
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

The present investigation deals with preparation of three different adsorbent materials namely; potassium hydroxide activated carbon based apricot stone (C), calcium alginate beads (G) and calcium alginate/activated carbon composite beads (GC) were used for the removal of arsenic. The prepared adsorbent materials were characterized by scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), N2-adsorption at -196°C and point of zero charge. From the obtained results, it was found that the porosity, surface area and total pore volume of the adsorbent material C>GC>G respectively, however, the G adsorbent has more acidic function group than the other adsorbents. The influence of pH, time, temperature and initial concentration of arsenic(V) were studied and optimized. GC exhibits the maximum As(V) adsorption (66.7mg/g at 30°C). The adsorption of arsenic ions was observed to follow pseudo-second order mechanism as well as the thermodynamic parameters confirm also the endothermic spontaneous and a physisorption process.

• Klíčová slova
• Adsorption, Alginate beads, Apricot stone, Arsenic, Composite,
• MeSH
• adsorpce MeSH
• algináty chemie   MeSH
• arsen izolace a purifikace   MeSH
• časové faktory MeSH
• dřevěné a živočišné uhlí chemie   MeSH
• kinetika MeSH
• koncentrace vodíkových iontů MeSH
• kyselina glukuronová chemie   MeSH
• kyseliny hexuronové chemie   MeSH
• mikrosféry * MeSH
• mikroskopie elektronová rastrovací MeSH
• spektroskopie infračervená s Fourierovou transformací MeSH
• teplota MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• algináty MeSH
• arsen MeSH
• dřevěné a živočišné uhlí MeSH
• kyselina glukuronová MeSH
• kyseliny hexuronové MeSH