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This paper reviews the properties of methanesulfonic acid (MSA) and its potential for use in hydrometallurgy. Although MSA is much less known than sulfuric, hydrochloric or nitric acid, it has several appealing properties that makes it very attractive for the development of new circular flowsheets in hydrometallurgy. Unlike other organic acids such as acetic acid, MSA is a very strong acid (pKa = − 1.9). In addition, it is very stable against chemical oxidation and reduction, and has no tendency to hydrolyze in water. In terms of its environmental impact, MSA has low toxicity and is biodegradable. In nature, it is part of the geochemical sulfur cycle. A useful property is the high solubility of its salts in water: methanesulfonate salts have a much higher solubility in water than sulfate salts. Additionally, MSA and its salts are compatible with the electrowinning of metals because the anode reaction involves the formation of oxygen gas (unlike chlorine gas formation in chloride electrolytes) and no cathodic reduction of the anion occurs (unlike nitrate reduction in nitrate electrolytes). MSA is particularly interesting for lead hydrometallurgy, where it offers more environment-friendly alternatives to HBF4 and H2SiF6. However, MSA can also be adopted in all hydrometallurgical processes that require strong Brønsted acids. It can be used in the metallurgy of copper, zinc, cobalt, nickel, and rare earths, as well as in the recycling of metals from end-of-life products. Although MSA itself is a non-oxidizing acid, in combination with hydrogen peroxide it yields strongly oxidizing lixiviants that can leach copper from chalcopyrite or dissolve metallic silver. The global production of MSA is expected to increase rapidly in the near future thanks to both the industrialization of a new sustainable synthesis process and its many applications (cleaning fluids, electrolytes for electroplating, redox-flow batteries, catalysts in organic synthesis, and as a solvent for high-molecular-weight polymers). As a result, MSA will become more widely available and a lower price will make it an increasingly attractive option. Graphical Abstract

The thorium sorption onto Pongamia Pinnata leaves was studied in relation to pH, initial thorium concentration, column bed height, flow rate, and flow time. The breakthrough curve was plotted. The experimental data were analyzed using the Thomas, Yoon-Nelson, and Adams-Bohart models to identify the column parameters relevant for constructing column procedures. All the parameters showed good agreement with the results of the Thomas model. Thus, Karanja leaves can be utilized to remove Th(IV) ions from monazite sand for a low cost and without any treatment.

ispartof: SEPARATION AND PURIFICATION TECHNOLOGY vol:313 status: accepted

Purpose: In this study, the effects of pH, biosorbent dosage, contact time and initial lead concentration on the treatment of lead ion by using pepper seeds were examined. The removal of lead from both synthetic and real wastewater was studied. Various isotherm and kinetic models were used to clearly identify the biosorption process. The performance of this biomass on storage battery industry wastewaters was exhibited. Theory and Methods: Peppers used in this study were purchased from a local market in Dikili, Izmir, Turkey. Seeds were disassociated from the body of pepper and then cleaned down by using tap water, pure and ultra-pure water, respectively before the drying process. Dried seeds were crushed and sifted between the range of 125-250 mu m. The reagent Pb(NO3)2 was used to prepare synthetic wastewater. Storage industry wastewaters containing 2.0 and 4.3 mg/L were used in real wastewaters tests. Experimental studies were conducted in Erlenmeyer flasks of 250 mL using lead-containing solutions (100 mL). Known biosorbent doses were inserted to these flasks including 100 mL of contaminated solution. The final suspensions were mixed at 150 rpm shaking rate and 25 degrees C'in an incubator shaker for different test periods. After proper treatment time, suspensions were centrifuged for 8 minutes at 5000 rpm by using a centrifugal machine. The lead ion concentrations in the solutions separated from the biomass were analyzed with photometer using lead test kits. Results: The optimum pH for this biosorption system was 5.0 at 25 degrees C. The system was reached equilibrium in nearly 90 minutes. The biosorbent amount of 0.6 g/L gave the maximum uptake capacity of this Capia pepper residual. The maximum uptake capacity of biosorbent and the R2 value according to Langmuir model were determined to be 29.67 mg/g and 0.99, respectively. The mostly suitable kinetic model was found to be pseudo-second order kinetic model (0.99). It was shown in the studies that intraparticle diffusion was not the only mechanism limiting the rate in biosorption of lead by capia pepper residual. Storage battery industry wastewater containing very low lead concentrations was treated with an efficiency of 71%. Conclusion: Lead ions were successfully removed from synthetic and storage battery industry wastewaters by capia pepper residuals. As a cost-effective and novel biosorbent, the capia pepper residual carries an important potential for further biosorption tests of lead ions in real wastewaters. Consequently, it has been demonstrated that this residual material can be brought into the economy to be used for treatment purposes.

Thermoresponsive polymers with the appropriate structure form physical networks upon changes in temperature, and they find utility in formulation science, tissue engineering, and drug delivery. Here, we report a cost-effective biocompatible alternative, namely OEGMA30015-b-BuMA26-b-DEGMA13, which forms gels at low concentrations (as low as 2% w/w); OEGMA300, BuMA, and DEGMA stand for oligo(ethylene glycol) methyl ether methacrylate (MM = 300 g mol–1), n-butyl methacrylate, and di(ethylene glycol) methyl ether methacrylate, respectively. This polymer is investigated in depth and is compared to its commercially available counterpart, Poloxamer P407 (Pluronic F127). To elucidate the differences in their macroscale gelling behavior, we investigate their nanoscale self-assembly by means of small-angle neutron scattering and simultaneously recording their rheological properties. Two different gelation mechanisms are revealed. The triblock copolymer inherently forms elongated micelles, whose length increases by temperature to form worm-like micelles, thus promoting gelation. In contrast, Pluronic F127’s micellization is temperature-driven, and its gelation is attributed to the close packing of the micelles. The gel structure is analyzed through cryogenic scanning and transmission electron microscopy. Ex vivo gelation study upon intracameral injections demonstrates excellent potential for its application to improve drug residence in the eye.

In this study, the high-resolution ultrasonic spectroscopy (HR-US) technique was applied to examine interpolyelectrolyte neutralization. The mentioned method was tested on the example of complexation between poly(allylammonium) cations and poly(acrylate) anions in aqueous solutions at pH = 7. It was confirmed by HR-US that the type of titration (stepwise or abrupt), the direction of titration, and the type of background salt affect the outcome of interpolyelectrolyte neutralization. The obtained results were explained on the basis of ultrasonic velocity and attenuation changes in the context of suspension compressibility, a parameter that is extremely sensitive to molecular organization and intermolecular interactions. Moreover, the results of HR-US measurements proved to be consistent with previous results obtained by more traditional methods such as dynamic light scattering, microcalorimetry, and electrokinetics. This research demonstrates that HR-US is a convenient and reliable method that can be employed for the investigation of interpolyelectrolyte neutralization and polyelectrolyte-related processes.

This study evaluates the performance of commercial reverse osmosis (RO) and nanofiltration (NF) membranes for the removal of metal ions from synthetic water and surface water carried from the north-west of Lake Tanganyika in the city of Uvira, in the east of the Democratic Republic of Congo. Metal ion analyses were performed by the standardized ICP-MS and ICP-OES methods. The RO membrane showed higher metal ion rejection in high-concentration solutions (synthetic samples) prepared in the laboratory as well as in low-concentration samples from real raw water collected near Lake Tanganyika. Rejection levels were higher than 98% for Cr3+, Pb2+, Cd2+, As3+, Ni2+, and Sb+3 ions in the synthetic solutions, and 99.2, 98.8, 98.6, 99.2, 98.4, and 98.8%, respectively, in the real samples. The concentrations of metals in the permeate varied depending on the feed concentration and were 0.15 to 1.02 mg/L, 0.33 to 22 mg/L, and 0.11 to 22 mg/L in RO, NF90, and NF270 membranes, respectively. Regarding the NF membranes, the rejection of Cr, Ni, and Cd ions was interesting: 98.2, 97.8, and 92.3%, respectively. However, it was lower for Pb, As, and Sb ions: 76.9, 52.5 and 64.1%, respectively. The flux of NF was 329 to 375 L/m2.h, much higher than for RO membranes, which had a flux of 98 to 132 L/m2.h. The studied membranes are thus a feasible solution to remove the studied metals from real water sources at low concentrations since they meet the standards of the World Health Organization on specific values assigned to chemicals from industrial sources and human habitation areas where these ions are present in drinking water.

Here is described the preparation and characterization of iron oxide@silicon oxide-graphene oxide hybrid nanoparticles to remove and recover lead and cadmium from water samples. The high surface area from sorption capacity and low masses used for recovery and removal studies makes these particles attractive for preconcentration and water treatment. The results show that the method provided 97% recovery and 91% removal for lead and 78% recovery and 93% removal for cadmium from water at pH 8.0. Under the optimized conditions, the limits of detection were 37.0 mu g L-1 and 11.7 mu g L-1 and limits of quantification were 123.2 mu g L-1 and 45.0 mu g L-1 for lead and cadmium, respectively. The trueness of the method was confirmed by analyzing a certified reference material (BCR 715) with -11.0% and -15.0% relative error for lead and cadmium, respectively. The results from the certified reference material provided good accuracy (>85%). The method was employed to various water samples using the method of standard addition.

Colloidal stability was investigated in two types of particle systems, namely, with bare (h-HNT) and polyimidazolium-functionalized (h-HNT-IP-2) alkali-treated halloysite nanotubes in solutions of metal salts and ionic liquids (ILs). The valence of the metal ions and the number of carbon atoms in the hydrocarbon chain of the IL cations (1-methylimidazolium (MIM+), 1-ethyl-3-methylimidazolium (EMIM+), 1-butyl-3-methylimidazolium (BMIM+), and 1-hexy1-3-methylimidazolium (HMIM+)) were altered in the measurements. For the bare h-HNT with a negative surface charge, multivalent counterions destabilized the dispersions at low values of critical coagulation concentration (CCC) in line with the Schulze-Hardy rule. In the presence of ILs, significant adsorption of HMIM+ took place on the h-HNT surface, leading to charge neutralization and overcharging at appropriate concentrations. A weaker affinity was observed for MIM+, EMIM+, and BMIM+, while they adsorbed on the particles to different extents. The order HMIM+ < BMIM+ < EMIM+ < MIM+ was obtained for the CCCs of h-HNT, indicating that HMIM+ was the most effective in the destabilization of the colloids. For h-HNT-IP-2 with a positive surface charge, no specific interaction was observed between the salt and the IL constituent cations and the particles, i.e., the determined charge and aggregation parameters were the same within experimental error, irrespective of the type of co-ions. These results clearly indicate the relevance of ion adsorption in the colloidal stability of the nanotubes and thus provide useful information for further design of processable h-HNT dispersions.

In this work, pseudo-stem banana (Musa acuminata) (PBF) fiber was utilized as a potential low-cost natural adsorbent to uptake methylene blue (MB) dye from synthetic wastewater by batch adsorption process. Different adsorption factors like contact time, pH, initial concentration, and adsorbent dosage were explored and found that the separation process is strongly pH dependent. Additionally, the adsorption data were fitted with various adsorption isotherms like Langmuir, Freundlich, Temkin, and Dubinin–Radhushkevich models to detect the adsorption equilibrium phenomena. Reaction kinetics was inspected using pseudo-first-order and second-order kinetic models. Mass transfer and intra-particle diffusion analyses indicate the adsorption mechanism of the system described particularly in the context. Furthermore, scanning electron spectroscopy (SEM) and Fourier transformed infrared spectroscopy (FTIR) were conducted to get the morphology and surface properties of the adsorbent, respectively. As a result, the as-prepared banana fiber can be proposed as a cheap suitable adsorbent to separate dyestuffs from industrial wastewater.

Carbon monoxide (CO) is the second most abundant identified product of dissolved organic matter (DOM) photodegradation after CO2, but its formation mechanism remains unknown. Previous work showed that aqueous photodegradation of methoxy-substituted aromatics (ArOCH3) produces CO considerably more efficiently than aromatic carbonyls. Following on this precedent, we propose that the methoxy aromatic groups of lignin act as the C source for the photochemical formation of CO from terrestrial DOM via a two-step pathway: formal hydrolytic demethylation to methanol and methanol oxidation to CO. To test the reasonableness of this mechanism, we investigated the photochemistry of eight lignin model compounds. We first observed that initial CO production rates are positively correlated with initial substrate degradation rates only for models containing at least one ArOCH3 group, regardless of other structural features. We then confirmed that all ArOCH3-containing substrates undergo formal hydrolytic demethylation by detecting methanol and the corresponding phenolic transformation products. Finally, we showed that hydroxyl radicals, likely oxidants to initiate methanol oxidation to CO, form during irradiation of all models. This work proposes an explicit mechanism linking ubiquitous, abundant, and easily quantifiable DOM functionalities to CO photoproduction. Our results further hint that methanol may be an abundant (yet overlooked) DOM photoproduct and a likely precursor of formaldehyde, formic acid, and CO2 and that lignin photodegradation may represent a source of hydroxyl radicals., Environmental Science & Technology, 56 (18), ISSN:0013-936X, ISSN:1520-5851

Thermoreversible polymer hydrogels (TRGs) are physical aqueous networks triggered by temperature, that find potential applications in tissue engineering (TE) and drug/gene delivery. When systems with lower critical solution temperature (LCST) behaviour are used, the aqueous solution of polymer is mixed with cells or drugs/genes, depending on the desired application, at room temperature and then injected in vivo to form a hydrogel. This in-situ forming hydrogel acts as a matrix for tissue regeneration or controlled and targeted release of the compound. This review focuses on discussing the studies in which synthetic TRGs with LCST behaviour have been applied in vivo in model animals. These studies are categorised depending on the general structure of the polymer, as follows: i) poloxamer (also known as Pluronics®), ii) degradable polymers, iii) poly(N-isopropylacrylamide) (PNIPAAm), iv) poly(organophosphazene), and v) poly(2-ethyl-2-oxazoline). In general, when the system is optimised, TRGs provide sustained and topical release of the drugs, thus minimising the undesired side effects. When applied in the TE field, tissue formation was observed. Interestingly, two polymers have reached clinical trials, namely poloxamer 407 (P407, Pluronic® F127, often combined with P188, F68), and Regel® (the formulation of Regel® with the anticancer agent paclitaxel is known as Oncogel®), indicating the challenges need to be overcome before successful application in clinics.

There is an increasing urge to make the transition toward biobased materials. Lignin, originating from lignocellulosic biomass, can be potentially valorized as humic acid (HA) adsorbents via lignin-based mesoporous carbon (MC). In this work, these materials were synthesized for the first time starting from modified lignin as the carbon precursor, using the soft-template methodology. The use of a novel synthetic approach, Claisen rearrangement of propargylated lignin, and a variety of surfactant templates (Pluronic, Kraton, and Solsperse) have been demonstrated to tune the properties of the resulting MCs. The obtained materials showed tunable properties (BET surface area: 95-367 m(2)/g, pore size: 3.3-36.6 nm V-BJH pore volume: 0.05-0.33 m(3)/g, and carbon land oxygen content: 55.5-91.1 and 3.0-12.2%, respectively) and good performance in terms of one of the highest HA adsorption capacities reported for carbon adsorbents (up to 175 mg/g).

In an interlaboratory study we compare different methods to determine the weight-average molecular weight (Mw) and molecular weight distribution of six cereal beta-glucan isolates of nutritional importance. Size-exclusion chromatography (SEC) with multi-angle light scattering (MALS), capillary viscometry, sedimentation velocity analytical ultracentrifugation and one asymmetric flow field-flow fractionation (AF4)-MALS method all yielded similar Mw values for mostly individual chains of dissolved beta-glucan molecules. SEC with post-column calcofluor detection underestimated the Mw of beta-glucan >500 × 103 g/mol. The beta-glucan molecules analysed by these methods were primarily in a random coil conformation as evidenced from individual Mark-Houwink-Kuhn-Sakurada (MHKS) scaling coefficients between 0.5 and 0.6 and Wales-Van Holde ratios between 1.4 and 1.7. In contrast, a second AF4-MALS method yielded much larger Mw values for these same samples indicating the presence and detection of beta-glucan aggregates. Storage of the six beta-glucan solutions in the dark at 4 °C for 4 years revealed them to be stable. This suggests an absence of storage-induced irreversible aggregation phenomena or chain-scission. Shear forces in SEC and the viscometer capillary and hydrostatic pressure in analytical ultracentrifugation probably led to the reversable dissociation of beta-glucan aggregates into molecularly dissolved species. Thus, all these methods yield true weight-average molecular weight values not biased by the presence of aggregates as was the case in one of the AF4 based methods employed.

MOF-derived carbon-based materials have attracted widespread attention due to their relatively large surface area, morphology, and their stability in water. Considering these advantages, these materials present themselves as excellent adsorbents. In this work, a novel method was designed for the fabrication of a nano zero-valent-iron (nZVI) carbon composite. The utilization of zinc oxide nanorods (ZnONRs) in the role of sacrificial consumable nuclei for the synthesis of MIL-53 sacrificial zinc oxide nanorods (MIL-53-SNR) and the subsequent pyrolysis at 700 °C in the inert atmosphere led to a graphitic-supported nZVI material (Fe-C-SNR). Fe-C-SNR was compared with a commercial zinc oxide bulk (MIL-53-SB) and with a pristine MIL-53. By virtue of the ZnONRs, Fe-C-SNR exhibited a greatly improved mesoporous structure. Consequently, the pyrolyzed materials were applied as adsorbents for methylene blue. Fe-C-SNR’s performance increased to more than double of the pyrolyzed MIL-53 (Fe-C), with a remarkably fast adsorption time (10 min) for a concentration of 10 mg L−1 with only 200 mg L−1 adsorbent required. This functional composite also displayed exceptional recyclability; after ten complete cycles, Fe-C-SNR was still capable of completely adsorbing the methylene blue. The utilization of ZnONRs proves itself advantageous and could further be extended to other MOFs for a wide range of applications.

Within the framework of metal separations and solvent extraction, chloride media are among the most studied systems. Bromide and iodide media have received much less attention, but can allow a diff...

Granular activated carbon (GAC) is used in drinking water treatment plants worldwide to remove micro-pollutants such as pesticides. Early breakthrough of problematic micro-pollutants leads to frequent and costly thermal regeneration off-site. A potential alternative approach is to chemically regenerate GAC on-site (possibly in situ) with an appropriate solution capable of desorbing organic contaminants, having a range of physico-chemical properties. In this study, four types of regenerant solution were evaluated in batch tests for their ability to desorb five target contaminants. The solutions were: high purity water, sodium hydroxide, ethanol, and a mixture of sodium hydroxide and ethanol. The contaminants included: phenol and nitrobenzene, as representative aromatic compounds; clopyralid and metaldehyde, as poorly-adsorbed pesticides; and isoproturon, a well-adsorbed pesticide. Among the properties of the contaminants, their hydrophobicity and aqueous solubility had the most significant influence on the desorption efficiency. NaOH/CH3CH2OH was found to be more effective than individual solutions in desorbing the target contaminants, indicating an ability to desorb both hydrophobic and hydrophilic compounds. The NaOH/CH3CH2OH regenerant solution yielded desorption efficiencies in the range of approximately 40–90%, with the efficiency dependent on the contaminant. A thermodynamic study provided valuable fundamental information regarding the adsorption and desorption mechanisms, and the existence of two binding sites involving a weak physisorption and a stronger chemisorption-like interaction between the contaminants and the GAC.

Ion specific effects of ionic liquid (IL) constituents on the surface charge and aggregation properties of two types of particles (positively charged amidine (AL) and polyimidazolium-functionalized sulfate (SL-IP-2) latexes) were investigated in IL solutions containing different anions and the 1-butyl-3-methylimidazolium cation. For the AL systems, the affinity of IL anions to the particle surface followed the sequence chloride < bromide < nitrate < acetate. The critical coagulation concentration values decreased in the same order indicating that ion specific adsorption determines the surface charge density and the extent of the repulsive interparticle forces. In contrast, no tendencies were observed for the SL-IP-2 particles, i.e., both charge and aggregation features were insensitive to the type of anions. This surprising behavior sheds light on that surface functionalization with the polyimidazolium compound effectively masks interfacial ion specific effects. These results indicate new possible routes to the design of processable particle dispersions in ILs irrespective of their composition.

Increased antibiotic use worldwide has become a major concern because of their health and environmental impacts. Since most antibiotic residues can hardly be removed from wastewater using conventional treatments, alternative methods receive great attention. Adsorption is one of the most efficient and cost-effective treatment methods for antibiotics. Among the adsorbents, clay minerals have garnered increasing attention due to their unique properties including availability, high specific surface area, low cost, cation exchange capacity, and good removal efficiency. This paper reviews the recent progress made in the use of natural and modified clay minerals for the removal of antibiotics from water. First, the sources, occurrence, removal and health effects of the antibiotics commonly encountered in water bodies are described. Antibiotic concentration levels and average removal efficiencies measured in conventional activated sludge treatment systems worldwide are also provided to better address the problem. Second, the review explores the characteristics of clay minerals as adsorbent of antibiotics and the factors affecting the adsorption. The review identifies and discusses the future trends and strategies used to increase the adsorption capacity of clay minerals by modification and combination techniques (intercalation of novel functional groups such as organocations, biopolymers and metal pillared-clay minerals, combination with biochar or thermal activation). The quantitative comparisons of clay minerals\" ability for antibiotic removal are given. Some natural clay minerals have good removal potential for antibiotics, with maximum adsorption capacities over 100 mg/g. For most other adsorbents, surface modifications and combination techniques resulted in improved adsorption properties (including higher surface area, enhanced adsorption capacity, increased stability and mechanical strength). Finally, the application of these adsorbents at pilot scale, using real wastewater samples, their reuse, economic analysis and life cycle assessment are other issues that have been considered.

This work presents for the first time the coupling of a biodegradable polymer, sodium lignosulfonate (SLS), with ultrafiltration to remove Zn2+ ions from model solution as well as zinc plating bath solution. SLS was first characterized using Fourier transform infrared spectroscopy to determine the functional groups of the biopolymer. Elemental analyses were performed to determine the polymer's C, H, and S content. The effect of polymer:Zn2+ molar ratio, initial solution pH, and stirring time on Zn2+ removal was investigated. The results showed that the pH of the initial solution significantly affected the removal of Zn2+, and the maximum removal was achieved in the pH range of 3-7. Increasing the molar ratio of lignosulfonate to zinc from 5 to 30 improved the removal of Zn2+ from 72 to 90%. Furthermore, the ion exchange reaction between functional groups of lignosulfonate and Zn2+ reached equilibrium within 30 min. The presence of monovalent ions, Na+ and K+, did not affect the removal rate; however, divalent cations, Ca2+, and Mg2+ reduced the removal rate of Zn2+ from 90 to 80%. In a later stage of the work, Zn2+ was removed from zinc plating bath water sample by biopolymer-enhanced ultrafiltration. The optimum conditions were applied to the actual water sample, and 80% of Zn2+ was removed from the solution.

Modification of metal oxides with organophosphonic acids (PAs) provides the ability to control and tailor the surface properties. The metal oxide phosphonic acid bond (M-O-P) is known to be stable under harsh conditions, making PAs a promising candidate for the recovery of metals from complex acidic leachates. The thiol functional group is an excellent regenerable scavenging group for these applications. However, the research on organophosphonic acid grafting with thiol groups is very limited. In this study, four different metal sorbent materials were designed with different thiol surface coverages. An aqueous-based grafting of 3-mercaptopropylphosphonic acid (3MPPA) on mesoporous TiO2 was employed. Surface grafted thiol groups could be obtained in the range from 0.9 to 1.9 groups per nm(2). The different obtained surface properties were studied and correlated to the Pd adsorption performance. High Pd/S adsorption efficiencies were achieved, indicating the presence of readily available sorption sites. A large difference in their selectivity towards Pd removal from a spend automotive catalyst leachate was observed due to the co-adsorption of Fe on the titania support. The highest surface coverage showed the highest selectivity (K-d: 530 mL g(-1)) and adsorption capacity (Q(max): 0.32 mmol g(-1)) towards Pd, while strongly reducing the co-adsorption of Fe on remaining TiO2 sites. This work is supported by the Research Foundation Flanders (FWO) and Hasselt University via the Hercules project AUHL/15/ 2 – GOH3816N. Part of the presented work was executed within the PLATIRUS project, which has received funding from the European Union's Horizon 2020 research and innovation program under grant agreement No 730224. This work reects only the author's views and the agency is not responsible for any use that may be made of the information it contains. The authors are grateful to all project partners for discussions and input, and in particular to Monolithos Ltd (Athens. Greece) for providing the spend automotive catalyst material used in this work. V. Meynen acknowledges the Research FoundationFlanders (FWO) for project K801621N. All calculations were performed using the Hopper HPC infrastructure at the CalcUA core facility of the University of Antwerp, a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flemish Government (department EWI) and the University of Antwerp. Furthermore, the authors would like to acknowledge S. Defoss´e and K. Leyssens for the N2 sorption measurements, J. Lievens and A. Deibe Varela for the Pd sorption experiments, K. Duyssens and W. Brusten for the ICP measurements and M. Mertens for the XRD measurements.

Carbon nanofibers are promising green materials for sustainable technology within a wide range of applications including environment, energy, health and high-technology. Accordingly, drug adsorption is an important subject in connection with its environmental and pharmaceutical applications. This study aims to investigate the adsorption performance of carbon nanofibers in batch and fixed bed column processes. Carbon nanofibers were used as adsorbent to remove triflupromazine hdyrochloride from aqueous solutions. Adsorption kinetics were studied using Lagergren first order and Pseudo second order models. Intraparticle diffusion graph was plotted using kinetic data and showed that intraparticle diffusion is the single step controlling the adsorption rate. Experimental equilibrium data was modeled by using Langmuir and Freundlich equations and has a better fit to the Langmuir model. Triflupromazine adsorption on carbon nanofibers was found to be H-type according to Giles classification. The effect of temperature and the effect of pH on adsorption were studied to determine optimum adsorption conditions. Adsorption capacity of carbon nanofibers was decreased with increasing temperature due to the exothermic and physical nature of the process. Thermodynamic parameters confirmed the exothermic nature of the adsorption. Results showed the effective adsorption of drug molecules by carbon nanofibers. Maximum adsorption capacity was calculated as 165.41 mg/g at pH 9 using Langmuir equation. Modeling of the fixed bed column data was done by using Thomas model and Yoon-Nelson model. Results showed the important effect of the operating conditions on the removal performance of carbon nanofibers. Removal capacity was increased with an increase in the flow rate and the increase in the fixed bed length.

The global need to expand the design of energy-storage devices led to the investigation of alkali metal - Ionic Liquid (IL) mixtures as a possible class of electrolytes. In this study, 1D and 2D Nuclear Magnetic Resonance (NMR) and Electrochemical Impedance Spectroscopy (EIS) as well as Molecular Dynamics (MD) simulations were used to study the intermolecular interactions in imidazolium-based IL - water - alkali halide ternary mixtures. The 1H and 23Na 1D and 1H DOSY NMR spectra revealed that the presence of small quantities of NaCl does not influence the aggregation of water molecules in the IL nano-domains. The order of adding ionic compounds to water, as well as the certain water and NaCl molecular ratios, lead to the formation of isolated water clusters. Two ternary solutions representing different orders of compounds mixing (H2O+ IL + NaCl or H2O+ NaCl + IL) showed a strong dependence of the initial solvation shell of Na+ and the self-clustering of water. Furthermore, the behaviour of water was found to be independent from the conditions applied during the solution preparation, such as temperature and/or duration of stirring and aging. These findings could be confirmed by large differences in the amount of ionic species, observed in the ternary solutions and depending on the order of mixing/solute preparation.

Sensitized triplet-triplet annihilation-based photon upconversion is a photo-physical process that affords anti-Stokes-shifted emission after annihilation of two metastable triplet excitons of an emitter dye and the formation of a fluorescent singlet state. While this process readily occurs in solutions under conditions where the mobility of the dye molecules is high, particular architectures are required to facilitate efficient energy transfers in solid polymers. One possibility is to incorporate liquid upconverting domains into solid polymer matrices. Another possibility is to reduce the intermolecular distance between the dyes below the Dexter radius, allowing exciton migration via triplet hopping. We introduce herein nanostructured materials that combine both of these features. These glassy nanostructured polymer systems contain liquid upconverting nanodroplets that are stabilized with a block copolymer surfactant and are fabricated under ambient conditions in a facile one-step protocol. The dyes concentrate in the nanostructured liquid domains, and this enables hopping-mediated ET and TTA between the dyes and leads to an upconversion efficiency of similar to 20%.

Agradecimentos: This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, Brasil - CAPES, finance code 001 Abstract: Studies have been conducted on detoxification of hemicellulose hydrolysates, but an effective detoxification method remains to be developed. The use of layered double hydroxides (LDHs) as adsorbents may be a solution to this problem. In this study, LDHs composed of 30, 63, or 70% MgO were used in their uncalcined and calcined states to adsorb acetic acid, formic acid, hydroxymethylfurfural, and furfural from a synthetic hemicellulose hydrolysate. Kinetic studies revealed that calcined LDH composed of 70% MgO (MG70c) had the best performance: it was able to remove 73% of acetic acid and 90% of formic acid in 6 h of incubation at 50 °C. Hydroxymethylfurfural and furfural were not adsorbed (C/C0 ˜ 1) by calcined or uncalcined LDHs under the studied conditions. The adsorption equilibrium was determined at different temperatures. Adsorption isotherms were best described by the Langmuir-Freundlich model. These results show the potential of MG70c to remove acetic and formic acids from hemicellulose hydrolysates, thereby increasing their suitability as fermentation substrates COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPES Fechado

The practical application of Shilov-type Pt catalysis to the selective hydroxylation of terminal aliphatic C-H bonds remains a formidable challenge, due to difficulties in replacing PtIV with a more economically viable oxidant, particularly O2 . We report the potential of employing FeCl2 as a suitable redox mediator to overcome the kinetic hurdles related to the direct use of O2 in the Pt reoxidation. For the selective conversion of butyric acid to γ-hydroxybutyric acid (GHB), a significantly enhanced catalyst activity and stability (turnover numbers (TON)>30) were achieved under 20 bar O2 in comparison to current state-of-the-art systems (TON60). Altogether, a useful catalytic system for the selective hydroxylation of primary aliphatic C-H bonds with O2 is presented. ispartof: CHEMISTRY-A EUROPEAN JOURNAL vol:25 issue:45 pages:10724-10734 ispartof: location:Germany status: published

Treatment of industrial effluents (EFs) from the polluted wastewater sources using membrane technologies is an effective and attractive alternative to overcome the weaknesses of some of the conventional wastewater treatment processes, especially when dealing with EFs loaded with recalcitrant organic pollutants and toxic substances. The application of various polymeric and inorganic membrane based technologies to be used for the treatment of industrial EFs has attracted a considerable attention in the past decades. In this regard, a critical discussion on the sustainability of various aspects of membrane technologies would promote the commercialization of these technologies. In this review, various sustainability criteria in technical, economic, environmental, and social categories have been considered for a critical discussion on the current status and improvement opportunities of membrane technologies for the treatment of industrial EFs. While the application of polymeric membranes has been restricted by some bottlenecks to deal with some industrial effluents, metal oxides fabricated ceramic membranes, and especially those fabricated with nanostructured materials such as nano-zeolites, those made of metal organic frameworks as well as carbon-based fabricated membranes have shown a promising performance in the rejection of recalcitrant organic pollutants. In addition, the combinations of inorganic membrane technologies with other novel methods such as advanced oxidation processes (e.g., using engineered nanomaterials) can be considered among the best options to deal with such highly polluted effluents.

The efficiency of mixtures of ionic liquids (ILs) and molecular solvents in cellulose dissolution and derivatization depends on the structures of both components. We investigated the ILs 1-(1-butyl)-3-methylimidazolium acetate (C 4 MeImAc) and 1-(2-methoxyethyl)-3-methylimidazolium acetate (C 3 OMeImAc) and their solutions in dimethyl sulfoxide, DMSO, to assess the effect of presence of an ether linkage in the IL side-chain. Surprisingly, C 4 MeImAc-DMSO was more efficient than C 3 OMeImAc-DMSO for the dissolution and acylation of cellulose. We investigated both solvents using rheology, NMR spectroscopy, and solvatochromism. Mixtures of C 3 OMeImAc-DMSO are more viscous, less basic, and form weaker hydrogen bonds with cellobiose than C 4 MeImAc-DMSO. We attribute the lower efficiency of C 3 OMeImAc to “deactivation” of the ether oxygen and C2–H of the imidazolium ring due to intramolecular hydrogen bonding. Using the corresponding ILs with C2–CH 3 instead of C2–H, namely, 1-butyl-2,3-dimethylimidazolium acetate (C 4 Me 2 ImAc) and 1-(2-methoxyethyl)-2,3-dimethylimidazolium acetate (C 3 OMe 2 ImAc) increased the concentration of dissolved cellulose; without noticeable effect on biopolymer reactivity.