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Within the present study, novel chelating resins containing a layer loaded with N-methyl-D-glucamine functionalities were synthesized. The procedure involved impregnation of macroporous Amberlite XAD-4 adsorbent using mixture of vinylbenzyl chloride (VBC) and divinylbenzene (DVB) further subjected to free radical suspension polymerization. The so-obtained 1PTN and 2PTN adsorbents were characterized by expanded-gel or microporous structure of VBC-co-DVB layer, respectively. The both materials were used in desalination of geothermal water aimed to decrease levels of boron and arsenic. As a part of this, he research on boron and arsenic removal included batch adsorption and kinetic studies. The results have shown that the resin 1PTN showed maximum boron removal of 64% and arsenic removal of 18% from the geothermal water. The resin 2PTN exhibited competitive boron removal performance as compared to the commercial Diaion CRB 05 resin, reaching its efficiency by removing over 96% of boron. Also, the sample 2PTN outmatched Diaion CRB 05, removing 97% of arsenic and leading to decrease of its concentration to permissible level., bilateral collaboration program between Turkey and Poland [TUBITAK-NCBR-2549, TuBTAK 117M023]; Turkish Higher Education CouncilMinistry of National Education - Turkey [YoK 100-2000], This research has been financially supported by bilateral collaboration program (TUBITAK-NCBR-2549) between Turkey and Poland (Project No: TuBTAK 117M023).; E. Altok is grateful for the PhD scholarship of Turkish Higher Education Council (YoK 100-2000). We thank Izmir Geothermal Co. for the kind support to get geothermal water samples. We also acknowledge Mitsubishi Chem. Japan for Diaion CRB 05 resin.

2-s2.0-85071772766, The solvent impregnated resin (SIR) was prepared by using Diaion HP-2MG as a hydrophilic polymer adsorbent and commercial Aliquat 336 as extractant for hexavalent chromium Cr(VI) removal from aqueous solution. The resulting SIRs were stabilized by coating using poly(vinyl alcohol) (PVA) and divinylsulfone as crosslinking reagent with different amounts. In order to predict the mechanism involved in the adsorption process, several kinetic models were used. Among them, the sorption kinetics was usually described by pseudo-first or pseudo-second order models. The kinetic behavior of stabilized SIRs was investigated as a function of amount of crosslinking reagent by batch adsorption equilibrium. Uncoated resins exhibited a faster kinetics than coated ones. It was possible to improve the kinetic performance of crosslinked resins with conditioning by using NaOH-NaCl mixture. The breakthrough profiles of SIRs were also influenced by amount of crosslinking reagent. © 2019 Sociedad Chilena de Quimica. All rights reserved., Fondo Nacional de Desarrollo Científico y Tecnológico, FONDECYT Fondo Nacional de Desarrollo Científico, Tecnológico y de Innovación Tecnológica, FONDECYT: 1150510, The authors thank to 7FP-MC Actions Grant CHILTURPOL2 (PIRSES-GA-2009 Project, Grant No 269153) and FONDECYT (Grant No 1150510) for the financial support. The authors are grateful to Mitsubishi Chem., Japan for sending Diaion HP-2MG adsorbent as a gift. We thank Mr. Mehmet Akçay for AAS analyses and Esra Altiok for the kind help in the laboratory., The authors thank to 7FP-MC Actions Grant CHILTURPOL2 (PIRSESGA-2009 Project, Grant No 269153) and FONDECYT (Grant No 1150510) for the financial support. The authors are grateful to Mitsubishi Chem., Japan for sending Diaion HP-2MG adsorbent as a gift. We thank Mr. Mehmet Ak?ay for AAS analyses and Esra Altiok for the kind help in the laboratory.

Novel anion exchange membranes that blocks the co-ions effect and improve the desorption step in hybrid capacitive deionization (HCDI) process have been presented. The membranes were prepared by chemical modification of poly(vinylidene fluoride) by ethylene diamine. To confirm ion exchange character and electrical properties of obtained membranes such methods as FTIR, SEM and EIS were applied. Transport phenomenon was described by Arrhenius and Eyring-Polanyi equations. On their bases, taking into account desorption efficiency, membrane modified for 24 h was selected for the further investigation. Its application to the HCDI system allowed to obtain desorption efficiency at 96% level with over 0.9 current efficiency. The salt adsorption capacity of the system reached over 30 mg per 1 g of electrode. For these reasons the evaluated membrane could be considered as perspective material for salt concentration with electro driven process.

Downstream processing of ABE fermentation broth is challenging issue. In this work, results of the application of both hydrophobic and hydrophilic commercial membranes during the pervaporation of ABE aqueous mixtures were investigated and presented. Hydrophobic pervaporation experiments were performed using ABE-water mixtures containing 0-5 wt% of organics in feed, using commercial membranes: POMS, PEBAX, and PervapTM4060. Separation factor and Pervaporation Separation Index were employed to discuss hydrophobic pervaporation results. PervapTM4060 membrane revealed the best separation performance in the removal of ABE components from diluted aqueous mixtures mimicking the fermentation broth, resulting in two-phase permeate containing ca. 34 wt% of organics. The subsequent liquid-liquid phase separation resulted in the organic phase containing 62 wt% of ABE. Hydrophilic pervaporation experiments were performed in contact with ABE-water system initially comprising 38 wt% of water applying both the PervapTM4100 PVA based polymeric membrane and modified silica ceramic one. Application of hydrophilic membranes allowed for the complete dewatering of ABE-water mixtures. Eventually, the combination of membrane separation processes (microfiltration, hydrophobic pervaporation, hydrophobic thermopervaporation, membrane distillation, and hydrophilic pervaporation) enhanced by the liquid-liquid phase separation was suggested for the recovery and dehydration of ABE aqueous mixture.

The paper presents a studies on decreasing boron and arsenic concentrations in processed geothermal water. Reverse osmosis leads to obtain permeate and concentrate characterized by concentrations of 3.99 and 9.82 mg B L-1, as well as 2.93 and 120 mu g As L-1, respectively. This disqualifies the possible use of forth streams for irrigation and makes them inacceptable to be discharged to the surface aquifers. Hence, they have to be treated using chelating resins to further decrease concentrations of boron and arsenic. the new chelating resins 1PTN and 2PTN were synthesized by polymerization of vinylbenzyl chloride (VBC) within a matrix of Amberlite XAD-4 followed by the modification with N-methyl-D-glucamine (NMDG). the so-synthesized NMDG-functionalized resins were evaluated for the removal of boron and arsenic from RO streams and compared to commercial boron selective chelating resin (Diaion CRB 05). Removals and its kinetics followed the pseudo-second order model. Based on diffusional and reactional kinetic models, it was determined that diffusion in pores of the chelating resins was the critical step and the boron sorption rate of epidermal-activated resin was mostly controlled by the reacted layer mechanism. Based on the obtained results, it was found that the resin 2PTN, characterized by macroporous, epidermal-like structure revealed 94% removal of boron and 97% removal of arsenic from RO concentrate. These performances allowed to effectively decrease concentrations of both species to the permissible levels for drinking and irrigation water. What is more, the synthesized resins successfully competed with the commercial boron selective resin Diaion CRB 05 in the boron removal, and outperformed the commercial resin in the arsenic removal, making them a very attractive alternative for reclamation of geothermal water., Bilateral Collaboration Program between Turkey and Poland [TUBITAK-NCBR-2549, TUBITAK 117M023]; Turkish Higher Education CouncilMinistry of National Education - Turkey [YOK 100-2000], This research has been financially supported by Bilateral Collaboration Program (TUBITAK-NCBR-2549) between Turkey and Poland (Project No: TUBITAK 117M023). E. Altiok is grateful for the PhD scholarship of Turkish Higher Education Council (YOK 100-2000). We thank Izmir Geothermal Co. for the kind support to get geothermal water samples. We also acknowledge Mitsubishi Chem., Japan for Diaion CRB05.

WOS: 000439324900017, Ion exchange resins based on the water-insoluble polymers poly(acrylamide-co-styrene sodium sulfonate) (P(AAm-co-ESS)), poly(2-acrylamide-2-methyl-1-propanesulfonic acid-co-acrylicacid) (P(APSA-co-AAc)), poly(2-acrylamidoglycolic acid-co-2-acrylamide-2-methyl-1-propane sulfonic acid) (P(AAGA-co-APSA)), and poly(2-acrylamidoglycolic acid-co-4-styrene sodium sulfonate) (P(AAGA-co-ESS)) were synthesized by radical polymerization. These polymers were employed to remove Cr(III) from an aqueous solution. The optimum sorption parameters of amount of resin and sorption time were obtained through batch-mode sorption tests. Following batch elution tests to identify the best eluting agent. Finally, the column-mode sorption/elution behaviors of ion exchange resins were studied. The ion exchange resins exhibited excellent removal of Cr(III). The P(AAGA-co-APSA) resin exhibited 89.4% removal, while P(AAGA-co-ESS) displayed 88.3%, P(AAm-co-ESS) 86.8%, and P(APSA-co-AAc) 89.3%. The column-mode was studied by the P(AAGA-co-APSA) resingave a breakthrough capacity of 1.5 mg Cr(III)/mL resin in the first cycle. The elution efficiency was almost 100%. The breakthrough capacity was 1.2 mg Cr(III)/mL resin in the second cycle. The elution efficiency was 90.2% in the second cycle., FONDECYTComision Nacional de Investigacion Cientifica y Tecnologica (CONICYT)CONICYT FONDECYT [1150510]; 7FP-MC Actions Grant CHILTURPOL2 (PIRSES-GA-2009 Project) [269153], The authors thank FONDECYT (Grant No 1150510) and the7FP-MC Actions Grant CHILTURPOL2 (PIRSES-GA-2009 Project, Grant No 269153) for financial support.

We demonstrate a novel mode for hybrid capacitive deionization, HCDI, that allows selective extraction of lithium ions from geothermal water. The HCDI cell was comprised with cathode made of lithium selective material and anode consisting of activated carbon coated with anion-exchange membrane. To confirm ion-exchange character of the process, based on ions diffusion/migration into electrodes, impedance spectroscopy and cyclic voltammetry were applied. By optimizing the process mode it was possible to obtain lithium enriched stream and remove up to 73% of lithium captured by the electrode. The process was characterized by an extremely high salt adsorption capacity of 800 mg/g and total energy consumption on the level of 0.183 Wh per 1 g of adsorbed salt.

In this paper, our studies on the extraction of lithium using a new desalination technology are presented. The combination of capacitive deionization with ion pumping batteries resulted in the hybrid CDI process. Hybrid CDI was composed by an electrode prepared from inorganic adsorbents (blended manganese and titanium oxides) and a counter electrode made of activated carbon. The structure and porosity of the adsorbents were investigated by SEM, XRD and BET analyses, while the pore size distribution was calculated according to the QSDFT model. The adsorbent with the best electrochemical performance was manganese oxide with a 5% content of titanium dioxide. It was characterized by enhanced electron conductivity and a structure that offers the highest hybrid CDI adsorption capacity for lithium. This material was used to build a negatively polarized electrode of the hybrid system that allowed ∼36 mg/g sorption capacity for LiCl to be reached. The uptake of KCl and NaCl was 16 mg/g and 11 mg/g, respectively. Additionally, the best adsorbent was characterized by a 2 times smaller consumption of energy needed to extract lithium chloride in comparison to other monovalent salts.

Lithium is a critical element due to its use in lithium-ion batteries, required for electric vehicles and stationary energy storage devices. Various approaches have been applied to extract it from the available resources. One of the developed lithium-capturing methods is hybrid capacitive deionization (HCDI), where the cathode is made of spinel-type material. This paper presents our study on the most effective Li, Mn, and Ti spinel-type materials, for which we analysed their structure, efficiency for lithium capturing, and energy consumption in the HCDI system. We found spinel with Li:Mn:Ti ratio of 1:3:0.15 to be the best material for lithium recovery. The natural geothermal water was applied for testing lithium recovery by HCDI equipped with the investigated material. By applying the asymmetrical electric mode, the lithium capturing efficiency reached near 80% with 8 min. The separation factors for other cations such as sodium, potassium, calcium, magnesium, and strontium were over three-times smaller.

In this study the efficiency of three various commercial membranes based on poly(octylmethyl siloxane), poly(ether-block-amide), and poly(dimethylsiloxane) polymers were investigated in pervaporative separation of acetone, butanol, and ethanol from aqueous binary solutions (0–5 wt% of organics) at 60 °C. The influence of fermentation broth microfiltration on membrane performances in pervaporative removal of ethanol was also investigated. The use of microfiltration improved the effectiveness of the removal of ethanol from the broth comparing with the unfiltered one. Molar ratios of organics to water fluxes and Pervaporative Separation Index (PSI) values were employed to discuss membranes' performance in removal of organic solvents from binary aqueous mixture. It was found that PDMS based (Pervap4060) membrane shows the best separation efficiency in all tested binary aqueous mixtures. Modelling of the process proved the feasibility of pervaporation process for the removal of acetone, butanol and ethanol from binary and quaternary aqueous mixtures.

A method for the synthesis of anion-exchange membranes by the grafting of ethylenediamine (EDA), diethylenetriamine (DETA) or pentaethylenehexamine (PEHA) onto poly(vinyl chloride) (PVC) film has b...

In this study, commercial polymers containing N -methyl- d -glucamine-quaternary ammonium ion-exchange ligands were subjected to a series of sorption tests. Mo(VI) and V(V) sorption were performed using strong (Amberlite IRA-400) and weak (Amberlite IRA-743) ion-exchange resins as adsorbents under equilibrium and kinetic conditions. The tests involved evaluating the influence of the adsorbent dose, pH, and temperature. The adsorbed Mo(VI) and V(V) levels reached maximum values at fixed pHs of 6.0 and 4.0 for IRA-400 and IRA-743, respectively. The maximum Mo(VI) and V(V) batch uptakes were determined to be 208 and 177 mg·g − 1 for IRA-743 and IRA-400, respectively. The increase in temperature resulted in increasing Mo(VI) and V(V) sorption capacities for both resins, indicating the endothermic nature of the process. The most rapid adsorption equilibrium was achieved after 30 min during sorption of Mo(VI) on the IRA-400 resin, which resulted in the removal of nearly all metal from the solution. Molybdenum and vanadium adsorption/desorption cycles were performed to estimate the adsorbent lifetime, and good efficiency was observed during three cycles of elution and reuse. FTIR analysis confirmed the presence of Mo and V species within the structures of the IRA-400 and IRA-743 resins after the sorption process.

Pervap™ 2200, 2201, 2216, 2255, and 2510 hydrophilic, PVA membranes were investigated in pervaporation of water-tetrafluoropropanol mixtures. Physicochemical properties of membranes were characterized by determining the contact angle (CA) of water and glycerol and the surface free energy (SFE). The separation and transport properties of membranes were determined during vacuum pervaporation in contact with water-TFP mixtures containing up to 22 wt.% water. It was found that all membranes were hydrophilic (CA < 90°) and the polar component of SFE was much higher than the dispersive one. The apparent activation energy for water transport was very high (Eapp = 81.3 kJ/mol), indicated that water transport is activated thermally. Pervap™ membranes were very selective during the dehydration process of TFP. In contact with the Pervap™ 2200, 2201, and 2216 permeate contained practically pure water, regardless the feed composition. The process separation index (PSI) for Pervap™ 2200 and 2216 was close to 5000 kg m−2 h−1, suggesting that both membranes can be efficiently applied in the batch pervaporation process for TFP dehydration.

This paper presents a method for producing nanofibrous composite membranes for the separation of a vegetable oil–water mixture. Neat polyvinylidene fluoride (PVDF), polyacrylonitrile (PAN) nanofibres and PVDF/PAN mixtures were used to prepare the membranes. Argon plasma treatment, followed by a chemical surface modification, was applied to alter the hydrophilicity and oleophobicity of the membranes. The obtained results showed that the membranes change their surface character (hydrophilicity and oleophilicity) in relation to the mixing ratio of the PVDF/PAN nanofibres and the surface modification parameters. These results can extend the application of PVDF, PAN and PVDF/PAN nanofibrous membranes to the treatment of oily water.

The poly([(2-methacryloyloxy)ethyl]trimethylammonium chloride) [P(MOTA)] based chelating resin was synthesized by radical polymerization and employed for Cr(VI) removal. The sorption capacity of this resin was very high with a fast sorption rate for Cr(VI) obeying a pseudo-second order kinetic model. In agreement to diffusion model equations, the rate determining step was film diffusion according to the infinite solution volume (ISV) model and reacted layer in accordance with the unreacted core (UC) model. In a column-mode sorption study, the breakthrough capacity obtained was 24.3 mg Cr/mL-resin. The elution of Cr(VI) from the resin was achieved using a mixture of 1.0 mol/L NaOH and 1.0 mol/L NaCl with an elution efficiency of about 100 %. Based on FT-IR measurements, it was clearly understood that Cr(VI) was sorbed by the resin through the quaternary amine functional groups.

The combination of microscopic (atomic force microscopy and scanning electron microscopy) and goniometric (static and dynamic measurements) techniques, and surface characterization (surface free energy determination, critical surface tension, liquid entry pressure, hydraulic permeability) was implemented to discuss the influence of perfluoroalkylsilanes structure and grafting time on the physicochemistry of the created hydrophobic surfaces on the titania ceramic membranes of 5 kD and 300 kD. The impact of molecular structure of perfluoroalkylsilanes modifiers (possessing from 6 to 12 carbon atoms in the fluorinated part of the alkyl chain) and the time of the functionalization process in the range of 5 to 35 h was studied. Based on the scanning electron microscopy with energy-dispersive X-ray spectroscopy, it was found that the localization of grafting molecules depends on the membrane pore size (5 kD or 300 kD). In the case of 5 kD titania membranes, modifiers are attached mainly on the surface and only partially inside the membrane pores, whereas, for 300 kD membranes, the perfluoroalkylsilanes molecules are present within the whole porous structure of the membranes. The application of 4 various types of PFAS molecules enabled for interesting observations and remarks. It was explained how to obtain ceramic membrane surfaces with controlled material (contact angle, roughness, contact angle hysteresis) and separation properties. Highly hydrophobic surfaces with low values of contact angle hysteresis and low roughness were obtained. These surfaces possessed also low values of critical surface tension, which means that surfaces are highly resistant to wetting. This finding is crucial in membrane applicability in separation processes. The obtained and characterized hydrophobic membranes were subsequently applied in air-gap membrane distillation processes. All membranes were very efficient in MD processes, showing good transport and selective properties (∼99% of NaCl salt rejection). Depending on the membrane pore size and used modifiers, the permeate flux was in the range of 0.5-4.5 kg·m(-2)·h(-1) and 0.3-4.2 kg·m(-2)·h(-1) for 5 kD and 300 kD membranes, respectively.

Air gap membrane distillation technique (AGMD) was applied for removal of ethanol, butanol and acetone–butanol–ethanol mixture from water. The influence of various parameters (feed temperature, cooling wall temperature) on pure water transport in AGMD was determined and the efficiency of organic solvents removal from water through two porous membranes (PTFE and PP) was investigated in the detail. Selectivity of organic components recovery did not change significantly with an increase of feed temperature from 41 °C to 63 °C in case of AGMD applied for ethanol and butanol recovery, however significantly higher fluxes were obtained at higher feed temperature. Slightly higher fluxes were obtained during experiments performed with PTFE membrane comparing with PP one. It was found that both PTFE and PP membranes are wetted during AGMD process of water–butanol feed mixture if organic concentration exceeds 2.5 wt% (PTFE) and 1 wt% (PP) at 63 °C feed temperature. This fact limits the possibility of wider AGMD application in organic solvent recovery. The comparison of the efficiency of AGMD with the efficiency of thermopervaporation (TPV) was also performed. In case of 1 wt% ethanol feed mixture it was found that AGMD seems to be more suitable due to higher process separation index value (PSI in the range of 6 kg m −2 h −1 ) than in the case of TPV (PSI in the range of 3 kg m −2 h −1 ). On the contrary, in the case of water–butanol or water–ABE systems TPV is much more efficient method for organics recovery from aqueous mixtures than AGMD. In contact with 3 wt% ABE mixture PSI is equal to 28 and 9 kg m −2 h −1 for TPV and AGMD processes, respectively.

The initially hydrophilic micro- and macroporous ceramic membranes were successfully hydrophobized by grafting with fluoroalkylsilane (FAS) molecules. The influence of diverse parameters (e.g. type of molecule, duration of grafting, concentration of FAS solution, type of solvent) on the resulting hydrophobic surface was investigated. The liquid entry pressure of water (LEPw) was used as a measure of the hydrophobization efficiency. The prepared membranes were subsequently investigated in vacuum membrane distillation (VMD) process using pure water and water–organic solvent solutions as feed mixtures. It was found that permeate flux of pure water is strictly correlated with LEPw value. The selectivity of membranes in contact with water–organic mixtures depends strongly on the pore size of the hydrophobized membrane. Microporous membrane are much less efficient in the separation of organics from water (separation factor of ethyl acetate – EtAc in the range 1.3–30) comparing with macroporous ones (separation factor of EtAc in the range 32–60). The results were also discussed assuming the various mechanism of transports through porous ceramic membranes. These latter results were additionally compared with the results obtained for hydrophobic polymeric membranes (separation factor of EtAc in the range 25–450).

In this paper, we show the effects of various types of polyelectrolytes and functionalized particles on the properties of soft electrodes in the CapMix process. To build negatively charged electrodes, poly(acrylic acid), poly(methacrylic acid), mixture poly(acrylic acid) and poly(methacrylic acid) and poly (4-styrenesulfonic acid) sodium salt polyelectrolytes were selected, while ethylenediamine, polyethyleneimine 25,000 g/mol, polyethyleneimine 750,000 g/mol were employed as positively charged electrodes. Based on the power production, system effectiveness, operating potential window and potential rise, the best pair of soft electrodes was composed of ethylenediamine and mixture poly(acrylic acid) and poly(methacrylic acid). This combination exhibited power production at a level of 293 mW/m2 and a power efficacy of 61.4%; furthermore, it showed very stable performance over 20 cycles. The investigated charge-doped ethylenediamine and mixture poly(acrylic acid) and poly(methacrylic acid). pair of electrodes exhibited power production that was almost 1 and 10 times higher than the power production in systems with ion-exchange membranes or neat AC electrodes, respectively.

The aim of this study is to investigate the performances of new N-methyl-D-glucamine functionalized resins revealing gel (1JW), expanded gel (2JW) and epidermal-like structure (2PTN) for simultaneous removal of boron and arsenic from saline geothermal water by means of adsorption-membrane filtration hybrid process. the effects of adsorbent concentration and resin replacement rate were particularly studied for boron removal from geothermal water. Boron removal with 1JW resin increased from 66% to 86% by doubling the resin concentration while the respective values found for 2PTN resin were 61% and 73%. in the case of the microporous 2PTN resin, due to its epidermal-like structure, the efficiency of the hybrid process was improved by increasing the replacement rate of fresh and saturated resins. Unlike the 2JW resin as the most efficient resin for boron removal among novel resins, the maximum arsenic removal of 35.8% was obtained by the 1JW resin using a resin concentration of 4 g/L. the Dowex XUS 43594.00 resin exhibited lower arsenic removal of 21.5% than 2PTN (4 g/L) and 2JW (2 g/L) giving arsenic removals of 22.4% and 28.8%, respectively., bilateral collaboration programme between Turkey and Poland [TUBITAK 117M023, TUBITAK-NCBR-2549]; Turkish Higher Education CouncilMinistry of National Education - Turkey [YOK 100-2000], This research has been financially supported by bilateral collaboration programme (TUBITAK-NCBR-2549) between Turkey and Poland (Project No: TUBITAK 117M023). Esra Altiok is grateful for the PhD scholarship of Turkish Higher Education Council (YOK 100-2000). We thank Izmir Geothermal Co. for geothermal water samples.

The relatively new exploitation of nanoassemblies used for the recovery of clean water from oily emulsions has received a great deal of attention recently. Among the different innovations, nanofibrous membranes decorated with nanoparticles seem to be the most promising option due to their versatility, recyclability, and high oil/water separation performance. In the current study, we introduce a laser-mediated strategy to produce polyvinylidene fluoride nanofibrous membranes decorated with a low loading of Ag nanoparticles. The pristine membranes were firstly modified by an alkaline treatment to obtain hydroxyl groups on their surface, which then facilitated the nanoparticle decoration. The synthesis and decoration of the nanoparticles were achieved by the laser-mediated reduction of silver nitrate dissolved in water, while no hazardous reducing or stabilizing agents were employed in the process. In comparison with the unmodified membrane, the modified one displayed an outstanding hydrophilic behavior and a remarkable 3.9-fold improvement in the separation of water from oily emulsions with a nearly negligible permeability decline through the time. In sum, the introduced methodology not only enables the improvement over the oil/water separation performance in polymer-based membranes but also promises to reduce the environmental impact related to the design of nanotechnology-based solutions used in the sector.

In the presented paper interpolymeric ions exchange membranes were used in a capacitive mixing process. This was reach to increase the amount of energy generated during mixing waters with two different salinities. Membranes were prepared by extrusion of ethylene/styrene-co-divinylbenzene interpolymer followed by chemical modification of obtained foils. The extrudate contained 30 wt% of polystyrene crosslinked with different amount of divinylbenzene. Four pairs of membranes of different thickness were tested in CapMix process. It was found that the best membranes for energy harvesting were obtained from interpolymer with 2 wt% of DVB.

A surface modification of polyamide 6 (PA), polyethylene terephthalate (PET) and polypropylene (PP) textiles was performed using zinc oxide to obtain antibacterial layer. ZnO microrods were synthesized on ZnO nanoparticles (NPs) as a nucleus centers by chemical bath deposition (CBD) process. Scanning Electron Microscopy (SEM) and X-ray diffraction (XRD) indicated that wurzite ZnO microrods were obtained on every sample. Differential Scanning Calorimetry (DSC), Fourier Transform Infrared Spectroscopy (FTIR), Atomic Force Microscopy (AFM) and Liquid Absorption Capacity (LAC) analysis indicate that the amount and structure of antibacterial layer is dependent on roughness and wettability of textile surface. The rougher and more hydrophilic is the material, the more ZnO were deposited. All studied textiles show significant bactericidal activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). A possible mechanism and difference in sensitivity between Gram-negative and Gram-positive bacteria to ZnO is discussed. Considering that antibacterial activity of ZnO is caused by Reactive Oxygen Species (ROS) generation, an influence of surface to volume ratio and crystalline parameters is also discussed.

The result of synthesizing anion exchangers bearing trimethylammonium functionalities is presented. Ion exchange resins of poly(4-vinylbenzyltrimethylammonium chloride) (PVBTAC) (Resin 1) and poly(3-acrylamidopropyltrimethylammonium chloride) (PAPTAC) (Resin 2) were obtained via the radical polymerization technique and studies on the sorption of molybdenum and vanadium ions were conducted at 20, 30, and 40 °C using the batch method from single-component aqueous solutions. The greatest total sorption capacities were 198 mg Mo(VI) g−1 at 20 °C and 193 mg V(V) g−1 at 40 °C for Resin 1. The calculated thermodynamic parameters demonstrated that the sorption of Mo(VI) was an exothermic process, while the uptake of V(V) was endothermic. The kinetic studies revealed the compliance of the process with a quasi-second-order kinetic model. Simultaneously, equilibrium was achieved within 15 min in two rate-controlled stages. The fitting of the Langmuir and Freundlich mathematical models demonstrated the chemical character of the sorption processes. Elution and reuse studies showed that Mo(VI) may be completely recovered from both resins using a sodium carbonate solution. Moreover, the investigated materials are suitable for repeated sorption/desorption cycles.

The paper deals with extraction of lithium by means of two capacitive deionization systems: one composed of lithium selective electrode and second with electrode wrapped with Li-selective membrane. In the case of the first system, hybrid electrodes where obtained by mixing I»-MnO 2 sorbent with activated carbon .The best Li-capacity was determined for electrode with 20 wt.-% of manganese oxide. For larger amounts of I»-MnO 2 the electrode capacity decreased significantly. The second system was composed of carbon electrodes wrapped with ion-exchange membranes. The lithium selective membranes were synthesized by plasma induced interpolymerization of (meth)acrylic monomersinpores of Celgard 2400 support. Two functional monomers, poly(di(ethylene glycol)methyl ether methacrylate) and poly(glycidylmethacylate modified with hydroxymethyl-12-crown-4) were copolymerized with acrylic acid. It was found that the extraction of lithium chloride was the best for membrane caring copolymers of acrylic acid and glycidyl methacrylate modified with crown ether, andit was better than for membranes with sole poly(acrylic acid).

Arsenic is a very toxic element that must be removed efficiently from aqueous streams. Among the most promising techniques used for the removal of arsenic are separation methods using membranes. In this study, a regenerated cellulose ultrafiltration (UF) membrane and a poly(diallyl dimethyl ammonium chloride) P(DADMAC) were coupled and used in combination to remove As(V) from an aqueous solution. The influences of pH, the polymer:As(V) molar ratio, and the presence of interfering ions such as chloride and sulfate were investigated in arsenic removal via the washing method. The efficient retention of arsenic was observed at pH 7 with a 5:1 polymer:As molar ratio and with an efficiency of approximately 85 % at Z = 10 for P(DADMAC). The maximum retention capacity of As(V) was determined by the enrichment method, and the results indicated that 194 mg of As(V) was removed per gram of polymer. Finally, using enrichment and washing methods sequentially, the sorption–desorption process and regeneration of P(DADMAC) were performed successfully.

Temperature driven membrane thermopervaporation was studied in this work. Impact of various experimental conditions (feed temperature – T f , type of membrane, type of organic solvent in binary aqueous mixture, feed composition) on transport and selectivity in TPV was investigated experimentally. Two commercially available dense PDMS based membranes (Pervatech and Pervap 4060) were utilized during TPV experiments in contact with pure water and binary aqueous mixtures of acetone, butanol and ethanol. Intrinsic properties (permeance and selectivity coefficient) of membranes were determined and discussed. Transport in thermopervaporation increases with an increase of feed temperature (at constant temperature of permeate). During TPV experiments performed with Pervatech in contact with acetone–water system, permeance of acetone increased from 0.12 mol m −2 h −1 kPa −1 at T f = 30 °C to 0.24 mol m −2 h −1 kPa −1 at T f = 42 °C, whereas permeance of butanol increased from 0.45 mol m −2 h −1 kPa −1 at T f = 30 °C to 0.64 mol m −2 h −1 kPa −1 at T f = 41 °C. Pervap 4060 membrane showed better properties in thermopervaporative recovery of butanol and ethanol from water than Pervatech membrane. It was also found that the application of stainless steel porous support reduces ethanol and water fluxes, but it does not affect the selectivity up to 3 wt.% of ethanol in feed.

Butanol has a great potential as a biofuel and to date a lot of research has been done both in terms of more efficient butanol production as well as in developing product recovery methods. Many of them deal with separation techniques which can be used for selective recovery of acetone, n-butanol and ethanol from model solutions and fermentation broths. This work is a review of techniques used for ABE recovery, such as distillation, adsorption, gas stripping, liquid–liquid extraction, pertraction, membrane distillation, sweeping gas pervaporation, thermopervaporation and vacuum pervaporation. Advantages and disadvantages of using particular methods, examples of applications and integrated processes are also described.

The chloromethyl groups have been introduced into commercial S/DVB copolymer matrixes via interpenetrating polymer networks (IPN) synthesis. The procedure involves impregnation of the Amberlite XAD-4 adsorbent, with use of the vinylbenzyl chloride (VBC) and divinylbenzene (DVB) monomers mixture, and suspension polymerization process. The syntheses were evaluated by FT-IR spectra and SEM analyses and furthermore by chlorine content determination as well as characterization of porous structure by nitrogen adsorption at liquid nitrogen temperature. Designed synthesis approach allowed determining organic and water phases composition. Furthermore, impact of an excess of the organic phase removal method has been investigated. Basing on the obtained results it could be stated that the chloromethyl groups, derived from VBC monomer, were successfully introduced into the XAD-4 structure. Captured SEM images revealed significant changes in the beads' surface morphology after polymerization processes. The presented studies reveal designed and executed synthesis processes, which involve the use of a proper water phase and excess of organic phase removal. Observed changes in the beads' morphology suggest that introduced functionalities are concentrated on the porous surface of the XAD-4 adsorbent.

A facile and low-cost method has been developed for separation of oily wastewater. Polyvinylidene fluoride/polyacrylonitrile (PVDF/PAN) nanofibers laminated on a supporting layer were tested. In order to create highly permeable and fouling-resistant membranes, surface modifications of both fibers were conducted. The results of oily wastewater separation showed that, after low vacuum microwave plasma treatment with Argon (Ar) and chemical modification with sodium hydroxide (NaOH), the membranes had excellent hydrophilicity, due to the formation of active carboxylic groups. However, the membrane performance failed during the cleaning procedures. Titanium dioxide (TiO₂) was grafted onto the surface of membranes to give them highly permeable and fouling-resistance properties. The results of the self-cleaning experiment indicated that grafting of TiO₂ on the surface of the membranes after their pre-treatment with Ar plasma and NaOH increased the permeability and the anti-fouling properties. A new surface modification method using a combination of plasma and chemical treatment was introduced.

Dielectric barrier discharge plasma was used to modify track etched poly(ethylene terephthalate) membranes followed by grafting of poly(acrylic acid) and copolymers of acrylic acid and di(ethylene glycol)methyl ether methacrylate. The evaluation by IR and XPS spectroscopies showed that both polymers were successfully grafted to the porous membranes. Determination of permeate fluxes pointed the membranes to have excellent responses to pH changes when grafting yield was not so high. When grafting exceeded 0.1 mg cm −2 stimuli response gel-filled membranes were formed that could be used for transport of alkaline ions. The best permselectivity was observed for poly(ethylene terephthalate) membranes grafted with 1:2 copolymer of acrylic acid and di(ethylene glycol)methyl ether methacrylate. The dialysis was more effectively facilitated for lithium than for potassium or sodium salts at solution of pH = 5.5.

This paper presents a systematic study of boron removal from simulated and real aqueous systems in northern Chile by means of polymer-enhanced ultrafiltration. Poly(glycidyl methacrylate-N-methyl-D-glucamine), P(GMA-NMG), was used to form complexes with boron, and a cellulose-regenerated membrane was used as a complex separator. The first tests were performed using two simulated water samples from northern Chile with the same pH and concentrations of boron, arsenic, and chloride. P(GMA-NMG) showed a maximum of 60% boron retention for these artificial waters. Studies of boron enrichment using P(GMA-NMG) with simulated water showed that the soluble polymer reached maximum retention capacity values between 2.0 and 4.0 mg of B retained per gram of polymer. SEM images and FTIR spectroscopy confirm the deposition of the polymer on the surface of the membrane after polymer-enhanced ultrafiltration, which explains the permeate flux decay observed in retention experiments. Finally, sorption–desorption test...

Results of research on the effectiveness of selected hydrophobic PDMS-based membranes in the pervaporative removal of acetone, butanol and ethanol from binary and quaternary aqueous mixtures are presented. Various investigated PDMS membranes exhibit high selectivity towards butanol. Values of separation factor β in contact with 1 wt.% BuOH are in the range from 27 (Pervatech PDMS 2.0) to 40 (Pervap 1070 PDMS 0.2). Pervatech PDMS 2.0 membrane, showing the highest PSI value, was chosen for experiments with binary and quaternary aqueous mixtures. Simulation of batch pervaporation process showed that during 300 min of the process it is possible to remove over 95% of organics from the feed mixture, containing initially 3 wt.% of ABE mixture and with feed to membrane area ratio of 100 kg m−2. It was also found that a longer batch pervaporation process results in a more diluted permeate. Such phenomenon is caused by the fact that organic fluxes decrease with time whereas water flux is constant during batch process.

Uniformly sized polymeric molecularly imprinted microspheres have been synthesized by membrane emulsification and suspension polymerization of methyl methacrylate and ethyl glycol dimethacrylate in the presence of bisphenol A as a template. At the beginning the best monomer compositions were selected by bulk polymerization of eight different mixtures of monomer and crosslinking agent. For the selected compositions that had the highest affinity to bisphenol A, a two-step process composed of membrane emulsification and suspension polymerization was used. Materials prepared by the two-step process showed the higher efficiency to the bisphenol A removal than their analogues prepared by bulk polymerization. The best material was synthesized from a mixture of methyl methacrylate and ethylene glycol dimethacrylate as 4:6 in the presence of n-octane as a solvent, and with 3 wt.% of bisphenol A. The logKBPA value for this sample was 4.9. The experimental sorption isotherms were fitted by Scatchard plots and hetero...

Poly(acrylic acid) and copolymers of acrylic acid and di(ethylene glycol)methyl ether methacrylate were grafted onto polycarbonate and poly(ethylene terephthalate) membranes using dielectric barrier discharge plasma. The obtained membranes exhibited responses to pH change. When they were porous, they behaved as pH-sensitive valves. When pores were filled with gel, they were able to work in dialysis and separated LiCl, KCl, and NaCl salts. The best selectivity for alkaline ions was obtained for poly(ethylene terephthalate) membranes grafted onto copolymer of acrylic acid and di(ethylene glycol)methyl ether methacrylate with a grafting yield of 0.16 mg/cm2. The separation should be conducted at pH = 5.5. It was noted that there is better membrane selectivity towards lithium and potassium than sodium ions.

The effect of ethanol concentration on the removal of bisphenol A (BPA) from water-ethanol mixtures using pulverized activated carbon (PAC) was studied. Adsorption equilibria and kinetics were measured using batch uptake experiments. Equilibrium and kinetic data were correlated with the Langmuir model and the non-ideal competitive adsorption (NICA) model. Finally, BPA removal in an adsorption-microfiltration hybrid system was tested and simulated with a non-steady model. Ethanol has a strong influence on the binding capacity of BPA on PAC and the uptake from 10 mol/L (50.4 wt-%) aqueous ethanol is less than 10% of the value measured in water. The experimental adsorption isotherms were modeled using several isotherm models and by considering the effect of ethanol on solution activity coefficients. The best correlation was obtained with the NICA model assuming that part of the binding sites is inaccessible for BPA. The BPA adsorption rate was described using a pore diffusion model and reasonably good correl...

Water-soluble poly[glycidyl methacrylate N-methyl d-glucamine], P(GMA-NMG), was synthesized and purified by ultrafiltration membranes. It was subsequently used for arsenic removal by coupling electro-oxidation (EO) and polymer-enhanced ultrafiltration (PEU) processes. In the EO-PEU combined process, P(GMA-NMG) was first used as supporting electrolyte during the exhaustive electro-oxidation of As(III) to As(V) and then it was used to remove As(V) from aqueous solution through PEU. At first stage, the complete EO of As(III) to As(V) was performed with a platinum reticulated vitreous carbon (RVC)-modified electrode and the advancement of the electrolysis was monitored by analytical electrodes. After the oxidation of As(III) to As(V), the PEU was carried out by washing method using regenerate cellulose membrane and 1 bar of pressure. The effects of supporting electrolytes and pH on EO-PEU combined process were investigated. The best results showed that by using P(GMA-NMG) as supporting electrolyte during the complete electro-oxidation of As(III) to As(V) followed by PEU separation, almost 80% of As(V) was removed at pH 10. © 2013 American Institute of Chemical Engineers Environ Prog, 33: 918–924, 2014

In this study, regenerated cellulose membrane was used as a filter in liquid-phase polymer-based retention technique. The poly(4-vinyl-1-methylpyridinium bromide), P(BrVMP), was used as extracting reagent of As(V). The role of pH, polymer:As(V) molar ratio, and influence of regenerated cellulose membrane were investigated by washing method. It was observed that the efficient retention was obtained at pH 9 with 20:1 polymer:As molar ratio and it was about 100 % at Z = 10 for P(BrVMP). Experimental data showed that the regenerated cellulose membrane, compared to poly(ethersulfone) membrane, has a capacity to interact with As(V). The maximum retention capacity of P(BrVMP) was determined by enrichment method, and then, using alternately washing and enrichment methods, the charge–discharge process and recovery of P(BrVMP) were performed.

The effect of acrylonitrile co-polymerization and molecular imprinting on bisphenol A (BPA) affinity by the polystyrene-divinylbenzene adsorbents was studied. Adsorption equilibria were measured using batch uptake experiments and equilibrium data were analyzed by means of Langmuir isotherm and Scatchard approach. The calculated parameters were utilized for modeling of adsorption–microfiltration hybrid system. The highest BPA capacity, 27 mg/g, is achieved for the material synthesized with 10% BPA template concentration in relation to monomer. Acrylonitrile does not improve BPA affinity or adsorption capacities of sorbents. BPA sorption rate can be described assuming pore diffusion control and using a tortuosity factor of 3. The estimated equilibrium and mass transport parameters describe reasonably well the removal of BPA in the adsorption–microfiltration hybrid system. Model calculations show that 97% reduction in BPA concentration is attained with sufficiently high amount of the adsorbent.

Preparation and properties of anion-exchange membranes for Donnan dialysis of borates were described. It was shown that grafting of polyethyleneimine to surface of Celgard 2500 membrane resulted in preparation of well-permeable membranes. Fluxes of NaCl and Na 2 SO 4 through new membranes were larger than flux of the same salts across commercial FumaTech anion-exchange membranes. However, the collapse of polyethyleneimine chains, generated by higher ionic strength of solution, caused poor selectivity of the grafted membranes and their malfunctioning in the Donnan dialysis process.

The manuscript gathers knowledge on boron — its properties, sources, presence in the environment, effects on plants and animals and methods for its removal. It is shown that so far used recovery technologies should be developed and there is still a room for new separation methods. It seems that introduction of new sorption materials as well as the use of sorption–membrane filtration hybrid, combining sorption on fine B-sensitive sorbent with membrane separation, can offer promising features for technological approach. The intention of this review is to update the information on methods for boron removal and to show the direction of its development.

Desalination by capacitive deionization (CDI) is an emerging technology for the energy- and cost-efficient removal of ions from water by electrosorption in charged porous carbon electrodes. A variety of carbon materials, including activated carbons, templated carbons, carbon aerogels, and carbon nanotubes, have been studied as electrode materials for CDI. Using carbide-derived carbons (CDCs) with precisely tailored pore size distributions (PSD) of micro- and mesopores, we studied experimentally and theoretically the effect of pore architecture on salt electrosorption capacity and salt removal rate. Of the reported CDC-materials, ordered mesoporous silicon carbide-derived carbon (OM SiC-CDC), with a bimodal distribution of pore sizes at 1 and 4 nm, shows the highest salt electrosorption capacity per unit mass, namely 15.0 mg of NaCl per 1 g of porous carbon in both electrodes at a cell voltage of 1.2 V (12.8 mg per 1 g of total electrode mass). We present a method to quantify the influence of each pore size increment on desalination performance in CDI by correlating the PSD with desalination performance. We obtain a high correlation when assuming the ion adsorption capacity to increase sharply for pore sizes below one nanometer, in line with previous observations for CDI and for electrical double layer capacitors, but in contrast to the commonly held view about CDI that mesopores are required to avoid electrical double layer overlap. To quantify the dynamics of CDI, we develop a two-dimensional porous electrode modified Donnan model. For two of the tested materials, both containing a fair degree of mesopores (while the total electrode porosity is ∼95 vol%), the model describes data for the accumulation rate of charge (current) and salt accumulation very well, and also accurately reproduces the effect of an increase in electrode thickness. However, for TiC-CDC with hardly any mesopores, and with a lower total porosity, the current is underestimated. Calculation results show that a material with higher electrode porosity is not necessarily responding faster, as more porosity also implies longer transport pathways across the electrode. Our work highlights that a direct prediction of CDI performance both for equilibrium and dynamics can be achieved based on the PSD and knowledge of the geometrical structure of the electrodes.

WOS: 000378145500001, The method of synthesis and the arsenic removal properties of ion-exchange resins based on N-methyl-D-glucamine and trimethylammonium groups are presented. The N-methyl-D-glucamine based monomer was synthesized by the reaction of 4-vinyl benzyl chloride with N-methyl-D-glucamine, along with the use of N, N-methylene-bis-acrylamide as a crosslinker reagent for polymerization. In addition, poly(4-vinylbenzyl) trimethylammonium was synthesized. Arsenate sorption studies were conducted and the pH effect, kinetics, sorption capacity, and elution performance were studied. The experimental data were fitted to kinetic models, such as the pseudo-first order and pseudo-second order models. The pseudo-second order model exhibited the best correlation with the experimental data. The Langmuir and Freundlich isotherms were fitted to the experimental data, and the Freundlich isotherm exhibited the best fit., 7FP-MC Actions Grant CHILTURPOL2 (PIRSES-GA Project) [269153]; FONDECYTComision Nacional de Investigacion Cientifica y Tecnologica (CONICYT)CONICYT FONDECYT [1110079]; PIA [Anillo ACT 130]; Grant CONICYT-CNRS; REDOC (MINEDUC Project) [UCO1202]; CIPA CONICYT Regional Project [R08C1002], The authors thank the 7FP-MC Actions Grant CHILTURPOL2 (PIRSES-GA-2009 Project, grant number: 269153), FONDECYT (Grant No 1110079), PIA (Anillo ACT 130), Grant CONICYT-CNRS, and REDOC (MINEDUC Project UCO1202 at U. de Concepcion). B.F. Urbano thanks FONDECYT Initiation 11121291 and CIPA CONICYT Regional Project R08C1002.