Ultrafast water permeation through nanochannels with a densely fluorous interior surface.

Ultrafast water permeation in aquaporins is promoted by their hydrophobic interior surface. Polytetrafluoroethylene has a dense fluorine surface, leading to its strong water repellence. We report a series of fluorous oligoamide nanorings with interior diameters ranging from 0.9 to 1.9 nanometers. These nanorings undergo supramolecular polymerization in phospholipid bilayer membranes to form fluorous nanochannels, the interior walls of which are densely covered with fluorine atoms. The nanochannel with the smallest diameter exhibits a water permeation flux that is two orders of magnitude greater than those of aquaporins and carbon nanotubes. The proposed nanochannel exhibits negligible chloride ion (Cl-) permeability caused by a powerful electrostatic barrier provided by the electrostatically negative fluorous interior surface. Thus, this nanochannel is expected to show nearly perfect salt reflectance for desalination.

Heat flows in rock cracks naturally optimize salt compositions for ribozymes.

Catalytic nucleic acids, such as ribozymes, are central to a variety of origin-of-life scenarios. Typically, they require elevated magnesium concentrations for folding and activity, but their function can be inhibited by high concentrations of monovalent salts. Here we show that geologically plausible high-sodium, low-magnesium solutions derived from leaching basalt (rock and remelted glass) inhibit ribozyme catalysis, but that this activity can be rescued by selective magnesium up-concentration by heat flow across rock fissures. In contrast to up-concentration by dehydration or freezing, this system is so far from equilibrium that it can actively alter the Mg:Na salt ratio to an extent that enables key ribozyme activities, such as self-replication and RNA extension, in otherwise challenging solution conditions. The principle demonstrated here is applicable to a broad range of salt concentrations and compositions, and, as such, highly relevant to various origin-of-life scenarios.

Complexions therapy and severe intoxication by Thallium salts.

The aim of this paper is to study the clinical features of severe intoxications with thallium salts and developing effective care schemes for the application of potassium hexacyanoferrate (II) and deferasirox for correction of detected disorders. A total of 39 patients diagnosed with severe thallium salt poisoning were examined in two groups. Group I comprised 20 patients with severe thallium salt poisoning, who were prescribed with potassium-iron hexacyanoferrate in a dose of 250 mg/kg/day per os, intravenous potassium infusions, furosemide intravenously in amount of 40 mg three times per, and hemodialysis until the thallium level in the blood dropped below 10 mg/L, lactulose 30 mL two times per day per os. Group II consisted of 19 people with severe thallium salt poisoning, which in addition to the above treatment, received Deferasirox in a dosage of 500 mg two times per day per os. The clinical picture of severe poisoning with thallium salts is characterized by lesions of the gastrointestinal tract, nervous system (central and peripheral), alopecia, heart rhythm disorders, and myocardial ischemia zones. Extension of standard therapy with potassium-iron by adding hexacyanoferrate deferasirox showed better effect on thallium elimination rate and improved functional state of liver and kidneys in patients with severe thallium salt poisoning.

Application of NF Polymeric Membranes for Removal of Multicomponent Heat-Stable Salts (HSS) Ions from Methyl Diethanolamine (MDEA) Solutions.

This study presents an efficient and scalable process for removing the heat-stable salts (HSS) ions from amine solution while recovering methyl diethanolamine (MDEA) solution for its reuse in gas sweetening plants. The presence of HSS in the amine solution causes the loss of solvent capacity, foaming, fouling, and corrosion in gas sweetening units so their removal is crucial for a more well-performing process. Furthermore, the recovery of the amine solution can make the sweetening step a more sustainable process. In this study, for the first time, the removal of a multicomponent mixture of HSS from MDEA solution was investigated via a nanofiltration process using flat-sheet NF-3 membranes. The impact of operating parameters on salts and amine rejection, and flux, including the operating pressure, HSS ions concentration, and MDEA concentration in the feed solution was investigated. Results based on the nanofiltration of an amine stream with the same composition (45 wt.% MDEA solution) as that circulating in a local gas refinery (Ilam Gas refinery), demonstrated a removal efficiency of HSS ions in the range from 75 to 80% and a MDEA rejection of 0% indicating the possibility of reusing this stream in the new step of gas sweetening.

Fast and Sensitive Detection of Oligosaccharides Using Desalting Paper Spray Mass Spectrometry (DPS-MS).

Conventional mass spectrometry (MS)-based analytical methods for small carbohydrate fragments (oligosaccharides, degree of polymerization 2-12) are time-consuming due to the need for an offline sample pretreatment such as desalting. Herein, we report a new paper spray ionization method, named desalting paper spray (DPS), which employs a piece of triangular filter paper for both sample desalting and ionization. Unlike regular paper spray ionization (PSI) and nanoelectrospray ionization (nanoESI), DPS-MS allows fast and sensitive detection of oligosaccharides in biological samples having complex matrices (e.g., Tris, PBS, HEPES buffers, or urine). When an oligosaccharide sample is loaded onto the filter paper substrate (10 × 5 mm, height × base) made mostly of cellulose, oligosaccharides are adsorbed on the paper via hydrophilic interactions with cellulose. Salts and buffers can be washed away using an ACN/H2O (90/10 v/v) solution, while oligosaccharides can be eluted from the paper using a solution of ACN/H2O/formic acid (FA) (10/90/1 v/v/v) and directly spray-ionized from the tip of the paper. Various saccharides at trace levels (e.g., 50 fmol) in nonvolatile buffer can be quickly analyzed by DPS-MS (<5 min per sample). DPS-MS is also applicable for direct detection of oligosaccharides from glycosyltransferase (GT) reactions, a challenging task that typically requires a radioactive assay. Quantitative analysis of acceptor and product oligosaccharides shows increased product with increased GT enzymes used for the reaction, a result in line with the radioactivity assay. This work suggests that DPS-MS has potential for rapid oligosaccharide analysis from biological samples.

Novel antifouling and antibacterial polyethersulfone membrane prepared by embedding nitrogen-doped carbon dots for efficient salt and dye rejection.

Novel antifouling and antibacterial nanofiltration membranes were prepared by addition of nitrogen-doped carbon dots (NCDs) to the polyethersulfone (PES). The antibacterial NCDs were successfully fabricated using hydrothermal technique and then were characterized using photoluminescence (PL) spectra, FTIR, XRD, and dynamic light scattering (DLS). The resulted nanoparticles were introduced to PES through the phase separation method. The effect of adding NCDs into the PES membrane, as a novel nanofiller was studied in terms of surface and cross-sectional morphology, hydrophilicity, porosity, permeation, fouling resistance, antibacterial properties, and nanofiltration performance. All the NCD-blended membranes exhibited better performance compared to the bare PES. The water flux was significantly increased from 16.5 kg/m2h for the bare PES to 44.6 kg/m2h for the 0.50 wt% NCD-blended membrane. The 0.50 wt% of NCD-blended PES membrane also showed the best antifouling properties, with a flux recovery ratio (FRR) of 73.1%. The retention sequence of the salts was Na2SO4 (80.3%) > MgSO4 (63.5%) > NaCl (20.7%), showing the common behavior of the negative charge nanofiltration membranes. The antibacterial assessment showed a zone of inhibition for both Gram-negative and Gram-positive bacteria in disks membranes containing higher than 0.10 wt% of NCD concentrations. The results offer NCD-blended membranes as a high potential hydrophilic and antibacterial nanofillers.

A novel method for salts removal from municipal solid waste incineration fly ash through the molten salt thermal treatment.

The disposal of the hazardous municipal solid waste (MSW) incineration fly ash is a critical environmental issue in China and the high contents of salts in the fly ash make the ash disposal extremely difficult. The present study proposes a novel method for the salts removal from MSW incineration fly ash using molten carbonates and chlorides at moderate temperatures from 773 K to 1073 K. The results showed that molten salts could effectively extract alkali and alkaline earth metals chlorides and sulfates from the fly ash. Other ash components, like Si/Al-compounds, were precipitated from the molten salts and concentrated in residues. By comparison, molten carbonates showed greater capability in the salts extraction while molten chlorides showed better selectivity in chlorides removal from MSW incineration fly ash. These findings suggest that the optimization of molten salts system could further prove the potential applicability of molten salts thermal treatment method for the salts removal from MSW incineration fly ash.

Tandem Cation/Anion Exchange SPE Cartridge Method for Sample Desalting for HPLC Analysis of Soluble Dietary Fiber: Development and Inter-laboratory Validation.

In HPLC analyses of soluble dietary fiber, desalting processes using open, mixed-bed ion-exchange columns are time-consuming and labor-intensive. We developed and validated a simple desalting method using tandem cation/anion exchange SPE cartridges. We found that combining Bond Elut Jr SCX (upstream) and Bond Elut PSA (downstream) cartridges provided adequate desalting of test solutions. The developed method was then validated in an inter-laboratory study. Five test samples were prepared by mixing food matrixes with purified soluble dietary fiber and treated to generate solutions to test the desalting process. These solutions were then analyzed by eight different laboratories. The results demonstrated that the developed method is simple and reliable for desalting samples containing 140 to 945 mg/100 mL of soluble dietary fiber in preparation for HPLC analysis of soluble dietary fiber.

Impacts of biofouling on the removal of pharmaceutically active compounds by a nanofiltration membrane.

The impacts of biofouling on the retention of pharmaceutically active compounds (PhACs) by a commercially available nanofiltration membrane (NF 270) were systematically studied. Biofouling was achieved through inoculating live and dead Pseudomonas aeruginosa into artificial wastewater. In comparison to a clean membrane, an increase in PhAC rejection during biofouling with live cells was observed. However, the rejection behaviors presented more complex changes during biofouling with dead cells: PhAC rejection was below the clean membrane in the early biofouling stage; however, in the later stage, PhAC rejection was above the clean membrane. In addition, PhAC rejection behaviors present the similar tendency as salt rejection under both biofouling conditions. In addition, solute rejections were much lower for biofouling with dead cells than those for biofouling with live cells. Combined with biofilm characterization under both biofouling conditions, we could conclude that biofilm enhanced osmotic pressure (BEOP) due to higher cell counts and biofilm thickness led to a decrease in PhAC retention, especially for the dead cells. In addition, more dominant steric exclusion in the later stage of biofouling due to higher extracellular polymeric substances (EPS) concentration on the membrane surface resulted in an increase in PhAC retention.

Reduction of organic matter and disinfection byproducts formation potential by titanium, aluminum and ferric salts coagulation for micro-polluted source water treatment.

Typical Chinese source water has high content of low molecular weight and aromatic protein-like organic matter which is difficult to remove and poses a great challenge to conventional coagulation/flocculation. To investigate coagulation performance of this typical water, this research focused on organic matter removal characteristics and the associated disinfection byproducts formation potentials (DBPFPs) during the coagulation process by titanium salts compared with traditional aluminum and ferric salts. Results showed that based on the dissolved organic matter (DOM) removal, the optimal coagulant dosages of AlCl3, FeCl3 and TiCl4 were 0.5 mM and the optimal initial pH values were 8, indicating that the DOM in the typical Chinese water could be effectively removed through sweeping and adsorption by metal hydroxides rather than the complexation and charge neutralization effect under acidic conditions. Compared these three coagulants, the highest ultra violet absorbance at 254 nm removal rate of 72.9% was achieved by TiCl4. The three-dimensional excitation emission matrix results showed that the removal ability of humic acids by AlCl3 was poorer than FeCl3 and TiCl4. The removal rate of low molecular weight components (1600 Da) by TiCl4 was 20% higher than using AlCl3 and 14% higher than FeCl3. Comparing with AlCl3 and FeCl3, TiCl4 had a better performance on the control of DBPFPs, especially for chloroform and dichloroacetic acid, due to its higher removal ability of aromatic organics. The trihalomethane formation potentials removal rate by TiCl4 was three times higher than that by AlCl3 and twice by FeCl3, by which could be inferred that titanium salts achieved better removal of low molecular weight organic matter than aluminum and ferric salts.

Efficient and robust proteome-wide approaches for cross-linking mass spectrometry.

Cross-linking mass spectrometry (XL-MS) has received considerable interest, owing to its potential to investigate protein-protein interactions (PPIs) in an unbiased fashion in complex protein mixtures. Recent developments have enabled the detection of thousands of PPIs from a single experiment. A unique strength of XL-MS, in comparison with other methods for determining PPIs, is that it provides direct spatial information for the detected interactions. This is accomplished by the use of bifunctional cross-linking molecules that link two amino acids in close proximity with a covalent bond. Upon proteolytic digestion, this results in two newly linked peptides, which are identifiable by MS. XL-MS has received the required boost to tackle more-complex samples with recent advances in cross-linking chemistry with MS-cleavable or reporter-based cross-linkers and faster, more sensitive and more versatile MS platforms. This protocol provides a detailed description of our optimized conditions for a full-proteome native protein preparation followed by cross-linking using the gas-phase cleavable cross-linking reagent disuccinimidyl sulfoxide (DSSO). Following cross-linking, we demonstrate extensive sample fractionation and substantially simplified data analysis with XlinkX in Proteome Discoverer, as well as subsequent protein structure investigations with DisVis and HADDOCK. This protocol produces data of high confidence and can be performed within ~10 d, including structural investigations.

Demand driven salt clean-up in a molten salt fast reactor - Defining a priority list.

The PUREX technology based on aqueous processes is currently the leading reprocessing technology in nuclear energy systems. It seems to be the most developed and established process for light water reactor fuel and the use of solid fuel. However, demand driven development of the nuclear system opens the way to liquid fuelled reactors, and disruptive technology development through the application of an integrated fuel cycle with a direct link to reactor operation. The possibilities of this new concept for innovative reprocessing technology development are analysed, the boundary conditions are discussed, and the economic as well as the neutron physical optimization parameters of the process are elucidated. Reactor physical knowledge of the influence of different elements on the neutron economy of the reactor is required. Using an innovative study approach, an element priority list for the salt clean-up is developed, which indicates that separation of Neodymium and Caesium is desirable, as they contribute almost 50% to the loss of criticality. Separating Zirconium and Samarium in addition from the fuel salt would remove nearly 80% of the loss of criticality due to fission products. The theoretical study is followed by a qualitative discussion of the different, demand driven optimization strategies which could satisfy the conflicting interests of sustainable reactor operation, efficient chemical processing for the salt clean-up, and the related economic as well as chemical engineering consequences. A new, innovative approach of balancing the throughput through salt processing based on a low number of separation process steps is developed. Next steps for the development of an economically viable salt clean-up process are identified.

Microbial desalination cell with sulfonated sodium poly(ether ether ketone) as cation exchange membranes for enhancing power generation and salt reduction.

Microbial desalination cell (MDC) is a bioelectrochemical system capable of oxidizing organics, generating electricity, while reducing the salinity content of brine streams. As it is designed, anion and cation exchange membranes play an important role on the selective removal of ions from the desalination chamber. In this work, sulfonated sodium (Na+) poly(ether ether ketone) (SPEEK) cation exchange membranes (CEM) were tested in combination with quaternary ammonium chloride poly(2,6-dimethyl 1,4-phenylene oxide) (QAPPO) anion exchange membrane (AEM). Non-patterned and patterned (varying topographical features) CEMs were investigated and assessed in this work. The results were contrasted against a commercially available CEM. This work used real seawater from the Pacific Ocean in the desalination chamber. The results displayed a high desalination rate and power generation for all the membranes, with a maximum of 78.6±2.0% in salinity reduction and 235±7mWm-2 in power generation for the MDCs with the SPEEK CEM. Desalination rate and power generation achieved are higher with synthesized SPEEK membranes when compared with an available commercial CEM. An optimized combination of these types of membranes substantially improves the performances of MDC, making the system more suitable for real applications.

Exploration of an innovative draw solution for a forward osmosis-membrane distillation desalination process.

Forward osmosis (FO) has emerged as a viable technology to alleviate the global water crisis. The greatest challenge facing the application of FO technology is the lack of an ideal draw solution with high water flux and low reverse salt flux. Hence, the objective of this study was to enhance FO by lowering reverse salt flux and maintaining high water flux; the method involved adding small concentrations of Al2(SO4)3 to a MgCl2 draw solution. Results showed that 0.5 M MgCl2 mixed with 0.05 M of Al2(SO4)3 at pH 6.5 achieved a lower reverse salt flux (0.53 gMH) than that of pure MgCl2 (1.55 gMH) using an FO cellulose triacetate nonwoven (CTA-NW) membrane. This was due possibly to the flocculation of aluminum hydroxide in the mixed draw solution that constricted membrane pores, resulting in reduced salt diffusion. Moreover, average water fluxes of 4.09 and 1.74 L/m2-h (LMH) were achieved over 180 min, respectively, when brackish water (5 g/L) and sea water (35 g/L) were used as feed solutions. Furthermore, three types of membrane distillation (MD) membranes were selected for draw solution recovery; of these, a polytetrafluoroethylene membrane with a pore size of 0.45 µm proved to be the most effective in achieving a high salt rejection (99.90%) and high water flux (5.41 LMH) in a diluted draw solution.

Application of guar gum in brine clarification and oily water treatment.

The increasing amount of oil wastewater is causing serious damage to the environment. Oily water is a worrisome by-product of the oil industry due to its growing volume in mature basins and complex chemical composition. Low-cost polymers are being used as alternative materials to treat oily waters after treatment by conventional methods, oil and grease (O&G) concentration being the primary parameter for final disposal. In this respect, guar gum can be used to treat petroleum-contaminated waters, with the advantage of being a low-cost, highly-hydrophilic natural polymer. In this study, guar gum, under specific conditions, shapes itself into three-dimensional structures with interesting physicochemical properties. The salting out effect occurs with reticulation of the polymeric chains by borate ions and in the presence of electrolytes, reducing the solubility of the polymeric network in the solution and leading to an electrolyte- and polymer-rich phase. When the guar gum gel was prepared in situ in the produced water, after the salting out effect, the oil was imprisoned in the interstices of the collapsed gel. The gelling guar gum was highly efficient in synthetic oily waters. In the case of initial O&G above 100ppm, the oil removal percentage was above 90%.

Removal of organic matter of electrodialysis reversal brine from a petroleum refinery wastewater reclamation plant by UV and UV/H202 process.

Direct (UV) and hydrogen peroxide-assisted (UV/H2O2) photolysis were investigated in bench-scale for removing the organic compounds present in the electrodialysis reversal (EDR) brine from a refinery wastewater reclamation plant. In the UV/H2O2 experiments, a COD:H2O2 molar ratios of 1:1, 1:2 and 1:3 were tested by recirculating the brine in the UV reactor for 120 min. Results showed a significant reduction in UVA254, whereas no reduction was observed for chemical oxygen demand (COD), in the UV process, suggesting great cleavage but limited mineralization of the organic matter. UV/H2O2 with C:H2O2 ratio of 1:3 exhibited high efficiency in removing the organic matter (COD removal of 92% with an electrical energy per removal order (EEO) value of 22 kW h m-3). Although the EDR brine has high salinity, no strong scavenging effect of •OH was found in the water matrix due to the high concentration of anions, especially chloride and bicarbonate. Finally, UV/H2O2 with C:H2O2 ratio of 1:3 and residence time of 120 min is an efficient alternative for organic matter removal of EDR brine from refinery wastewater reclamation plant showing total capital cost (CapEx) estimated at US$ 369,653.00 and total operational cost (OpEx), at US$ 1.772 per cubic meter of effluent.

Ionic Liquid-Liquid Chromatography: A New General Purpose Separation Methodology.

Ionic liquids can form biphasic solvent systems with many organic solvents and water, and these solvent systems can be used in liquid-liquid separations and countercurrent chromatography. The wide range of ionic liquids that can by synthesised, with specifically tailored properties, represents a new philosophy for the separation of organic, inorganic and bio-based materials. A customised countercurrent chromatograph has been designed and constructed specifically to allow the more viscous character of ionic liquid-based solvent systems to be used in a wide variety of separations (including transition metal salts, arenes, alkenes, alkanes, bio-oils and sugars).

Ozonation as a pretreatment process for nanofiltration brines: Monitoring of transformation products and toxicity evaluation.

Considerable interest has been given to using nanofiltration (NF) in lieu of reverse osmosis for water reclamation schemes due to lower energy consumption, higher flux rates while ensuring good micropollutants rejection. The application NF results in the generation of a large concentrated waste stream. Treatment of the concentrate is a major hurdle for the implementation of membrane technologies since the concentrate is usually unusable due to a large pollutants content. This work focuses on the application of ozonation as pretreatment of urban NF concentrates, the generation of transformation products and their relative toxicity. Three pharmaceutical micropollutants largely encountered in water cycle were selected as target molecules: acetaminophen, carbamazepine and atenolol. Through accurate-mass Q-TOF LC-MS/MS analyses, more than twenty ozonation products were detected, structure proposals and formation pathways were elaborated. Attempts were made to understand the correlation between the transformation products and acute toxicity on Vibrio fischeri strain. It is the first time that an integrated study reported on the ozonation of pharmaceuticals in urban membrane concentrates, in terms of transformation products, kinetics, degradation mechanisms, as well as toxicity assessment.

Comparative Evaluation of Small Molecular Additives and Their Effects on Peptide/Protein Identification.

Detergents and salts are widely used in lysis buffers to enhance protein extraction from biological samples, facilitating in-depth proteomic analysis. However, these detergents and salt additives must be efficiently removed from the digested samples prior to LC-MS/MS analysis to obtain high-quality mass spectra. Although filter-aided sample preparation (FASP), acetone precipitation (AP), followed by in-solution digestion, and strong cation exchange-based centrifugal proteomic reactors (CPRs) are commonly used for proteomic sample processing, little is known about their efficiencies at removing detergents and salt additives. In this study, we (i) developed an integrative workflow for the quantification of small molecular additives in proteomic samples, developing a multiple reaction monitoring (MRM)-based LC-MS approach for the quantification of six additives (i.e., Tris, urea, CHAPS, SDS, SDC, and Triton X-100) and (ii) systematically evaluated the relationships between the level of additive remaining in samples following sample processing and the number of peptides/proteins identified by mass spectrometry. Although FASP outperformed the other two methods, the results were complementary in terms of peptide/protein identification, as well as the GRAVY index and amino acid distributions. This is the first systematic and quantitative study of the effect of detergents and salt additives on protein identification. This MRM-based approach can be used for an unbiased evaluation of the performance of new sample preparation methods. Data are available via ProteomeXchange under identifier PXD005405.

Development of a High-Throughput Ion-Exchange Resin Characterization Workflow.

A novel high-throughout (HTR) ion-exchange (IEX) resin workflow has been developed for characterizing ion exchange equilibrium of commercial and experimental IEX resins against a range of different applications where water environment differs from site to site. Because of its much higher throughput, design of experiment (DOE) methodology can be easily applied for studying the effects of multiple factors on resin performance. Two case studies will be presented to illustrate the efficacy of the combined HTR workflow and DOE method. In case study one, a series of anion exchange resins have been screened for selective removal of NO3- and NO2- in water environments consisting of multiple other anions, varied pH, and ionic strength. The response surface model (RSM) is developed to statistically correlate the resin performance with the water composition and predict the best resin candidate. In case study two, the same HTR workflow and DOE method have been applied for screening different cation exchange resins in terms of the selective removal of Mg2+, Ca2+, and Ba2+ from high total dissolved salt (TDS) water. A master DOE model including all of the cation exchange resins is created to predict divalent cation removal by different IEX resins under specific conditions, from which the best resin candidates can be identified. The successful adoption of HTR workflow and DOE method for studying the ion exchange of IEX resins can significantly reduce the resources and time to address industry and application needs.