STUDIES ON REVERSE OSMOSIS SEPARATION OF AQUEOUS ORGANIC SOLUTIONS BY PAA/PSF COMPOSITE MEMBRANE

The reverse osmosis (RO) separation of aqueous organic solutions, such as alcohols, amines, aldehydes, acids, ketones, and esters etc., by PAA (polyacrylic acid)/PSF (polysulfone) composite membrane has been studied. It was found that the separation results for aliphatic alcohols, amines and aldehydes are satisfactory, the solute rejection (R-a) and the volume fluxes of solutions (J(V)) for 1000 ppm ethanol, ethylamine and ethyl aldehyde are 66.2%, 61.0%, 84.0% and 0.90 x 10(-6), 0.35 x 10(-6), 0.40 X 10(-6) m(3)/m(2) . s, respectively, at 5.0 MPa and 30 degrees C. R-a increased with increasing molecular weights of alcohols, amines and aldehydes, and the R-a for n-amyl alcohol, n-butylamine and n-butyl aldehyde reached 94.3%, 88.6% and 96.0%, respectively. Satisfactory separation results (R-a > 70%) for ketones, esters, phenols and polyols have been obtained with the PAA/PSF composite membrane. The effect of operating pressure on the properties of reverse osmosis has also been investigated. Analysis of experimental data with Spiegler-Kedem's transport model has been carried out and the membrane constants such as reflection coefficient sigma, solute and hydraulic permeabilities omega and L-p for several organic solutes have been obtained.

Liquid-phase synthesis of Li_(2)S and Li_(3)PS_(4) with lithium-based organic solutions

Sulfide solid electrolytes are widely regarded as one of the most promising technical routes to realize all-solid-state batteries(ASSBs)due to their high ionic conductivity and favorable deformability.However,the relatively high price of the crucial starting material,Li_(2)S,results in high costs of sulfide solid electrolytes,limiting their practical application in ASSBs.To solve this problem,we develop a new synthesis route of Li_(2)S via liquid-phase synthesis method,employing lithium and biphenyl in 1,2-dimethoxyethane(DME)ether solvent to form a lithium solution as the lithium precursor.Because of the comparatively strong reducibility of the lithium solution,its reaction with sulfur proceeds effectively even at room temperature.This new synthesis route of Li_(2)S starts with cheap precursors of lithium,sulfur,biphenyl and DME solvent,and the only remaining byproduct(DME solution of biphenyl)after the collection of Li_(2)S product can be recycled and reused.Besides,the reaction can proceed effectively at room temperature with mild condition,reducing energy cost to a great extent.The as-synthesized Li_(2)S owns uniform and extremely small particle size,proved to be feasible in synthesizing sulfide solid electrolytes(such as the solid-state synthesis of Li_(6)PS_(5)C_(l)).Spontaneously,this lithium solution can be directly employed in the synthesis of Li_(3)PS_(4) solid electrolytes via liquid-phase synthesis method,in which the centrifugation and heat treatment processes of Li_(2)S are not necessary,providing simplified production process.The as-synthesized Li_(3)PS_(4) exhibits typical Li+conductivity of 1.85×10^(-4) S·cm^(-1) at 30℃.

Atmospheric Pressure Plasma Jet in Organic Solution:Spectra,Degradation Effects of Solution Flow Rate and Initial pH Value

The organic compounds of p-nitrophenol （PNP） solution was treated by the active species generated in a stirred reactor by an atmospheric pressure plasma jet （APPJ）. The emission intensities of hydroxyl （OH）, oxygen （O）, nitric oxide （NO）, hydrogen （H） and molecular （N2） were measured by optical emission spectroscopy （OES）. The relations between the flow rates of the PNP solution and degradation, the degradation effects and initial pH value of the solution were also investigated. Experimental results show that there exist intense emissions of O （777.1 nm）, N（337.1 nm）, OH （306-310 nm） and NO band （200-290 nm） in the region of plasma. Given the treatment time and gas flow rate, the degradation increased as a function of discharge energy and solution flow rate, respectively. The solution flow rate for the most efficient degradation ranged from 1.414 m/s to 1.702 m/s, and contributed very little when it exceeded 2.199 m/s. This indicates the existence of diffusion-controlled reactions at a low solution flow rate and activation- controlled reactions at a high solution flow rate. Moreover, increasing or decreasing the initial pH value of neutral PNP solution （pH=5.95） could improve the degradation efficiency. Treated by APPJ, the PNP solutions with different initial pH values of 5.95, 7.47 and 2.78 turned more acidic in the end, while the neutral solution had the lowest degradation efficiency. This work clearly demonstrates the close coupling of active species, photolysis of ultraviolet, the organic solution flow rate and the initial pH value, and thus is helpful in the study of the mechanism and application of plasma in wastewater treatment.

Synergic Mechanism of an Organic Corrosion Inhibitor for Preventing Carbon Steel Corrosion in Chloride Solution

The inhibition effect of dimethylethanolamine（DMEA） and its composite with carboxylic acid was studied with the electrochemical tests. The experimental results indicate that DMEA is not a good inhibitor but the composite of DMEA with caprylic acid exhibits excellent inhibiting efficiency. The synergic mechanism of the organic corrosion inhibitors（OCIs） was studied with quantum chemical calculations. It is found that the DMEA forms a quaternary ammonium salt with the proton in carboxylic acid, and a cyclic complex formed between the salt and Fe may be responsible for the enhancement of inhibiting efficiency. The possible hydrogen bond formed between DMEA and carboxylic acid is not enough for the inhibiting effect. This work is helpful to proposing theoretical interpretation as well as developing a functional organic inhibitor to improve the durability of reinforced concrete contaminated with chloride.

Apoptosis of rat liver in cold preservation with custom-designed KYL solution

BACKGROUND: A suitable perfusate is very important in reducing various problems in liver preservation, prolonging the time of organ preservation and enhancing the quality of donor tissue. University of Wisconsin (UW) solution is the most successful solution for preserving multiple organs at present, but it has many shortcomings. We set out to develop a new liver preservation solution (KYL solution) and study its effects on apoptosis in rat liver undergoing cold preservation. METHODS: Using non-circulated isolated perfused rat liver (IPRL), we randomly preserved Sprague-Dawley rat livers for 0, 4, 8, 16, 24, and 48 hours with KYL solution or UW solution. The effects were assessed by measuring the content of free radicals in Krebs-Henseleit solution and the intracellular calcium content of hepatocytes, assessing hepatocellular apoptosis and related-gene expression, and observing the morphological changes in liver. To evaluate the protection by KYL and UW solutions in rat liver perfusion and preservation, we chosed normal saline for negative comparison. RESULTS: The intracellular calcium content of the liver preserved in KYL solution was less than that preserved in UW solution. At every different period of preservation, the malonaldehyde and superoxide dismutase content in Krebs-Henseleit solution, the percentage of apoptotic cells and the expression patterns of apoptosis-related-genes were similar in livers preserved in KYL and UW solutions. Morphological changes in the two groups were almost the same. The variables in both groups were better than those of livers preserved in normal saline. Both KYL and UW solutions protected rat liver from ischemia-reperfusion injury. CONCLUSIONS: KYL solution is superior to UW solution in preventing calcium overload. More severe hepatocyte damage may appear in the KYL group than in the UW group and the effect of KYL solution on apoptosis in rat liver preservation is similar to that of UW solution.

Experimental Study on the Cryopreservation of LLC-PK1 Epithelial Cells with Hypoxic UW Solution

The effects of oxygen partial pressure on cryopreservation of the cells with organ preservation solution were explored. Hypoxic UW solution was made by purging the UW solution with argon. The pig proximal tubule epithelial cells （LLC-PK1 cells） were cryopreserved in hypoxic UW solution （Ar-UW group） or standard UW solution （UW group） at 4℃ for 48 h. Trypan blue staining and LDH detection were performed to evaluate the injury of the cells. The results showed that the oxygen partial pressure in Ar-UW group was significantly declined from 242±6 mmHg to 83±10 mmHg. After cryopreservation at 4℃ for 48 h, LDH leakage rate and Trypan blue-stained rate in Ar-UW group were （11.3±3.4）% and （10.5±4.7）%, respectively, which were significantly lower than in UW group [（49.5±6.9）% and （47.6±9.3）% respectively, both P〈0.01]. It was concluded that lower oxygen partial pressure of UW solution was more beneficial to the cryopreservation of LLC.

Preparation and Preservation of Hypoxia UW Solution

In order to explore the method to prepare hypoxia UW solution and the stability and preservation of hypoxia UW solution, UW solution was purged by argon or air for 15 min or 60 at a flow rate of 0.8 or 2 L/min, and the oxygen partial pressure of UW solution was detected. The hypoxia UW solution was exposed to the air or sealed up to preserve by using different methods, and the changes of oxygen partial pressure was tested. The results showed that oxygen partial pressure of 50 mL UW solution, purged by argon for 15 min at a flow rate of 2 L/min, was declined from 242±6 mmHg to 83±10 mmHg. After exposure to the air, oxygen partial pressure of hypoxia UW solution was gradually increased to 160±7 mmHg at 48 h. After sealed up by the centrifuge tube and plastic bad filled with argon, oxygen partial pressure of hypoxia UW solution was stable, about 88±13 mmHg at 72 h. It was concluded that oxygen of UW solution could be purged by argon efficiently. Sealed up by the centrifuge tube and plastic bag filled with argon, oxygen partial pressure of UW solution could be stabilized.

Luminescent properties of a new Nd^(3+)-doped complex with two different carboxylic acids and pyridine derivative

A new Nd3＋-doped organic complex featuring two different perfluorinated carboxylic acids as the first ligand and pyridine derivative 2-amino-3-chloro-5-（tri- fluoromethyl）pyridine as the second ligand was designed and synthesized. Successful coordination between the ligands and central rare earth ions was confirmed by Fourier transform infrared spectroscopy （FT-IR） spectra, 1H nuclear magnetic resonance （1H NMR） spectra, and UV spectra, and the synthesized complex is inferred to be eight-coordinate structure. Solution of the complex dis- solved in DMSO-d6 was prepared and then its fluorescence spectrum, UV-Vis-NIR absorption spectrum, and fluorescence decay curve were tested. The fluorescent lifetime is about 7 txs. Based on the above experimental research, Judd-Ofelt analysis was carried out, and the results indi- cate that appropriate coordination environment around Nd3＋ in this solution results in a high fluorescent quantum efficiency 2 % and a large stimulated emission cross-section about 3.2 × 10^-20 cm^2 at 1,064 nm.

Novel Al-doped carbon nanotubes with adsorption and coagulation promotion for organic pollutant removal

Al-doped carbon nanotubes（Al-doped CNTs） were prepared as a multifunctional integrated material of adsorbent and coagulant aid for organic pollutant removal from aqueous solution. It was observed that aluminum species were dispersed homogeneously on the surface of CNTs, and mainly anchored onto defect structures of the CNTs. The introduction of aluminium efficiently improved adsorption ability for methyl orange（MO） onto the CNTs,and maximum adsorption capacity calculated from the Langmuir isotherm model can reach 69.7 mg/g. The MO adsorption kinetics can be better described by the pseudo-second-order and pore diffusion kinetic models, and the diffusion of MO anions into pores of the Al-doped CNT adsorbent should be the rate-determining step.Thermodynamic analyses indicated that the adsorption of MO onto Al-CNTs-2.0 was endothermic and spontaneous. Moreover, adsorption capacity for MO on the Al-doped CNTs was evidently dependent on the CNT dose, solution p H and adsorbent dose. From the perspective of low-cost and multifunctional, suspension obtained during the Al-doped CNT adsorbent preparation, was tested as coagulant to remove humic acid（HA）. A significant observation is that the suspension exhibited an excellent coagulation performance for HA,because abundant aluminous polymer and Al-doped CNTs existed in the suspension.

Characterization and Thermodynamics of Al_2O_3-MnO-SiO_2(-MnS)Inclusion Formation in Carbon Steel Billet

A method to extract inclusion particles from solid steel by electrolysis with organic electrolyte solution was introduced; meanwhile, thermodynamics of inclusion formation was calculated using FaetSage software. The results showed that there were two kinds of inclusions in the billet, i.e. Al2O3-MnO-SiO2-MnS （AMS-MnS） and Al2O3- MnO-SiO2 （AMS）. Most of AMS-MnS inclusion particles, with diameter of 10--30 μm, showed three-layer structures： SiO2-rich core with a small quantity of Mn, intermediate AMS layer, and MnS outer layer containing small quanti- ties of A1 and O. Most AMS inclusion particles were 50--90 μm and exhibited homogeneous composition. Thermo- dynamic results indicated that SiO2-rich core could form firstly by Si reacting with O in molten steel at temperatures above 1 923 K during Si-Fe alloy addition, and then, the SiO2-rich core could react with Mn and Al to form liquid AMS enveloping the SiO2 rich core at 1823- 1873 K. MnS began to precipitate from AMS when temperature reached 1 728 K. Liquid AMS could form by coupled reaction among Si, Mn, Al and O in molten steel.

A study on continuous low-flow perfusion with low-potassium dextran for donor isolated lung preservation

OBJECTIVE: To test the validity of continuous low-flow perfusion with low-potassium dextran (LPD) to preserve rabbit lung. METHODS: Isolated rabbit lungs were preserved for eight hours either in Ringer's solution by simple storage (Group I) or in continuous low-flow perfusion with LPD (Group II). After preservation, lung functions were assessed to compare these two methods. RESULTS: The water gain in Group I was higher than that in Group II. During reperfusion, the functional test values for the immersed lungs were lower than those for the perfused lungs. The lipid peroxidation product (MDA) was significantly decreased in perfused lungs during reperfusion. CONCLUSIONS: Low-flow perfusion with LPD is better than immersion for the lung preservation.