Non-flux purification behavior of AZ91 magnesium alloy

The effects of non-flux purification techniques on the mechanical properties and microstructure of AZ91 magnesium alloy were investigated by ICP,OM,XRD and SEM.The results show that Ar spraying with high flow rate could remove non-metallic inclusions and improve the mechanical properties of AZ91.The alloy obtains the best properties after argon spraying for 30 min at the melt temperature of 740 °C.The ceramic foam filter(CFF) could effectively improve the ultimate tensile strength and elongation of AZ91 alloy,especially the elongation,which increase with increasing pores per inch(ppi) and the thickness of CFF.Non-flux purification does not change the microstructure of AZ91 alloy.However,filtration has a certain effect on the fracture pattern of AZ91 alloy.To improve the mechanical properties effectively,both filtration and gas spraying should be utilized together.

Deep eutectic solvents for separation and purification applications in critical metal metallurgy:Recent advances and perspectives

Solvent extraction,a separation and purification technology,is crucial in critical metal metallurgy.Organic solvents commonly used in solvent extraction exhibit disadvantages,such as high volatility,high toxicity,and flammability,causing a spectrum of hazards to human health and environmental safety.Neoteric solvents have been recognized as potential alternatives to these harmful organic solvents.In the past two decades,several neoteric solvents have been proposed,including ionic liquids(ILs)and deep eutectic solvents(DESs).DESs have gradually become the focus of green solvents owing to several advantages,namely,low toxicity,degradability,and low cost.In this critical review,their classification,formation mechanisms,preparation methods,characterization technologies,and special physicochemical properties based on the most recent advancements in research have been systematically described.Subsequently,the major separation and purification applications of DESs in critical metal metallurgy were comprehensively summarized.Finally,future opportunities and challenges of DESs were explored in the current research area.In conclusion,this review provides valuable insights for improving our overall understanding of DESs,and it holds important potential for expanding separation and purification applications in critical metal metallurgy.

Superwetting Ag/α-Fe_(2)O_(3) anchored mesh with enhanced photocatalytic and antibacterial activities for efficient water purification

Superwetting materials have drawn unprecedented attention in the treatment of oily wastewater due to their preferable anti-fouling property and selective oil/water separation.However,it is still a challenge to fabricate multifunctional and environmentally friendly materials,which can be stably applied to purify the actual complicated wastewater.Here,a Ag/Ag/α-Fe_(2)O_(3) heterostructure anchored copper mesh was intentionally synthesized using a facile two-step hydrothermal method.The resultant mesh with superhydrophilicity and underwater superoleophobicity was capable of separating various oil/water mixtures with superior separation efficiency and high permeationflux driven by gravity.Benefiting from the joint effects of the smaller band gap of Ag/α-Fe_(2)O_(3) heterojunction,inherent antibacterial capacity of Ag/α-Fe_(2)O_(3) and Ag nanoparticles,favorable conductive substrate,as well as the hierarchical structure with superwettability,such mesh presented remarkably enhanced degradation capability toward organic dyes under visible light irradiation and antibacterial activity against both Escherichia coli(E.coli)and Staphylococcus aureus(S.aureus)compared with the pure Ag/α-Fe_(2)O_(3) coated mesh.Impressively,the mesh exhibited bifunctional water purification performance,in which organic dyes were eliminated simultaneously from water during oil/water separation in onefiltration process.More importantly,this mesh behaved exceptional chemical resistance,mechanical stability and long-term reusability.Therefore,this material with multifunctional integration may hold promising potential for steady water purification in practice.

Purification of copper foils driven by single crystallization

High-purity copper(Cu) with excellent thermal and electrical conductivity, is crucial in modern technological applications, including heat exchangers, integrated circuits, and superconducting magnets. The current purification process is mainly based on the zone/electrolytic refining or anion exchange, however, which excessively relies on specific integrated equipment with ultra-high vacuum or chemical solution environment, and is also bothered by external contaminants and energy consumption. Here we report a simple approach to purify the Cu foils from 99.9%(3N) to 99.99%(4N) by a temperature-gradient thermal annealing technique, accompanied by the kinetic evolution of single crystallization of Cu.The success of purification mainly relies on(i) the segregation of elements with low effective distribution coefficient driven by grain-boundary movements and(ii) the high-temperature evaporation of elements with high saturated vapor pressure.The purified Cu foils display higher flexibility(elongation of 70%) and electrical conductivity(104% IACS) than that of the original commercial rolled Cu foils(elongation of 10%, electrical conductivity of ~ 100% IACS). Our results provide an effective strategy to optimize the as-produced metal medium, and therefore will facilitate the potential applications of Cu foils in precision electronic products and high-frequency printed circuit boards.

Simultaneous purification of minor components in natural products using twin-column recycling chromatography with a step solvent gradient

The isolation of minor components from complex natural product matrices presents a significant challenge in the field of purification science due to their low concentrations and the presence of structurally similar compounds.This study introduces an optimized twin-column recycling chromatography method for the efficient and simultaneous purification of these elusive constituents.By introducing water at a small flowing rate between the twin columns,a step solvent gradient is created,by which the leading edge of concentration band would migrate at a slower rate than the trailing edge as it flowing from the upstream to downstream column.Hence,the band broadening is counterbalanced,resulting in an enrichment effect for those minor components in separation process.Herein,two target substances,which showed similar peak position in high performance liquid chromatography(HPLC)and did not exceed 1.8%in crude paclitaxel were selected as target compounds for separation.By using the twin-column recycling chromatography with a step solvent gradient,a successful purification was achieved in getting the two with the purity almost 100%.We suggest this method is suitable for the separation of most components in natural produces,which shows higher precision and recovery rate compared with the common lab-operated separation ways for natural products(thin-layer chromatography and prep-HPLC).

Research Progress on Purification Process, Content Determination and Pharmacological Action of Atractylodin

Atractylodis Rhizoma comes from the dry rhizome of Atractylis lancea or Atractylodes chinensis in the Compositae family,and it is suitable for preventing and treating diseases such as cold,edema,night blindness and rheumatic arthralgia.Atractylodin is the main active component extracted and isolated from Atractylodis Rhizoma.A large number of studies have found that atractylodin has excellent drug activity in improving gastrointestinal emptying,anti-inflammation,inhibiting malignant tumor and reducing blood lipid.In this paper,the purification process and pharmacological activity of Atractylodin were summarized to provide a theoretical basis for basic research,clinical application and further development and utilization of atractylodin.

Research on Purification Process and Pharmacological Action of Andrographolide

This paper reviews the purification process,content determination methods and pharmacological action of Andrographolide,aiming to provide new ideas for the subsequent study of Andrographolide and its related drug development and application.

An Affordable and Easily Accessible Approach for Acrylonitrile Monomer Purification through a Simple Column Technique

This manuscript presents a dataset detailing a method for purifying monomers. Purification plays a crucial role in every chemical process, as it leads to an improvement in product quality through the removal of impurities. The primary method for monomer purification, like acrylonitrile (AN), is the distillation technique. However, this technique is unsafe and hard to set up or handle. A straightforward, risk-free, low-cost method like the column technique resolves these issues. A simple column technique demonstrated the successful execution of purifying AN. Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR) analyses confirmed that AN was successfully purified, with purity reaching 99.8%. FTIR spectra revealed changes in the position and intensity of the stretching vibration peaks after purification. Also, the functional groups of the inhibitor monomethyl ether of hydroquinone (MeHQ) were undetected after purification. Furthermore, after purification, NMR spectra revealed the absence of aromatic protons and carbons associated with MeHQ. In conclusion, the column technique is a successful and inexpensive way to purify AN monomers. This makes it useful for a wide range of applications, especially in polymerization reactions where MeHQ needs to be removed to prevent self-polymerization during the initiation process.

Si purification by solidification of Al-Si melt with super gravity

The investigation on purification of metallurgical grade silicon by solidification of hypereutectic Al-Si melt with super gravity as an intensified separation way was carried out.The results indicate that the refined silicon grains are successfully enriched at the bottom of the Al-Si alloy along the direction of super gravity.Then the refined silicon was collected by aqua regia leaching.The purity of the collected silicon is analyzed as 99.92%,which is obviously improved compared with the purity of the metallurgical grade silicon of 99.59%,proving the feasibility of this purification method.Furthermore,the mass fraction of B is reduced from 8.33×10-6 to 5.25×10-6 and that of P from 33.65×10-6 to13.50×10-6.

Optimization of Preparative Separation and Purification of Total Flavonoids from Radix Puerariae by Macroporous Resin Method

Aim To screen the optimum macroporous resin and conditions for the isolation and purification of flavonoids from Radix Puerariae. Methods The static and dynamic adsorption/desorption methods were used, and the separation and purification process was evaluated by measuring the concentration of total flavonoid in the fractions with UV spectrophotometer. Results The SP70 macroporous resin was the most effective compared with other macroporous resins. The optimum conditions were screened, which were 0.5 g· mL^- 1 corresponding to crude drug for concentration of extract, pH 5 - 6, and appended 60 times the volume of the resin bed （BV） with the adsorption speed 2 BV·h^-1, and the volume of aq. 70% （V/V） ethanol as eluant was 5 BV with desorption speed 2 BV·h^-1. By this method, the final contents of total flavonoids exceeded 80%. Conclusion The SP70 macroporous resin is the most effective one for large-scale isolation and purification of flavonoids from Radix Pueraria, which meets industrial needs.

Purification and Characterization of Flammulin,a Basic Protein with Anti-tumor Activities from Flammulina velutipes

Aim To purify and characterize flammulin, a basic protein with anti-tumoractivities. Methods Ammonium sulfate, ethanol fractionation and column chromatography were used forseparation and purification. Electrophoretic analysis, amino acid analysis, and MS of flammulin werecarried out. Results Flammulin was purified to electrophoretic homogeneity and crystallized. With amolecular mass of 19891.13 Da, pI 8.9, λ_(max) = 276 - 278 nm, λ_(min) = 250 nm, flammulin wascharacterized by its lack of methionine. Fingerprint mapping of flammulin was determined by MALDI-MSfollowing in-gel protease digestion; no close matches were identified. Conclusion Flammulin waspurified to electrophoretic homogeneity, and its characteristics are discussed for the first time.

Separation and recovery of Cu and As during purification of copper electrolyte

Cu, As, Sb and Bi in copper electrolyte could be efficiently removed by reducing with SO2 followed by evaporative crystallization. As2O3 and CuSO4·5H2O were obtained after crystallized product was treated by dissolution, oxidation, neutralization, sedimentation, filtration and evaporative crystallization. The removal rates of Cu, As, Sb and Bi are 87.1%, 83.9%, 21.0% and 84.7%, respectively, when As （Ⅴ） in copper electrolyte is fully reduced to As （Ⅲ） by SO2, and the H2SO4 in concentrated copper electrolyte is 645 g/L. The removal rate of As is 92.81% when 65 g crystallized product is dissolved in 200 mL water at 30 ℃. The CuSO4·5H2O content is 98.8% when the filtrate is purified under the conditions that n（Fe）：n（As） is 1.2, the dosage of H2O2 is 19 times the stoichiometric needed, temperature is 45 ℃, time is 40 min, pH is 3.7, and then is evaporation crystallized.

Low-temperature purification process of metallurgical silicon

The removal of B and P consumes most of heat energy in Si metallurgical purification process for solar-grade Si. Metal-liquating purification of metallurgical grade silicon （MG-Si）, also called Si-recrystallization from metal liquid, was a potential energy-saving method for the removal of B and P efficiently, since Si could be melted at lower temperature by alloying with metal. The selection criteria of metal-liquating system was elaborated, and Al, Sn and In were selected out as the optimum metallic mediums. For Sn-Si system, the segregation coefficient of B decreased to 0.038 at 1 500 K, which was much less than 0.8 at the melting point of Si. The mass fraction of B was diminished from 15×10^-6 to 0.1×10^-6 as MG-Si was purified by twice, while that of most metallic elements could be decreased to 0.1×10^-6 by purifying just once. During the metal-liquating process, the formation of compounds between impurity elements and Si was also an important route of impurity removal. Finally, one low-temperature metallurgical process based on metal-liquating method was proposed.

Purification of metallurgical grade silicon by electrorefining in molten salts

Electrochemical studies on silicon deposition were performed in molten salt electrolytes. Purification of metallurgical grade silicon by electrorefining was carried out in molten Si-chloride salts at temperatures from 973 K to 1223 K. It was found that the use of a liquid alloy anode of silicon and copper was beneficial in molten CaCl2 with NaCl, CaO and dissolved Si. ICP-AES analysis results showed efficient removal of metal impurities, such as titanium, aluminum and iron, which are present in significant quantities in the feedstock. The contents of boron and phosphorus in the silicon after electrorefining were reduced from 36×10-6 and 25×10-6 to 4.6×10-6 and 2.8 ×10-6, respectively. The energy consumption of electrorefining was estimated to be about 9.3 kW?h/kg.

Purification and Antimicrobial Activity of Antimicrobial Protein from Brown-spotted Grouper, Epinephelus fario

Antimicrobial proteins and peptides had been found from a wide variety of organisms in the last few years These molecules have attracted much research interest because of their biochemical diversity, broad specificity on anti-viral, anti-bacterial, anti-fungi, anti-protozoan parasites, anti-tumoural, and wound-healing effects. Antimicrobial proteins and peptides play key roles in innate immunity. They interact directly with bacteria and kill them. The brown-spotted grouper, Epinephelusfario, is an important marine fish cultured in southem China. Recently, bacteria and virus have caused high mortality in E. fario cultures, but its endogenous antimicrobial peptides and proteins have not been explored. An antimicrobial component was found from the skin homogenate of E. fario. After the skin homogenate was digested with trypsin, its antimicrobial activity was lost, which showed that the antimicrobial component is a protein. The antimicrobial protein （Efap） was purified from the skin homogenate of E. fario by successive ion-exchange and gel filtration chromatography. Efap was demonstrated to be single protein band by SDS-PAGE, with the apparent molecular weight of 41 kD. Efap exhibited antimicrobial activity both for the Gram-positive bacteria, Staphylococcus aureus, Micrococcus luteus and Bacillus subtilis, and for the Gram-negative bacteria, Vibrio alginolyticus, Vibrio parahaemolyticus, Vibrio fluvialis, Pasteurella multocida, Aeromonas hydrophila, Eschrrichiu coli, and Pseudomonas aeruginosa. Except A. hydrophila, P. aeruginosa, and E. coli （MIC〉20 mol/L）, most of the tested Gram-negative bacteria were sensitive to Efap （MIC〈20 mol/L）. Interestingly, Efap showed potent antimicrobial activity against Gram-positive bacteria S. aureus （MIC 5-10 mol/L） but comparatively weak antimicrobial activity against M. luteus and B. subtilis. The broad antimicrobial activities of Efap suggest that it contributes to the innate host defence of E. fario.

Separation and Purification of Recombinant Hirudin Variant 3 from Bacillus subtilis

[ Objective] The research aimed to get the optimized separation and purification conditions of the hirudin produced from Bacillus subtilis DB403 （pUBH5）. [Method] Through the systemic pretreatment, preliminary chromatography and fine chromatography. [Result]The optimized separation and purification conditions were that： Supernatant was treated by trichloroacetic acid, then by ultrafiltration desalt and anion exchange chromatography. Strong anion Q F. F. was better than weak anion DEAE F.F. The proper balanced solution was Tris-HCI （ pH 8.0）. The proper conductivity was 6 ms/cm. The maximum applied sample was 240 ATU/ml to matrix of strong anion Q F. F. This optimized procedure was magnified in strong anion exchange HiPrep 16/10Q with the 90% recovery and 70.2% purity. The purification of gel filtration of Sephacryl S-100 to hirudin was not relative to flow rate within certain scope. The application size of sample was 10 ml. The purity checked by HPLC was 95.1%, and the recovery was 93%, and the band of SDS-PAGE was single. [ Conclusion] The research provided the reference of the further industrialization separation and purification of hiruin.

Expression of Porcine Reproductive and Respiratory Syndrome Virus ORF7 Gene and Purification and Immunological Activity Analysis of the Recombinant Protein

[Objective] The aim of this study was to realize efficient expression of the porcine reproductive and respiratory syndrome virus （PRRSV） ORF7 gene in genetic engineering bacteria and analYze the immunological activity of the recombinant protein after purification. [ Method] The constructed recombinant expression vector pET-ORF7 was transformed into Escherichia co1BL21 （DE3） and induced by IPTG under the optimal condition. After analysis of SDS-PAGE and Western Blot, the expression products were purified by Ni-NTA His · Bind Resin chrom- atographic column under denaturing condition and renatured by gradient dialysis. Subsequently, the immunological activity of the renatured recombinant protein was detected by Westem Blot and indirect ELISA. [ Result] The recombinant plasmid pET-ORF7 expressed in E. coli successfully, and the fusion protein was in the form of inclusion body. By SDS-PAGE detection, the molecular weight of the expression protein was approximate 33 kD, according with the expectation. Analysis by Bandscan software showed that the expressed fusion protein was about 50% of total bacterial protein of BL21 （DE3）. Wastem Blot and indirect ELISA detection showed that the renatured protein could react with PRRSV positive serum specifically, indicating its good immunological activity. [ Conclusion] This study lays a foundation for the preparation of PRRSV monoclonal antibody and diagnostic kit.

Effect of purification treatment on corrosion resistance of Mg-Gd-Y-Zr alloy

Mg-Gd-Y-Zr alloys were purified by filtering purification with and without vacuum. The type, morphology, size distribution and volume fraction of inclusion were analyzed with OM and SEM. The effect of inclusion in Mg-Gd-Y-Zr alloys on anticorrosion ability was investigated with salt spray test and electrochemical test. The results show that the inclusions in the alloy can be removed effectively by filtering purification. The average size of inclusions in the alloys is decreased from 12.7 μm to 2.0 μm and the volume fraction of inclusions is reduced from 0.30% to 0.04%. With the decrease of the size of inclusions in the alloys, the corrosion rate of the alloys decreases dramatically from 38.8 g/（m 2 ·d） to 2.4 g/（m 2 ·d） in the salt spray test. The corrosion potential increases while the corrosion current decreases and the polarization resistance increases in the electrochemical tests, which indicates that the anticorrosion ability is improved.

The Effect of Baffled Surface Flow Wetlands on Water Purification

[Objective] The effect of baffled surface flow wetlands on water purification was studied in order to provide a reference for the ecological restoration of polluted river.[Method] Contents of some indexes like DO,TN,TP,NH＋4-N,CODCr,SS,SD,etc.were determined in the band baffled surface flow wetlands with total area of 7 400 m2 at JiaLu riverside.[Result] Baffled surface flow wetlands could improve the effluent quality significantly,could enhance transparency and dissolved oxygen content and also could decrease SS content.The removal rate of TN was kept at more than 73% in summer and decreased to 23% in early winter;The removal rate of TP was little influenced by temperature,and it was kept at more than 77% in summer and still kept at more than 69% in autumn and winter;The removal rate of NH＋4-N was kept at more than 83% in summer and decreased slightly in autumn and winter,but still kept at more than 75%;The removal rate of CODCr ranged from 14% to 50%.[Conclusion] Baffled surface flow wetlands could effectively improve the purification effect of surface flow wetlands,which is a feasible way for ecological restoration.

Study on Purification and Properties of Antibacterial Substance from Antagonistic Bacteria P72 against Wheat Scab

[Objective] The study aimed to explore the antibacterial activity and stability of antagonistic bacteria P72 against wheat scab.[Method] The Bacillus subtilis P72 was inoculated into fermentation media with the inoculation amount 5%,then cultured on shaking table at 28 ℃ for 48 h and centrifuged at 8 000 r/min for 10 min.The supernatant of fermentation broth was purified and then the genetic stability,thermal stability and pH stability were detected.[Result] By DEAE-52 ion exchange chromatography,the protein eluted by 0.5 mol/L NaCl solution possessed the strongest antagonistic ability against wheat scab pathogen.The SDS-PAGE electrophoresis showed that the molecular weight of the purified protein with antibacterial effect was 40 kD.By stability test,the antibacterial substance produced by P72 strain showed heritable antagonistic activity,high stability below 60 ℃,stability to acid and unstability to alkali.[Conclusion] The antagonistic bacteria P72 had strong antagonistic ability to wheat scab pathogen,stable antibacterial activity and thermal stability,so it would possess a wide development prospect.