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Sample records for dilute organic acids

  1. Exploring orange peel treatment with deep eutectic solvents and diluted organic acids

    NARCIS (Netherlands)

    van den Bruinhorst, A.; Kouris, P.; Timmer, J.M.K.; de Croon, M.H.J.M.; Kroon, M.C.

    2016-01-01

    The disintegration of orange peel waste in deep eutectic solvents and diluted organic acids is presented in this work. The albedo and flavedo layers of the peel were studied separately, showing faster disintegration of the latter. Addition of water to the deep eutectic solvents lowered the amount of

  2. Hydrogen isotope exchange of organic compounds in dilute acid at elevated temperatures

    International Nuclear Information System (INIS)

    Werstiuk, N.H.

    1987-01-01

    Introduction of one or more deuterium (or tritium) atoms into organic molecules can be accomplished in many ways depending on the nature of the substrate and the extent and sterochemistry of deuteriation or tritiation required. Some of the common methods include acid- and base-catalyzed exchange of carbonyl compounds, metal hydride reductions, dissolving metal reductions, catalytic reduction of double bonds, chromatographic exchange, homogeneous and heterogeneous metal-catalyzed exchange, base-catalyzed exchange of carbon acids other than carbonyl compounds and acid-catalyzed exchange via electrophilic substitution. Only the latter three methods have been used for perdeuteriation of organic compounds. A very useful compendium of labeling methods with examples has been available to chemists for some time. Although metal-catalyzed exchange has been used extensively, the method suffers from some deficiencies: irreproducibility of catalyst surfaces, catalyst poisoning, side reactions such as coupling and hydrogenolysis of labile groups and low deuterium incorporation. Usually a number of cycles are required with fresh catalyst and fresh deuterium source to achieve substantial isotope incorporation. Acid-catalyzed exchange of aromatics and alkenes, strongly acidic media such as liquid DBr, concentrated DBr, acetic acid/stannic chloride, concentrated D 3 PO 4 , concentrated DC1, D 3 PO 4 /BF 3 SO 2 , 50-80% D 2 SO 4 and DFSO 4 /SbF 5 at moderate temperatures (<100 degrees) have been used to effect exchange. The methods are not particularly suitable for large scale deuteriations because of the cost and the fact that the recovery and upgrading of the diluted deuterium pool is difficult. This paper describes the hydrogen isotope exchange of a variety of organic compounds in dilute aqueous acid (0.1-0.5 M) at elevated temperatures (150-300 degrees)

  3. Third phase formation in organic solutions in the extraction of mono-acids by tertiary trialcoyl-amines diluted in very slightly polar organic solvents

    International Nuclear Information System (INIS)

    Robaglia, Michele

    1973-01-01

    The phenomena of third phase formation which can occur during the extraction of an acid with a tertiary amine diluted in a low polarity diluent are studied. In the first part a system including water (TnOA - C 6 H 12 - HCl - H 2 O) is compared with an anhydrous system (TnOA - C 6 H 12 - HCl - N 2 ). There are two kinds of gaps. One during amine salification, another one during the extraction of excess acid. The important part of the water content of the organic phase is demonstrated. The presence of water enhances the gaps. The polar water molecules are dissolved inside the tri-octylamine salt micelles. The heavy phase is formed by aggregates, the light phase represents the solubility of the non soluble species in the medium. In the second part are studied the influence of some parameters (like nature of diluent, acid, amine and temperature) on the gaps formation and on the extraction of excess acid and water. In every cases the part played by water remains the same. Finally some comparisons are made between tertiary systems and binary systems which formed them. The binary systems were studied by the mean of crystallization curves. (author) [fr

  4. Interaction Studies of Dilute Aqueous Oxalic Acid

    Directory of Open Access Journals (Sweden)

    Kiran Kandpal

    2007-01-01

    Full Text Available Molecular conductance λm, relative viscosity and density of oxalicacid at different concentration in dilute aqueous solution were measured at 293 K.The conductance data were used to calculate the value association constant.Viscosity and density data were used to calculate the A and B coefficient ofJone-Dole equation and apparent molar volume respectively. The viscosityresults were utilized for the applicability of Modified Jone-Dole equation andStaurdinger equations. Mono oxalate anion acts, as structure maker and thesolute-solvent interaction were present in the dilute aqueous oxalic acid.

  5. Dilute acid/metal salt hydrolysis of lignocellulosics

    Science.gov (United States)

    Nguyen, Quang A.; Tucker, Melvin P.

    2002-01-01

    A modified dilute acid method of hydrolyzing the cellulose and hemicellulose in lignocellulosic material under conditions to obtain higher overall fermentable sugar yields than is obtainable using dilute acid alone, comprising: impregnating a lignocellulosic feedstock with a mixture of an amount of aqueous solution of a dilute acid catalyst and a metal salt catalyst sufficient to provide higher overall fermentable sugar yields than is obtainable when hydrolyzing with dilute acid alone; loading the impregnated lignocellulosic feedstock into a reactor and heating for a sufficient period of time to hydrolyze substantially all of the hemicellulose and greater than 45% of the cellulose to water soluble sugars; and recovering the water soluble sugars.

  6. Optimisation of Dilute Sulphuric Acid Hydrolysis of Waste ...

    African Journals Online (AJOL)

    Dilute sulphuric acid hydrolysis of waste paper was investigated in this study. The effects of acid concentration, time, temperature and liquid to solid ratio on the total reducing sugar concentration were studied over three levels using a four variable Box-Behnken design (BBD). A statistical model was developed for the ...

  7. Optimization of dilute acid hydrolysis of Enteromorpha

    Science.gov (United States)

    Feng, Dawei; Liu, Haiyan; Li, Fuchao; Jiang, Peng; Qin, Song

    2011-11-01

    Acid hydrolysis is a simple and direct way to hydrolyze polysaccharides in biomass into fermentable sugars. To produce fermentable sugars effectively and economically for fuel ethanol, we have investigated the hydrolysis of Enteromorpha using acids that are typically used to hydrolyze biomass: H2SO4, HCl, H3PO4 and C4H4O4 (maleic acid). 5%(w/w) Enteromorpha biomass was treated for different times (30, 60, and 90 min) and with different acid concentrations (0.6, 1.0, 1.4, 1.8, and 2.2%, w/w) at 121°C. H2SO4 was the most effective acid in this experiment. We then analyzed the hydrolysis process in H2SO4 in detail using high performance liquid chromatography. At a sulfuric acid concentration of 1.8% and treatment time of 60 min, the yield of ethanol fermentable sugars (glucose and xylose) was high, (230.5 mg/g dry biomass, comprising 175.2 mg/g glucose and 55.3 mg/g xylose), with 48.6% of total reducing sugars being ethanol fermentable. Therefore, Enteromorpha could be a good candidate for production of fuel ethanol. In future work, the effects of temperature and biomass concentration on hydrolysis, and also the fermentation of the hydrolysates to ethanol fuel should be focused on.

  8. Sugar yields from dilute oxalic acid pretreatment of maple wood compared to those with other dilute acids and hot water.

    Science.gov (United States)

    Zhang, Taiying; Kumar, Rajeev; Wyman, Charles E

    2013-01-30

    Dilute oxalic acid pretreatment was applied to maple wood to improve compatibility with downstream operations, and its performance in pretreatment and subsequent enzymatic hydrolysis was compared to results for hydrothermal and dilute hydrochloric and sulfuric acid pretreatments. The highest total xylose yield of ∼84% of the theoretical maximum was for both 0.5% oxalic and sulfuric acid pretreatment at 160 °C, compared to ∼81% yield for hydrothermal pretreatment at 200 °C and for 0.5% hydrochloric acid pretreatment at 140 °C. The xylooligomer fraction from dilute oxalic acid pretreatment was only 6.3% of the total xylose in solution, similar to results with dilute hydrochloric and sulfuric acids but much lower than the ∼70% value for hydrothermal pretreatment. Combining any of the four pretreatments with enzymatic hydrolysis with 60 FPU cellulase/g of glucan plus xylan in the pretreated maple wood resulted in virtually the same total glucose plus xylose yields of ∼85% of the maximum possible. Copyright © 2012 Elsevier Ltd. All rights reserved.

  9. Bioethanol productions from rice polish by optimization of dilute acid ...

    African Journals Online (AJOL)

    Lignocellulose materials are abundant renewable resource for the production of biofuel from fermentative organism (Sacchromyces cervesiae). Rice polish is cheapest and abundant lignocelluloses resource and has potential to produce bioethanol. The main steps for the conversion of biomass into glucose required dilute ...

  10. Study of Enzymatic Hydrolysis of Dilute Acid Pretreated Coconut Husk

    Directory of Open Access Journals (Sweden)

    Rudy Agustriyanto

    2012-12-01

    Full Text Available Coconut husk is classified as complex lignocellulosic material that contains cellulose, hemicellulose, lignin, and some other extractive compounds. Cellulose from coconut husk can be used as fermentation substrate after enzymatic hydrolysis. In contrary, lignin content from the coconut husk will act as an inhibitor in this hydrolysis process. Therefore, a pretreatment process is needed to enhance the hydrolysis of cellulose. The objective of this research is to investigate the production of the glucose through dilute acid pretreatment and to obtain its optimum operating conditions. In this study, the pretreatment was done using dilute sulfuric acid in an autoclave reactor. The pretreatment condition were varied at 80°C, 100°C, 120°C and 0.9%, 1.2%, 1.5% for temperature and acid concentration respectively. The acid pretreated coconut husk was then hydrolyzed using commercial cellulase (celluclast and β-glucosidase (Novozyme 188. The hydrolysis time was 72 hours and the operating conditions were varied at several temperature and pH. From the experimental results it can be concluded that the delignification temperature variation has greater influence than the acid concentration. The optimum operating condition was obtained at pH 4 and 50°C which was pretreated at 100°C using 1.5% acid concentration. Copyright © 2012 by BCREC UNDIP. All rights reserved. (Selected Paper from International Conference on Chemical and Material Engineering (ICCME 2012Received: 28th September 2012, Revised: 2nd October 2012, Accepted: 4th October 2012[How to Cite: R. Agustriyanto, A. Fatmawati, Y. Liasari. (2012. Study of Enzymatic Hydrolysis of Dilute Acid Pretreated Coconut Husk. Bulletin of Chemical Reaction Engineering & Catalysis, 7(2: 137-141. doi:10.9767/bcrec.7.2.4046.137-141] [How to Link / DOI: http://dx.doi.org/10.9767/bcrec.7.2.4046.137-141 ] | View in 

  11. Hydrolysis of dilute acid-pretreated cellulose under mild hydrothermal conditions.

    Science.gov (United States)

    Chimentão, R J; Lorente, E; Gispert-Guirado, F; Medina, F; López, F

    2014-10-13

    The hydrolysis of dilute acid-pretreated cellulose was investigated in a conventional oven and under microwave heating. Two acids--sulfuric and oxalic--were studied. For both hydrothermal conditions (oven and microwave) the resultant total organic carbon (TOC) values obtained by the hydrolysis of the cellulose pretreated with sulfuric acid were higher than those obtained by the hydrolysis of the cellulose pretreated with oxalic acid. However, the dicarboxylic acid exhibited higher hydrolytic efficiency towards glucose. The hydrolysis of cellulose was greatly promoted by microwave heating. The Rietveld method was applied to fit the X-ray patterns of the resultant cellulose after hydrolysis. Oxalic acid preferentially removed the amorphous region of the cellulose and left the crystalline region untouched. On the other hand, sulfuric acid treatment decreased the ordering of the cellulose by partially disrupting its crystalline structure. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Ethanol production from industrial hemp: effect of combined dilute acid/steam pretreatment and economic aspects

    DEFF Research Database (Denmark)

    Gunnarsson, Ingólfur Bragi; Svensson, Sven-Erik; Prade, Thomas

    2014-01-01

    In the present study, combined steam (140-180 °C) and dilute-acid pre-hydrolysis (0.0-2.0%) were applied to industrial hemp (Cannabis sativa L.), as pretreatment for lignocellulosic bioethanol production. The influence of the pretreatment conditions and cultivation type on the hydrolysis and etha......In the present study, combined steam (140-180 °C) and dilute-acid pre-hydrolysis (0.0-2.0%) were applied to industrial hemp (Cannabis sativa L.), as pretreatment for lignocellulosic bioethanol production. The influence of the pretreatment conditions and cultivation type on the hydrolysis...... pretreated at the optimal conditions showed positive economic results. The type of hemp cultivation (organic or conventional) did not influence significantly the effectiveness of the pretreatment and subsequent enzymatic hydrolysis and ethanol fermentation....

  13. Evaluation of continuous ethanol fermentation of dilute-acid corn stover hydrolysate using thermophilic anaerobic bacterium Thermoanaerobacter BG1L1

    DEFF Research Database (Denmark)

    Georgieva, Tania I.; Ahring, Birgitte Kiær

    2007-01-01

    Dilute sulfuric acid pretreated corn stover is potential feedstock of industrial interest for second generation fuel ethanol production. However, the toxicity of corn stover hydrolysate (PCS) has been a challenge for fermentation by recombinant xylose fermenting organisms. In this work...

  14. Comparison of bile acid synthesis determined by isotope dilution versus fecal acidic sterol output in human subjects

    International Nuclear Information System (INIS)

    Duane, W.C.; Holloway, D.E.; Hutton, S.W.; Corcoran, P.J.; Haas, N.A.

    1982-01-01

    Fecal acidic sterol output has been found to be much lower than bile acid synthesis determined by isotope dilution. Because of this confusing discrepancy, we compared these 2 measurements done simultaneously on 13 occasions in 5 normal volunteers. In contrast to previous findings, bile acid synthesis by the Lindstedt isotope dilution method averaged 16.3% lower than synthesis simultaneously determined by fecal acidic sterol output (95% confidence limit for the difference - 22.2 to -10.4%). When one-sample determinations of bile acid pools were substituted for Lindstedt pools, bile acid synthesis by isotope dilution averaged 5.6% higher than synthesis by fecal acidic sterol output (95% confidence limits -4.9 to 16.1%). These data indicate that the 2 methods yield values in reasonably close agreement with one another. If anything, fecal acidic sterol outputs are slightly higher than synthesis by isotope dilution

  15. Calorimetric study of interaction of barium hydroxide with diluted solutions of hydrofluoric acid

    International Nuclear Information System (INIS)

    Kurbanov, A.R.; Sharipov, D.Sh.

    1993-01-01

    Present article is devoted to calorimetric study of interaction of barium hydroxide with diluted solutions of hydrofluoric acid. The calorimetric study of interaction of barium hydroxide with diluted solutions of hydrofluoric acid was carried out in order to determine the thermal effects of reactions. The results of interaction of Ba(OH) 4 ·8H 2 O with 5, 10, and 20% solution of hydrofluoric acid were considered.

  16. Effects of organic acid and probiotic on performance and gut ...

    African Journals Online (AJOL)

    user

    2015-12-02

    Dec 2, 2015 ... The effects of organic acid, probiotic and a combination of the two on performance and gut .... −3 dilution level. One mL of the dilution was pipetted and inoculated on .... animal by stimulating synthesis of vitamins of the B-group, improving .... Cowan and Steel's Manual for Identification of Medical Bacteria.

  17. Separation of glycols from dilute aqueous solutions via complexation with boronic acids

    Energy Technology Data Exchange (ETDEWEB)

    Randel, L.A.; King, C.J.

    1991-07-01

    This work examines methods of separating low molecular weight glycols from dilute aqueous solution. Extraction into conventional solvents is generally not economical, since, in the literature reviewed, distribution ratios for the two- to four-carbon glycols are all less than one. Distribution ratios can be increased, however, by incorporating into the organic phase an extracting agent that will complex with the solute of interest. The extracting agent investigated in this work is 3-nitrophenylboronic acid (NPBA). NPBA, a boric acid derivative, reversibly complexes with many glycols. The literature on complexation of borate and related compounds with glycols, including mechanistic data, measurement techniques, and applications to separation processes, provides information valuable for designing experiments with NPBA and is reviewed herein. 88 refs., 15 figs., 24 tabs.

  18. Oxic limestone drains for treatment of dilute, acidic mine drainage

    Science.gov (United States)

    Cravotta, Charles A.

    1998-01-01

    Limestone treatment systems can be effective for remediation of acidic mine drainage (AMD) that contains moderate concentrations of dissolved O2 , Fe3+ , or A13+ (1‐5 mg‐L‐1 ). Samples of water and limestone were collected periodically for 1 year at inflow, outflow, and intermediate points within underground, oxic limestone drains (OLDs) in Pennsylvania to evaluate the transport of dissolved metals and the effect of pH and Fe‐ and Al‐hydrolysis products on the rate of limestone dissolution. The influent was acidic and relatively dilute (pH 1 mg‐L‐1 ) but was near neutral (pH = 6.2‐7.0); Fe and Al decreased to less than 5% of influent concentrations. As pH increased near the inflow, hydrous Fe and Al oxides precipitated in the OLDs. The hydrous oxides, nominally Fe(OH)3 and AI(OH)3, were visible as loosely bound, orange‐yellow coatings on limestone near the inflow. As time elapsed, Fe(OH)3 and AI(OH)3 particles were transported downflow. During the first 6 months of the experiment, Mn 2+ was transported conservatively through the OLDs; however, during the second 6 months, concentrations of Mn in effluent decreased by about 50% relative to influent. The accumulation of hydrous oxides and elevated pH (>5) in the downflow part of the OLDs promoted sorption and coprecipitation of Mn as indicated by its enrichment relative to Fe in hydrous‐oxide particles and coatings on limestone. Despite thick (~1 mm) hydrous‐oxide coatings on limestone near the inflow, CaCO3 dissolution was more rapid near the inflow than at downflow points within the OLD where the limestone was not coated. The rate of limestone dissolution decreased with increased residence time, pH, and concentrations of Ca2+ and HCO3‐ and decreased PCO2. The following overall reaction shows alkalinity as an ultimate product of the iron hydrolysis reaction in an OLD:Fe2+ + 0.25 O2 +CaCO3 + 2.5 H2O --> Fe(OH)3 + 2 Ca2+ + 2 HCO3-where 2 moles of CaCO3 dissolve for each mole of Fe(OH)3 produced

  19. Response to Comment on "Dilution limits dissolved organic carbon utilization in the deep ocean"

    KAUST Repository

    Arrieta, Jesus

    2015-12-18

    Our recent finding that dilution limits dissolved organic carbon (DOC) utilization in the deep ocean has been criticized based on the common misconception that lability equates to rapid and complete utilization. Even when considering the redefinition of recalcitrant DOC recently proposed by Jiao et al., the dilution hypothesis best explains our experimental observations.

  20. Nucleic acid-binding glycoproteins which solubilize nucleic acids in dilute acid: re-examination of the Ustilago maydis glycoproteins

    Energy Technology Data Exchange (ETDEWEB)

    Unrau, P.; Champ, D.R.; Young, J.L.; Grant, C.E.

    1980-01-01

    Holloman reported the isolation from Ustilago maydis of a glycoprotein which prevented the precipitation of nucleic acids in cold 5% trichloroacetic acid. Two glycoprotein fractions from U. maydis with this nucleic acid-solubilizing activity were isolated in our laboratory using improved purification procedures. The activity was not due to nuclease contamination. The glycoproteins are distinguished by: their ability to bind to concanavalin A-Sepharose; their differential binding to double- and single-stranded deoxyribonucleic acid, and to ribonucleic acid; their molecular weights (46,000 and 69,000); and the relative amounts present in growing versus nongrowing cells. Both fractions required sulfhydryl-reducing conditions for optimal yields, specific activity, and stability. Nucleic acid binding was cooperative, the minimum number of glycoproteins required to make a native T7 DNA molecule soluble in dilute acid being estimated at 2 and 15, respectively.

  1. The separation and determination of fatty acids by isotopic dilution and radiogas-liquid chromatography

    International Nuclear Information System (INIS)

    Beardsley, D.A.

    1981-01-01

    A number of static phases have been evaluated for the GLC separation of fatty acids. Of those investigated, only AT 1200 was capable of resolving the isomeric forms of the acids. A radiogas-liquid chromatographic method incorporating isotopic dilution analysis has been developed for the determination of n-butyric acid. The proposed method has been applied to the determination of the acid in hydrolysed butter fat and milk chocolate extracts. (author)

  2. High-Yield Production of Levulinic Acid from Pretreated Cow Dung in Dilute Acid Aqueous Solution

    Directory of Open Access Journals (Sweden)

    Jialei Su

    2017-02-01

    Full Text Available Agricultural waste cow dung was used as feedstock for the production of a high value–added chemical levulinic acid (LA in dilute acid aqueous solutions. A high LA yield of 338.9 g/kg was obtained from the pretreated cow dung, which was much higher than that obtained from the crude cow dung (135 g/kg, mainly attributed to the breakage of the lignin fraction in the lignocellulose structure of the cow dung by potassium hydroxide (KOH pretreatment, and thus enhanced the accessibility of cow dung to the acid sites in the catalytic reaction. Meanwhile, another value-added chemical formic acid could be obtained with a yield of ca. 160 g/kg in the process, implying a total production of ca. 500 g/kg yield for LA and formic acid from the pretreated cow dung with the proposed process. The developed process was shown to be tolerant to high initial substrate loading with a satisfied LA yield. This work provides a promising strategy for the value-increment utilization of liglocellulosic agricultural residues.

  3. Response to Comment on "Dilution limits dissolved organic carbon utilization in the deep ocean"

    KAUST Repository

    Arrieta, J M; Mayol, E.; Hansman, R. L.; Herndl, G. J.; Dittmar, T.; Duarte, Carlos M.

    2015-01-01

    Our recent finding that dilution limits dissolved organic carbon (DOC) utilization in the deep ocean has been criticized based on the common misconception that lability equates to rapid and complete utilization. Even when considering

  4. Dilute oxalic acid pretreatment for biorefining giant reed (Arundo donax L.)

    Science.gov (United States)

    Danilo Scordia; Salvatore L. Cosentino; Jae-Won Lee; Thomas W. Jeffries

    2011-01-01

    Biomass pretreatment is essential to overcome recalcitrance of lignocellulose for ethanol production. In the present study we pretreated giant reed (Arundo donax L.), a perennial, rhizomatous lignocellulosic grass with dilute oxalic acid. The effects of temperature (170-190 ºC), acid loading (2-10% w/w) and reaction time (15-40 min) were handled as a single...

  5. Dilute-acid pretreatment of barley straw for biological hydrogen production using Caldicellulosiruptor saccharolyticus

    NARCIS (Netherlands)

    Panagiotopoulos, I.A.; Bakker, R.R.C.; Vrije, de G.J.; Claassen, P.A.M.; Koukios, E.G.

    2012-01-01

    The main objective of this study was to use the fermentability test to investigate the feasibility of applying various dilute acids in the pretreatment of barley straw for biological hydrogen production. At a fixed acid loading of 1% (w/w dry matter) 28-32% of barley straw was converted to soluble

  6. Effect of temperature on the dilution enthalpies of α,ω-amino acids in aqueous solutions

    International Nuclear Information System (INIS)

    Romero, C.M.; Cadena, J.C.; Lamprecht, I.

    2011-01-01

    Highlights: → The dilution of 3-amino propanoic acid, 4-amino butanoic acid, 5-amino pentanoic acid, and 6-amino hexanoic acid in water is an exothermic process at T = (293.15, 298.15, 303.15, and 308.15) K. → The limiting experimental slopes of the enthalpies of dilution with respect to the molality change Δm, are negative suggesting that the solutes interact with water primarily through their alkyl groups. → The value of the pairwise coefficient is positive at the temperatures considered, and the magnitude increases linearly with the number of methylene groups. → The comparison between the pairwise interaction coefficients for α,ω-amino acids and α-amino acids shows that the change in the enthalpic interaction coefficient is related to the relative position of the polar groups. - Abstract: Dilution enthalpies of aqueous solutions of 3-amino propanoic acid, 4-amino butanoic acid, 5-amino pentanoic acid, and 6-amino hexanoic acid were determined at T = (293.15, 298.15, 303.15, and 308.15) K using an LKB flow microcalorimeter. The homotactic interaction coefficients were obtained according to the McMillan-Mayer theory from the experimental data. For all the systems studied, the dilution of α,ω-amino acids in water is an exothermic process; the pair coefficients have positive values which increases with chain length. The obtained values of the interaction coefficients are interpreted in terms of solute-solvent and solute-solute interactions and are used as indicative of hydrophobic behavior of the amino acid studied.

  7. Thermal decomposition of dilute aqueous formic acid solutions

    DEFF Research Database (Denmark)

    Bjerre, A.B.; Sørensen, E.

    1992-01-01

    or a decarboxylation. In particular the second one is dependent on the reactor vessel used. It is shown to be catalyzed by a mixture of oxides of stainless steel components. The presence of CH3COOH or CH3CHO promotes the decomposition of HCOOH by way of both decarboxylation and oxidation. In any case formic acid...

  8. Dilution limits dissolved organic carbon utilization in the deep ocean

    NARCIS (Netherlands)

    Arrieta, J.M.; Mayol, E.; Hansman, R.L.; Herndl, G.J.; Dittmar, T.; Duarte, C.M.

    2015-01-01

    Oceanic dissolved organic carbon (DOC) is the second largest reservoir of organic carbon in the biosphere. About 72% of the global DOC inventory is stored in deep oceanic layers for years to centuries, supporting the current view that it consists of materials resistant to microbial degradation. An

  9. Elucidating the role of ferrous ion cocatalyst in enhancing dilute acid pretreatment of lignocellulosic biomass

    Directory of Open Access Journals (Sweden)

    Wei Hui

    2011-11-01

    Full Text Available Abstract Background Recently developed iron cocatalyst enhancement of dilute acid pretreatment of biomass is a promising approach for enhancing sugar release from recalcitrant lignocellulosic biomass. However, very little is known about the underlying mechanisms of this enhancement. In the current study, our aim was to identify several essential factors that contribute to ferrous ion-enhanced efficiency during dilute acid pretreatment of biomass and to initiate the investigation of the mechanisms that result in this enhancement. Results During dilute acid and ferrous ion cocatalyst pretreatments, we observed concomitant increases in solubilized sugars in the hydrolysate and reducing sugars in the (insoluble biomass residues. We also observed enhancements in sugar release during subsequent enzymatic saccharification of iron cocatalyst-pretreated biomass. Fourier transform Raman spectroscopy showed that major peaks representing the C-O-C and C-H bonds in cellulose are significantly attenuated by iron cocatalyst pretreatment. Imaging using Prussian blue staining indicated that Fe2+ ions associate with both cellulose/xylan and lignin in untreated as well as dilute acid/Fe2+ ion-pretreated corn stover samples. Analyses by scanning electron microscopy and transmission electron microscopy revealed structural details of biomass after dilute acid/Fe2+ ion pretreatment, in which delamination and fibrillation of the cell wall were observed. Conclusions By using this multimodal approach, we have revealed that (1 acid-ferrous ion-assisted pretreatment increases solubilization and enzymatic digestion of both cellulose and xylan to monomers and (2 this pretreatment likely targets multiple chemistries in plant cell wall polymer networks, including those represented by the C-O-C and C-H bonds in cellulose.

  10. Xylanase supplementation on enzymatic saccharification of dilute acid pretreated poplars at different severities

    Science.gov (United States)

    Chao Zhang; Xinshu Zhuang; Zhao Jiang Wang; Fred Matt; Franz St. John; J.Y. Zhu

    2013-01-01

    Three pairs of solid substrates from dilute acid pretreatment of two poplar wood samples were enzymatically hydrolyzed by cellulase preparations supplemented with xylanase. Supplementation of xylanase improved cellulose saccharification perhaps due to improved cellulose accessibility by xylan hydrolysis. Total xylan removal directly affected enzymatic cellulose...

  11. Comparison of Dilute Acid and Ionic Liquid Pretreatment of Switchgrass: Biomass Recalcitrance, Delignification and Enzymatic Saccharification

    Science.gov (United States)

    The efficiency of two biomass pretreatment technologies, dilute acid hydrolysis and dissolution in an ionic liquid, are compared in terms of delignification, saccharification efficiency and saccharide yields with switchgrass serving as a model bioenergy crop. When subject to ionic liquid pretreatme...

  12. High temperature dilute phosphoric acid pretreatment of corn stover for furfural and ethanol production

    Science.gov (United States)

    Furfural was produced from corn stover by one stage pretreatment process using dilute H3PO4 and solid residues following furfural production were used for ethanol production by Saccharomyces cerevisiae NRRL- Y2034. A series of experiments were conducted at varied temperatures (140-200 oC) and acid ...

  13. Mercury dilution by autochthonous organic matter in a fertilized mangrove wetland.

    Science.gov (United States)

    Machado, Wilson; Sanders, Christian J; Santos, Isaac R; Sanders, Luciana M; Silva-Filho, Emmanoel V; Luiz-Silva, Wanilson

    2016-06-01

    A dated sediment core from a highly-fertilized mangrove wetland located in Cubatão (SE Brazil) presented a negative correlation between mercury (Hg) and organic carbon contents. This is an unusual result for a metal with well-known affinity to organic matter. A dilution of Hg concentrations by autochthonous organic matter explained this observation, as revealed by carbon stable isotopes signatures (δ(13)C). Mercury dilution by the predominant mangrove-derived organic matter counterbalanced the positive influences of algal-derived organic matter and clay contents on Hg levels, suggesting that deleterious effects of Hg may be attenuated. Considering the current paradigm on the positive effect of organic matter on Hg concentrations in coastal sediments and the expected increase in mangrove organic matter burial due to natural and anthropogenic stimulations of primary production, predictions on the influences of organic matter on Hg accumulation in mangrove wetlands deserve caution. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Isotope dilution mass spectrometry of inorganic and organic substances

    International Nuclear Information System (INIS)

    Heumann, K.G.

    1986-01-01

    The aim of this short review of IDMS is to provide an introduction into the principles of this analytical method and to show possible applications of this accurate technique, e.g. negative thermal ionization IDMS for inorganic anion analysis or the analysis of organic compounds in the field of clinical chemistry. (orig./RB)

  15. Dilution limits dissolved organic carbon utilization in the deep ocean

    KAUST Repository

    Arrieta, Jesus

    2015-03-19

    Oceanic dissolved organic carbon (DOC) is the second largest reservoir of organic carbon in the biosphere. About 72% of the global DOC inventory is stored in deep oceanic layers for years to centuries, supporting the current view that it consists of materials resistant to microbial degradation. An alternative hypothesis is that deep-water DOC consists of many different, intrinsically labile compounds at concentrations too low to compensate for the metabolic costs associated to their utilization. Here, we present experimental evidence showing that low concentrations rather than recalcitrance preclude consumption of a substantial fraction of DOC, leading to slow microbial growth in the deep ocean. These findings demonstrate an alternative mechanism for the long-term storage of labile DOC in the deep ocean, which has been hitherto largely ignored. © 2015, American Association for the Advancement of Science. All rights reserved.

  16. Dilution limits dissolved organic carbon utilization in the deep ocean

    KAUST Repository

    Arrieta, J M; Mayol, Eva; Hansman, Roberta L.; Herndl, Gerhard J.; Dittmar, Thorsten; Duarte, Carlos M.

    2015-01-01

    Oceanic dissolved organic carbon (DOC) is the second largest reservoir of organic carbon in the biosphere. About 72% of the global DOC inventory is stored in deep oceanic layers for years to centuries, supporting the current view that it consists of materials resistant to microbial degradation. An alternative hypothesis is that deep-water DOC consists of many different, intrinsically labile compounds at concentrations too low to compensate for the metabolic costs associated to their utilization. Here, we present experimental evidence showing that low concentrations rather than recalcitrance preclude consumption of a substantial fraction of DOC, leading to slow microbial growth in the deep ocean. These findings demonstrate an alternative mechanism for the long-term storage of labile DOC in the deep ocean, which has been hitherto largely ignored. © 2015, American Association for the Advancement of Science. All rights reserved.

  17. Kinetic study of dilute nitric acid treatment of corn stover at relatively high temperature

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, R.; Lu, X.; Liu, Y.; Wang, X.; Zhang, S. [Tianjin University, School of Environmental Science and Technology, Tianjin (China)

    2011-03-15

    Corn stover was hydrolyzed using dilute nitric acid at 150 C. Several concentrations of HNO{sub 3} (0.2, 0.4 and 0.6 wt-%) and reaction times (0-60 min) were evaluated. The kinetic parameters of mathematical models for predicting the concentrations of xylose, glucose, arabinose, acetic acid, and furfural in the hydrolysates were determined. The hydrolysates obtained from corn stover can be used to produce methane by an anaerobic fermentation process. Thus, the hydrolysis process of corn stover using dilute nitric acid can be conceived as the first stage of an integrated strategy for corn stover utilization. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  18. Estimation of the volatility distribution of organic aerosol combining thermodenuder and isothermal dilution measurements

    Science.gov (United States)

    Louvaris, Evangelos E.; Karnezi, Eleni; Kostenidou, Evangelia; Kaltsonoudis, Christos; Pandis, Spyros N.

    2017-10-01

    A method is developed following the work of Grieshop et al. (2009) for the determination of the organic aerosol (OA) volatility distribution combining thermodenuder (TD) and isothermal dilution measurements. The approach was tested in experiments that were conducted in a smog chamber using organic aerosol (OA) produced during meat charbroiling. A TD was operated at temperatures ranging from 25 to 250 °C with a 14 s centerline residence time coupled to a high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) and a scanning mobility particle sizer (SMPS). In parallel, a dilution chamber filled with clean air was used to dilute isothermally the aerosol of the larger chamber by approximately a factor of 10. The OA mass fraction remaining was measured as a function of temperature in the TD and as a function of time in the isothermal dilution chamber. These two sets of measurements were used together to estimate the volatility distribution of the OA and its effective vaporization enthalpy and accommodation coefficient. In the isothermal dilution experiments approximately 20 % of the OA evaporated within 15 min. Almost all the OA evaporated in the TD at approximately 200 °C. The resulting volatility distributions suggested that around 60-75 % of the cooking OA (COA) at concentrations around 500 µg m-3 consisted of low-volatility organic compounds (LVOCs), 20-30 % of semivolatile organic compounds (SVOCs), and around 10 % of intermediate-volatility organic compounds (IVOCs). The estimated effective vaporization enthalpy of COA was 100 ± 20 kJ mol-1 and the effective accommodation coefficient was 0.06-0.07. Addition of the dilution measurements to the TD data results in a lower uncertainty of the estimated vaporization enthalpy as well as the SVOC content of the OA.

  19. Estimation of the volatility distribution of organic aerosol combining thermodenuder and isothermal dilution measurements

    Directory of Open Access Journals (Sweden)

    E. E. Louvaris

    2017-10-01

    Full Text Available A method is developed following the work of Grieshop et al. (2009 for the determination of the organic aerosol (OA volatility distribution combining thermodenuder (TD and isothermal dilution measurements. The approach was tested in experiments that were conducted in a smog chamber using organic aerosol (OA produced during meat charbroiling. A TD was operated at temperatures ranging from 25 to 250 °C with a 14 s centerline residence time coupled to a high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS and a scanning mobility particle sizer (SMPS. In parallel, a dilution chamber filled with clean air was used to dilute isothermally the aerosol of the larger chamber by approximately a factor of 10. The OA mass fraction remaining was measured as a function of temperature in the TD and as a function of time in the isothermal dilution chamber. These two sets of measurements were used together to estimate the volatility distribution of the OA and its effective vaporization enthalpy and accommodation coefficient. In the isothermal dilution experiments approximately 20 % of the OA evaporated within 15 min. Almost all the OA evaporated in the TD at approximately 200 °C. The resulting volatility distributions suggested that around 60–75 % of the cooking OA (COA at concentrations around 500 µg m−3 consisted of low-volatility organic compounds (LVOCs, 20–30 % of semivolatile organic compounds (SVOCs, and around 10 % of intermediate-volatility organic compounds (IVOCs. The estimated effective vaporization enthalpy of COA was 100 ± 20 kJ mol−1 and the effective accommodation coefficient was 0.06–0.07. Addition of the dilution measurements to the TD data results in a lower uncertainty of the estimated vaporization enthalpy as well as the SVOC content of the OA.

  20. Enzymatic saccharification of dilute acid pretreated saline crops for fermentable sugar production

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Yi; Zhang, Ruihong [Biological and Agricultural Engineering Department, University of California, Davis One Shields Avenue, Davis, CA 95616 (United States); Pan, Zhongli [Biological and Agricultural Engineering Department, University of California, Davis One Shields Avenue, Davis, CA 95616 (United States); Processed Foods Research Unit, USDA-ARS-WRRC, 800 Buchanan Street, Albany, CA 94710 (United States); Wang, Donghai [Biological and Agricultural Engineering Department, Kansas State University, Manhattan, KS 66506 (United States)

    2009-11-15

    Four saline crops [athel (Tamarix aphylla L), eucalyptus (Eucalyptus camaldulensis), Jose Tall Wheatgrass (Agropyron elongatum), and Creeping Wild Ryegrass (Leymus triticoides)] that are used in farms for salt uptake from soil and drainage irrigation water have the potential for fuel ethanol production because they don't take a large number of arable lands. Dilute sulfuric acid pretreatment and enzymatic hydrolysis were conducted to select the optimum pretreatment conditions and the best saline crop for further enzymatic hydrolysis research. The optimum dilute acid pretreatment conditions included T = 165 C, t = 8 min, and sulfuric acid concentration 1.4% (w/w). Creeping Wild Ryegrass was decided to be the best saline crop. Solid loading, cellulase and {beta}-glucosidase concentrations had significant effects on the enzymatic hydrolysis of dilute acid pretreated Creeping Wild Ryegrass. Glucose concentration increased by 36 mg/mL and enzymatic digestibility decreased by 20% when the solid loading increased from 4 to 12%. With 8% solid loading, enzymatic digestibility increased by over 30% with the increase of cellulase concentration from 5 to 15 FPU/g-cellulose. Under given cellulase concentration of 15 FPU/g-cellulose, 60% increase of enzymatic digestibility of pretreated Creeping Wild Ryegrass was obtained with the increase of {beta}-glucosidase concentration up to 15 CBU/g-cellulose. With a high solid loading of 10%, fed-batch operation generated 12% and 18% higher enzymatic digestibility and glucose concentration, respectively, than batch process. (author)

  1. Laboratory studies of 2H evaporator scale dissolution in dilute nitric acid

    International Nuclear Information System (INIS)

    Oji, L.

    2014-01-01

    The rate of 2H evaporator scale solids dissolution in dilute nitric acid has been experimentally evaluated under laboratory conditions in the SRNL shielded cells. The 2H scale sample used for the dissolution study came from the bottom of the evaporator cone section and the wall section of the evaporator cone. The accumulation rate of aluminum and silicon, assumed to be the two principal elemental constituents of the 2H evaporator scale aluminosilicate mineral, were monitored in solution. Aluminum and silicon concentration changes, with heating time at a constant oven temperature of 90 deg C, were used to ascertain the extent of dissolution of the 2H evaporator scale mineral. The 2H evaporator scale solids, assumed to be composed of mostly aluminosilicate mineral, readily dissolves in 1.5 and 1.25 M dilute nitric acid solutions yielding principal elemental components of aluminum and silicon in solution. The 2H scale dissolution rate constant, based on aluminum accumulation in 1.5 and 1.25 M dilute nitric acid solution are, respectively, 9.21E-04 ± 6.39E-04 min -1 and 1.07E-03 ± 7.51E-05 min -1 . Silicon accumulation rate in solution does track the aluminum accumulation profile during the first few minutes of scale dissolution. It however diverges towards the end of the scale dissolution. This divergence therefore means the aluminum-to-silicon ratio in the first phase of the scale dissolution (non-steady state conditions) is different from the ratio towards the end of the scale dissolution. Possible causes of this change in silicon accumulation in solution as the scale dissolution progresses may include silicon precipitation from solution or the 2H evaporator scale is a heterogeneous mixture of aluminosilicate minerals with several impurities. The average half-life for the decomposition of the 2H evaporator scale mineral in 1.5 M nitric acid is 12.5 hours, while the half-life for the decomposition of the 2H evaporator scale in 1.25 M nitric acid is 10.8 hours

  2. Dissolution of magnetite in a dilute chemical decontaminant formulation containing gallic acid as a reductant

    International Nuclear Information System (INIS)

    Kishore, Kamal; Rajesh, Puspalata; Dey, G.R.

    2000-01-01

    Gallic acid (GA) was tried as a reductant in place of ascorbic acid in dilute chemical decontaminant (DCD) formulations. Dissolution of magnetite in GA based DCD formulations was studied at 50 deg as well as 80 degC. It was found to be a good substitute for ascorbic acid in EDTA/ascorbic acid/citric acid i.e. EAC formulation. The efficiency of EDTA/GA/CA formulation was as good as that of EAC formulation. 2.8 was found to be the optimum pH for this formulation and dissolution decreased at lower as well as higher pHs. The ion-exchange behaviour of GA is also appropriate for using it in a regenerating type of formulation. Being an aromatic compound, gallic acid has inherent stability against radiation degradation. (author)

  3. A dilute chemical decontaminant formulation containing gallic acid as a reductant

    International Nuclear Information System (INIS)

    Kishore, K.; Rajesh, P.; Kumbhar, A.G.

    2001-01-01

    Gallic acid (GA) was tried as a reductant in place of ascorbic acid in dilute chemical decontaminant (DCD) formulations. Dissolution of magnetite in GA based DCD formulations was studied at 50 C as well as 80 C. It was found to be a good substitute for ascorbic acid in EDTA/ascorbic acid/citric acid, i.e., EAC formulation. The efficiency of EDTA/GA/CA formulation was as good as that of EAC formulation. 2.8 was found to be the optimum pH for this formulation and dissolution decreased at lower as well as higher pHs. The ion exchange behaviour of GA is also appropriate for using it in a regenerating type of formulation. Being an aromatic compound, Gallic acid has inherent stability against radiation degradation. (orig.)

  4. Anomalous Capacitance Maximum of the Glassy Carbon-Ionic Liquid Interface through Dilution with Organic Solvents.

    Science.gov (United States)

    Bozym, David J; Uralcan, Betül; Limmer, David T; Pope, Michael A; Szamreta, Nicholas J; Debenedetti, Pablo G; Aksay, Ilhan A

    2015-07-02

    We use electrochemical impedance spectroscopy to measure the effect of diluting a hydrophobic room temperature ionic liquid with miscible organic solvents on the differential capacitance of the glassy carbon-electrolyte interface. We show that the minimum differential capacitance increases with dilution and reaches a maximum value at ionic liquid contents near 5-10 mol% (i.e., ∼1 M). We provide evidence that mixtures with 1,2-dichloroethane, a low-dielectric constant solvent, yield the largest gains in capacitance near the open circuit potential when compared against two traditional solvents, acetonitrile and propylene carbonate. To provide a fundamental basis for these observations, we use a coarse-grained model to relate structural variations at the double layer to the occurrence of the maximum. Our results reveal the potential for the enhancement of double-layer capacitance through dilution.

  5. Optical spacing effect in organic photovoltaic cells incorporating a dilute acceptor layer

    Energy Technology Data Exchange (ETDEWEB)

    Menke, S. Matthew; Lindsay, Christopher D.; Holmes, Russell J. [Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455 (United States)

    2014-06-16

    The addition of spacing layers in organic photovoltaic cells (OPVs) can enhance light absorption by optimizing the spatial distribution of the incident optical field in the multilayer structure. We explore the optical spacing effect in OPVs achieved using a diluted electron acceptor layer of C{sub 60}. While optical spacing is often realized by optimizing buffer layer thickness, we find that optical spacing via dilution leads to cells with similar or enhanced photocurrent. This is observed despite a smaller quantity of absorbing molecules, suggesting a more efficient use of absorbed photons. In fact, dilution is found to concentrate optical absorption near the electron donor-acceptor interface, resulting in a marked increase in the exciton diffusion efficiency. Contrasting the use of changes in thickness to engineer optical absorption, the use of dilution does not significantly alter the overall thickness of the OPV. Optical spacing via dilution is shown to be a viable alternative to more traditional optical spacing techniques and may be especially useful in the continued optimization of next-generation, tandem OPVs where it is important to minimize competition for optical absorption between individual sub-cells.

  6. Optical spacing effect in organic photovoltaic cells incorporating a dilute acceptor layer

    International Nuclear Information System (INIS)

    Menke, S. Matthew; Lindsay, Christopher D.; Holmes, Russell J.

    2014-01-01

    The addition of spacing layers in organic photovoltaic cells (OPVs) can enhance light absorption by optimizing the spatial distribution of the incident optical field in the multilayer structure. We explore the optical spacing effect in OPVs achieved using a diluted electron acceptor layer of C 60 . While optical spacing is often realized by optimizing buffer layer thickness, we find that optical spacing via dilution leads to cells with similar or enhanced photocurrent. This is observed despite a smaller quantity of absorbing molecules, suggesting a more efficient use of absorbed photons. In fact, dilution is found to concentrate optical absorption near the electron donor-acceptor interface, resulting in a marked increase in the exciton diffusion efficiency. Contrasting the use of changes in thickness to engineer optical absorption, the use of dilution does not significantly alter the overall thickness of the OPV. Optical spacing via dilution is shown to be a viable alternative to more traditional optical spacing techniques and may be especially useful in the continued optimization of next-generation, tandem OPVs where it is important to minimize competition for optical absorption between individual sub-cells.

  7. The pitting resistance of AISI 316 stainless steel passivated in diluted nitric acid

    International Nuclear Information System (INIS)

    Barbosa, M.A.

    1983-01-01

    The pitting resistance of AISI 316 stainless steel after passivation in diluted nitric acid was studied in comparison with that of non-passivated specimens. The passivation treatment increased the pitting potential but decreased the resistance to crevice corrosion under open circuit conditions in aerated sea water. Immersion in the nitric acid solution was found to remove the sulphide inclusions from the metal surface, thus eliminating the most susceptible sites for attack. In the absence of sulphide particles pitting nucleated at aluminium-rich oxides. (author)

  8. Conversion of rice straw to sugars by dilute-acid hydrolysis

    International Nuclear Information System (INIS)

    Karimi, Keikhosro; Kheradmandinia, Shauker; Taherzadeh, Mohammad J.

    2006-01-01

    Hydrolysis of rice straw by dilute sulfuric acid at high temperature and pressure was investigated in one and two stages. The hydrolyses were carried out in a 10-l reactor, where the hydrolysis retention time (3-10 min), pressure (10-35 bar) and acid concentration (0-1%) were examined. Optimization of first stage hydrolysis is desirable to achieve the highest yield of the sugars from hemicellulose and also as a pretreatment for enzymatic hydrolysis. The results show the ability of first stage hydrolysis to depolymerize xylan to xylose with a maximum yield of 80.8% at hydrolysis pressure of 15 bar, 10 min retention time and 0.5% acid concentration. However, the yield of glucose from glucan was relatively low in first stage hydrolysis at a maximum of 25.8%. The solid residuals were subjected to further dilute-acid hydrolysis in this study. This second-stage hydrolysis without addition of the acid could not increase the yield of glucose from glucan beyond 26.6%. On the other hand, the best results of the hydrolysis were achieved, when 0.5% sulfuric acid was added prior to each stage in two-stage hydrolysis. The best results of the second stage of the hydrolysis were achieved at the hydrolysis pressure and the retention time of 30 bar and 3 min in the second stage hydrolysis, where a total of 78.9% of xylan and 46.6% of glucan were converted to xylose and glucose, respectively in the two stages. Formation of furfural and HMF were functions of the hydrolysis pressure, acid concentration, and retention time, whereas the concentration of acetic acid was almost constant at pressure of higher than 10 bar and a total retention time of 10 min

  9. Optimisation of dilute acid pre-treatment of artisan rice hulls for ethanol production

    International Nuclear Information System (INIS)

    Lopez, Yoney; Martin, Carlos; Gullon, Beatriz; Parajo, Juan Carlos

    2011-01-01

    Rice hulls are potential low-cost feedstocks for fuel ethanol production in many countries. In this work, the dilute-acid pre-treatment of artisan rice hulls was investigated using a central composite rotatable experimental design. The experimental variables were temperature (140-210 C), biomass load (5-20%) and sulphuric acid concentration (0.5-1.5 g per 100 g of reaction mixture). A total of 16 experimental runs, including a 23-plan, two replicates at the central point and six star points, were carried out. Low temperatures were found to be favourable for the hydrolysis of xylan and of the easily hydrolyzable glucan fraction. High glucose formation (up to 15.3 g/100 g), attributable to starch hydrolysis, was detected in the hydrolysates obtained under the least severe pre-treatment conditions. Using the experimental results, several models for predicting the effect of the operational conditions on the yield of pretreated solids, xylan and glucan conversion upon pre-treatment, and on enzymatic convertibility of cellulose were developed. Optimum results were predicted for the conversion of easily-hydrolyzable glucan in the material pretreated at 140.7 C, and for the enzymatic saccharification of cellulose in the material pretreated at 169 C. These results suggested the use of two-step acid hydrolysis as future pre-treatment strategy for artisan rice hulls. Key words: Dilute acid hydrolysis, enzymatic hydrolysis, pre-treatment, rice hulls. (author)

  10. EFFECTIVENESS OF USING DILUTE OXALIC ACID TO DISSOLVE HIGH LEVEL WASTE IRON BASED SLUDGE SIMULANT

    International Nuclear Information System (INIS)

    Ketusky, E

    2008-01-01

    At the Savannah River Site (SRS), near Aiken South Carolina, there is a crucial need to remove residual quantities of highly radioactive iron-based sludge from large select underground storage tanks (e.g., 19,000 liters of sludge per tank), in order to support tank closure. The use of oxalic acid is planned to dissolve the residual sludge, hence, helping in the removal. Based on rigorous testing, primarily using 4 and 8 wt% oxalic acid solutions, it was concluded that the more concentrated the acid, the greater the amount of residual sludge that would be dissolved; hence, a baseline technology on using 8 wt% oxalic acid was developed. In stark contrast to the baseline technology, reports from other industries suggest that the dissolution will most effectively occur at 1 wt% oxalic acid (i.e., maintaining the pH near 2). The driver for using less oxalic acid is that less (i.e., moles) would decrease the severity of the downstream impacts (i.e., required oxalate solids removal efforts). To determine the initial feasibility of using 1 wt% acid to dissolve > 90% of the sludge solids, about 19,000 liters of representative sludge was modeled using about 530,000 liters of 0 to 8 wt% oxalic acid solutions. With the chemical thermodynamic equilibrium based software results showing that 1 wt% oxalic acid could theoretically work, simulant dissolution testing was initiated. For the dissolution testing, existing simulant was obtained, and an approximate 20 liter test rig was built. Multiple batch dissolutions of both wet and air-dried simulant were performed. Overall, the testing showed that dilute oxalic acid dissolved a greater fraction of the stimulant and resulted in a significantly larger acid effectiveness (i.e., grams of sludge dissolved/mole of acid) than the baseline technology. With the potential effectiveness confirmed via simulant testing, additional testing, including radioactive sludge testing, is planned

  11. In vivo synthesized 34S enriched amino acid standards for species specific isotope dilution of proteins

    DEFF Research Database (Denmark)

    Hermann, Gerrit; Moller, Laura Hyrup; Gammelgaard, Bente

    2016-01-01

    (ICP-MS) combined to anion exchange showed that very high concentrated spike material could be produced with [small mu ]mol amounts of proteinogenic sulfur containing amino acids per g cell dry weight. An enrichment of 34S to 96.3 +/- 0.4% (n = 3) and 98.5 +/- 0.4% (n = 3) for cysteic acid...... with the concept of species specific isotope dilution analysis (IDA). The method relies on the determination of the two sulfur containing amino acids, cysteine and methionine by sulfur speciation analysis and is hence applicable to any protein containing sulfur. In vivo synthesis using 34S as sulfur source...... and methionine sulfone, respectively, was assessed. The established IDA method was validated for the absolute quantification of commercially available lysozyme and ceruloplasmin standards including the calculation of a total combined uncertainty budget....

  12. Bioconversion of dilute-acid pretreated sorghum bagasse to ethanol by Neurospora crassa

    Energy Technology Data Exchange (ETDEWEB)

    Dogaris, Ioannis; Gkounta, Olga; Mamma, Diomi; Kekos, Dimitris [National Technical Univ. of Athens, Zografou (Greece). Biotechnology Lab.

    2012-07-15

    Bioethanol production from sweet sorghum bagasse (SB), the lignocellulosic solid residue obtained after extraction of sugars from sorghum stalks, can further improve the energy yield of the crop. The aim of the present work was to evaluate a cost-efficient bioconversion of SB to ethanol at high solids loadings (16 % at pretreatment and 8 % at fermentation), low cellulase activities (1-7 FPU/g SB) and co-fermentation of hexoses and pentoses. The fungus Neurospora crassa DSM 1129 was used, which exhibits both depolymerase and co-fermentative ability, as well as mixed cultures with Saccharomyces cerevisiae 2541. A dilute-acid pretreatment (sulfuric acid 2 g/100 g SB; 210 C; 10 min) was implemented, with high hemicellulose decomposition and low inhibitor formation. The bioconversion efficiency of N. crassa was superior to S. cerevisiae, while their mixed cultures had negative effect on ethanol production. Supplementing the in situ produced N. crassa cellulolytic system (1.0 FPU/g SB) with commercial cellulase and {beta}-glucosidase mixture at low activity (6.0 FPU/g SB) increased ethanol production to 27.6 g/l or 84.7 % of theoretical yield (based on SB cellulose and hemicellulose sugar content). The combined dilute-acid pretreatment and bioconversion led to maximum cellulose and hemicellulose hydrolysis 73.3 % and 89.6 %, respectively. (orig.)

  13. Bioconversion of dilute-acid pretreated sorghum bagasse to ethanol by Neurospora crassa.

    Science.gov (United States)

    Dogaris, Ioannis; Gkounta, Olga; Mamma, Diomi; Kekos, Dimitris

    2012-07-01

    Bioethanol production from sweet sorghum bagasse (SB), the lignocellulosic solid residue obtained after extraction of sugars from sorghum stalks, can further improve the energy yield of the crop. The aim of the present work was to evaluate a cost-efficient bioconversion of SB to ethanol at high solids loadings (16 % at pretreatment and 8 % at fermentation), low cellulase activities (1-7 FPU/g SB) and co-fermentation of hexoses and pentoses. The fungus Neurospora crassa DSM 1129 was used, which exhibits both depolymerase and co-fermentative ability, as well as mixed cultures with Saccharomyces cerevisiae 2541. A dilute-acid pretreatment (sulfuric acid 2 g/100 g SB; 210 °C; 10 min) was implemented, with high hemicellulose decomposition and low inhibitor formation. The bioconversion efficiency of N. crassa was superior to S. cerevisiae, while their mixed cultures had negative effect on ethanol production. Supplementing the in situ produced N. crassa cellulolytic system (1.0 FPU/g SB) with commercial cellulase and β-glucosidase mixture at low activity (6.0 FPU/g SB) increased ethanol production to 27.6 g/l or 84.7 % of theoretical yield (based on SB cellulose and hemicellulose sugar content). The combined dilute-acid pretreatment and bioconversion led to maximum cellulose and hemicellulose hydrolysis 73.3 % and 89.6 %, respectively.

  14. The urinary excretion of orotic acid and orotidine, measured by an isotope dilution assay

    International Nuclear Information System (INIS)

    Tax, W.J.M.; Veerkamp, J.H.; Schretlen, E.D.A.M.

    1978-01-01

    Unknown concentrations of orotic acid can be measured by competition with a known amount of [carboxyl- 14 C]orotic acid for reaction with a limiting amount of phosphoribosylpyrophosphate in the presence of orotate phosphoribosyltransferase and orotidine monophosphate decarboxylase. The dilution of the specific radioactivity in the product 14 CO 2 is a sensitive and accurate measure of the amount of orotic acid present in the sample. Orotidine can also be determined after hydrolytic cleavage to orotic acid. The method was used to measure orotic acid and orotidine in urine samples from newborns, healthy controls and patients with gout or deficiency of hypoxanthine-guanine phosphoribosyltransferase receiving allopurinol. Urinary excretion of orotic acid and orotidine in newborns was similar whether the infants were breast-fed or received milk powder. The excretion of orotidine was increased in all patients receiving allopurinol. After allopurinol administration orotic acid excretion was increased in gouty patients but close to normal values in patients with deficiency of hypoxanthine-guanine phosphoribosyltransferase. The results are discussed in relation to the mechanism by which allopurinol inhibits pyrimidine metabolism. (Auth.)

  15. Beech wood Fagus sylvatica dilute-acid hydrolysate as a feedstock to support Chlorella sorokiniana biomass, fatty acid and pigment production.

    Science.gov (United States)

    Miazek, Krystian; Remacle, Claire; Richel, Aurore; Goffin, Dorothee

    2017-04-01

    This work evaluates the possibility of using beech wood (Fagus sylvatica) dilute-acid (H 2 SO 4 ) hydrolysate as a feedstock for Chlorella sorokiniana growth, fatty acid and pigment production. Neutralized wood acid hydrolysate, containing organic and mineral compounds, was tested on Chlorella growth at different concentrations and compared to growth under phototrophic conditions. Chlorella growth was improved at lower loadings and inhibited at higher loadings. Based on these results, a 12% neutralized wood acid hydrolysate (Hyd12%) loading was selected to investigate its impact on Chlorella growth, fatty acid and pigment production. Hyd12% improved microalgal biomass, fatty acid and pigment productivities both in light and in dark, when compared to photoautotrophic control. Light intensity had substantial influence on fatty acid and pigment composition in Chlorella culture during Hyd12%-based growth. Moreover, heterotrophic Chlorella cultivation with Hyd12% also showed that wood hydrolysate can constitute an attractive feedstock for microalgae cultivation in case of lack of light. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Selection of anion exchangers for detoxification of dilute-acid hydrolysates from spruce.

    Science.gov (United States)

    Horváth, Ilona Sárvári; Sjöde, Anders; Nilvebrant, Nils-Olof; Zagorodni, Andrei; Jönsson, Leif J

    2004-01-01

    Six anion-exchange resins with different properties were compared with respect to detoxification of a dilute-acid hydrolysate of spruce prior to ethanolic fermentation with Saccharomyces cerevisiae. The six resins encompassed strong and weak functional groups as well as styrene-, phenol-, and acrylic-based matrices. In an analytical experimental series, fractions from columns packed with the different resins were analyzed regarding pH, glucose, furfural, hydroxymethylfurfural, phenolic compounds, levulinic acid, acetic acid, formic acid, and sulfate. An initial adsorption of glucose occurred in the strong alkaline environment and led to glucose accumulation at a later stage. Acetic and levulinic acid passed through the column before formic acid, whereas sulfate had the strongest affinity. In a preparative experimental series, one fraction from each of six columns packed with the different resins was collected for assay of the fermentability and analysis of glucose, mannose, and fermentation inhibitors. The fractions collected from strong anion-exchange resins with styrene-based matrices displayed the best fermentability: a sevenfold enhancement of ethanol productivity compared with untreated hydrolysate. Fractions from a strong anion exchanger with acrylic-based matrix and a weak exchanger with phenol-based resin displayed an intermediate improvement in fermentability, a four- to fivefold increase in ethanol productivity. The fractions from two weak exchangers with styrene- and acrylic-based matrices displayed a twofold increase in ethanol productivity. Phenolic compounds were more efficiently removed by resins with styrene- and phenol-based matrices than by resins with acrylic-based matrices.

  17. Recovery of acids from dilute streams : A review of process technologies

    International Nuclear Information System (INIS)

    Talnikar, Vivek Digambar; Mahajan, Yogesh Shankar

    2014-01-01

    Chemical process industries convert raw materials into useful products. Acids, among other chemicals, are used in many industries as reactants, solvents and also as catalysts in a few instances as well. Resulting streams are dilute, from which the acids must be recovered. For recovery, many technologies can be used by which acids can be regained as such or can be converted into other value-added products like esters. Membrane processes and biological processes are being researched academically and practiced industrially. These have their own advantages and disadvantages in view of conversion, energy consumption etc. These are not always advantageous and hence an alternate process technology is necessary like reactive separation (RS). RS is advantageous especially when the acid is to be converted to other useful products by reaction, due to additional advantages or because no other technology is well suited or due to cost considerations alone. Conventional process technologies use the reactor configuration followed by the subsequent separation sequence. This approach can sometimes suffer from lesser conversion, difficulties in separation etc. To overcome these problems, RS has an edge over other processes in terms of the recovery of the useful compounds. Reactive distillation (RD), reactive extraction (RE) and reactive chromatography (RC) are the separation technologies that can be useful for acid recovery in an economically feasible way. This review covers the various processes of acid recovery along with the recent work in the field of reactive separations

  18. Dilute acid pretreatment of rye straw and bermudagrass for ethanol production

    Energy Technology Data Exchange (ETDEWEB)

    Ye Sun; Jay J Cheng [North Carolina State Univ., Dept. of Biological and Agricultural Engineering, Raleigh, NC (United States)

    2005-09-01

    Ethanol production from lignocellulosic materials provides an alternative energy production system. Rye and bermudagrass that are used in hog farms for nutrient uptake from swine wastewater have the potential for fuel ethanol production because they have a relative high cellulose and hemicellulose content. Dilute sulfuric acid pretreatment of rye straw and bermudagrass before enzymatic hydrolysis of cellulose was investigated in this study. The biomass at a solid loading rate of 10% was pretreated at 121 deg C with different sulfuric acid concentrations (0.6, 0.9, 1.2 and 1.5%, w/w) and residence times (30, 60, and 90 min). Total reducing sugars, arabinose, galactose, glucose, and xylose in the prehydrolyzate were analyzed. In addition, the solid residues were hydrolyzed by cellulases to investigate the enzymatic digestibility. With the increasing acid concentration and residence time, the amount of arabinose and galactose in the filtrates increased. The glucose concentration in the prehydrolyzate of rye straw was not significantly influenced by the sulfuric acid concentration and residence time, but it increased in the prehydrolyzate of bermudagrass with the increase of pretreatment severity. The xylose concentration in the filtrates increased with the increase of sulfuric acid concentration and residence time. Most of the arabinan, galactan and xylan in the biomass were hydrolyzed during the acid pretreatment. Cellulose remaining in the pretreated feedstock was highly digestible by cellulases from Trichoderma reesei. (Author)

  19. Acid digestion of organic materials

    International Nuclear Information System (INIS)

    Capp, P.D.

    1988-01-01

    To overcome the high temperatures involved in straight incineration of organic waste and the difficulty of extracting actinides from the ash various research establishments throughout the world, including Winfrith and Harwell in the UK, have carried out studies on an alternative chemical combustion method known as acid digestion. The basis of the technique is to digest the waste in concentrated sulphuric acid containing a few percent of nitric acid at a temperature of about 250 0 C. Acid digestion residues consist mainly of non-refractory inorganic sulphates and oxides from which any actinide materials can easily be extracted. (author)

  20. Impact of recycling stillage on conversion of dilute sulfuric acid pretreated corn stover to ethanol.

    Science.gov (United States)

    Mohagheghi, Ali; Schell, Daniel J

    2010-04-01

    Both the current corn starch to ethanol industry and the emerging lignocellulosic biofuels industry view recycling of spent fermentation broth or stillage as a method to reduce fresh water use. The objective of this study was to understand the impact of recycling stillage on conversion of corn stover to ethanol. Sugars in a dilute-acid pretreated corn stover hydrolysate were fermented to ethanol by the glucose-xylose fermenting bacteria Zymomonas mobilis 8b. Three serial fermentations were performed at two different initial sugar concentrations using either 10% or 25% of the stillage as makeup water for the next fermentation in the series. Serial fermentations were performed to achieve near steady state concentration of inhibitors and other compounds in the corn stover hydrolysate. Little impact on ethanol yields was seen at sugar concentrations equivalent to pretreated corn stover slurry at 15% (w/w) with 10% recycle of the stillage. However, ethanol yields became progressively poorer as the sugar concentration increased and fraction of the stillage recycled increased. At an equivalent corn stover slurry concentration of 20% with 25% recycled stillage the ethanol yield was only 5%. For this microorganism with dilute-acid pretreated corn stover, recycling a large fraction of the stillage had a significant negative impact on fermentation performance. Although this finding is of concern for biochemical-based lignocellulose conversion processes, other microorganism/pretreatment technology combinations will likely perform differently. (c) 2009 Wiley Periodicals, Inc.

  1. Pretreatment of corn stover for sugar production using dilute hydrochloric acid followed by lime.

    Science.gov (United States)

    Zu, Shuai; Li, Wen-zhi; Zhang, Mingjian; Li, Zihong; Wang, Ziyu; Jameel, Hasan; Chang, Hou-min

    2014-01-01

    In this study, a two stage process was evaluated to increase the sugar recovery. Firstly, corn stover was treated with diluted hydrochloric acid to maximize the xylose yield, and then the residue was treated with lime to alter the lignin structure and swell the cellulose surface. The optimal condition was 120 °C and 40 min for diluted hydrochloric acid pretreatment followed by lime pretreatment at 60 °C for 12h with lime loading at 0.1 g/g of substrate. The glucose and xylose yield was 78.0% and 97.0%, respectively, with cellulase dosage at 5 FPU/g of substrate. The total glucose yield increased to 85.9% when the cellulase loading was increased to 10 FPU/g of substrate. This two stage process was effective due to the swelling of the internal surface, an increase in the porosity and a decrease in the degree of polymerization. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. Revealing the Molecular Structural Transformation of Hardwood and Softwood in Dilute Acid Flowthrough Pretreatment

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Libing; Pu, Yunqiao; Cort, John R.; Ragauskas, Arthur J.; Yang, Bin

    2016-12-05

    To better understand the intrinsic recalcitrance of lignocellulosic biomass, the main hurdle to its efficient deconstruction, the effects of dilute acid flowthrough pretreatment on the dissolution chemistry of hemicellulose, cellulose, and lignin for both hardwood (e.g. poplar wood) and softwood (e.g. lodgepole pine wood) were investigated at temperatures of 200 °C to 270 °C and a flow rate of 25 mL/minute with 0.05% (w/w) H2SO4. Results suggested that the softwood cellulose was more readily to be degraded into monomeric sugars than that of hardwood under same pretreatment conditions. However, while the hardwood lignin was completely removed into hydrolysate, ~30% of the softwood lignin remained as solid residues under identical conditions, which was plausibly caused by vigorous C5-active recondensation reactions (C-C5). Unique molecular structural features that pronounced the specific recalcitrance of hardwood and softwood to dilute acid pretreatment were identified for the first time in this study, providing important insights to establish the effective biomass pretreatment.

  3. Dilute Sulfuric Acid Pretreatment of Agricultural and Agro-Industrial Residues for Ethanol Production

    Science.gov (United States)

    Martin, Carlos; Alriksson, Björn; Sjöde, Anders; Nilvebrant, Nils-Olof; Jönsson, Leif J.

    The potential of dilute-acid prehydrolysis as a pretreatment method for sugarcane bagasse, rice hulls, peanut shells, and cassava stalks was investigated. The prehydrolysis was performed at 122°C during 20, 40, or 60 min using 2% H2SO4 at a solid-to-liquid ratio of 1∶10. Sugar formation increased with increasing reaction time. Xylose, glucose, arabinose, and galactose were detected in all of the prehydrolysates, whereas mannose was found only in the prehydrolysates of peanut shells and cassava stalks. The hemicelluloses of bagasse were hydrolyzed to a high-extent yielding concentrations of xylose and arabinose of 19.1 and 2.2 g/L, respectively, and a xylan conversion of more than 80%. High-glucose concentrations (26-33.5 g/L) were found in the prehydrolysates of rice hulls, probably because of hydrolysis of starch of grain remains in the hulls. Peanut shells and cassava stalks rendered low amounts of sugars on prehydrolysis, indicating that the conditions were not severe enough to hydrolyze the hemicelluloses in these materials quantitatively. All prehydrolysates were readily fermentable by Saccharomyces cerevisiae. The dilute-acid prehydrolysis resulted in a 2.7-to 3.7-fold increase of the enzymatic convertibility of bagasse, but was not efficient for improving the enzymatic hydrolysis of peanut shells, cassava stalks, or rice hulls.

  4. Changes in lignocellulosic supramolecular and ultrastructure during dilute acid pretreatment of Populus and switchgrass

    International Nuclear Information System (INIS)

    Foston, Marcus; Ragauskas, Art J.

    2010-01-01

    Dilute acid pretreatment (DAP) is commonly employed prior to enzymatic deconstruction of cellulose to increase overall sugar and subsequent ethanol yields from downstream bioconversion processes. Typically optimization of pretreatment is evaluated by determining hemicellulose removal, subsequent reactivity towards enzymatic deconstruction, and recoverable polysaccharide yields. In this study, the affect of DAP on the supramolecular and ultrastructure of lignocellulosic biomass was evaluated. A series of dilute acidic pretreatments, employing ∼0.10-0.20 mol/m 3 H 2 SO 4 at ∼160-180 o C, for varying residence times were conducted on both Populus and switchgrass samples. The untreated and pretreated biomass samples were characterized by carbohydrate and lignin analysis, gel permeation chromatography (GPC) and 13 C cross polarization magic angle spinning (CPMAS) NMR spectroscopy. GPC analysis shows a reduction in the molecular weight of cellulose and change in its polydispersity index (PDI) with increasing residence time, indicating that pretreatment is actually degrading the cellulose chains. 13 C CPMAS and non-linear line-fitting of the C 4 region in the carbon spectrum of the isolated cellulose not only showed that the crystallinity index increases with residence time, but that the lateral fibril dimension (LFD) and lateral fibril aggregate dimension (LFAD) increase as well.

  5. Application of a continuous twin screw-driven process for dilute acid pretreatment of rape straw.

    Science.gov (United States)

    Choi, Chang Ho; Oh, Kyeong Keun

    2012-04-01

    Rape straw, a processing residue generated from the bio-oil industry, was used as a model biomass for application of continuous twin screw-driven dilute acid pretreatment. The screw rotation speed and feeding rate were adjusted to 19.7rpm and 0.5g/min, respectively to maintain a residence time of 7.2min in the reaction zone, respectively. The sulfuric acid concentration was 3.5wt% and the reaction temperature was 165°C. The enzymatic digestibility of the glucan in the pretreated solids was 70.9%. The continuous process routinely gave around 28.8% higher yield for glucan digestibility than did the batch processing method. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. Titanium leaching from red mud by diluted sulfuric acid at atmospheric pressure

    International Nuclear Information System (INIS)

    Agatzini-Leonardou, S.; Oustadakis, P.; Tsakiridis, P.E.; Markopoulos, Ch.

    2008-01-01

    Laboratory-scale research has focused on the recovery of titanium from red mud, which is obtained from bauxite during the Bayer process for alumina production. The leaching process is based on the extraction of this element with diluted sulfuric acid from red mud under atmospheric conditions and without using any preliminary treatment. Statistical design and analysis of experiments were used, in order to determine the main effects and interactions of the leaching process factors, which were: acid normality, temperature and solid to liquid ratio. The titanium recovery efficiency on the basis of red mud weight reached 64.5%. The characterization of the initial red mud, as well as this of the leached residues was carried out by X-ray diffraction, TG-DTA and scanning electron microscopy

  7. Repletion of branched chain amino acids reverses mTORC1 signaling but not improved metabolism during dietary protein dilution

    DEFF Research Database (Denmark)

    Maida, Adriano; Chan, Jessica S K; Sjøberg, Kim Anker

    2017-01-01

    OBJECTIVE: Dietary protein dilution (PD) has been associated with metabolic advantages such as improved glucose homeostasis and increased energy expenditure. This phenotype involves liver-induced release of FGF21 in response to amino acid insufficiency; however, it has remained unclear whether...... dietary dilution of specific amino acids (AAs) is also required. Circulating branched chain amino acids (BCAAs) are sensitive to protein intake, elevated in the serum of obese humans and mice and thought to promote insulin resistance. We tested whether replenishment of dietary BCAAs to an AA-diluted (AAD......) diet is sufficient to reverse the glucoregulatory benefits of dietary PD. METHODS: We conducted AA profiling of serum from healthy humans and lean and high fat-fed or New Zealand obese (NZO) mice following dietary PD. We fed wildtype and NZO mice one of three amino acid defined diets: control, total...

  8. The effect of dilute acid pre-treatment process in bioethanol production from durian (Durio zibethinus) seeds waste

    Science.gov (United States)

    Ghazali, K. A.; Salleh, S. F.; Riayatsyah, T. M. I.; Aditiya, H. B.; Mahlia, T. M. I.

    2016-03-01

    Lignocellulosic biomass is one of the promising feedstocks for bioethanol production. The process starts from pre-treatment, hydrolysis, fermentation, distillation and finally obtaining the final product, ethanol. The efficiency of enzymatic hydrolysis of cellulosic biomass depends heavily on the effectiveness of the pre-treatment step which main function is to break the lignin structure of the biomass. This work aims to investigate the effects of dilute acid pre-treatment on the enzymatic hydrolysis of durian seeds waste to glucose and the subsequent bioethanol fermentation process. The yield of glucose from dilute acid pre-treated sample using 0.6% H2SO4 and 5% substrate concentration shows significant value of 23.4951 g/L. Combination of dilute acid pre-treatment and enzymatic hydrolysis using 150U of enzyme able to yield 50.0944 g/L of glucose content higher compared to normal pre-treated sample of 8.1093 g/L. Dilute acid pre-treatment sample also shows stable and efficient yeast activity during fermentation process with lowest glucose content at 2.9636 g/L compared to 14.7583g/L for normal pre-treated sample. Based on the result, it can be concluded that dilute acid pre-treatment increase the yield of ethanol from bioethanol production process.

  9. A whole cell biocatalyst for cellulosic ethanol production from dilute acid-pretreated corn stover hydrolyzates

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Seunghyun; Karim, Muhammad Nazmul [Texas Tech Univ., Lubbock, TX (United States). Dept. of Chemical Engineering

    2011-08-15

    In this research, a recombinant whole cell biocatalyst was developed by expressing three cellulases from Clostridium cellulolyticum - endoglucanase (Cel5A), exoglucanase (Cel9E), and {beta}-glucosidase - on the surface of the Escherichia coli LY01. The modified strain is identified as LY01/pRE1H-AEB. The cellulases were displayed on the surface of the cell by fusing with an anchor protein, PgsA. The developed whole cell biocatalyst was used for single-step ethanol fermentation using the phosphoric acid-swollen cellulose (PASC) and the dilute acid-pretreated corn stover. Ethanol production was 3.59 {+-} 0.15 g/L using 10 g/L of PASC, which corresponds to a theoretical yield of 95.4 {+-} 0.15%. Ethanol production was 0.30 {+-} 0.02 g/L when 1 g/L equivalent of glucose in the cellulosic fraction of the dilute sulfuric acid-pretreated corn stover (PCS) was fermented for 84 h. A total of 0.71 {+-} 0.12 g/L ethanol was produced in 48 h when the PCS was fermented in the simultaneous saccharification and co-fermentation mode using the hemicellulosic (1 g/L of total soluble sugar) and as well as the cellulosic (1 g/L of glucose equivalent) parts of PCS. In a control experiment, 0.48 g/L ethanol was obtained from 1 g/L of hemicellulosic PCS. It was concluded that the whole cell biocatalyst could convert both cellulosic and hemicellulosic substrates into ethanol in a single reactor. The developed C. cellulolyticum-E. coli whole cell biocatalyst also overcame the incompatible temperature problem of the frequently reported fungal-yeast systems. (orig.)

  10. STUDY OF ORGANIC ACIDS IN ALMOND LEAVES

    Directory of Open Access Journals (Sweden)

    Lenchyk L.V.

    2015-05-01

    Full Text Available Introduction. Almond (Amygdalus communis is a stone fruit, from the Rosaceae family, closest to the peach. It is spread throughout the entire Mediterranean region and afterwards to the Southwestern USA, Northern Africa, Turkey, Iran, Australia and South Africa. It is sensitive to wet conditions, and therefore is not grown in wet climates. Iran is located in the semi-arid region of the world. Because of its special tolerance to water stress, almond is one of the main agricultural products in rainfed condition in Iran. Almond leaves have been investigated for their phenolic content and antioxidant activity. It was found that total antioxidant activity and phenolic compounds exhibited variations according to season, plant organ (leaf and stem and variety. Analysis of previous research on almonds focused on investigating compounds mostly in seeds and phenolic compounds in leaves, but organic acids in leaves have not been studied. Aim of this study was investigation of organic acids in leaves of almond variety which is distributed in Razavi Khorasan province of Iran. Materials and Methods. In August 2012 almond leaves were collected in Iran, dried and grinded. The study of qualitative composition and quantitative determination of carboxylic acids in almond leaves was carried out by gas chromatography with mass spectrometric detection. For determination organic acids content, to 50 mg of dried plant material in 2 ml vial internal standard (50 μg of tridecane in hexane was added and filled up with 1.0 ml of methylating agent (14 % BCl3 in methanol, Supelco 3-3033. The mixture was kept in a sealed vial during 8 hours at 65 °C. At this time fatty oil was fully extracted, and hydrolyzed into its constituent fatty acids and their methylation was done. At the same time free organic and phenolcarbonic acids were methylated too. The reaction mixture was poured from the plant material sediment and was diluted with 1 ml of distilled water. To extract methyl

  11. Acid digestion of organic liquids

    International Nuclear Information System (INIS)

    Partridge, J.A.; Bosuego, G.P.

    1980-10-01

    Laboratory studies on the destruction of liquid organic wastes by acid digestion are discussed. A variety of liquid waste types was tested, including those encountered in the nuclear industry as well as some organic liquids representative of non-nuclear industrial wastes. The liquids tested were vacuum pump oil, tri-n-butyl phosphate (TBP), normal paraffin hydrocarbon solvent (NPH), a mixture of 30 vol% TBP in NPH, carbon tetrachloride (CCl 4 ), trichloroethane, toluene, hexone (methyl isobutyl ketone), a mixture of hexone and NPH, polychlorobiphenyl (PCB), isopropanol, normal-decane, and two waste organic solutions from Hanford radioactive waste tanks. The tests demonstrated that several types of organic liquids can be destroyed by the acid digestion process. 8 figures, 19 tables

  12. Comparison of aqueous ammonia and dilute acid pretreatment of bamboo fractions: Structure properties and enzymatic hydrolysis.

    Science.gov (United States)

    Xin, Donglin; Yang, Zhong; Liu, Feng; Xu, Xueru; Zhang, Junhua

    2015-01-01

    The effect of two pretreatments methods, aqueous ammonia (SAA) and dilute acid (DA), on the chemical compositions, cellulose crystallinity, morphologic change, and enzymatic hydrolysis of bamboo fractions (bamboo yellow, timber, green, and knot) was compared. Bamboo fractions with SAA pretreatment had better hydrolysability than those with DA pretreatment. High crystallinity index resulted in low hydrolysis yield in the conversion of SAA pretreated bamboo fractions, not DA pretreated fractions. The increase of cellulase loading had modestly positive effect in the hydrolysis of both SAA and DA pretreated bamboo fractions, while supplement of xylanase significantly increased the hydrolysis of the pretreated bamboo fractions, especially after SAA pretreatment. The results indicated that SAA pretreatment was more effective than DA pretreatment in conversion of bamboo fractions, and supplementation of xylanase was necessary in effective conversion of the SAA pretreated fractions into fermentable sugars. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. An evaluation of dilute acid and ammonia fiber explosion pretreatment for cellulosic ethanol production.

    Science.gov (United States)

    Mathew, Anil Kuruvilla; Parameshwaran, Binod; Sukumaran, Rajeev Kumar; Pandey, Ashok

    2016-01-01

    The challenge associated with cellulosic ethanol production is maximizing sugar yield at low cost. Current research is being focused to develop a pretreatment method to overcome biomass recalcitrance in an efficient way. This review is focused on two major pretreatments: dilute acid (DA) and ammonia fiber explosion (AFEX) pretreatment of corn stover and how these pretreatment cause morphological and chemical changes to corn stover in order to overcome the biomass recalcitrance. This review highlights the key differences of these two pretreatments based on compositional analysis, cellulose and its crystallinity, morphological changes, structural changes to lignin, enzymatic reactivity and enzyme adsorption onto pretreated solids and finally cellulosic ethanol production from the hydrolysate of DA and AFEX treated corn stover. Each stage of the process, AFEX pretreated corn stover was superior to DA treated corn stover. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Towards integrated biorefinery from dried distillers grains: Selective extraction of pentoses using dilute acid hydrolysis

    International Nuclear Information System (INIS)

    Fonseca, Dania A.; Lupitskyy, Robert; Timmons, David; Gupta, Mayank; Satyavolu, Jagannadh

    2014-01-01

    The abundant availability and high level of hemicellulose content make dried distillers grains (DDG) an attractive feedstock for production of pentoses (C5) and conversion of C5 to bioproducts. One target of this work was to produce a C5 extract (hydrolyzate) with high yield and purity with a low concentration of C5 degradation products. A high selectivity towards pentoses was achieved using dilute acid hydrolysis of DDG in a percolation reactor with liquid recirculation. Pretreatment of starting material using screening and ultrasonication resulted in fractional increase of the pentose yield by 42%. A 94% yield of pentoses on the DDG (280.9 g kg −1 ) was obtained. Selective extraction of individual pentoses has been achieved by using a 2-stage hydrolysis process, resulting in arabinose-rich (arabinose 81.5%) and xylose-rich (xylose 85.2%) streams. A broader impact of this work is towards an Integrated Bio-Refinery based on DDG – for production of biofuels, biochemical intermediates, and other bioproducts. - Highlights: • A process for selective extraction of pentoses from DDG was presented as a part of integrated biorefinery approach. • The selectivity for pentoses was high using dilute acid hydrolysis in a percolation reactor with liquid recirculation. • Pretreatment of DDG using screening and ultrasonication resulted in fractional increase of the pentose yield by 42 %. • A 94% yield in pentoses (280.9 g kg −1 of DDG) was obtained. • A 2-stage hydrolysis process, developed to extract individual pentoses, resulted in arabinose and xylose rich streams

  15. Mild-temperature dilute acid pretreatment for integration of first and second generation ethanol processes.

    Science.gov (United States)

    Nair, Ramkumar B; Kalif, Mahdi; Ferreira, Jorge A; Taherzadeh, Mohammad J; Lennartsson, Patrik R

    2017-12-01

    The use of hot-water (100°C) from the 1st generation ethanol plants for mild-temperature lignocellulose pretreatment can possibly cut down the operational (energy) cost of 2nd generation ethanol process, in an integrated model. Dilute-sulfuric and -phosphoric acid pretreatment at 100°C was carried out for wheat bran and whole-stillage fibers. Pretreatment time and acid type influenced the release of sugars from wheat bran, while acid-concentration was found significant for whole-stillage fibers. Pretreatment led up-to 300% improvement in the glucose yield compared to only-enzymatically treated substrates. The pretreated substrates were 191-344% and 115-300% richer in lignin and glucan, respectively. Fermentation using Neurospora intermedia, showed 81% and 91% ethanol yields from wheat bran and stillage-fibers, respectively. Sawdust proved to be a highly recalcitrant substrate for mild-temperature pretreatment with only 22% glucose yield. Both wheat bran and whole-stillage are potential substrates for pretreatment using waste heat from the 1st generation process for 2nd generation ethanol. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Effect of dilution and L-malic acid addition on bio-hydrogen production with Rhodopseudomonas palustris from effluent of an acidogenic anaerobic reactor

    International Nuclear Information System (INIS)

    Azbar, N.; Tuba, F.; Dokgoz, C.

    2009-01-01

    production reactor was not suitable for photo-fermentative hydrogen production. It was concluded that dilution of the feeding helps to reduce the nitrogen content and the volatile fatty acid content that might be otherwise harmful to the photo-heterotrophic organisms. The second conclusion that can be drawn is that cheese whey effluent should be mixed with L-malic acid rich co-substrates such as fruit juice processing effluents before fed into the photo-fermentation reactor. Finally, the two-stage H 2 -producing process could be applied in remediation of lactose-containing industrial wastes, H 2 being used on-site, to reduce process costs via generation of electricity by the help of hydrogen fuel cells. (author)

  17. Effect of dilution and L-malic acid addition on bio-hydrogen production with Rhodopseudomonas palustris from effluent of an acidogenic anaerobic reactor

    Energy Technology Data Exchange (ETDEWEB)

    Azbar, N.; Tuba, F.; Dokgoz, C. [Bioengineering Dept., Faculty of Engineering, Ege Univ., Izmir (Turkey)], E-mail: nuri.azbar@ege.edu.tr

    2009-07-01

    effluent from dark hydrogen production reactor was not suitable for photo-fermentative hydrogen production. It was concluded that dilution of the feeding helps to reduce the nitrogen content and the volatile fatty acid content that might be otherwise harmful to the photo-heterotrophic organisms. The second conclusion that can be drawn is that cheese whey effluent should be mixed with L-malic acid rich co-substrates such as fruit juice processing effluents before fed into the photo-fermentation reactor. Finally, the two-stage H{sub 2}-producing process could be applied in remediation of lactose-containing industrial wastes, H{sub 2} being used on-site, to reduce process costs via generation of electricity by the help of hydrogen fuel cells. (author)

  18. Nozzle Printed-PEDOT:PSS for Organic Light Emitting Diodes with Various Dilution Rates of Ethanol

    Directory of Open Access Journals (Sweden)

    Dai Geon Yoon

    2018-01-01

    Full Text Available In this study, we investigated the ink formulation of poly(3,4-ethylenedioxythiophene polystyrene sulfonate (PEDOT:PSS as the hole injection layer (HIL in an organic light emitting diode (OLED structure. Generally, in a PEDOT:PSS solution, water is incorporated in the solution for the solution process. However, the fabrication of thin film which contained the water, main solvent, could not easily form by using printing technology except spin-coating process because of the high surface tension of water. On the other hand, mixing PEDOT:PSS solution and ethanol (EtOH, a dilution solvent, could restrain the non-uniform layer that forms by the high surface tension and low volatility of water. Therefore, we printed a PEDOT:PSS solution with various concentrations of EtOH by using a nozzle printer and obtained a uniform pattern. The line width of PEDOT:PSS diluted with 90% (volume ratio ehtanol was measured as about 4 mm with good uniformity with a 0.1 mm nozzle. Also, imaging software and a scanning electron microscope (SEM were used to measure the uniformity of PEDOT:PSS coated on a substrate. Finally, we fabricated a green phosphorescent OLED device with printed-PEDOT:PSS with specific concentrations of EtOH and we achieved a current efficiency of 27 cd/A with uniform quality of luminance in the case of device containing 90% EtOH.

  19. Spectroscopic analysis of hot-water- and dilute-acid-extracted hardwood and softwood chips

    Science.gov (United States)

    Lehto, Joni; Louhelainen, Jarmo; Huttunen, Marko; Alén, Raimo

    2017-09-01

    Hot-water and dilute sulfuric acid pretreatments were performed prior to chemical pulping for silver/white birch (Betula pendula/B. pubescens) and Scots pine (Pinus sylvestris) chips to determine if varying pretreatment conditions on the original wood material were detectable via attenuated total reflectance (ATR) infrared spectroscopy. Pretreatment conditions varied with respect to temperature (130 °C and 150 °C) and treatment time (from 30 min to 120 min). The effects of the pretreatments on the composition of wood chips were determined by ATR infrared spectroscopy. The spectral data were compared to those determined by common wood chemistry analyses to evaluate the suitability of ATR spectroscopy method for rapid detection of changes in the wood chemical composition caused by different pretreatment conditions. In addition to determining wood species-dependent differences in the wood chemical composition, analytical results indicated that most essential lignin- and carbohydrates-related phenomena taking place during hot-water and acidic pretreatments could be described by applying this simple spectral method requiring only a small sample amount and sample preparation. Such information included, for example, the cleavage of essential lignin bonds (i.e., mainly β-O-4 linkages in guaiacyl and syringyl lignin) and formation of newly condensed lignin structures under different pretreatment conditions. Carbohydrate analyses indicated significant removal of hemicelluloses (especially hardwood xylan) and hemicelluloses-derived acetyl groups during the pretreatments, but they also confirmed the highly resistant nature of cellulose towards mild pretreatments.

  20. Understanding longitudinal wood fiber ultra-structure for producing cellulose nanofibrils using disk milling with diluted acid prehydrolysis

    Science.gov (United States)

    Yanlin Qin; Xueqing Qiu; Junyong Zhu

    2016-01-01

    Here we used dilute oxalic acid to pretreat a kraft bleached Eucalyptus pulp (BEP) fibers to facilitate mechanical fibrillation in producing cellulose nanofibrils using disk milling with substantial mechanical energy savings. We successfully applied a reaction kinetics based combined hydrolysis factor (CHFx) as a severity factor to quantitatively...

  1. Dilute-acid hydrolysis of apple, orange, apricot and peach pomaces as potential candidates for bioethanol production

    OpenAIRE

    Üçüncü, Can; Tarı, Canan; Demir, Hande; Büyükkileci, Ali Oğuz; Özen, Banu

    2013-01-01

    Chemical composition of four selected fruit pomaces (agro-industrial wastes) was evaluated. The effect of temperature, time, acid concentration and solid:liquid (S:L) ratio on dilute-acid hydrolysis of selected pomaces were investigated using 24 factorial and central composite design and optimum hydrolysis conditions were determined. A preliminary study was initiated using apple hydrolysate and the fungus Tricoderma harzianum in order to explore and demonstrate their potential uses in bioetha...

  2. Optimization of alkaline and dilute acid pretreatment of agave bagasse by response surface methodology

    Directory of Open Access Journals (Sweden)

    Abimael I. Ávila-Lara

    2015-09-01

    Full Text Available Utilization of lignocellulosic materials for the production of value-added chemicals or biofuels generally requires a pretreatment process to overcome the recalcitrance of the plant biomass for further enzymatic hydrolysis and fermentation stages. Two of the most employed pretreatment processes are the ones that used dilute acid (DA and alkaline (AL catalyst providing specific effects on the physicochemical structure of the biomass such as high xylan and lignin removal for DA and AL, respectively. Another important effect that need to be studied is the use of a high solids pretreatment (≥15% since offers many advantaged over lower solids loadings, including increased sugar and ethanol concentrations (in combination with a high solids saccharification which will be reflected in lower capital costs, however this data is currently limited. In this study, several variables such as catalyst loading, retention time and solids loading, were studied using Response Surface Methodology (RSM based on a factorial Central Composite Design (CCD of DA and AL pretreatment on agave bagasse using a range of solids from 3 to 30% (w/w to obtain optimal process conditions for each pretreatment. Subsequently enzymatic hydrolysis was performed using Novozymes Cellic CTec2 and HTec2 presented as total reducing sugar (TRS yield. Pretreated biomass

  3. Multistage dilute acid leaching of a medium grade iron ore to super-concentrate

    Directory of Open Access Journals (Sweden)

    Adeleke A.A.

    2014-01-01

    Full Text Available The phosphorous laden Koton Karfe iron ore is a medium grade iron ore deposit in Nigeria that can be upgraded as a super-concentrate for use at the Aladja Steel Midrex plant. The 75 μm size sample fraction of the ore was preconcentrated with shaking table and leached in the oven at atmospheric pressure with dilute hydrochloric acid in single and multistage leaching sequences of H2O-HCl-H2O and HCl-H2O-H2O. The as-received, as-tabled and asleached samples were then subjected to X-ray fluorescence and microscopic analyses. The results obtained showed that the H2O-HCl-H2O route produced a higher grade concentrate that assayed 68.54% Fe indicating about 58% upgrade in iron content; while the phosphorus and sulphur contents were reduced by about 77 and 99.6% respectively. In addition, the silicon, manganese, and titanium contents were drastically reduced, while potassium was completely eliminated. The upgrade of iron content in the ore to 68.54% and the drastic reduction in phosphorous and sulphur contents has thus rendered the Koton Karfe iron ore suitable for use as a super concentrate for the Aladja steel plant direct reduction iron making process.

  4. Overall process considerations for using dilute acid cellulose hydrolysis technology to produce ethanol from biomass

    International Nuclear Information System (INIS)

    Elander, R.; Ibsen, K.; Hayward, T.; Nagle, N.; Torget, R.

    1997-01-01

    Recent advances in reactors, designed for the dilute acid thermochemical treatment of biomass, have resulted in the development of process alternatives in which both cellulose and hemicellulose are hydrolyzed to soluble sugars in high yields. The optimal extent of cellulose hydrolysis will depend on both the performance and economics of the thermochemical treatment operation, and on subsequent unit operations in the bioethanol production process. Examples of subsequent unit operation interactions include the extent to which cellulase enzymes are used to hydrolyze any remaining cellulose, kinetics and conditions of a largely soluble mixed sugar cofermentation, and the extent to which removal of compounds that inhabit fermenting microorganisms is required. In addition, a number of process operation and economic considerations affect the ultimate economic viability of this type of biomass hydrolysis process. These considerations include reactor design issues to accommodate the kinetic parameters of the various hydrolysis and sugar degradation reactions, liquid volume requirements to achieve acceptable sugar yields, sugar concentrations that result from such a process and their impact on subsequent fermentation volumes and ethanol recovery operations, potential co-product opportunities that result from solubilized lignin, and process steam requirements. Several potential whole-process configurations are presented and key process and economic issues for each are discussed. (author)

  5. Lower pressure heating steam is practical for the distributed dry dilute sulfuric acid pretreatment.

    Science.gov (United States)

    Shao, Shuai; Zhang, Jian; Hou, Weiliang; Qureshi, Abdul Sattar; Bao, Jie

    2017-08-01

    Most studies paid more attention to the pretreatment temperature and the resulted pretreatment efficiency, while ignored the heating media and their scalability to an industry scale. This study aimed to use a relative low pressure heating steam easily provided by steam boiler to meet the requirement of distributed dry dilute acid pretreatment. The results showed that the physical properties of the pretreated corn stover were maintained stable using the steam pressure varying from 1.5, 1.7, 1.9 to 2.1MPa. Enzymatic hydrolysis and high solids loading simultaneous saccharification and fermentation (SSF) results were also satisfying. CFD simulation indicated that the high injection velocity of the low pressure steam resulted in a high steam holdup and made the mixing time of steam and solid corn stover during pretreatment much shorter in comparison with the higher pressure steam. This study provides a design basis for the boiler requirement in distributed pretreatment concept. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Optimization of Alkaline and Dilute Acid Pretreatment of Agave Bagasse by Response Surface Methodology

    Science.gov (United States)

    Ávila-Lara, Abimael I.; Camberos-Flores, Jesus N.; Mendoza-Pérez, Jorge A.; Messina-Fernández, Sarah R.; Saldaña-Duran, Claudia E.; Jimenez-Ruiz, Edgar I.; Sánchez-Herrera, Leticia M.; Pérez-Pimienta, Jose A.

    2015-01-01

    Utilization of lignocellulosic materials for the production of value-added chemicals or biofuels generally requires a pretreatment process to overcome the recalcitrance of the plant biomass for further enzymatic hydrolysis and fermentation stages. Two of the most employed pretreatment processes are the ones that used dilute acid (DA) and alkaline (AL) catalyst providing specific effects on the physicochemical structure of the biomass, such as high xylan and lignin removal for DA and AL, respectively. Another important effect that need to be studied is the use of a high solids pretreatment (≥15%) since offers many advantaged over lower solids loadings, including increased sugar and ethanol concentrations (in combination with a high solids saccharification), which will be reflected in lower capital costs; however, this data is currently limited. In this study, several variables, such as catalyst loading, retention time, and solids loading, were studied using response surface methodology (RSM) based on a factorial central composite design of DA and AL pretreatment on agave bagasse using a range of solids from 3 to 30% (w/w) to obtain optimal process conditions for each pretreatment. Subsequently enzymatic hydrolysis was performed using Novozymes Cellic CTec2 and HTec2 presented as total reducing sugar (TRS) yield. Pretreated biomass was characterized by wet-chemistry techniques and selected samples were analyzed by calorimetric techniques, and scanning electron/confocal fluorescent microscopy. RSM was also used to optimize the pretreatment conditions for maximum TRS yield. The optimum conditions were determined for AL pretreatment: 1.87% NaOH concentration, 50.3 min and 13.1% solids loading, whereas DA pretreatment: 2.1% acid concentration, 33.8 min and 8.5% solids loading. PMID:26442260

  7. Production of spent mushroom substrate hydrolysates useful for cultivation of Lactococcus lactis by dilute sulfuric acid, cellulase and xylanase treatment.

    Science.gov (United States)

    Qiao, Jian-Jun; Zhang, Yan-Fei; Sun, Li-Fan; Liu, Wei-Wei; Zhu, Hong-Ji; Zhang, Zhijun

    2011-09-01

    Spent mushroom substrate (SMS) was treated with dilute sulfuric acid followed by cellulase and xylanase treatment to produce hydrolysates that could be used as the basis for media for the production of value added products. A L9 (3(4)) orthogonal experiment was performed to optimize the acid treatment process. Pretreatment with 6% (w/w) dilute sulfuric acid at 120°C for 120 min provided the highest reducing sugar yield of 267.57 g/kg SMS. No furfural was detected in the hydrolysates. Exposure to 20PFU of cellulase and 200 XU of xylanase per gram of pretreated SMS at 40°C resulted in the release of 79.85 g/kg or reducing sugars per kg acid pretreated SMS. The dilute sulfuric acid could be recycled to process fresh SMS four times. SMS hydrolysates neutralized with ammonium hydroxide, sodium hydroxide, or calcium hydroxide could be used as the carbon source for cultivation of Lactococcus lactis subsp. lactis W28 and a cell density of 2.9×10(11)CFU/mL could be obtained. The results provide a foundation for the development of value-added products based on SMS. Copyright © 2011 Elsevier Ltd. All rights reserved.

  8. Capture of elemental and organic iodine from dilute gas streams by silver-exchanged mordenite

    Energy Technology Data Exchange (ETDEWEB)

    Bruffey, S.H.; Jubin, R.T.; Jordan, J.A. [Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 37831 (United States)

    2016-07-01

    The treatment of off-gas streams arising from reprocessing of used nuclear fuel (UNF) is an area of active study by the U.S. Department of Energy. Such off-gas streams contain volatile fission products, including long-lived {sup 129}I. Although {sup 129}I is released into the off-gas at multiple points within the chemical reprocessing flowsheet, previous research has focused on removal from the dissolver off-gas stream (DOG). The DOG is expected to contain up to 98% of iodine in UNF at ppm levels within the stream. Other off-gas streams will also contain iodine but at substantially lower concentrations. Recent work has shown that compliance with U.S. regulations will likely require capture of iodine from these dilute streams in addition to capture from DOG. In particular, the vessel off-gas (VOG) stream is expected to contain 1-3% of the total iodine inventory at ppb concentrations. A review of literature also indicates that the speciation of iodine in the VOG stream will differ from that of the DOG, with the DOG containing primarily I{sub 2} and the VOG containing a mixture of I{sub 2} and organic iodine species. Silver-exchanged mordenite (AgZ) has been identified for use in the removal of iodine from off-gas streams. It is an effective capture material for I{sub 2} at the concentrations expected in the DOG, but little is known about its performance in gas streams that may contain both I{sub 2} and organic iodides at very dilute concentrations. The experiments to be described were designed to separately characterize the adsorption of I{sub 2} and methyl iodide on AgZ through extended duration testing. Simulated vessel off-gases containing low levels of either I{sub 2} or methyl iodide were contacted with AgZ sorbent beds for up to four months. Through the use of sorbent beds in series and varied sampling times, key parameters such as adsorption rate, decontamination factor, and performance over time could be determined for the capture of each species by AgZ. This

  9. Comparing oxidative and dilute acid wet explosion pretreatment of Cocksfoot grass at high dry matter concentration for cellulosic ethanol production

    DEFF Research Database (Denmark)

    Njoku, Stephen Ikechukwu; Uellendahl, Hinrich; Ahring, Birgitte Kiær

    2013-01-01

    into cellulose monomeric C6 sugars was achieved for WEx condition AC-E (180°C, 15 min, and 0.2% sulfuric acid). For that condition, the highest ethanol yield of 197 g/kg DM (97% of theoretical maximum value) was achieved for SSF process by Saccharomyces cerevisiae. However, the highest concentration...... of hemicellulose C5 sugars was found for WEx pretreatment condition O2-A (160°C, 15 min, and 6 bar O2) which means that the highest potential ethanol yield was found at this moderate pretreatment condition with oxygen added. Increasing the pretreatment temperature to 180–190°C with addition of oxygen or dilute...... was investigated for cellulosic ethanol production. The biomass raw materials were pretreated using wet explosion (WEx) at 25% dry matter concentration with addition of oxygen or dilute sulfuric acid. The enzymatic hydrolysis of cellulose was significantly improved after pretreatment. The highest conversion...

  10. Converting Eucalyptus biomass into ethanol: Financial and sensitivity analysis in a co-current dilute acid process. Part II

    International Nuclear Information System (INIS)

    Gonzalez, R.; Treasure, T.; Phillips, R.; Jameel, H.; Saloni, D.; Wright, J.; Abt, R.

    2011-01-01

    The technical and financial performance of high yield Eucalyptus biomass in a co-current dilute acid pretreatment followed by enzymatic hydrolysis process was simulated using WinGEMS registered and Excel registered . Average ethanol yield per dry Mg of Eucalyptus biomass was approximately 347.6 L of ethanol (with average carbohydrate content in the biomass around 66.1%) at a cost of 0.49 L -1 of ethanol, cash cost of ∝0.46 L -1 and CAPEX of 1.03 L -1 of ethanol. The main cost drivers are: biomass, enzyme, tax, fuel (gasoline), depreciation and labor. Profitability of the process is very sensitive to biomass cost, carbohydrate content (%) in biomass and enzyme cost. Biomass delivered cost was simulated and financially evaluated in Part I; here in Part II the conversion of this raw material into cellulosic ethanol using the dilute acid process is evaluated. (author)

  11. Structural features of dilute acid, steam exploded, and alkali pretreated mustard stalk and their impact on enzymatic hydrolysis.

    Science.gov (United States)

    Kapoor, Manali; Raj, Tirath; Vijayaraj, M; Chopra, Anju; Gupta, Ravi P; Tuli, Deepak K; Kumar, Ravindra

    2015-06-25

    To overcome the recalcitrant nature of biomass several pretreatment methodologies have been explored to make it amenable to enzymatic hydrolysis. These methodologies alter cell wall structure primarily by removing/altering hemicelluloses and lignin. In this work, alkali, dilute acid, steam explosion pretreatment are systematically studied for mustard stalk. To assess the structural variability after pretreatment, chemical analysis, surface area, crystallinity index, accessibility of cellulose, FT-IR and thermal analysis are conducted. Although the extent of enzymatic hydrolysis varies upon the methodologies used, nevertheless, cellulose conversion increases from adsorption capacity. However, no such relationship is observed for xylose yield. Mass balance of the process is also studied. Dilute acid pretreatment is the best methodology in terms of maximum sugar yield at lower enzyme loading. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Application of isotope dilution method for measuring bioavailability of organic contaminants sorbed to dissolved organic matter (DOM)

    Energy Technology Data Exchange (ETDEWEB)

    Delgado-Moreno, Laura, E-mail: laura.delgado@eez.csic.es; Wu, Laosheng; Gan, Jay

    2015-08-15

    Natural waters such as surface water and sediment porewater invariably contain dissolved organic matter (DOM). Association of strongly hydrophobic contaminants (HOCs) with DOM leads to decreased toxicity and bioavailability, but bioavailability of DOM-sorbed HOCs is difficult to measure. Current methods to estimate bioavailability of HOCs in water are based on only the freely dissolved concentration (C{sub free}). The ignorance of the exchangeable fraction of HOCs sorbed on DOM may result in an underestimation of the toxicity potential of HOCs to aquatic organisms. Here we explore the applicability of an isotope dilution method (IDM) to measuring the desorption fraction of DOM-sorbed pyrene and bifenthrin and determining their exchangeable pool (E) as an approximation of bioavailability. E values, expressed as percentage of the total concentration, ranged between 0.80 and 0.92% for pyrene and 0.74 and 0.85% for bifenthrin, depending primarily on the amount of chemical in the freely dissolved form. However, between 34 and 78% of the DOM-sorbed pyrene was exchangeable. This fraction ranged between 23% and 82% for bifenthrin. The ability of IDM to predict bioavailability was further shown from a significant relationship (r{sup 2} > 0.72, P < 0.0001) between E and bioaccumulation into Daphnia magna. Therefore, IDM may be used to improve the bioavailability measurement and risk assessment of HOCs in aquatic systems.

  13. Application of isotope dilution method for measuring bioavailability of organic contaminants sorbed to dissolved organic matter (DOM)

    International Nuclear Information System (INIS)

    Delgado-Moreno, Laura; Wu, Laosheng; Gan, Jay

    2015-01-01

    Natural waters such as surface water and sediment porewater invariably contain dissolved organic matter (DOM). Association of strongly hydrophobic contaminants (HOCs) with DOM leads to decreased toxicity and bioavailability, but bioavailability of DOM-sorbed HOCs is difficult to measure. Current methods to estimate bioavailability of HOCs in water are based on only the freely dissolved concentration (C free ). The ignorance of the exchangeable fraction of HOCs sorbed on DOM may result in an underestimation of the toxicity potential of HOCs to aquatic organisms. Here we explore the applicability of an isotope dilution method (IDM) to measuring the desorption fraction of DOM-sorbed pyrene and bifenthrin and determining their exchangeable pool (E) as an approximation of bioavailability. E values, expressed as percentage of the total concentration, ranged between 0.80 and 0.92% for pyrene and 0.74 and 0.85% for bifenthrin, depending primarily on the amount of chemical in the freely dissolved form. However, between 34 and 78% of the DOM-sorbed pyrene was exchangeable. This fraction ranged between 23% and 82% for bifenthrin. The ability of IDM to predict bioavailability was further shown from a significant relationship (r 2 > 0.72, P < 0.0001) between E and bioaccumulation into Daphnia magna. Therefore, IDM may be used to improve the bioavailability measurement and risk assessment of HOCs in aquatic systems

  14. Dilute NiO/carbon nanofiber composites derived from metal organic framework fibers as electrode materials for supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Ying; Yang, Feng; Hu, Hongru; Lee, Sungsik; Wang, Yue; Zhao, Hairui; Zeng, Dehong; Zhou, Biao; Hao, Shijie

    2017-01-01

    A new type of carbon nanofiber (CNF) dominated electrode materials decorated with dilute NiO particles (NiO/CNF) has been in situ fabricated by direct pyrolysis of Ni, Zn-containing metal organic framework fibers, which are skillfully constructed by assembling different proportional NiCl2·6H2O and Zn(Ac)2·2H2O with trimesic acid in the presence of N,N-dimethylformamide. With elegant combination of advantages of CNF and evenly dispersed NiO particles, as well as successful modulation of conductivity and porosity of final composites, our NiO/CNF composites display well-defined capacitive features. A high capacitance of 14926 F g–1 was obtained in 6 M KOH electrolyte when the contribution from 0.43 wt% NiO was considered alone, contributing to over 35% of the total capacitance (234 F g–1 ). This significantly exceeds its theoretical specific capacitance of 2584 F g–1. It has been established from the Ragone plot that a largest energy density of 33.4 Wh kg–1 was obtained at the current density of 0.25 A g–1. Furthermore, such composite electrode materials show good rate capability and outstanding cycling stability up to 5000 times (only 10% loss). The present study provides a brand-new approach to design a high capacitance and stable supercapacitor electrode and the concept is extendable to other composite materials. Keywords: Metal organic framework; Nickel oxide; Carbon nanofiber; In situ synthesis; Capacitance

  15. Corrosion control of carbon steel using inhibitor of banana peel extract in acid diluted solutions

    Science.gov (United States)

    Komalasari; Utami, S. P.; Fermi, M. I.; Aziz, Y.; Irianti, R. S.

    2018-04-01

    Issues of corrosion happened in pipes, it was used as fluid transportation in the chemical industry. Corrosion cannot be preventing, however it could be controlled or blocked. Inhibitor addition is one of the method to control the corrosion inside the pipe. Corrosion inhibitors consisted of inorganic and organic compound inhibitors. Organic inhibitor is composed from synthetic and natural material. This study focused to evaluate the inhibition’s efficiency from banana peel to carbon steel in different concentration of inhibitor and immersing time in acid solution variation. The research employed inhibitor concentration of 0 gram/liter, 2 gram/liter, 4 gram/liter and 6 gram/liter, immersed time of carbon steel for 2, 4, 6, 8 and 10 hours. It was immersed in chloride acid solution of 0.5 M and 1.5 M. Carbon Steel AISI 4041 was used as specimen steel. Results were analyzed using corrosion rate evaluation for each specimens and inhibitor efficiencies determination. It was found that the specimen without inhibitor yielded fast corrosion rate in long immersing time and high concentration of HCl. However, the specimens with inhibitor gave lowest corrosion rate which was 78.59% for 6 gram/litre and 10 hours in 0.5 M HCl.

  16. A structured understanding of cellobiohydrolase I binding to poplar lignin fractions after dilute acid pretreatment.

    Science.gov (United States)

    Yao, Lan; Yoo, Chang Geun; Meng, Xianzhi; Li, Mi; Pu, Yunqiao; Ragauskas, Arthur J; Yang, Haitao

    2018-01-01

    Cellulase adsorption to lignin is considered a cost barrier for bioethanol production; however, its detailed association mechanism is still not fully understood. In this study, two natural poplar variants with high and low sugar release performance were selected as the low and high recalcitrant raw materials (named L and H , respectively). Three different lignin fractions were extracted using ethanol, followed by p -dioxane and then cellulase treatment from the dilute acid pretreated poplar solids (fraction 1, 2, and 3, respectively). Each lignin fraction had different physicochemical properties. Ethanol-extracted lignin had the lowest weight average molecular weight, while the molecular weights for the other two lignin fractions were similar. 31 P NMR analysis revealed that lignin fraction with higher molecular weight contained more aliphatic hydroxyl groups and less phenolic hydroxyl groups. Semi-quantitative analysis by 2D HSQC NMR indicated that the lignin fractions isolated from the natural variants had different contents of syringyl (S), guaiacyl (G) and interunit linkages. Lignin extracted by ethanol contained the largest amount of S units, the smallest amounts of G and p -hydroxybenzoate (PB) subunits, while the contents of these lignin subunits in the other two lignin fractions were similar. The lignin fraction obtained after cellulase treatment was primarily comprised of β- O -4 linkages with small amounts of β-5 and β-β linkages. The binding strength of these three lignin fractions obtained by Langmuir equations were in the order of L 1  >  L 3  >  L 2 for the low recalcitrance poplar and H 1  >  H 2  >  H 3 for the high recalcitrance poplar. Overall, adsorption ability of lignin was correlated with the sugar release of poplar. Structural features of lignin were associated with its binding to CBH. For natural poplar variants, lignin fractions with lower molecular weight and polydispersity index (PDI) exhibited more CBH adsorption

  17. Aerobic co-treatment of landfill leachate and domestic wastewater - are slowly biodegradable organics removed or simply diluted?

    Science.gov (United States)

    Campos, R; Ferraz, F M; Vieira, E M; Povinelli, J

    2014-01-01

    This study investigated the co-treatment of landfill leachate/domestic wastewater in bench-scale activated sludge (AS) reactors to determine whether the slowly biodegradable organic matter (SBOM) was removed rather than diluted. The AS reactors were loaded with mixtures of raw leachate and leachate that was pretreated by air stripping. The tested volumetric ratios were 0%, 0.2%, 2% and 5%. For all of the tested conditions, the reactors performed better when pretreated leachate was used rather than raw leachate, and the best volumetric ratio was 2%. The following removals were obtained: 97% for the biochemical oxygen demand (BOD5,20), 79% for total suspended solids, 77% for dissolved organic carbon and 84% for soluble chemical oxygen demand. Most of the pretreated leachate SBOM (65%) was removed rather than diluted or adsorbed into the sludge, as confirmed by Fourier transform infrared (FTIR) spectroscopy analyses.

  18. Activity coefficients at infinite dilution and physicochemical properties for organic solutes and water in the ionic liquid 1-(3-hydroxypropyl)pyridinium bis(trifluoromethylsulfonyl)-amide

    Energy Technology Data Exchange (ETDEWEB)

    Marciniak, Andrzej, E-mail: a.marciniak@ch.pw.edu.pl [Department of Physical Chemistry, Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw (Poland)

    2011-10-15

    Highlights: > The {gamma}{sub 13}{sup {infinity}} and KL for 46 solutes in the ionic liquid [N-C3OHPY][NTf2] were determined by GLC at different temperatures. > The partial molar excess Gibbs energies {Delta}G{sub 1}{sup E,{infinity}}, enthalpies {Delta}H{sub 1}{sup E,{infinity}} and entropies {Delta}S{sub 1}{sup E,{infinity}} at infinite dilution were calculated. > The selectivities for aliphatics/aromatics hydrocarbons separation problem were calculated and compared to other ILs, NMP and sulfolane. > The selectivities for selected compounds which form azeotropic mixtures were calculated. - Abstract: The activity coefficients at infinite dilution, {gamma}{sub 13}{sup {infinity}} and gas-liquid partition coefficients, K{sub L} for 46 solutes: alkanes, alkenes, alkynes, cycloalkanes, aromatic hydrocarbons, alcohols, thiophene, ethers, ketones, acetic acid, and water in the ionic liquid 1-(3-hydroxypropyl)pyridinium bis(trifluoromethylsulfonyl)-amide were determined by gas-liquid chromatography at the temperatures from (308.15 to 378.15) K. The partial molar excess Gibbs free energies {Delta}G{sub 1}{sup E,{infinity}}, enthalpies {Delta}H{sub 1}{sup E,{infinity}} and entropies {Delta}S{sub 1}{sup E,{infinity}} at infinite dilution were calculated from the experimental {gamma}{sub 13}{sup {infinity}} values obtained over the temperature range. The selectivities for aliphatic/aromatic hydrocarbons separation problem were calculated from the {gamma}{sub 13}{sup {infinity}} and compared to the literature values for other ionic liquids based on bis(trifluoromethylsulfonyl)-amide anion, NMP and sulfolane. It was found that the investigated ionic liquid shows much higher selectivity at infinite dilution than the general used organic solvents such as NMP, sulfolane and other ionic liquids. Additionally the selectivities for selected compounds which form azeotropic mixtures were calculated.

  19. Activity coefficients at infinite dilution and physicochemical properties for organic solutes and water in the ionic liquid 1-(3-hydroxypropyl)pyridinium bis(trifluoromethylsulfonyl)-amide

    International Nuclear Information System (INIS)

    Marciniak, Andrzej

    2011-01-01

    Highlights: → The γ 13 ∞ and KL for 46 solutes in the ionic liquid [N-C3OHPY][NTf2] were determined by GLC at different temperatures. → The partial molar excess Gibbs energies ΔG 1 E,∞ , enthalpies ΔH 1 E,∞ and entropies ΔS 1 E,∞ at infinite dilution were calculated. → The selectivities for aliphatics/aromatics hydrocarbons separation problem were calculated and compared to other ILs, NMP and sulfolane. → The selectivities for selected compounds which form azeotropic mixtures were calculated. - Abstract: The activity coefficients at infinite dilution, γ 13 ∞ and gas-liquid partition coefficients, K L for 46 solutes: alkanes, alkenes, alkynes, cycloalkanes, aromatic hydrocarbons, alcohols, thiophene, ethers, ketones, acetic acid, and water in the ionic liquid 1-(3-hydroxypropyl)pyridinium bis(trifluoromethylsulfonyl)-amide were determined by gas-liquid chromatography at the temperatures from (308.15 to 378.15) K. The partial molar excess Gibbs free energies ΔG 1 E,∞ , enthalpies ΔH 1 E,∞ and entropies ΔS 1 E,∞ at infinite dilution were calculated from the experimental γ 13 ∞ values obtained over the temperature range. The selectivities for aliphatic/aromatic hydrocarbons separation problem were calculated from the γ 13 ∞ and compared to the literature values for other ionic liquids based on bis(trifluoromethylsulfonyl)-amide anion, NMP and sulfolane. It was found that the investigated ionic liquid shows much higher selectivity at infinite dilution than the general used organic solvents such as NMP, sulfolane and other ionic liquids. Additionally the selectivities for selected compounds which form azeotropic mixtures were calculated.

  20. Activity coefficients at infinite dilution measurements for organic solutes and water in the ionic liquid 1-ethyl-3-methylimidazolium tetracyanoborate

    International Nuclear Information System (INIS)

    Domanska, Urszula; Krolikowska, Marta; Acree, William E.; Baker, Gary A.

    2011-01-01

    Research highlights: → Measurements of activity coefficients at infinite dilution using GLC. → 36 organic solvents and water in the ionic liquid 1-ethyl-3-methylimidazolium tetracyanoborate, [EMIM][TCB]. → Possible entrainer for different separation processes. → The partial molar excess thermodynamic functions at infinite dilution were calculated. - Abstract: The activity coefficients at infinite dilution, γ 13 ∞ , for 36 solutes, including alkanes, cycloalkanes, alkenes, alkynes, aromatic hydrocarbons, alcohols, thiophene, tetrahydrofuran, ethers, acetone, and water, in the ionic liquid 1-ethyl-3-methylimidazolium tetracyanoborate, [EMIM][TCB], were determined by gas-liquid chromatography at temperatures from 298.15 K to 358.15 K. These values are compared to those previously published for selected solutes in the same ionic liquid. The values of the partial molar excess Gibbs free energy ΔG 1 E,∞ , enthalpy ΔH 1 E,∞ , and entropy ΔS 1 E,∞ at infinite dilution were calculated from the experimental γ 13 ∞ values obtained over the temperature range. Three gas-liquid partition coefficients, K L were calculated for all solutes and the Abraham solvation parameter model is discussed. The values of the selectivity for different separation problems were calculated from γ 13 ∞ and compared to literature values for N-methyl-2-pyrrolidinone (NMP), sulfolane, 1-decyl-3-methylimidazolium tetracyanoborate, [DMIM][TCB], and additional ionic liquids.

  1. Nicotinic acid as a nontoxic corrosion inhibitor for hot dipped Zn and Zn-Al alloy coatings on steels in diluted hydrochloric acid

    Energy Technology Data Exchange (ETDEWEB)

    Ju Hong [Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071 (China); Graduate School, Chinese Academy of Sciences, Beijing 100039 (China); Li Yan [Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071 (China)], E-mail: yanlee@ms.qdio.ac.cn

    2007-11-15

    The inhibition effect of nicotinic acid for corrosion of hot dipped Zn and Zn-Al alloy coatings in diluted hydrochloric acid was investigated using quantum chemistry analysis, weight loss test, electrochemical measurement, and scanning electronic microscope (SEM) analysis. Quantum chemistry calculation results showed that nicotinic acid possessed planar structure with a number of active centers, and the populations of the Mulliken charge, the highest occupied molecular orbital (HOMO), and the lowest unoccupied molecular orbital (LUMO) were found mainly focused around oxygen and nitrogen atoms, and the cyclic of the benzene as well. The results of weight loss test and electrochemical measurement indicated that inhibition efficiency (IE%) increased with inhibitor concentration, and the highest inhibition efficiency was up to 96.7%. The corrosion inhibition of these coatings was discussed in terms of blocking the electrode reaction by adsorption of the molecules at the active centers on the electrode surface. It was found that the adsorption of nicotinic acid on coating surface followed Langmuir adsorption isotherm with single molecular layer, and nicotinic acid adsorbed on the coating surface probably by chemisorption. Nicotinic acid, therefore, can act as a good nontoxic corrosion inhibitor for hot dipped Zn and Zn-Al alloy coatings in diluted hydrochloric acid solution.

  2. Prediction of activity coefficients at infinite dilution for organic solutes in ionic liquids by artificial neural network

    Energy Technology Data Exchange (ETDEWEB)

    Nami, Faezeh [Department of Chemistry, Shahid Beheshti University, G.C., Evin-Tehran 1983963113 (Iran, Islamic Republic of); Deyhimi, Farzad, E-mail: f-deyhimi@sbu.ac.i [Department of Chemistry, Shahid Beheshti University, G.C., Evin-Tehran 1983963113 (Iran, Islamic Republic of)

    2011-01-15

    To our knowledge, this work illustrates for the first time the ability of artificial neural network (ANN) to predict activity coefficients at infinite dilution for organic solutes in ionic liquids (ILs). Activity coefficient at infinite dilution ({gamma}{sup {infinity}}) is a useful parameter which can be used for the selection of effective solvent in the separation processes. Using a multi-layer feed-forward network with Levenberg-Marquardt optimization algorithm, the resulting ANN model generated activity coefficient at infinite dilution data over a temperature range of 298 to 363 K. The unavailable input data concerning softness (S) of organic compounds (solutes) and dipole moment ({mu}) of ionic liquids were calculated using GAMESS suites of quantum chemistry programs. The resulting ANN model and its validation are based on the investigation of up to 24 structurally different organic compounds (alkanes, alkenes, alkynes, cycloalkanes, aromatics, and alcohols) in 16 common imidazolium-based ionic liquids, at different temperatures within the range of 298 to 363 K (i.e. a total number of 914 {gamma}{sub Solute}{sup {infinity}}for each IL data point). The results show a satisfactory agreement between the predicted ANN and experimental data, where, the root mean square error (RMSE) and the determination coefficient (R{sup 2}) of the designed neural network were found to be 0.103, 0.996 for training data and 0.128, 0.994 for testing data, respectively.

  3. Prediction of activity coefficients at infinite dilution for organic solutes in ionic liquids by artificial neural network

    International Nuclear Information System (INIS)

    Nami, Faezeh; Deyhimi, Farzad

    2011-01-01

    To our knowledge, this work illustrates for the first time the ability of artificial neural network (ANN) to predict activity coefficients at infinite dilution for organic solutes in ionic liquids (ILs). Activity coefficient at infinite dilution (γ ∞ ) is a useful parameter which can be used for the selection of effective solvent in the separation processes. Using a multi-layer feed-forward network with Levenberg-Marquardt optimization algorithm, the resulting ANN model generated activity coefficient at infinite dilution data over a temperature range of 298 to 363 K. The unavailable input data concerning softness (S) of organic compounds (solutes) and dipole moment (μ) of ionic liquids were calculated using GAMESS suites of quantum chemistry programs. The resulting ANN model and its validation are based on the investigation of up to 24 structurally different organic compounds (alkanes, alkenes, alkynes, cycloalkanes, aromatics, and alcohols) in 16 common imidazolium-based ionic liquids, at different temperatures within the range of 298 to 363 K (i.e. a total number of 914 γ Solute ∞ for each IL data point). The results show a satisfactory agreement between the predicted ANN and experimental data, where, the root mean square error (RMSE) and the determination coefficient (R 2 ) of the designed neural network were found to be 0.103, 0.996 for training data and 0.128, 0.994 for testing data, respectively.

  4. Degradation of chitosan hydrogel dispersed in dilute carboxylic acids by solution plasma and evaluation of anticancer activity of degraded products

    Science.gov (United States)

    Chokradjaroen, Chayanaphat; Rujiravanit, Ratana; Theeramunkong, Sewan; Saito, Nagahiro

    2018-01-01

    Chitosan is a polysaccharide that has been extensively studied in the field of biomedicine, especially its water-soluble degraded products called chitooligosaccharides (COS). In this study, COS were produced by the degradation of chitosan hydrogel dispersed in a dilute solution (i.e., 1.55 mM) of various kinds of carboxylic acids using a non-thermal plasma technology called solution plasma (SP). The degradation rates of chitosan were influenced by the type of carboxylic acids, depending on the interaction between chitosan and each carboxylic acid. After SP treatment, the water-soluble degraded products containing COS could be easily separated from the water-insoluble residue of chitosan hydrogel by centrifugation. The production yields of the COS were mostly higher than 55%. Furthermore, the obtained COS products were evaluated for their inhibitory effect as well as their selectivity against human lung cancer cells (H460) and human lung normal cells (MRC-5).

  5. Facile preparation of super-hydrophilic poly(ethylene terephthalate) fabric using dilute sulfuric acid under microwave irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Fang [College of Textiles and Garments, Southwest University, Chongqing 400715 (China); Chongqing Engineering Research Center of Biomaterial Fiber and Modern Textile, Chongqing 400715 (China); Zhang, Guangxian, E-mail: zgx656472@sina.com.cn [College of Textiles and Garments, Southwest University, Chongqing 400715 (China); Chongqing Engineering Research Center of Biomaterial Fiber and Modern Textile, Chongqing 400715 (China); Zhang, Fengxiu [College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China); Zhang, Yuansong [College of Textiles and Garments, Southwest University, Chongqing 400715 (China); Chongqing Engineering Research Center of Biomaterial Fiber and Modern Textile, Chongqing 400715 (China)

    2015-09-15

    Highlights: • A durable super-hydrophilic PET fabric was prepared using dilute H{sub 2}SO{sub 4} under microwave irradiation. • Dilute sulfuric acid was gradually concentrated enough to sulfonate PET fabric. • Microwave irradiation made PET fabric modification highly efficient. • The mechanical properties of modified PET fibers were kept well. • The method was novel, rapid, and eco-friendly. - Abstract: The hydrophilicity of a poly(ethylene terephthalate) (PET) fabric was greatly modified by using dilute sulfuric acid, which gradually became concentrated enough to sulfonate the fabric when microwave irradiation (MW) was applied. The modified PET fabric was super-hydrophilic. Modifying the fabric caused the water contact angle to decrease from 132.46 (for the unmodified fabric) to 0°, the water absorption rate to increase from 36.45 to 119.78%, and the capillary rise height to increase from 0.4 to 14.4 cm. The hydrophilicity of the modified PET fabric was not affected by washing it many times. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy analyses showed that there were sulfonic acid groups on the modified fibers. Almost no difference between the surfaces of the unmodified and modified PET fibers was found using scanning electron microscopy. Analysis by differential scanning calorimetry showed that the unmodified and modified fabrics had similar thermostabilities. X-ray diffraction analysis of the crystalline structures of the unmodified and modified fibers showed that they were almost the same. The strength, elasticity, and rigidity of the unmodified fabric were retained by the modified fabric. The modified fabric had better dyeing properties than the unmodified fabric.

  6. Direct determination of mercury in cosmetic samples by isotope dilution inductively coupled plasma mass spectrometry after dissolution with formic acid

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Ying; Shi, Zeming; Zong, Qinxia; Wu, Peng; Su, Jing [Sichuan Provincial Key Laboratory of Nuclear Technology in Geology, College of Nuclear Technology and Automation Engineering, Chengdu University of Technology, Chengdu 610059 (China); Liu, Rui, E-mail: liur.ray@gmail.com [Mineral Resources Chemistry Key Laboratory of Sichuan Higher Education Institutions, College of Materials and Chemistry and Chemical Engineering, Chengdu University of Technology, Chengdu 610059 (China)

    2014-02-17

    Graphical abstract: -- Highlights: •Simple, sensitive, and accurate method is established for mercury determination in cosmetics. •The sample preparation procedure is highly simplified. •Isotope dilution efficiently eliminates matrix effect. •First report of using formic acid based method in combination with PVG-ID-ICP MS for mercury quantitation in cosmetics. -- Abstract: A new method was proposed for the accurate determination of mercury in cosmetic samples based on isotopic dilution (ID)-photochemical vapor generation (PVG)-inductively coupled plasma mass spectrometry (ICP MS) measurement. Cosmetic samples were directly dissolved in formic acid solution and subsequently subjected to PVG for the reduction of mercury into vapor species following by ICP MS detection. Therefore, the risks of analyte contamination and loss were avoided. Highly enriched {sup 201}Hg isotopic spike is added to cosmetics and the isotope ratios of {sup 201}Hg/{sup 202}Hg were measured for the quantitation of mercury. With ID calibration, the influences originating from sample matrixes for the determination of mercury in cosmetic samples have been efficiently eliminated. The effects of several experimental parameters, such as the concentration of the formic acid, and the flow rates of carrier gas and sample were investigated. The method provided good reproducibility and the detection limits were found to be 0.6 pg mL{sup −1}. Finally, the developed method was successfully applied for the determination of mercury in six cosmetic samples and a spike test was performed to verify the accuracy of the method.

  7. Quantitation of 5-Methyltetrahydrofolic Acid in Dried Blood Spots and Dried Plasma Spots by Stable Isotope Dilution Assays.

    Directory of Open Access Journals (Sweden)

    Markus Kopp

    Full Text Available Because of minimal data available on folate analysis in dried matrix spots (DMSs, we combined the advantages of stable isotope dilution assays followed by LC-MS/MS analysis with DMS sampling to develop a reliable method for the quantitation of plasma 5-methyltetrahydrofolic acid in dried blood spots (DBSs and dried plasma spots (DPSs as well as for the quantitation of whole blood 5-methyltetrahydrofolic acid in DBSs. We focused on two diagnostically conclusive parameters exhibited by the plasma and whole blood 5-methyltetrahydrofolic acid levels that reflect both temporary and long-term folate status. The method is performed using the [2H4]-labeled isotopologue of the vitamin as the internal standard, and three steps are required for the extraction procedure. Elution of the punched out matrix spots was performed using stabilization buffer including Triton X-100 in a standardized ultrasonication treatment followed by enzymatic digestion (whole blood only and solid-phase extraction with SAX cartridges. This method is sensitive enough to quantify 27 nmol/L whole blood 5-methyltetrahydrofolic acid in DBSs and 6.3 and 4.4 nmol/L plasma 5-methyltetrahydrofolic acid in DBSs and DPSs, respectively. The unprecedented accurate quantification of plasma 5-methyltetrahydrofolic acid in DBSs was achieved by thermal treatment prior to ultrasonication, inhibiting plasma conjugase activity. Mass screenings are more feasible and easier to facilitate for this method in terms of sample collection and storage compared with conventional clinical sampling for the assessment of folate status.

  8. Organic acids in naturally colored surface waters

    Science.gov (United States)

    Lamar, William L.; Goerlitz, D.F.

    1966-01-01

    Most of the organic matter in naturally colored surface waters consists of a mixture of carboxylic acids or salts of these acids. Many of the acids color the water yellow to brown; however, not all of the acids are colored. These acids range from simple to complex, but predominantly they are nonvolatile polymeric carboxylic acids. The organic acids were recovered from the water by two techniques: continuous liquid-liquid extraction with n-butanol and vacuum evaporation at 50?C (centigrade). The isolated acids were studied by techniques of gas, paper, and column chromatography and infrared spectroscopy. About 10 percent of the acids recovered were volatile or could be made volatile for gas chromatographic analysis. Approximately 30 of these carboxylic acids were isolated, and 13 of them were individually identified. The predominant part of the total acids could not be made volatile for gas chromatographic analysis. Infrared examination of many column chromatographic fractions indicated that these nonvolatile substances are primarily polymeric hydroxy carboxylic acids having aromatic and olefinic unsaturation. The evidence suggests that some of these acids result from polymerization in aqueous solution. Elemental analysis of the sodium fusion products disclosed the absence of nitrogen, sulfur, and halogens.

  9. Capillary Electrophoresis Analysis of Organic Amines and Amino Acids in Saline and Acidic Samples Using the Mars Organic Analyzer

    Science.gov (United States)

    Stockton, Amanda M.; Chiesl, Thomas N.; Lowenstein, Tim K.; Amashukeli, Xenia; Grunthaner, Frank; Mathies, Richard A.

    2009-11-01

    The Mars Organic Analyzer (MOA) has enabled the sensitive detection of amino acid and amine biomarkers in laboratory standards and in a variety of field sample tests. However, the MOA is challenged when samples are extremely acidic and saline or contain polyvalent cations. Here, we have optimized the MOA analysis, sample labeling, and sample dilution buffers to handle such challenging samples more robustly. Higher ionic strength buffer systems with pKa values near pH 9 were developed to provide better buffering capacity and salt tolerance. The addition of ethylaminediaminetetraacetic acid (EDTA) ameliorates the negative effects of multivalent cations. The optimized protocol utilizes a 75 mM borate buffer (pH 9.5) for Pacific Blue labeling of amines and amino acids. After labeling, 50 mM (final concentration) EDTA is added to samples containing divalent cations to ameliorate their effects. This optimized protocol was used to successfully analyze amino acids in a saturated brine sample from Saline Valley, California, and a subcritical water extract of a highly acidic sample from the Río Tinto, Spain. This work expands the analytical capabilities of the MOA and increases its sensitivity and robustness for samples from extraterrestrial environments that may exhibit pH and salt extremes as well as metal ions.

  10. Selection of suitable mineral acid and its concentration for biphasic dilute acid hydrolysis of the sodium dithionite delignified Prosopis juliflora to hydrolyze maximum holocellulose.

    Science.gov (United States)

    Naseeruddin, Shaik; Desai, Suseelendra; Venkateswar Rao, L

    2016-02-01

    Two grams of delignified substrate at 10% (w/v) level was subjected to biphasic dilute acid hydrolysis using phosphoric acid, hydrochloric acid and sulfuric acid separately at 110 °C for 10 min in phase-I and 121 °C for 15 min in phase-II. Combinations of acid concentrations in two phases were varied for maximum holocellulose hydrolysis with release of fewer inhibitors, to select the suitable acid and its concentration. Among three acids, sulfuric acid in combination of 1 & 2% (v/v) hydrolyzed maximum holocellulose of 25.44±0.44% releasing 0.51±0.02 g/L of phenolics and 0.12±0.002 g/L of furans, respectively. Further, hydrolysis of delignified substrate using selected acid by varying reaction time and temperature hydrolyzed 55.58±1.78% of holocellulose releasing 2.11±0.07 g/L and 1.37±0.03 g/L of phenolics and furans, respectively at conditions of 110 °C for 45 min in phase-I & 121 °C for 60 min in phase-II. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Interaction Between Some Monosaccharides and Aspartic Acid in Dilute Aqueous Solutions

    OpenAIRE

    Kulikova, Galina A.; Parfenyuk, Elena V.

    2007-01-01

    Interaction between aspartic acid and d-glucose, d-galactose, and d-fructose has been studied by isothermal titration calorimetry, calorimetry of dissolution, and densimetry. It has been found that d-glucose and d-fructose form thermodynamically stable associates with aspartic acid, in contrast to d-galactose. The selectivity in the interaction of aspartic acid with monosaccharides is affected by their stereochemical structures.

  12. Prehydrolysis of aspen wood with water and with dilute aqueous sulfuric acid

    Science.gov (United States)

    Edward L. Springer; John F. Harris

    1982-01-01

    Water prehydrolysis of aspen wood was compared with 0.40% sulfuric acid prehydrolysis at a reaction temperature of 170°C. Acid prehydrolysis gave much higher yields of total anhydroxylose units in the prehydrolyzate and removed significantly less anhydroglucose from the wood than did the water treatment. At maximum yields of total anhydroxylose units in the...

  13. Nanoparticles modified with multiple organic acids

    Science.gov (United States)

    Cook, Ronald Lee (Inventor); Luebben, Silvia DeVito (Inventor); Myers, Andrew William (Inventor); Smith, Bryan Matthew (Inventor); Elliott, Brian John (Inventor); Kreutzer, Cory (Inventor); Wilson, Carolina (Inventor); Meiser, Manfred (Inventor)

    2007-01-01

    Surface-modified nanoparticles of boehmite, and methods for preparing the same. Aluminum oxyhydroxide nanoparticles are surface modified by reaction with selected amounts of organic acids. In particular, the nanoparticle surface is modified by reactions with two or more different carboxylic acids, at least one of which is an organic carboxylic acid. The product is a surface modified boehmite nanoparticle that has an inorganic aluminum oxyhydroxide core, or part aluminum oxyhydroxide core and a surface-bonded organic shell. Organic carboxylic acids of this invention contain at least one carboxylic acid group and one carbon-hydrogen bond. One embodiment of this invention provides boehmite nanoparticles that have been surface modified with two or more acids one of which additional carries at least one reactive functional group. Another embodiment of this invention provides boehmite nanoparticles that have been surface modified with multiple acids one of which has molecular weight or average molecular weight greater than or equal to 500 Daltons. Yet, another embodiment of this invention provides boehmite nanoparticles that are surface modified with two or more acids one of which is hydrophobic in nature and has solubility in water of less than 15 by weight. The products of the methods of this invention have specific useful properties when used in mixture with liquids, as filler in solids, or as stand-alone entities.

  14. Nanoparticles modified with multiple organic acids

    Science.gov (United States)

    Cook, Ronald Lee; Luebben, Silvia DeVito; Myers, Andrew William; Smith, Bryan Matthew; Elliott, Brian John; Kreutzer, Cory; Wilson, Carolina; Meiser, Manfred

    2007-07-17

    Surface-modified nanoparticles of boehmite, and methods for preparing the same. Aluminum oxyhydroxide nanoparticles are surface modified by reaction with selected amounts of organic acids. In particular, the nanoparticle surface is modified by reactions with two or more different carboxylic acids, at least one of which is an organic carboxylic acid. The product is a surface modified boehmite nanoparticle that has an inorganic aluminum oxyhydroxide core, or part aluminum oxyhydroxide core and a surface-bonded organic shell. Organic carboxylic acids of this invention contain at least one carboxylic acid group and one carbon-hydrogen bond. One embodiment of this invention provides boehmite nanoparticles that have been surface modified with two or more acids one of which additional carries at least one reactive functional group. Another embodiment of this invention provides boehmite nanoparticles that have been surface modified with multiple acids one of which has molecular weight or average molecular weight greater than or equal to 500 Daltons. Yet, another embodiment of this invention provides boehmite nanoparticles that are surface modified with two or more acids one of which is hydrophobic in nature and has solubility in water of less than 15 by weight. The products of the methods of this invention have specific useful properties when used in mixture with liquids, as filler in solids, or as stand-alone entities.

  15. Effects of SPORL and dilute acid pretreatment on substrate morphology, cell physical and chemical wall structures, and subsequent enzymatic hydrolysis of lodgepole pine.

    Science.gov (United States)

    Li, Xinping; Luo, Xiaolin; Li, Kecheng; Zhu, J Y; Fougere, J Dennis; Clarke, Kimberley

    2012-11-01

    The effects of pretreatment by dilute acid and sulfite pretreatment to overcome recalcitrance of lignocellulose (SPORL) on substrate morphology, cell wall physical and chemical structures, along with the subsequent enzymatic hydrolysis of lodgepole pine substrate were investigated. FE-SEM and TEM images of substrate structural morphological changes showed that SPORL pretreatment resulted in fiber separation, where SPORL high pH (4.2) pretreatment exhibited better fiber separation than SPORL low pH (1.9) pretreatment. Dilute acid pretreatment produced very poor fiber separation, consisting mostly of fiber bundles. The removal of almost all hemicelluloses in the dilute acid pretreated substrate did not overcome recalcitrance to achieve a high cellulose conversion when lignin removal was limited. SPORL high pH pretreatment removed more lignin but less hemicellulose, while SPORL low pH pretreatment removed about the same amount of lignin and hemicelluloses in lodgepole pine substrates when compared with dilute acid pretreatment. Substrates pretreated with either SPORL process had a much higher cellulose conversion than those produced with dilute acid pretreatment. Lignin removal in addition to removal of hemicellulose in SPORL pretreatment plays an important role in improving the cellulose hydrolysis of the substrate.

  16. Comparison of isotope dilution and excretion methods for determining the half-life of ascorbic acid in the guinea pig

    International Nuclear Information System (INIS)

    Kipp, D.E.; Rivers, J.M.

    1984-01-01

    The half-life of ascorbic acid (AA) in guinea pigs was investigated by the isotope dilution and excretion methods. The dilution method measures [1-14C]AA disappearance from the plasma, whereas the excretion method measures the elimination of [1-14C]AA and the metabolites from the body. Two groups of animals underwent both isotope studies in reverse order. Animals were conditioned to the experimental procedures and fed 2.5 mg AA/100 g body weight orally to maintain a daily intake of the vitamin independent of food consumption. The two isotope procedures imposed similar stress on the animals, as determined by plasma cortisol levels and body weight changes. The AA half-life calculations of the rapidly exchangeable pool by the isotope dilution method yielded values of 1.23 and 0.34 hours for the two groups, respectively. The half-life of the slowly exchangeable pool for the two groups was 60.2 and 65.8 hours, respectively. The half-life of AA in the rapidly exchangeable pool, as measured by the excretion studies, was 4.57-8.75 hours. For the slowly exchangeable pool, it was 146-149 hours. The longer half-life of both pools obtained with the excretion method indicates that the isotope is disappearing from the plasma more rapidly than it is being excreted. This suggests that a portion of the [1-14C]AA leaving the plasma is removed to a body pool that is not sampled by the isotope excretion method

  17. An AFM and XPS study of corrosion caused by micro-liquid of dilute sulfuric acid on stainless steel

    International Nuclear Information System (INIS)

    Wang Rongguang

    2004-01-01

    Micro-liquid of dilute sulfuric acid deposited on SUS304 steel surface were observed with the ac non-contact mode of an atomic force microscopy (AFM), and the detail of the corrosion process caused by them was investigated with the contact mode of the AFM, X-ray photoelectron spectroscopy (XPS) and wavelength dispersive X-ray spectroscopy (WDXS). As a result, even not applying bias voltages between the tip of the cantilever and the specimen, micro-liquid of sulfuric acid can be successfully imaged using the ac non-contact mode of AFM. Two shapes of micro-acid, i.e., micro-droplets and micro-films, were found to co-exist on the specimen surface. On areas covered by micro-films of acid, only small corrosion product particles appeared and no corrosion pits were found. Beneath micro-droplets, corrosion reaction continue to produce pits until they were all consumed to form a corrosion product (mainly iron oxides) with almost the same shape with the droplet. The total corrosion reaction time was speculated to be between 690 and 1500 ks. The corrosion product formed from micro-droplets was believed to be a process of accumulating small corrosion product particles from the liquid/substrate interface to the surface of the formerly produced corrosion product. The XPS and WDXS analysis also supports the above results

  18. Acidity controls on dissolved organic carbon mobility in organic soils

    Czech Academy of Sciences Publication Activity Database

    Evans, Ch. D.; Jones, T.; Burden, A.; Ostle, N.; Zielinski, P.; Cooper, M.; Peacock, M.; Clark, J.; Oulehle, Filip; Cooper, D.; Freeman, Ch.

    2012-01-01

    Roč. 18, č. 11 (2012), s. 3317-3331 ISSN 1354-1013 Institutional support: RVO:67179843 Keywords : acidity * dissolved organic carbon * organic soil * peat * podzol * soil carbon * sulphur Subject RIV: EH - Ecology, Behaviour Impact factor: 6.910, year: 2012

  19. Simultaneous Recovery of Hydrogen and Chlorine from Industrial Waste Dilute Hydrochloric Acid

    Directory of Open Access Journals (Sweden)

    N. Paidimarri

    2016-01-01

    Full Text Available Recovery of chlorine from byproduct HCl has inevitable commercial importance in industries lately because of insufficient purity or too low concentration to recycle it. Instead it is being neutralized in industries before disposing to meet stringent environmental conditions. Although recovery through catalytic oxidation processes is studied since the 19th century, their high operating conditions combined with sluggish reaction kinetics and low single pass conversions make electrolysis a better alternative. The present motive of this work is to develop a novel electrolysis process which in contrast to traditional processes effectively recovers both hydrogen and chlorine from dilute HCl. For this, an electrolytic cell with an Anionic Exchange Membrane has been designed which only allows the passage of chlorine anions from catholyte to anolyte separating the gasses in a single step. The catholyte can be as low as 3.59 wt% because of fixed anolyte concentration of 1.99 wt% which minimizes oxygen formation. Preliminary results show that the simultaneous recovery of hydrogen and chlorine is possible with high conversion up to 98%. The maximum current density value for 4.96 cm2 membrane surface area (70% active surface area is 2.54 kAm−2, which is comparable with reported commercial processes. This study is expected to be useful for process intensification of the same in a continuous process environment.

  20. Determination of gamma-aminobutyric acid in food matrices by isotope dilution hydrophilic interaction chromatography coupled to mass spectrometry.

    Science.gov (United States)

    Zazzeroni, Raniero; Homan, Andrew; Thain, Emma

    2009-08-01

    The estimation of the dietary intake of gamma-aminobutyric acid (GABA) is dependent upon the knowledge of its concentration values in food matrices. To this end, an isotope dilution liquid chromatography-mass spectrometry method has been developed employing the hydrophilic interaction chromatography technique for analyte separation. This approach enabled accurate quantification of GABA in apple, potato, soybeans, and orange juice without the need of a pre- or post-column derivatization reaction. A selective and precise analytical measurement has been obtained with a triple quadrupole mass spectrometer operating in multiple reaction monitoring using the method of standard additions and GABA-d(6) as an internal standard. The concentrations of GABA found in the matrices tested are 7 microg/g of apple, 342 microg/g of potatoes, 211 microg/g of soybeans, and 344 microg/mL of orange juice.

  1. Enzymatic saccharification of liquid hot water and dilute sulfuric acid pretreated oil palm empty fruit bunch and sugarcane bagasse

    Science.gov (United States)

    Risanto, L.; Fitria; Fajriutami, T.; Hermiati, E.

    2018-03-01

    Oil palm empty fruit bunch (OPEFB) and sugarcane bagasse (SB) are potential feedstocks for the production of bioethanol. In this study OPEFB and SB were pretreated by liquid hot water and dilute sulfuric acid (3% H2SO4), and continued with enzymatic saccharification. Heating treatment for both methods was conducted in an autoclave at 121 °C for 1 hr. The saccharification was performed up to 72 hours with cellulase enzyme loading of 10, 20, and 30 FPU per g biomass. Results showed that OPEFB and SB pretreated with H2SO4 produced higher reducing sugars than those pretreated by liquid hot water. Higher enzyme loading also resulted in higher reducing sugars. Reducing sugars obtained from enzymatic saccharification of OPEFB were higher than those obtained from SB. The highest total reducing sugars (50.48 g/100 g biomass) was obtained from OPEFB pretreated with 3% H2SO4 at enzyme loading of 30 FPU per g biomass.

  2. Studying volatility from composition, dilution, and heating measurements of secondary organic aerosols formed during α-pinene ozonolysis

    Science.gov (United States)

    Sato, Kei; Fujitani, Yuji; Inomata, Satoshi; Morino, Yu; Tanabe, Kiyoshi; Ramasamy, Sathiyamurthi; Hikida, Toshihide; Shimono, Akio; Takami, Akinori; Fushimi, Akihiro; Kondo, Yoshinori; Imamura, Takashi; Tanimoto, Hiroshi; Sugata, Seiji

    2018-04-01

    Traditional yield curve analysis shows that semi-volatile organic compounds are a major component of secondary organic aerosols (SOAs). We investigated the volatility distribution of SOAs from α-pinene ozonolysis using positive electrospray ionization mass analysis and dilution- and heat-induced evaporation measurements. Laboratory chamber experiments were conducted on α-pinene ozonolysis, in the presence and absence of OH scavengers. Among these, we identified not only semi-volatile products, but also less volatile highly oxygenated molecules (HOMs) and dimers. Ozonolysis products were further exposed to OH radicals to check the effects of photochemical aging. HOMs were also formed during OH-initiated photochemical aging. Most HOMs that formed from ozonolysis and photochemical aging had 10 or fewer carbons. SOA particle evaporation after instantaneous dilution was measured at fraction remaining of SOAs decreased with time and the equilibration timescale was determined to be 24-46 min for SOA evaporation. The experimental results of the equilibration timescale can be explained when the mass accommodation coefficient is assumed to be 0.1, suggesting that the existence of low-volatility materials in SOAs, kinetic inhibition, or some combined effect may affect the equilibration timescale measured in this study.

  3. Pretreatment of Sugar Beet Pulp with Dilute Sulfurous Acid is Effective for Multipurpose Usage of Carbohydrates.

    Science.gov (United States)

    Kharina, M; Emelyanov, V; Mokshina, N; Ibragimova, N; Gorshkova, T

    2016-05-01

    Sulfurous acid was used for pretreatment of sugar beet pulp (SBP) in order to achieve high efficiency of both extraction of carbohydrates and subsequent enzymatic hydrolysis of the remaining solids. The main advantage of sulfurous acid usage as pretreatment agent is the possibility of its regeneration. Application of sulfurous acid as hydrolyzing agent in relatively low concentrations (0.6-1.0 %) during a short period of time (10-20 min) and low solid to liquid ratio (1:3, 1:6) allowed effective extraction of carbohydrates from SBP and provided positive effect on subsequent enzymatic hydrolysis. The highest obtained concentration of reducing substances (RS) in hydrolysates was 8.5 %; up to 33.6 % of all carbohydrates present in SBP could be extracted. The major obtained monosaccharides were arabinose and glucose (9.4 and 7.3 g/l, respectively). Pretreatment of SBP with sulfurous acid increased 4.6 times the yield of glucose during subsequent enzymatic hydrolysis of remaining solids with cellulase cocktail, as compared to the untreated SBP. Total yield of glucose during SBP pretreatment and subsequent enzymatic hydrolysis amounted to 89.4 % of the theoretical yield. The approach can be applied directly to the wet SBP. Hydrolysis of sugar beet pulp with sulfurous acid is recommended for obtaining of individual monosaccharides, as well as nutritional media.

  4. Effect of Hot water and dilute acid pretreatment on the chemical properties of liquorice root

    Directory of Open Access Journals (Sweden)

    zahra takzare

    2016-06-01

    Full Text Available Abstract In this study, the liquorice root (Glycyrrhiza glabra that was extracted in the factory in Kerman province, pre-hydrolyzed and then chemical compositions (Extractives, Lignin content, Holocellulose percent, the hydrolysis process yield and weight loss of the waste was measured. Pre-hydrolysis process was done on the above mentioned waste by hot water, hot water followed by 0.5 percent sulfuric acid and also alone sulfuric acid with different concentrations (0.5, 1, 1.5 and 2 percent The samples were pre-hydrolyzed in hot water at 150 °C and 30, 60 and 90 minutes as well as in the mixture of hot water and 0.5 % sulfuric acid at 150 °C and 60 minutes and also in pure sulfuric acid, at 130 °C and at 60 minutes. The results showed that the pre-hydrolyzed treatment with hot water in 60 minutes had been favorable performance in the respect of weight loss, lignin content and holocellulose percent. Also, in the case of pre-treatment including sulfuric acid, 2% dose can be good selected option in term of maximum holocellulose percent and minimum lignin content so that it can be suggested to produce higher value-added products such as bioethanol from licorice root bid.

  5. Disruption of sugarcane bagasse lignocellulosic structure by means of dilute sulfuric acid pretreatment with microwave-assisted heating

    International Nuclear Information System (INIS)

    Chen, Wei-Hsin; Tu, Yi-Jian; Sheen, Herng-Kuang

    2011-01-01

    Highlights: → Pretreatment of dilute sulfuric acid on bagasse using microwave heating. → An increase in reaction temperature destroyed bagasse significantly. → Pretreated bagasse particles were characterized by fragmentation and swelling. → When the temperature was 190 o C, the fragmentation of particles became pronounced. → The influence of heating time on bagasse structure was not significant. - Abstract: Disruption of lignocellulosic structure of biomass plays a key role in producing bioethanol from lignocelluloses. This study investigated the impact of dilute sulfuric acid pretreatment on bagasse structure using microwave heating. Three reaction temperatures of 130, 160 and 190 o C with two heating times of 5 and 10 min were considered and a number of instruments were employed to analyze the properties of the bagasse particles. On account of microwave irradiation into the solution with dielectric heating, the experiments indicated that an increase in reaction temperature destroyed the lignocellulosic structure of bagasse in a significant way. The pretreated bagasse particles were simultaneously characterized by fragmentation and swelling. When the reaction temperature was as high as 190 o C, the fragmentation of particles became fairly pronounced so that the specific surface area of the pretreated material grew substantially. Meanwhile, almost all hemicellulose was removed from bagasse and the crystalline structure of cellulose disappeared. In contrast, the feature of lignin was remained clearly. However, a comparison between the heating times of 5 and 10 min revealed that the influence of the heating time on the lignocellulosic structure was not significant, indicating that the pretreatment with 5 min was sufficiently long.

  6. Rheology of dilute acid hydrolyzed corn stover at high solids concentration.

    Science.gov (United States)

    Ehrhardt, M R; Monz, T O; Root, T W; Connelly, R K; Scott, C T; Klingenberg, D J

    2010-02-01

    The rheological properties of acid hydrolyzed corn stover at high solids concentration (20-35 wt.%) were investigated using torque rheometry. These materials are yield stress fluids whose rheological properties can be well represented by the Bingham model. Yield stresses increase with increasing solids concentration and decrease with increasing hydrolysis reaction temperature, acid concentration, and rheometer temperature. Plastic viscosities increase with increasing solids concentration and tend to decrease with increasing reaction temperature and acid concentration. The solids concentration dependence of the yield stress is consistent with that reported for other fibrous systems. The changes in yield stress with reaction conditions are consistent with observed changes in particle size. This study illustrates that torque rheometry can be used effectively to measure rheological properties of concentrated biomass.

  7. Characteristics of Lignin Fractions from Dilute Acid Pretreated Switchgrass and Their Effect on Cellobiohydrolase from Trichoderma longibrachiatum

    Directory of Open Access Journals (Sweden)

    Lan Yao

    2018-02-01

    Full Text Available To investigate the interactions between acid pretreated switchgrass lignin and cellobiohydrolase (CBH, three different lignin fractions were isolated from dilute acid pretreated switchgrass by (i ethanol extraction, followed by (ii dioxane/H2O extraction, and (iii cellulase treatment, respectively. Structural properties of each lignin fraction were elucidated by GPC, 13C-NMR, and 2D-HSQC NMR analyses. The adsorptions of CBH to the isolated lignin fractions were also studied by Langmuir adsorption isotherms. Ethanol-extractable lignin fraction, mainly composed of syringyl (S and guaiacyl (G units, had the lowest molecular weight, while dioxane/H2O-extracted lignin fraction had the lowest S/G ratio with higher content of p-coumaric acid (pCA unit. The residual lignin fraction after enzymatic treatment had the highest S/G ratio without hydroxyphenyl (H unit. Strong associations were found between lignin properties such as lignin composition and S/G ratio and its non-productive enzyme adsorption factors including the maximum adsorption capacity and binding strength.

  8. Formic acid hydrolysis/liquid chromatography isotope dilution mass spectrometry: An accurate method for large DNA quantification.

    Science.gov (United States)

    Shibayama, Sachie; Fujii, Shin-Ichiro; Inagaki, Kazumi; Yamazaki, Taichi; Takatsu, Akiko

    2016-10-14

    Liquid chromatography-isotope dilution mass spectrometry (LC-IDMS) with formic acid hydrolysis was established for the accurate quantification of λDNA. The over-decomposition of nucleobases in formic acid hydrolysis was restricted by optimizing the reaction temperature and the reaction time, and accurately corrected by using deoxynucleotides (dNMPs) and isotope-labeled dNMPs as the calibrator and the internal standard, respectively. The present method could quantify λDNA with an expanded uncertainty of 4.6% using 10fmol of λDNA. The analytical results obtained with the present method were validated by comparing with the results of phosphate-base quantification by inductively coupled plasma-mass spectrometry (ICP-MS). The results showed good agreement with each other. We conclude that the formic acid hydrolysis/LC-IDMS method can quantify λDNA accurately and is promising as the primary method for the certification of DNA as reference material. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Activity coefficients at infinite dilution of organic solutes in 1-hexyl-3-methylimidazolium trifluoroacetate and influence of interfacial adsorption using gas–liquid chromatography

    International Nuclear Information System (INIS)

    Jiang, Lin-Kun; Wang, Li-Sheng; Du, Chao-Jun; Wang, Xue-Yuan

    2014-01-01

    Highlights: • Activity coefficients at infinite dilution of organic solutes in [HMIM][TFA] were determined. • The contribution of interfacial adsorption to the retention mechanism was estimated. • The partial molar excess enthalpies and the solubility parameters of [HMIM][TFA] were calculated. -- Abstract: Activity coefficients at infinite dilution for a series of organic solutes in the ionic liquid 1-hexyl-3-methylimidazolium trifluoroacetate ([HMIM][TFA]) have been determined by gas–liquid chromatography at the temperature range from (303.15 to 363.15) K. The contribution of interfacial adsorption to the retention mechanism was estimated by changing the loading of ionic liquid in stationary phase. The partial molar excess enthalpies at infinite dilution and the solubility parameters of ionic liquid were also calculated from the experimental values of activity coefficients at infinite dilution

  10. Analytical and preparative separation of organic acids from water by extraction with trioctylamine

    International Nuclear Information System (INIS)

    Eberle, S.H.; Hoyer, O.; Knobel, K.P.; Hodenberg, S. von

    1977-12-01

    The extraction of pure organic acids and of humic and ligninsulfonic acid from water by a solution of trioctylamine in chloroform was investigated (technical grade amine = ALAMINE). Quantitative separation is achieved by double extraction with 5% ALAMINE at pH 3,5 - 4. The acids may be back-extracted with dilute sodium hydroxide solution. Procedures are described for the analytical extraction of water samples of 200 to 2.000 ml and for the flow-through processing of large water volumes. (orig.) [de

  11. Study of ion exchange behaviour of some elements at phosphonic-acid cationite in diluted solutions of nitric acid

    International Nuclear Information System (INIS)

    Razbash, A.A.; Sevast'yanov, Yu.G.

    1985-01-01

    Ce(3, 4), Eu(3), Gd(3), Sm(3), Sc(3) distribution coefficients are determined in the macroporic phosphonic acid cationite KRF-20T-60 in nitric acid solutions in 0.1-2.0 M concentration interval using statistical method. A simple method of cerium-139 radionuclide extraction from the industrial lanthanum target is developed. The product yield made up more than 99%, specific activity - 2.37x10 9 Bq/mg, radiochemical purity - no less than 99.9%

  12. Concentration and fractionation of hydrophobic organic acid constituents from natural waters by liquid chromatography

    Science.gov (United States)

    Thurman, E.M.; Malcolm, R.L.

    1979-01-01

    A scheme is presented which used adsorption chromatography with pH gradient elution and size-exclusion chromatography to concentrate and separate hydrophobic organic acids from water. A review of chromatographic processes involved in the flow scheme is also presented. Organic analytes which appear in each aqueous fraction are quantified by dissolved organic carbon analysis. Hydrophobic organic acids in a water sample are concentrated on a porous acrylic resin. These acids usually constitute approximately 30-50 percent of the dissolved organic carbon in an unpolluted water sample and are eluted with an aqueous eluent (dilute base). The concentrate is then passed through a column of polyacryloylmorpholine gel, which separates the acids into high- and low-molecular-weight fractions. The high- and low-molecular-weight eluates are reconcentrated by adsorption chromatography, then are eluted with a pH gradient into strong acids (predominately carboxylic acids) and weak acids (predominately phenolic compounds). For standard compounds and samples of unpolluted waters, the scheme fractionates humic substances into strong and weak acid fractions that are separated from the low molecular weight acids. A new method utilizing conductivity is also presented to estimate the acidic components in the methanol fraction.

  13. Effect of organic acids on the growth and lipid accumulation of oleaginous yeast Trichosporon fermentans

    Directory of Open Access Journals (Sweden)

    Huang Chao

    2012-01-01

    Full Text Available Abstract Background Microbial lipids have drawn increasing attention in recent years as promising raw materials for biodiesel production, and the use of lignocellulosic hydrolysates as carbon sources seems to be a feasible strategy for cost-effective lipid fermentation with oleaginous microorganisms on a large scale. During the hydrolysis of lignocellulosic materials with dilute acid, however, various kinds of inhibitors, especially large amounts of organic acids, will be produced, which substantially decrease the fermentability of lignocellulosic hydrolysates. To overcome the inhibitory effects of organic acids, it is critical to understand their impact on the growth and lipid accumulation of oleaginous microorganisms. Results In our present work, we investigated for the first time the effect of ten representative organic acids in lignocellulosic hydrolysates on the growth and lipid accumulation of oleaginous yeast Trichosporon fermentans cells. In contrast to previous reports, we found that the toxicity of the organic acids to the cells was not directly related to their hydrophobicity. It is worth noting that most organic acids tested were less toxic than aldehydes to the cells, and some could even stimulate the growth and lipid accumulation at a low concentration. Unlike aldehydes, most binary combinations of organic acids exerted no synergistic inhibitory effects on lipid production. The presence of organic acids decelerated the consumption of glucose, whereas it influenced the utilization of xylose in a different and complicated way. In addition, all the organic acids tested, except furoic acid, inhibited the malic activity of T. fermentans. Furthermore, the inhibition of organic acids on cell growth was dependent more on inoculum size, temperature and initial pH than on lipid content. Conclusions This work provides some meaningful information about the effect of organic acid in lignocellulosic hydrolysates on the lipid production of

  14. Behaviours of trinitratonitrosyl complexes of ruthenium in dilute nitric acid solutions

    Energy Technology Data Exchange (ETDEWEB)

    Sugimoto, S [Radia Industry Co. Ltd., Takasaki (Japan)

    1979-07-01

    This study aimed to elucidate the protolysis and condensation processes of the Ru complexes in relation to the concentration of nitric acid. The compositions of the dissociated and undissociated complexes were determined by the extraction with tributyl phosphate (TBP) and absorption spectroscopy in order to follow the rather rapid protolysis reaction of the complexes. The test solutions were prepared by dissolving the freshly obtained complexes into 0.50 - 0.001 M nitric acid solutions. The amounts of the undissociated complexes were determined at different elapses of time in the test solutions. The protolysis became significant when the concentration was below 0.15 M, and the dissociation rate suddenly increased at this concentration. At the concentrations above 0.2 M, the absorption peak of the complexes at 480 nm survived even after 144 hours. But below 0.15 M, the formation of dissociation products by protolysis was observed after the disappearance of the absorption peak. The amount of dissociation products rapidly increased after the preparation of the test solution as the concentration decreased below 0.15 M.

  15. Enhancement of the electrical characteristics of MOS capacitors by reducing the organic content of H2O-diluted Spin-On-Glass based oxides

    International Nuclear Information System (INIS)

    Molina, Joel; Munoz, Ana; Torres, Alfonso; Landa, Mauro; Alarcon, Pablo; Escobar, Manuel

    2011-01-01

    In this work, the physical, chemical and electrical properties of Metal-Oxide-Semiconductor (MOS) capacitors with Spin-On-Glass (SOG)-based thin films as gate dielectric have been investigated. Experiments of SOG diluted with two different solvents (2-propanol and deionized water) were done in order to reduce the viscosity of the SOG solution so that thinner films (down to ∼20 nm) could be obtained and their general characteristics compared. Thin films of SOG were deposited on silicon by the sol-gel technique and they were thermally annealed using conventional oxidation furnace and Rapid Thermal Processing (RTP) systems within N 2 ambient after deposition. SOG dilution using non-organic solvents like deionized water and further annealing (at relatively high temperatures ≥450 deg. C) are important processes intended to reduce the organic content of the films. Fourier-Transform Infrared (FTIR) Spectroscopy results have shown that water-diluted SOG films have a significant reduction in their organic content after increasing annealing temperature and/or dilution percentage when compared to those of undiluted SOG films. Both current-voltage (I-V) and capacitance-voltage (C-V) measurements show better electrical characteristics for SOG-films diluted in deionized water compared to those diluted in 2-propanol (which is an organic solvent). The electrical characteristics of H 2 O-diluted SOG thin films are very similar to those obtained from high quality thermal oxides so that their application as gate dielectrics in MOS devices is promising. Finally, it has been demonstrated that by reducing the organic content of SOG-based thin films, it is possible to obtain MOS devices with better electrical properties.

  16. An application of nitrogen microwave-induced plasma mass spectrometry to isotope dilution analysis of selenium in marine organisms

    Energy Technology Data Exchange (ETDEWEB)

    Shirasaki, Toshihiro [Hitachi Instruments Engineering Co. Ltd., Hitachinaka, Ibaraki (Japan); Yoshinaga, Jun; Morita, Masatoshi; Okumoto, Toyoharu; Oishi, Konosuke

    1996-01-01

    Nitrogen microwave-induced plasma mass spectrometry was studied for its applicability to the isotope dilution analysis of selenium in biological samples. Spectroscopic interference by calcium, which is present in high concentrations in biological samples, was investigated. No detectable background spectrum was observed for the major selenium isotopes of {sup 78}Se and {sup 80}Se. No detectable interferences by sodium, potassium, calcium and phosphorus on the isotope ratio {sup 80}Se/{sup 78}Se were observed up to concentration of 200 mg/ml. The method was applied to the analysis of selenium in biological reference materials of marine organisms. The results showed good agreement between the certified and found values. (author).

  17. Isolation and structural characterization of sugarcane bagasse lignin after dilute phosphoric acid plus steam explosion pretreatment and its effect on cellulose hydrolysis

    Science.gov (United States)

    Jijiao Zeng; Zhaohui Tong; Letian Wang; J.Y. Zhu; Lonnie Ingram

    2014-01-01

    The structure of lignin after dilute phosphoric acid plus steam explosion pretreatment process of sugarcane bagasse in a pilot scale and the effect of the lignin extracted by ethanol on subsequent cellulose hydrolysis were investigated. The lignin structural changes caused by pretreatment were identified using advanced nondestructive techniques such as gel permeation...

  18. Effects of SPORL and dilute acid pretreatment on substrate morphology, cell physical and chemical wall structures, and subsequent enzymatic hydrolysis of lodgepole pine

    Science.gov (United States)

    Xinping Li; Xiaolin Luo; Kecheng Li; J.Y. Zhu; J. Dennis Fougere; Kimberley Clarke

    2012-01-01

    The effects of pretreatment by dilute acid and sulfite pretreatment to overcome recalcitrance of lignocellulose (SPORL) on substrate morphology, cell wall physical and chemical structures, along with the subsequent enzymatic hydrolysis of lodgepole pine substrate were investigated. FE-SEM and TEM images of substrate structural morphological changes showed that SPORL...

  19. 3-D Topo Surface Visualization of Acid-Base Species Distributions: Corner Buttes, Corner Pits, Curving Ridge Crests, and Dilution Plains

    Science.gov (United States)

    Smith, Garon C.; Hossain, Md Mainul

    2017-01-01

    Species TOPOS is a free software package for generating three-dimensional (3-D) topographic surfaces ("topos") for acid-base equilibrium studies. This upgrade adds 3-D species distribution topos to earlier surfaces that showed pH and buffer capacity behavior during titration and dilution procedures. It constructs topos by plotting…

  20. Effect of low severity dilute-acid pretreatment of barley straw and decreased enzyme loading hydrolysis on the production of fermentable substrates and the release of inhibitory compounds

    NARCIS (Netherlands)

    Panagiotopoulos, I.A.; Lignos, G.D.; Bakker, R.R.C.; Koukios, E.G.

    2012-01-01

    The objective of this work was to investigate the feasibility of combining low severity dilute-acid pretreatment of barley straw and decreased enzyme loading hydrolysis for the high production of fermentable substrates and the low release of inhibitory compounds. For most of the pretreatments at 160

  1. Application and validation of isotope dilution method (IDM) for predicting bioavailability of hydrophobic organic contaminants in soil.

    Science.gov (United States)

    Wang, Jie; Taylor, Allison; Schlenk, Daniel; Gan, Jay

    2018-05-01

    Risk assessment of hydrophobic organic contaminants (HOCs) using the total chemical concentration following exhaustive extraction may overestimate the actual availability of HOCs to non-target organisms. Existing methods for estimating HOC bioavailability in soil have various operational limitations. In this study, we explored the application of isotope dilution method (IDM) to quantify the accessible fraction (E) of DDTs and PCBs in both historically-contaminated and freshly-spiked soils. After addition of 13 C or deuterated analogues to a soil sample, the phase distribution of isotope-labeled and native chemicals reached an apparent equilibrium within 48 h of mixing. The derived E values in the three soils ranged from 0.19 to 0.82, depending on the soil properties and also the contact time of HOCs (i.e., aging). The isotope dilution method consistently predicted greater accumulation into earthworm (Eisenia fetida) than that by polyethylene (PE) or solid phase microextraction (SPME) sampler, likely because desorption in the gut enhanced bioavailability of soil-borne HOCs. A highly significant linear regression (R 2  = 0.91) was found between IDM and 24-h Tenax desorption, with a slope statistically identical to 1. The IDM-derived accessible concentration (C e ) was further shown to accurately predict tissue residues in earthworm exposed in the same soils. Given the relatively short duration and simple steps, IDM has the potential to be readily adopted for measuring HOC bioaccessibility in soil and for improving risk assessment and evaluation of remediation efficiency. Copyright © 2018 Elsevier Ltd. All rights reserved.

  2. Barley Benefits from Organic Nitrogen in Plant Residues Applied to Soil using 15N Isotope Dilution

    International Nuclear Information System (INIS)

    Gadalla, A.M.; Galal, Y.G.M.; Abdel Aziz, H.A.; El-Degwy, S.M.A.; Abd El-Haleem, M.

    2008-01-01

    The experiment was carried out in pots (sandy soil cultivated with Barley plant) under greenhouse conditions, at Inshas, Egypt. The aim was to evaluate the transformation of nitrogen applied either as mineral form ( 15 NH 4 ) 2 SO 4 , or as organic-material-N (plant residues) .Basal recommended doses of P and K were applied. Labeled 15 N as( 15 NH 4 ) 2 SO 4 (5 % a.e) or plant residues (ground leuceana forage, compost, and mixture of them) were applied at a rate of 20 kg N/ ha). 15 N technique was used to evaluate N-uptake and fertilizer use efficiency. The treatments were arranged in a completely randomized block design under greenhouse conditions. The obtained results showed that the dry weight of barley shoots was positively affected by reinforcement of mineral- N with organic-N. On the other hand, the highest dry weight was estimated with leuceana either applied alone or reinforced with mineral N. Similar trend was noticed with N uptake but only with organic N, while with treatment received 50% organic-N. plus 50% mineral- N. the best value of N uptake was recorded with mixture of leuceana and compost. The amount of Ndff was lowest where fertilizer 15 N was applied alone. Comparing Ndff for the three organic treatments which received a combination of fertilizer- 15 N+organic-material-N, results showed that the highest Ndff was occurred with mixture of leuceana and compost, whereas the lowest was induced with individual leuceana treatment. 15 N recovery in shoots of barley ranged between 22.14 % to 82.16 %. The lowest occurred with application of mineral 15 N alone and; the highest occurred where mineral 15 N was mixed with compost or leucaena-compost mixture

  3. Weak organic acid stress in Bacillus subtilis

    NARCIS (Netherlands)

    ter Beek, A.S.

    2009-01-01

    Weak organic acids are commonly used food preservatives that protect food products from bacterial contamination. A variety of spore-forming bacterial species pose a serious problem to the food industry by causing extensive food spoilage or even food poisoning. Understanding the mechanisms of

  4. Direct hydrogen production from dilute-acid pretreated sugarcane bagasse hydrolysate using the newly isolated Thermoanaerobacterium thermosaccharolyticum MJ1.

    Science.gov (United States)

    Hu, Bin-Bin; Zhu, Ming-Jun

    2017-05-03

    Energy shortage and environmental pollution are two severe global problems, and biological hydrogen production from lignocellulose shows great potential as a promising alternative biofuel to replace the fossil fuels. Currently, most studies on hydrogen production from lignocellulose concentrate on cellulolytic microbe, pretreatment method, process optimization and development of new raw materials. Due to no effective approaches to relieve the inhibiting effect of inhibitors, the acid pretreated lignocellulose hydrolysate was directly discarded and caused environmental problems, suggesting that isolation of inhibitor-tolerant strains may facilitate the utilization of acid pretreated lignocellulose hydrolysate. Thermophilic bacteria for producing hydrogen from various kinds of sugars were screened, and the new strain named MJ1 was isolated from paper sludge, with 99% identity to Thermoanaerobacterium thermosaccharolyticum by 16S rRNA gene analysis. The hydrogen yields of 11.18, 4.25 and 2.15 mol-H 2 /mol sugar can be reached at an initial concentration of 5 g/L cellobiose, glucose and xylose, respectively. The main metabolites were acetate and butyrate. More important, MJ1 had an excellent tolerance to inhibitors of dilute-acid (1%, g/v) pretreated sugarcane bagasse hydrolysate (DAPSBH) and could efficiently utilize DAPSBH for hydrogen production without detoxication, with a production higher than that of pure sugars. The hydrogen could be quickly produced with the maximum hydrogen production reached at 24 h. The hydrogen production reached 39.64, 105.42, 111.75 and 110.44 mM at 20, 40, 60 and 80% of DAPSBH, respectively. Supplementation of CaCO 3 enhanced the hydrogen production by 21.32% versus the control. These results demonstrate that MJ1 could directly utilize DAPSBH for biohydrogen production without detoxication and can serve as an excellent candidate for industrialization of hydrogen production from DAPSBH. The results also suggest that isolating unique

  5. A Study of ext ration equilibrium in the system:phosphoric acid produced in Aqaba-uranium-0.5 M de pa-0.125M TOPO diluted in kerosene

    International Nuclear Information System (INIS)

    Al-Matar, K.A.; Rawajfeh, M.K.

    1995-01-01

    The extraction of uranium from purified wet process Jordanian phosphoric acid by synergistic solvent 0.5 M de pa and 0.125 M TOPO diluted in kerosene has been studied as a function of temperature and electro-motive force. The uranium distribution coefficient was found to be directly proportional to the electro-motive force up to a limiting point. The uranium distribution coefficient was found to decrease with temperature.Distribution coefficients for the Jordanian acid were found to be higher than those for similar acids from elsewhere.An Aqueous to Organic phase ratio (A/O) recommended for use with the Jordanian acid is 2.5. 11 refs., 6 figs., 2 tab.(Author)

  6. Rapid and Precise Measurement of Serum Branched-Chain and Aromatic Amino Acids by Isotope Dilution Liquid Chromatography Tandem Mass Spectrometry

    OpenAIRE

    Yang, Ruiyue; Dong, Jun; Guo, Hanbang; Li, Hongxia; Wang, Shu; Zhao, Haijian; Zhou, Weiyan; Yu, Songlin; Wang, Mo; Chen, Wenxiang

    2013-01-01

    BACKGROUND: Serum branched-chain and aromatic amino acids (BCAAs and AAAs) have emerged as predictors for the future development of diabetes and may aid in diabetes risk assessment. However, the current methods for the analysis of such amino acids in biological samples are time consuming. METHODS: An isotope dilution liquid chromatography tandem mass spectrometry (ID-LC/MS/MS) method for serum BCAAs and AAAs was developed. The serum was mixed with isotope-labeled BCAA and AAA internal standar...

  7. Effect of pelleting on the recalcitrance and bioconversion of dilute-acid pretreated corn stover

    Energy Technology Data Exchange (ETDEWEB)

    Allison E Ray; Amber Hoover; Gary Gresham

    2012-07-01

    Background: Knowledge regarding the performance of densified biomass in biochemical processes is limited. The effects of densification on biochemical conversion are explored here. Methods: Pelleted corn stover samples were generated from bales that were milled to 6.35 mm. Low-solids acid pretreatment and simultaneous saccharification and fermentation were performed to evaluate pretreatment efficacy and ethanol yields achieved for pelleted and ground stover (6.35 mm and 2 mm) samples. Both pelleted and 6.35-mm ground stover were evaluated using a ZipperClave® reactor under high-solids, process-relevant conditions for multiple pretreatment severities (Ro), followed by enzymatic hydrolysis of the washed, pretreated solids. Results: Monomeric xylose yields were significantly higher for pellets (approximately 60%) than for ground formats (approximately 38%). Pellets achieved approximately 84% of theoretical ethanol yield (TEY); ground stover formats had similar profiles, reaching approximately 68% TEY. Pelleting corn stover was not detrimental to pretreatment efficacy for both low- and high-solids conditions, and even enhanced ethanol yields.

  8. A comparative evaluation of a dipicolinic acid based dilute chemical decontaminant formulation with respect to its efficacy for dissolution of iron oxides

    Energy Technology Data Exchange (ETDEWEB)

    Kamal Kishore; Dey, G.R.; Naik, D.B.; Moorthy, P.N. [Applied Chemistry Division, Bhabha Atomic Research Centre, Mumbai-400 085 (India)

    1998-12-31

    A dilute chemical decontamination formulation containing dipicolinic acid (2,6-pyridine dicarboxylic acid PDCA) and ascorbic acid (AA) has been found to be effective in dissolving magnetite, nickel ferrite and haemetite. Its main advantages arise because of (i) good solubility of the two constituents (ii) lack of absorption on the cation exchanger from acidic media during regenerative decontamination process (iii) stability to ionizing radiation and (iv) low corrosion rate for carbon steel. Dissolution rates of iron oxides in this formulation are as good as or better than in other well known formulations. (author)

  9. Effect of Aging Temperature on Corrosion Behavior of Sintered 17-4 PH Stainless Steel in Dilute Sulfuric Acid Solution

    Science.gov (United States)

    Szewczyk-Nykiel, Aneta; Kazior, Jan

    2017-07-01

    The general corrosion behavior of sintered 17-4 PH stainless steel processed under different processing conditions in dilute sulfuric acid solution at 25 °C was studied by open-circuit potential measurement and potentiodynamic polarization technique. The corrosion resistance was evaluated based on electrochemical parameters, such as polarization resistance, corrosion potential, corrosion current density as well as corrosion rate. The results showed that the precipitation-hardening treatment could significantly improve the corrosion resistance of the sintered 17-4 PH stainless steel in studied environment. As far as the influence of aging temperature on corrosion behavior of the sintered 17-4 PH stainless steel is concerned, polarization resistance and corrosion rate are reduced with increasing aging temperature from 480 up to 500 °C regardless of the temperature of solution treatment. It can be concluded that the highest corrosion resistance in 0.5 M H2SO4 solution exhibits 17-4 PH after solution treatment at 1040 °C followed by aging at 480 °C.

  10. Optimization of dilute sulfuric acid pretreatment to maximize combined sugar yield from sugarcane bagasse for ethanol production.

    Science.gov (United States)

    Benjamin, Y; Cheng, H; Görgens, J F

    2014-01-01

    Increasing fermentable sugar yields per gram of biomass depends strongly on optimal selection of varieties and optimization of pretreatment conditions. In this study, dilute acid pretreatment of bagasse from six varieties of sugarcane was investigated in connection with enzymatic hydrolysis for maximum combined sugar yield (CSY). The CSY from the varieties were also compared with the results from industrial bagasse. The results revealed considerable differences in CSY between the varieties. Up to 22.7 % differences in CSY at the optimal conditions was observed. The combined sugar yield difference between the best performing variety and the industrial bagasse was 34.1 %. High ratio of carbohydrates to lignin and low ash content favored the release of sugar from the substrates. At mild pretreatment conditions, the differences in bioconversion efficiency between varieties were greater than at severe condition. This observation suggests that under less severe conditions the glucose recovery was largely determined by chemical composition of biomass. The results from this study support the possibility of increasing sugar yields or improving the conversion efficiency when pretreatment optimization is performed on varieties with improved properties.

  11. Evaluation of xylitol production using corncob hemicellulosic hydrolysate by combining tetrabutylammonium hydroxide extraction with dilute acid hydrolysis.

    Science.gov (United States)

    Jia, Honghua; Shao, Tingting; Zhong, Chao; Li, Hengxiang; Jiang, Min; Zhou, Hua; Wei, Ping

    2016-10-20

    In this paper, we produced hemicellulosic hydrolysate from corncob by tetrabutylammonium hydroxide (TBAH) extraction and dilute acid hydrolysis combined, further evaluating the feasibility of the resultant corncob hemicellulosic hydrolysate used in xylitol production by Candida tropicalis. Optimized conditions for corncob hemicellulose extraction by TBAH was obtained via response surface methodology: time of 90min, temperature of 60°C, liquid/solid ratio of 12 (v/w), and TBAH concentration of 55%, resulting in a hemicellulose extraction of 80.07% under these conditions. The FT-IR spectrum of the extracted corncob hemicellulose is consistent with that of birchwood hemicellulose and exhibits specific absorbance of hemicelluloses at 1380, 1168, 1050, and 900cm(-1). In addition, we found that C. tropicalis can ferment the resulting corncob hemicellulosic hydrolysate with pH adjustment and activated charcoal treatment leading to a high xylitol yield and productivity of 0.77g/g and 2.45g/(Lh), respectively. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Improvement of microwave-assisted digestion of milk powder with diluted nitric acid using oxygen as auxiliary reagent

    Energy Technology Data Exchange (ETDEWEB)

    Bizzi, Cezar A. [Departamento de Quimica, Universidade Federal de Santa Maria, 97105-900, Santa Maria, RS (Brazil); Instituto Nacional de Ciencia e Tecnologia de Bioanalitica, Campinas, SP (Brazil); Barin, Juliano S. [Departamento de Tecnologia e Ciencia dos Alimentos, Universidade Federal de Santa Maria, 97105-900, Santa Maria, RS (Brazil); Garcia, Edivaldo E. [Departamento de Quimica, Universidade Estadual de Maringa, 87100-900, Maringa, PR (Brazil); Nobrega, Joaquim A. [Departamento de Quimica, Universidade Federal de Sao Carlos, 13565-905, Sao Carlos, SP (Brazil); Dressler, Valderi L. [Departamento de Quimica, Universidade Federal de Santa Maria, 97105-900, Santa Maria, RS (Brazil); Instituto Nacional de Ciencia e Tecnologia de Bioanalitica, Campinas, SP (Brazil); Flores, Erico M.M., E-mail: ericommf@gmail.com [Departamento de Quimica, Universidade Federal de Santa Maria, 97105-900, Santa Maria, RS (Brazil); Instituto Nacional de Ciencia e Tecnologia de Bioanalitica, Campinas, SP (Brazil)

    2011-05-15

    The feasibility of using diluted HNO{sub 3} solutions under oxygen pressure for decomposition of whole and non-fat milk powders and whey powder samples has been evaluated. Digestion efficiency was evaluated by determining the carbon content in solution (digests) and the determination of Ca, Cd, Cu, Fe, K, Mg, Mn, Mo, Na, Pb and Zn was performed by inductively coupled plasma optical emission spectrometry and Hg by chemical vapor generation coupled to inductively coupled plasma mass spectrometry. Samples (up to 500 mg) were digested using HNO{sub 3} solutions (1 to 14 mol L{sup -1}) and the effect of oxygen pressure was evaluated between 2.5 and 20 bar. It was possible to perform the digestion of 500 mg of milk powder using 2 mol L{sup -1} HNO{sub 3} with oxygen pressure ranging from 7.5 to 20 bar with resultant carbon content in digests lower than 1700 mg L{sup -1}. Using optimized conditions, less than 0.86 mL of concentrated nitric acid (14 mol L{sup -1}) was enough to digest 500 mg of sample. The accuracy was evaluated by determination of metal concentrations in certified reference materials, which presented an agreement better than 95% (Student's t test, P < 0.05) for all the analytes.

  13. The molecular properties of biochar carbon released in dilute acidic solution and its effects on maize seed germination.

    Science.gov (United States)

    Sun, Jingling; Drosos, Marios; Mazzei, Pierluigi; Savy, Davide; Todisco, Daniele; Vinci, Giovanni; Pan, Genxing; Piccolo, Alessandro

    2017-01-15

    It is not yet clear whether the carbon released from biochar in the soil solution stimulates biological activities. Soluble fractions (AQU) from wheat and maize biochars, whose molecular content was thoroughly characterized by FTIR, 13 C and 1 H NMR, and high-resolution ESI-IT-TOF-MS, were separated in dilute acidic solution to simulate soil rhizospheric conditions and their effects evaluated on maize seeds germination activity. Elongation of maize-seeds coleoptile was significantly promoted by maize biochar AQU, whereas it was inhibited by wheat biochar AQU. Both AQU fractions contained relatively small heterocyclic nitrogen compounds, whose structures were accounted by their spectroscopic properties. Point-of-Zero-Charge (PZC) values and van Krevelen plots of identified masses of soluble components suggested that the dissolved carbon from maize biochar behaved as humic-like supramolecular material capable to adhere to seedlings and deliver bioactive molecules. These findings contribute to understand the biostimulation potential of biochars from crop biomasses when applied in agricultural production. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Enhanced enzymatic hydrolysis and acetone-butanol-ethanol fermentation of sugarcane bagasse by combined diluted acid with oxidate ammonolysis pretreatment.

    Science.gov (United States)

    Li, Hailong; Xiong, Lian; Chen, Xuefang; Wang, Can; Qi, Gaoxiang; Huang, Chao; Luo, Mutan; Chen, Xinde

    2017-03-01

    This study aims to propose a biorefinery pretreatment technology for the bioconversion of sugarcane bagasse (SB) into biofuels and N-fertilizers. Performance of diluted acid (DA), aqueous ammonia (AA), oxidate ammonolysis (OA) and the combined DA with AA or OA were compared in SB pretreatment by enzymatic hydrolysis, structural characterization and acetone-butanol-ethanol (ABE) fermentation. Results indicated that DA-OA pretreatment improves the digestibility of SB by sufficiently hydrolyzing hemicellulose into fermentable monosaccharides and oxidating lignin into soluble N-fertilizer with high nitrogen content (11.25%) and low C/N ratio (3.39). The enzymatic hydrolysates from DA-OA pretreated SB mainly composed of glucose was more suitable for the production of ABE solvents than the enzymatic hydrolysates from OA pretreated SB containing high ratio of xylose. The fermentation of enzymatic hydrolysates from DA-OA pretreated SB produced 12.12g/L ABE in 120h. These results suggested that SB could be utilized efficient, economic, and environmental by DA-OA pretreatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Stable isotope dilution HILIC-MS/MS method for accurate quantification of glutamic acid, glutamine, pyroglutamic acid, GABA and theanine in mouse brain tissues.

    Science.gov (United States)

    Inoue, Koichi; Miyazaki, Yasuto; Unno, Keiko; Min, Jun Zhe; Todoroki, Kenichiro; Toyo'oka, Toshimasa

    2016-01-01

    In this study, we developed the stable isotope dilution hydrophilic interaction liquid chromatography with tandem mass spectrometry (HILIC-MS/MS) technique for the accurate, reasonable and simultaneous quantification of glutamic acid (Glu), glutamine (Gln), pyroglutamic acid (pGlu), γ-aminobutyric acid (GABA) and theanine in mouse brain tissues. The quantification of these analytes was accomplished using stable isotope internal standards and the HILIC separating mode to fully correct the intramolecular cyclization during the electrospray ionization. It was shown that linear calibrations were available with high coefficients of correlation (r(2)  > 0.999, range from 10 pmol/mL to 50 mol/mL). For application of the theanine intake, the determination of Glu, Gln, pGlu, GABA and theanine in the hippocampus and central cortex tissues was performed based on our developed method. In the region of the hippocampus, the concentration levels of Glu and pGlu were significantly reduced during reality-based theanine intake. Conversely, the concentration level of GABA increased. This result showed that transited theanine has an effect on the metabolic balance of Glu analogs in the hippocampus. Copyright © 2015 John Wiley & Sons, Ltd.

  16. Comparing the Effect of Diets Treated with Different Organic Acids ...

    African Journals Online (AJOL)

    An experiment was conducted to compare the growth and economics of adding organic acids to diets of broiler chickens. The organic acids were sorbic benzoic lactic and propionic acids. 150 day old Hubbard chicks were used. There were five treatments. Diet 1 which served as control contained no organic acid. Diets 2, 3 ...

  17. Energy densification of biomass-derived organic acids

    Energy Technology Data Exchange (ETDEWEB)

    Wheeler, M. Clayton; van Walsum, G. Peter; Schwartz, Thomas J.; van Heiningen, Adriaan

    2013-01-29

    A process for upgrading an organic acid includes neutralizing the organic acid to form a salt and thermally decomposing the resulting salt to form an energy densified product. In certain embodiments, the organic acid is levulinic acid. The process may further include upgrading the energy densified product by conversion to alcohol and subsequent dehydration.

  18. Simultaneous analysis of small organic acids and humic acids using high performance size exclusion chromatography

    NARCIS (Netherlands)

    Qin, X.P.; Liu, F.; Wang, G.C.; Weng, L.P.

    2012-01-01

    An accurate and fast method for simultaneous determination of small organic acids and much larger humic acids was developed using high performance size exclusion chromatography. Two small organic acids, i.e. salicylic acid and 2,3-dihydroxybenzoic acid, and one purified humic acid material were used

  19. The impacts of pretreatment on the fermentability of pretreated lignocellulosic biomass: a comparative evaluation between ammonia fiber expansion and dilute acid pretreatment

    Directory of Open Access Journals (Sweden)

    Dale Bruce E

    2009-12-01

    Full Text Available Abstract Background Pretreatment chemistry is of central importance due to its impacts on cellulosic biomass processing and biofuels conversion. Ammonia fiber expansion (AFEX and dilute acid are two promising pretreatments using alkaline and acidic pH that have distinctive differences in pretreatment chemistries. Results Comparative evaluation on these two pretreatments reveal that (i AFEX-pretreated corn stover is significantly more fermentable with respect to cell growth and sugar consumption, (ii both pretreatments can achieve more than 80% of total sugar yield in the enzymatic hydrolysis of washed pretreated solids, and (iii while AFEX completely preserves plant carbohydrates, dilute acid pretreatment at 5% solids loading degrades 13% of xylose to byproducts. Conclusion The selection of pretreatment will determine the biomass-processing configuration, requirements for hydrolysate conditioning (if any and fermentation strategy. Through dilute acid pretreatment, the need for hemicellulase in biomass processing is negligible. AFEX-centered cellulosic technology can alleviate fermentation costs through reducing inoculum size and practically eliminating nutrient costs during bioconversion. However, AFEX requires supplemental xylanases as well as cellulase activity. As for long-term sustainability, AFEX has greater potential to diversify products from a cellulosic biorefinery due to lower levels of inhibitor generation and lignin loss.

  20. Multiresidue analysis of persistent organic pollutants in contaminated soil using GC-LRMS, GC-HRMS and isotope dilution analysis

    International Nuclear Information System (INIS)

    Badea, Silviu-Laurentiu; Lundstedt, Staffan; Liljelind, Per; Tysklind, Mats

    2009-01-01

    In this study we evaluated a multiresidue analytical protocol for selected Persistent Organic Pollutants (POPs) in soil, that later can be used in adsorption and leaching studies. The method used was based on Soxhlet extraction and open column chromatographic fractionation and clean-up, as well as liquid-liquid extraction and acetylation for phenolic compounds. Target analytes, i.e. polychlorinated phenols (PCPhs), hexachlorobenzene (HCB), polychlorinated dibenzodioxins and furans (PCDDs/Fs), polychlorinated biphenyl (PCBs) PAHs, were detected and quantified using Gas Chromatography-Low Resolution Mass Spectrometry (GC-LRMS) and Gas Chromatography-High Resolution Mass Spectrometry (GC-HRMS) and isotope dilution methodology. Generally, the results show a good recovery and a low standard deviation for those isomers that have also a 13 C labeled compound present in the sample: 4-mono, 2,4 di, 2,4,5 tri, 2,3,4,5 and penta chlorinated phenols. Our results clearly demonstrate that it is possible to analyse a wide range of compounds in complex soil matrixes. (authors(

  1. Activity coefficients at infinite dilution of organic solutes in diethylene glycol and triethylene glycol from gas–liquid chromatography

    International Nuclear Information System (INIS)

    Williams-Wynn, Mark D.; Letcher, Trevor M.; Naidoo, Paramespri; Ramjugernath, Deresh

    2013-01-01

    Highlights: • γ 13 ∞ values reported for 25 organic solutes in the solvents DEG and TEG. • Measurements undertaken using the glc technique at T = (333.2, 348.2, and 363.2) K. • Measurements at elevated temperature possible by pre-saturation of carrier gas. • Comparison of DEG and TEG performance with a number of solvents. -- Abstract: The infinite dilution activity coefficients for 25 hydrocarbon solutes in diethylene glycol (DEG) and triethylene glycol (TEG) were measured using the gas–liquid chromatography technique with pre-saturation of the carrier gas. The hydrocarbon solutes included n-alkanes, alk-1-enes, alk-1-ynes, cycloalkanes, alkylbenzenes and alkanols. At the temperatures at which measurements were conducted, the solvents were volatile, and pre-saturation was considered necessary. The measurements were made at T = (333.2, 348.2 and 363.2) K. Values of the selectivity and capacity relating to DEG and TEG, for two sets of mixtures, which are usually difficult to separate by distillation or solvent extraction, were calculated from the experimental results. The two sets of mixtures were: cyclohexane and benzene; and benzene and methanol. The results obtained in this work were then compared to values for other solvents, at similar temperatures, which were obtained or calculated from literature data

  2. Influence of solid loading on D-xylose production through dilute sulphuric acid hydrolysis of olive stones

    Directory of Open Access Journals (Sweden)

    Cuevas, M.

    2015-09-01

    Full Text Available The selective hydrolysis of hemicellulose from olive stones was attempted in order to achieve a maximum D-xylose yield. For this aim, batch hydrolysis was conducted under different operating conditions of temperature, acid concentration and solid loading. Firstly, distilled water, sulphuric acid and nitric acid were assessed as hydrolytic agents at different temperatures (200, 205, 210 and 220 °C and at a fixed acid concentration (0.025 M. Sulphuric acid and 200 °C were selected for the subsequent dilute acid hydrolysis optimization based on the obtained D-xylose yields. The combined influence of solid loading (from 29.3 to 170.7 g olive stones into 300 mL acid solution and sulphuric acid concentration (0.006–0.034 M on the release of D-xylose was then estimated by response surface methodology. According to a statistical analysis, both parameters had significant interaction effects on D-xylose production. The results illustrated that the higher the solid loading, the higher the required acid concentration. The decrease in the solid/liquid ratio in the reactor had a positive effect on D-xylose extraction and on the amount of acid used. The optimum solid loading and sulphuric acid concentration were determined to be 50 g (solid/liquid ratio 1/6 and 0.016 M, respectively. Under these conditions, the predicted D-xylose yield (expressed as g of sugar per 100 g of dry matter fed was 20.4 (87.2% of maximum attainable.Se ha desarrollado una hidrólisis selectiva de la fracción hemicelulósica del hueso de aceituna con el fin de obtener el máximo rendimiento de D-xilosa. Para ello las hidrólisis se llevaron a cabo en un reactor discontinuo a distintas condiciones de temperatura, concentración de ácido y carga de sólidos. En primer lugar se evaluó la capacidad hidrolítica del agua destilada y de los ácidos nítrico y sulfúrico a distintas temperaturas (200, 205, 210 y 220°C manteniendo fija la concentración de ácido (0,025 M. A partir de

  3. Process Design Report for Wood Feedstock: Lignocellulosic Biomass to Ethanol Process Desing and Economics Utilizing Co-Current Dilute Acid Prehydrolysis and Enzymatic Hydrolysis Current and Futuristic Scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Wooley, Robert [National Renewable Energy Lab. (NREL), Golden, CO (United States); Ruth, Mark [National Renewable Energy Lab. (NREL), Golden, CO (United States); Sheehan, John [National Renewable Energy Lab. (NREL), Golden, CO (United States); Ibsen, Kelly [National Renewable Energy Lab. (NREL), Golden, CO (United States); Majdeski, Henry [Delta-T Corporation, Lexington, KY (United States); Galves, Adrian [Delta-T Corporation, Lexington, KY (United States)

    1999-07-01

    The National Renewable Energy Laboratory (NREL) has undertaken a complete review and update of the process design and economic model for the biomass-to-ethanol process based on co-current dilute acid prehydrolysis, along with simultaneous saccharification (enzymatic) and co-fermentation. The process design includes the core technologies being researched by the U.S. Department of Energy (DOE): prehydrolysis, simultaneous saccharification and co-fermentation, and cellulase enzyme production.

  4. Determination of the Thermodynamic Properties of Poly [2-(3-phenyl-3-methylcyclobutyl)-2-hydroxyethyl methacrylate-co-methacrylic acid] at Infinite Dilution by Inverse Gas Chromatography

    OpenAIRE

    KAYA, İsmet

    2014-01-01

    Some thermodynamic quantities were obtained for the interactions of poly [2-(3-phenyl -3- methylcyclobutyl)-2-hydroxyethyl methacrylate-co-methacrylic acid] Poly (PCHEMA-co-MA) with alcohols, ketones, acetates, aromatics and n-alkanes by inverse gas chromatography in the temperature range of 150-180oC. The specific retention volumes, Vgo, weight fraction activity coefficients of solute probes at infinite dilution, W1\\infty and Flory-Huggins thermodynamic interaction parameters, c12...

  5. Diglycolic acid modified zirconium phosphate and studies on the extraction of Am(III) and Eu(III) from dilute nitric acid medium

    Energy Technology Data Exchange (ETDEWEB)

    Selvan, B. Robert; Suneesh, A.S.; Venkatesan, K.A.; Antony, M.P. [Indira Gandhi Centre for Atomic Research, Kalpakkam (India). Fuel Chemistry Division; Dasthaiah, K.; Gardas, R.L. [Indian Institute of Technology - Madras, Chennai (India). Dept. of Chemistry

    2017-06-01

    Diglycolic acid modified zirconium phosphate (ZrP-DGA) was prepared and studied for the extraction of Am(III) and Eu(III) from dilute nitric acid medium. The distribution coefficient (K{sub d}, mL.g{sup -1}) of Am(III) and Eu(III) was measured as a function of time, pH and concentration of Eu(III) ion etc. The K{sub d} of Am(III) and Eu(III) increased with increase of pH, reached a maximum value of distribution coefficient at pH 1.5 - 2, followed by decrease in K{sub d} values. Rapid extraction of Am(III) and Eu(III) in ZrP-DGA was observed followed by the establishment of equilibrium occurred in 100 min. Kinetics of extraction was fitted in to pseudo second order rate equation. The amount of Eu(III) loaded in ZrP-DGA increased with increase in the concentration of Eu(III) ion in aqueous phase and the isotherm was fitted in to Langmuir and Freundlich adsorption models. The extraction of Am(III) in ZrP-DGA was higher as compared to Eu(III) and the interference of Eu(III) on the extraction of Am(III) was studied. The distribution coefficient of some lanthanides in ZrP-DGA was measured and the K{sub d} of lanthanides increased across the lanthanide series. The extracted trivalent metal ions were recovered in three contacts of loaded ZrP-DGA with 0.5 M nitric acid.

  6. Economics of feeding drinking water containing organic acids to ...

    African Journals Online (AJOL)

    A feeding trial was conducted to determine the economic effect of acidifying drinking water of broiler chickens with organic acids. The organic acids were acetic, butyric, citric and formic acids, each offered at 0.25%. The control did not contain any of the acids. One hundred and fifty (150) day old AborAcre - plus chicks were ...

  7. Kinetic characterization for hemicellulose hydrolysis of corn stover in a dilute acid cycle spray flow-through reactor at moderate conditions

    International Nuclear Information System (INIS)

    Jin, Qiang; Zhang, Hongman; Yan, Lishi; Qu, Liang; Huang, He

    2011-01-01

    The kinetic characterization of hemicellulose hydrolysis of corn stover was investigated using a new reactor of dilute acid cycle spray flow-through (DCF) pretreatment. The primary purpose was to obtain kinetic data for hemicellulose hydrolysis with sulfuric acid concentrations (10-30 kg m -3 ) at relatively low temperatures (90-100 o C). A simplified kinetic model was used to describe its performance at moderate conditions. The results indicate that the rates of xylose formation and degradation are sensitive to flow rate, temperature and acid concentration. Moreover, the kinetic data of hemicellulose hydrolysis fit a first-order reaction model and the experimental data with actual acid concentration after accounting for the neutralization effect of the substrates at different temperatures. Over 90% of the xylose monomer yield and below 5.5% of degradation product (furfural) yield were observed in this reactor. Kinetic constants for hemicellulose hydrolysis models were analyzed by an Arrhenius-type equation, and the activation energy of xylose formation were 111.6 kJ mol -1 , and 95.7 kJ mol -1 for xylose degradation, respectively. -- Highlights: → Investigating a novel pretreatment reactor of dilute acid cycle spray flow-through. → Xylose yield is sensitive to flow rate, temperature and acid concentration. → Obtaining relatively higher xylose monomer yield and lower fermentation inhibitor. → Lumping hemicellulose and xylan oligmers together in the model is a valid way. → The kinetic model as a guide for reactor design, and operation strategy optimization.

  8. Infinite dilution activity coefficients of volatile organic compounds in two ionic liquids composed of the tris(pentafluoroethyl)trifluorophosphate ([FAP]) anion and a functionalized cation

    International Nuclear Information System (INIS)

    Órfão, Eliana Fernandes; Dohnal, Vladimír; Blahut, Aleš

    2013-01-01

    Highlights: • Limiting activity coefficients and gas–liquid partition coefficients for 30 VOCs were determined by GLC. • Solution thermodynamic quantities were derived and analyzed. • [MO-EMPYR][FAP] and [HO-EMIM][FAP] were identified as ILs of very low and very high cohesivity, respectively. • [HO-EMIM][FAP] is an IL of extreme H-bond acidity exhibiting superior performance for petrochemical separations. • Both studied [FAP] ILs were indicated to separate some azeotropic mixtures of alcohols with aprotic oxygenates. -- Abstract: Interactions of volatile organic compounds with two ionic liquids (ILs) containing tris(pentafluoroethyl)trifluorophosphate ([FAP]) anion and a functionalized cation, 1-(2-hydroxyethyl)-3-methylimidazolium ([HO-EMIM]) and 1-(2-methoxyethyl)-1-methylpyrrolidinium ([MO-EMPYR]), were explored through systematic GLC retention measurements. Infinite dilution activity coefficients γ 1 ∞ and gas–liquid partition coefficients K L of 30 selected solutes in [HO-EMIM][FAP] and [MO-EMPYR][FAP] were determined at five temperatures in the range from (318.15 to 353.15) K. Partial molar excess enthalpies and entropies at infinite dilution were derived from the temperature dependence of the γ 1 ∞ values. The Linear Free Energy Relationship (LFER) solvation model was used to correlate the K L values. The LFER correlation parameters and excess thermodynamic functions were analyzed to identify molecular interactions operating between the ILs and the individual solutes. By comparing the behaviors of the studied ILs and of their closely similar unfunctionalized analogs, net effects imparted by cation functionalization were also disclosed. The cohesivity of the two ILs was shown to differ dramatically: while [MO-EMPYR][FAP] ranks among ILs to the least cohesive, [HO-EMIM][FAP] belongs to the most cohesive ones. Both [HO-EMIM][FAP] and [MO-EMPYR][FAP] are capable of interacting with solutes specifically through dipolarity/polarizibility and

  9. Effect of organic acids on shrimp pathogen, Vibrio harveyi.

    Science.gov (United States)

    Mine, Saori; Boopathy, Raj

    2011-07-01

    Shrimp farming accounts for more than 40% of the world shrimp production. Luminous vibriosis is a shrimp disease that causes major economic losses in the shrimp industry as a result of massive shrimp kills due to infection. Some farms in the South Asia use antibiotics to control Vibrio harveyi, a responsible pathogen for luminous vibriosis. However, the antibiotic-resistant strain was found recently in many shrimp farms, which makes it necessary to develop alternative pathogen control methods. Short-chain fatty acids are metabolic products of organisms, and they have been used as food preservatives for a long time. Organic acids are also commonly added in feeds in animal husbandry, but not in aquaculture. In this study, growth inhibitory effects of short-chain fatty acids, namely formic acid, acetic acid, propionic acid, and butyric acid, on V. harveyi were investigated. Among four acids, formic acid showed the strongest inhibitory effect followed by acetic acid, propionic acid, and butyric acid. The minimum inhibitory concentration (MIC) of 0.035% formic acid suppressed growth of V. harveyi. The major inhibitory mechanism seems to be the pH effect of organic acids. The effective concentration 50 (EC50) values at 96 h inoculation for all organic acids were determined to be 0.023, 0.041, 0.03, and 0.066% for formic, acetic, propionic, and butyric acid, respectively. The laboratory study results are encouraging to formulate shrimp feeds with organic acids to control vibrio infection in shrimp aquaculture farms.

  10. Acidic organic compounds in beverage, food, and feed production.

    Science.gov (United States)

    Quitmann, Hendrich; Fan, Rong; Czermak, Peter

    2014-01-01

    Organic acids and their derivatives are frequently used in beverage, food, and feed production. Acidic additives may act as buffers to regulate acidity, antioxidants, preservatives, flavor enhancers, and sequestrants. Beneficial effects on animal health and growth performance have been observed when using acidic substances as feed additives. Organic acids could be classified in groups according to their chemical structure. Each group of organic acids has its own specific properties and is used for different applications. Organic acids with low molecular weight (e.g. acetic acid, lactic acid, and citric acid), which are part of the primary metabolism, are often produced by fermentation. Others are produced more economically by chemical synthesis based on petrochemical raw materials on an industrial scale (e.g. formic acid, propionic and benzoic acid). Biotechnology-based production is of interest due to legislation, consumer demand for natural ingredients, and increasing environmental awareness. In the United States, for example, biocatalytically produced esters for food applications can be labeled as "natural," whereas identical conventional acid catalyst-based molecules cannot. Natural esters command a price several times that of non-natural esters. Biotechnological routes need to be optimized regarding raw materials and yield, microorganisms, and recovery methods. New bioprocesses are being developed for organic acids, which are at this time commercially produced by chemical synthesis. Moreover, new organic acids that could be produced with biotechnological methods are under investigation for food applications.

  11. Separation and recovery of organic acids from fermented kitchen ...

    African Journals Online (AJOL)

    Organic acids produced from anaerobic digestion of kitchen waste were recovered using a new integrated method which consisted of freezing and thawing, centrifugation, filtration and evaporation. The main organic acid produced was lactic acid (98%). After the freezing and thawing process, 73% of the total suspended ...

  12. Physico-Chemical Properties of Kaolin-Organic Acid

    Directory of Open Access Journals (Sweden)

    Yeo S.W.

    2017-01-01

    Full Text Available Soil with more than 20% of organic content is classified as organic soil in Malaysia. Contents of organic soil consist of different types of organic and inorganic matter. Each type of organic matter has its own characteristic and its effect on the properties of the soil is different. Hence, a good understanding on the effect of specific organic and inorganic matter on the physico-chemical characteristic of organic soils can serve as a guide for predicting the properties of organic soils. The main objective is to unveil the effect of organic acid on the physico-chemical properties of soil. Artificial organic soil (kaolin mixed with organic acid was utilized in order to minimize the geochemical variability of studied soil. The organic acid which consists of humic acid and fulvic acid was extracted from highly humificated plant–based compost. The effect of organic acid on the physico-chemical properties of soil was determined by varying the concentration of organic acid. The specific gravity, Atterberg limits, pH, bulk chemical composition and the functional group of kaolin-organic acid were determined. It was found that the plasticity index, specific gravity and pH value were decreased with lowered concentration of organic acid. However, the liquid limits and plastic limits were found to be increased with the concentration decrement of organic acid. The analysis of XRF on the bulk chemical composition and analysis of FTIR spectra on the functional group of artificial organic soils with different concentration have confirmed little geochemical variability between samples.

  13. Introducing AAA-MS, a rapid and sensitive method for amino acid analysis using isotope dilution and high-resolution mass spectrometry.

    Science.gov (United States)

    Louwagie, Mathilde; Kieffer-Jaquinod, Sylvie; Dupierris, Véronique; Couté, Yohann; Bruley, Christophe; Garin, Jérôme; Dupuis, Alain; Jaquinod, Michel; Brun, Virginie

    2012-07-06

    Accurate quantification of pure peptides and proteins is essential for biotechnology, clinical chemistry, proteomics, and systems biology. The reference method to quantify peptides and proteins is amino acid analysis (AAA). This consists of an acidic hydrolysis followed by chromatographic separation and spectrophotometric detection of amino acids. Although widely used, this method displays some limitations, in particular the need for large amounts of starting material. Driven by the need to quantify isotope-dilution standards used for absolute quantitative proteomics, particularly stable isotope-labeled (SIL) peptides and PSAQ proteins, we developed a new AAA assay (AAA-MS). This method requires neither derivatization nor chromatographic separation of amino acids. It is based on rapid microwave-assisted acidic hydrolysis followed by high-resolution mass spectrometry analysis of amino acids. Quantification is performed by comparing MS signals from labeled amino acids (SIL peptide- and PSAQ-derived) with those of unlabeled amino acids originating from co-hydrolyzed NIST standard reference materials. For both SIL peptides and PSAQ standards, AAA-MS quantification results were consistent with classical AAA measurements. Compared to AAA assay, AAA-MS was much faster and was 100-fold more sensitive for peptide and protein quantification. Finally, thanks to the development of a labeled protein standard, we also extended AAA-MS analysis to the quantification of unlabeled proteins.

  14. Morphological study of fluorescent carbon Nanoparticles (F-CNPs) from ground coffee waste soot oxidation by diluted acid

    Science.gov (United States)

    Gea, S.; Tjandra, S.; Joshua, J.; Wirjosentono, B.

    2018-02-01

    Coffee ground waste utilization for fluorescent carbon nanoparticles (F-CNPs) through soot oxidation with diluted HNO3 has been conducted. Soot was obtained through three different treatments to coffee ground waste; which was burned in furnaceat 550°C and 650°C and directly burned in a heat-proofcontainer. Then they were analyzed morphologically with Scanning Electron Microscope (SEM) instrument. Soot from direct burning indicated the optimum result where it has denser pores compared to other two soots. Soot obtained from direct burning was refluxed in diluted HNO3 for 12 hours to perform the oxidation. Yellowish brown supernatant was later observed which lead to green fluorescent under the UV light. F-CNPs characterization was done in Transmission Electron Microscopy, which showed that 7.4-23.4 nm of particle size were distributed.

  15. Dilution Confusion: Conventions for Defining a Dilution

    Science.gov (United States)

    Fishel, Laurence A.

    2010-01-01

    Two conventions for preparing dilutions are used in clinical laboratories. The first convention defines an "a:b" dilution as "a" volumes of solution A plus "b" volumes of solution B. The second convention defines an "a:b" dilution as "a" volumes of solution A diluted into a final volume of "b". Use of the incorrect dilution convention could affect…

  16. Biobased organic acids production by metabolically engineered microorganisms

    DEFF Research Database (Denmark)

    Chen, Yun; Nielsen, Jens

    2016-01-01

    Bio-based production of organic acids via microbial fermentation has been traditionally used in food industry. With the recent desire to develop more sustainable bioprocesses for production of fuels, chemicals and materials, the market for microbial production of organic acids has been further...... expanded as organic acids constitute a key group among top building block chemicals that can be produced from renewable resources. Here we review the current status for production of citric acid and lactic acid, and we highlight the use of modern metabolic engineering technologies to develop high...... performance microbes for production of succinic acid and 3-hydroxypropionic acid. Also, the key limitations and challenges in microbial organic acids production are discussed...

  17. Kinetic and Modeling Investigation to Provide Design Guidelines for the NREL Dilute-Acid Process Aimed at Total Hydrolysis/Fractionation of Lignocellulosic Biomass: July 1998

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Y. Y.; Iyer, P.; Xiang, Q.; Hayes, J.

    2004-08-01

    Following up on previous work, subcontractor investigated three aspects of using NREL ''pretreatment'' technology for total hydrolysis (cellulose as well as hemicellulose) of biomass. Whereas historic hydrolysis of biomass used either dilute acid or concentrated acid technology for hydrolysis of both hemicellulose and cellulose, NREL has been pursuing very dilute acid hydrolysis of hemicellulose followed by enzymatic hydrolysis of cellulose. NREL's countercurrent shrinking-bed reactor design for hemicellulose hydrolysis (pretreatment) has, however, shown promise for total hydrolysis. For the first task, subcontractor developed a mathematical model of the countercurrent shrinking bed reactor operation and, using yellow poplar sawdust as a feedstock, analyzed the effect of: initial solid feeding rate, temperature, acid concentration, acid flow rate, Peclet number (a measure of backmixing in liquid flow), and bed shrinking. For the second task, subcontractor used laboratory trials, with yellow poplar sawdust and 0.07 wt% sulfuric acid at various temperatures, to verify the hydrolysis of cellulose to glucose (desired) and decomposition of glucose (undesired) and determine appropriate parameters for use in kinetic models. Unlike cellulose and hemicellulose, lignins, the third major component of biomass, are not carbohydrates that can be broken down into component sugars. They are, however, aromatic complex amorphous phenolic polymers that can likely be converted into low-molecular weight compounds suitable for production of fuels and chemicals. Oxidative degradation is one pathway for such conversion and hydrogen peroxide would be an attractive reagent for this, as it would leave no residuals. For the third task, subcontractor reacted lignin with hydrogen peroxide under various conditions and analyzed the resulting product mix.

  18. Pretreatment of Dried Distiller Grains with Solubles by Soaking in Aqueous Ammonia and Subsequent Enzymatic/Dilute Acid Hydrolysis to Produce Fermentable Sugars.

    Science.gov (United States)

    Nghiem, Nhuan P; Montanti, Justin; Kim, Tae Hyun

    2016-05-01

    Dried distillers grains with solubles (DDGS), a co-product of corn ethanol production in the dry-grind process, was pretreated by soaking in aqueous ammonia (SAA) using a 15 % w/w NH4OH solution at a solid/liquid ratio of 1:10. The effect of pretreatment on subsequent enzymatic hydrolysis was studied at two temperatures (40 and 60 °C) and four reaction times (6, 12, 24, and 48 h). Highest glucose yield of 91 % theoretical was obtained for the DDGS pretreated at 60 °C and 24 h. The solubilized hemicellulose in the liquid fraction was further hydrolyzed with dilute H2SO4 to generate fermentable monomeric sugars. The conditions of acid hydrolysis included 1 and 4 wt% acid, 60 and 120 °C, and 0.5 and 1 h. Highest yields of xylose and arabinose were obtained at 4 wt% acid, 120 °C, and 1 h. The fermentability of the hydrolysate obtained by enzymatic hydrolysis of the SAA-pretreated DDGS was demonstrated in ethanol fermentation by Saccharomyces cerevisiae. The fermentability of the hydrolysate obtained by consecutive enzymatic and dilute acid hydrolysis was demonstrated using a succinic acid-producing microorganism, strain Escherichia coli AFP184. Under the fermentation conditions, complete utilization of glucose and arabinose was observed, whereas only 47 % of xylose was used. The succinic acid yield was 0.60 g/g total sugar consumed.

  19. Quantification of transformation rates of soil amino sugars and amino acids by a novel isotope pool dilution approach via liquid chromatography/high resolution mass spectrometry (LC/HRMS)

    Science.gov (United States)

    Hu, Yuntao; Zheng, Qing; Noll, Lisa; Zhang, Shasha; Wanek, Wolfgang

    2017-04-01

    Organic nitrogen transformation processes are the key driver of soil nitrogen availability, strongly affecting the nitrogen turnover and carbon cycling of terrestrial ecosystems. Low molecular weight organic nitrogen compounds (e.g. amino acids and amino sugars) that can be directly utilized by plants or microorganisms are released by the extracellular cleavage of high molecular weight organic nitrogen compounds (e.g. proteins, peptidoglycan, and chitin) by hydrolytic enzymes. This decomposition process is believed to be the rate-limiting step in the soil N cycle. Direct measurements of the in situ transformation rates of these small N compounds is highly challenging but can be realized by applying the isotope pool dilution (IPD) technique, in which the target compound pool is labeled with isotopic tracers and subsequently the dilution of the tracers is measured. We have recently pioneered the development of IPD assays to investigate the in situ flux of proteinaceous amino acids and glucose due to decomposition of organic matter and microbial utilization, but the roles of fluxes of amino sugars and amino acid enantiomers in soil nitrogen transformation processes are still unknown due to the lack of feasible extraction, purification, separation and detection methods. Here we developed a 15N IPD assay by utilizing a novel LC/HRMS (Orbitrap) platform, with the aim to measure transformation rates of amino sugars and amino acid enantiomers. After the tracer experiments soil extracts were purified by solid phase extraction prior to the analysis by MS. The utilization of Orbitrap-HRMS allowed us to resolve the mass signals of unlabeled analytes, and their 15N labeled (tracers) and 13C labeled (internal standards) analogues. The commercially unavailable 15N and 13C labeled amino sugars and amino acid enantiomers were produced from bacterial cell walls after batch culture in labeled growth media. This workflow was validated with soils from two sampling sites, allowing us to

  20. Uranium leaching using mixed organic acids produced by Aspergillus niger

    International Nuclear Information System (INIS)

    Yong-dong Wang; Guang-yue Li; De-xin Ding; Zhi-xiang Zhou; Qin-wen Deng; Nan Hu; Yan Tan

    2013-01-01

    Both of culture temperature and pH value had impacts on the degree of uranium extraction through changing types and concentrations of mixed organic acids produced by Aspergillus niger, and significant interactions existed between them though pH value played a leading role. And with the change of pH value of mixed organic acids, the types and contents of mixed organic acids changed and impacted on the degree of uranium extraction, especially oxalic acid, citric acid and malic acid. The mean degree of uranium extraction rose to peak when the culture temperature was 25 deg C (76.14 %) and pH value of mixed organic acids was 2.3 (82.40 %) respectively. And the highest one was 83.09 %. The optimal culture temperature (25 deg C) of A. niger for uranium leaching was different from the most appropriate growing temperature (37 deg C). (author)

  1. An Organic Puzzle Using Meldrum's Acid

    Science.gov (United States)

    Crouch, R. David; Holden, Michael S.

    2002-04-01

    Meldrum's acid or 2,2-dimethyl-1,3-dioxane-4,6-dione undergoes a Knoevenagel condensation with formaldehyde to form an active Michael acceptor for a second molecule of Meldrum's acid. The structure of the resulting product is determined by correlation of the products of possible reactions of Meldrum's acid and formaldehyde with the NMR spectrum of the product.

  2. Preparation of fulvic acid and low-molecular organic acids by oxidation of weathered coal humic acid

    Energy Technology Data Exchange (ETDEWEB)

    Shinozuka, T.; Ito, A.; Sasaki, O.; Yazawa, Y.; Yamaguchi, T. [Chiba Institute of Technolgy, Chiba (Japan). Dept. of Industrial Chemistry

    2002-07-01

    Weathered coal contains much humic acid and a little fulvic acid. Therefore, the production of fulvic acid, the most valuable humic substance because of its water-solubility, was examined by ozone and hydrogen peroxide oxidation of humic acid extracted form Xinjiang (China) weathered coal. The resulting products of the oxidation were water soluble fulvic acid and organic acids, mainly formic acid and oxalic acid. The product yield of fulvic acid was 20 (C%) and that of organic acids were 39 (C%) for formic and acid 13 (C%) for oxalic acid. The formed fulvic acid showed a higher content of oxygen and carboxyl groups, than those of the extracted one from the original weathered coal.

  3. Incorporation of Mg and Ca into nanostructured Fe2O3 improves Fe solubility in dilute acid and sensory characteristics in foods.

    Science.gov (United States)

    Hilty, Florentine M; Knijnenburg, Jesper T N; Teleki, Alexandra; Krumeich, Frank; Hurrell, Richard F; Pratsinis, Sotiris E; Zimmermann, Michael B

    2011-01-01

    Iron deficiency is one of the most common micronutrient deficiencies worldwide. Food fortification can be an effective and sustainable strategy to reduce Fe deficiency but selection of iron fortificants remains a challenge. Water-soluble compounds, for example, FeSO(4), usually demonstrate high bioavailability but they often cause unacceptable sensory changes in foods. On the other hand, poorly acid-soluble Fe compounds, for example FePO(4), may cause fewer adverse sensory changes in foods but are usually not well bioavailable since they need to be dissolved in the stomach prior to absorption. The solubility and the bioavailability of poorly acid-soluble Fe compounds can be improved by decreasing their primary particle size and thereby increasing their specific surface area. Here, Fe oxide-based nanostructured compounds with added Mg or Ca were produced by scalable flame aerosol technology. The compounds were characterized by nitrogen adsorption, X-ray diffraction, transmission electron microscopy, and Fe solubility in dilute acid. Sensory properties of the Fe-based compounds were tested in 2 highly reactive, polyphenol-rich food matrices: chocolate milk and fruit yoghurt. The Fe solubility of nanostructured Fe(2)O(3) doped with Mg or Ca was higher than that of pure Fe(2)O(3). Since good solubility in dilute acid was obtained despite the inhomogeneity of the powders, inexpensive precursors, for example Fe- and Ca-nitrates, can be used for their manufacture. Adding Mg or Ca lightened powder color, while sensory changes when added to foods were less pronounced than for FeSO(4). The combination of high Fe solubility and low reactivity in foods makes these flame-made nanostructured compounds promising for food fortification. Practical Application: The nanostructured iron-containing compounds presented here may prove useful for iron fortification of certain foods; they are highly soluble in dilute acid and likely to be well absorbed in the gut but cause less severe

  4. Surfactant-Enhanced Organic Acid Inactivation of Tulane Virus, a Human Norovirus Surrogate.

    Science.gov (United States)

    Lacombe, Alison; Niemira, Brendan A; Gurtler, Joshua B; Kingsley, David H; Li, Xinhui; Chen, Haiqiang

    2018-02-01

    Combination treatments of surfactants and phenolic or short-chain organic acids (SCOA) may act synergistically or additively as sanitizers to inactive foodborne viruses and prevent outbreaks. The purpose of this study was to investigate the effect of gallic acid (GA), tannic acid, p-coumaric acid, lactic acid (LA), or acetic acid (AA), in combination with sodium dodecyl sulfate (SDS), against Tulane virus (TV), a surrogate for human norovirus. An aqueous stock solution of phenolic acids or SCOA with or without SDS was prepared and diluted in a twofold dilution series to 2× the desired concentration with cell growth media (M119 plus 10% fetal bovine serum). The solution was inoculated with an equal proportion of 6 log PFU/mL TV with a treatment time of 5 min. The survival of TV was quantified using a plaque assay with LLC-MK2 cells. The minimum virucidal concentration was 0.5:0.7% (v/v) for LA-SDS at pH 3.5 (4.5-PFU/mL reduction) and 0.5:0.7% (v/v) AA-SDS at pH 4.0 (2.6-log PFU/mL reduction). GA and SDS demonstrated a minimum virucidal concentration of 12.5 mM GA-SDS at pH 7.0 (0.2:0.3% GA-SDS) with an 0.8-log PFU/mL reduction and 50 mM GA-SDS (0.8:1.4% GA-SDS at pH 7.0) increased log reduction to 1.6 log PFU/mL. The combination treatments of AA or LA with SDS at pH 7.0 did not produce significant log reduction, nor did individual treatments of tannic acid, GA, p-coumaric acid, AA, LA, or SDS. This study demonstrates that a surfactant, such as SDS, aids in the phenolic acid and SCOA toxicities against viruses. However, inactivation of TV by combination treatments is contingent upon the pH of the sanitizing solution being lower than the pK a value of the organic acid being used. This information can be used to develop sanitizing washes to disinfect food contact surfaces, thereby aiding in the prevention of foodborne outbreaks.

  5. Dietary preferences of weaned piglets offered diets containing organic acids

    Directory of Open Access Journals (Sweden)

    K. PARTANEN

    2008-12-01

    Full Text Available A preference test and a performance trial were carried out to examine weaned piglets’ feed intake response to diets containing either lactic acid,formic acid,calcium formate,or sodium benzoate (8 g kg-1 feed.In Experiment 1, throughout a 21-d post-weaning period,30 entire litters (306 piglets weaned at the age of 30 d were allowed to choose between two organic-acid-supplemented diets. All of the four different organic-acid-supplemented diets were tested in pairs against each other,and the six possible combinations were lactic acid +formic acid,lactic acid +calcium formate,lactic acid + sodium benzoate,formic acid +calcium formate,formic acid +sodium benzoate,and calcium for-mate +sodium benzoate.Piglets preferred diets supplemented with sodium benzoate to ones supplemented with formic acid or calcium formate.The acceptability of diets supplemented with lactic acid,formic acid,or calcium formate was similar.In Experiment 2,until the age of 58 d,60 piglets from 10 litters weaned at the age of 28 or 38 d were fed non-acidified diets or ones supplemented with lactic acid,formic acid,calcium formate,or sodium benzoate.Feed consumption did not differ between piglets fed non-acidified and those fed organic-acid-supplemented diets. Growth performance was reduced by dietary calcium formate supplementation, while the performance of piglets fed other organic-acid-supplemented diets did not differ significantly from those fed the non-acidified control diet.The frequency of post-weaning diarrhoea was highest in piglets fed diets supplemented with calcium formate and lowest in piglets fed diets supplemented with formic acid.;

  6. Herbal additives and organic acids as antibiotic alternatives in ...

    African Journals Online (AJOL)

    Herbal additives and organic acids as antibiotic alternatives in broiler chickens diet for organic production. ... Significant increase in lactic acid bacteria counts in ileum and cecum of broiler chicken was shown by all treatments as compared to the control at day 21. In comparison to the control, all treatments significantly ...

  7. Effect of pretreatment severity on accumulation of major degradation products from dilute acid pretreated corn stover and subsequent inhibition of enzymatic hydrolysis of cellulose.

    Science.gov (United States)

    Um, Byung-Hwan; van Walsum, G Peter

    2012-09-01

    The concept of reaction severity, which combines residence time and temperature, is often used in the pulp and paper and biorefining industries. The influence of corn stover pretreatment severity on yield of sugar and major degradation products and subsequent effects on enzymatic cellulose hydrolysis was investigated. The pretreatment residence time and temperature, combined into the severity factor (Log R(o)), were varied with constant acid concentration. With increasing severity, increasing concentrations of furfural and 5-hydroxymethylfurfural (5-HMF) coincided with decreasing yields of oligosaccharides. With further increase in severity factor, the concentrations of furans decreased, while the formation of formic acid and lactic acid increased. For example, from severity 3.87 to 4.32, xylose decreased from 6.39 to 5.26 mg/mL, while furfural increased from 1.04 to 1.33 mg/mL; as the severity was further increased to 4.42, furfural diminished to 1.23 mg/mL as formate rose from 0.62 to 1.83 mg/mL. The effects of dilute acid hydrolyzate, acetic acid, and lignin, in particular, on enzymatic hydrolysis were investigated with a rapid microassay method. The microplate method gave considerable time and cost savings compared to the traditional assay protocol, and it is applicable to a broad range of lignocellulosic substrates.

  8. Rapid and precise measurement of serum branched-chain and aromatic amino acids by isotope dilution liquid chromatography tandem mass spectrometry.

    Directory of Open Access Journals (Sweden)

    Ruiyue Yang

    Full Text Available BACKGROUND: Serum branched-chain and aromatic amino acids (BCAAs and AAAs have emerged as predictors for the future development of diabetes and may aid in diabetes risk assessment. However, the current methods for the analysis of such amino acids in biological samples are time consuming. METHODS: An isotope dilution liquid chromatography tandem mass spectrometry (ID-LC/MS/MS method for serum BCAAs and AAAs was developed. The serum was mixed with isotope-labeled BCAA and AAA internal standards and the amino acids were extracted with acetonitrile, followed by analysis using LC/MS/MS. The LC separation was performed on a reversed-phase C18 column, and the MS/MS detection was performed via the positive electronic spray ionization in multiple reaction monitoring mode. RESULTS: Specific analysis of the amino acids was achieved within 2 min. Intra-run and total CVs for the amino acids were less than 2% and 4%, respectively, and the analytical recoveries ranged from 99.6 to 103.6%. CONCLUSION: A rapid and precise method for the measurement of serum BCAAs and AAAs was developed and may serve as a quick tool for screening serum BCAAs and AAAs in studies assessing diabetes risk.

  9. Production of organic acids in an immobilized cell reactor using ...

    African Journals Online (AJOL)

    Immobilized cell reactor (ICR) was developed as a novel bioreactor to convert hydrolyzed sugars to organic acids. Sugar fermentation by Propionibacterium acid-propionici entraped by calcium alginate was carried out in continuous mode to produce propionic and acetic acids. In continuous fermentation, more than 90 ...

  10. Nitric-phosphoric acid oxidation of solid and liquid organic materials

    International Nuclear Information System (INIS)

    Pierce, R.A.; Smith, J.R.; Poprik, D.C.

    1995-01-01

    Nitric-phosphoric acid oxidation has been developed specifically to address issues that face the Savannah River Site, other defense-related facilities, private industry, and small-volume generators such as university and medical laboratories. Initially tested to destroy and decontaminate SRS solid, Pu-contaminated job-control waste, the technology has also exhibited potential for remediating hazardous and mixed-hazardous waste forms. The process is unique to Savannah River and offers a valuable alternative to other oxidation processes that require extreme temperatures and/or elevated pressures. To address the broad categories of waste, many different organic compounds which represent a cross-section of the waste that must be treated have been successfully oxidized. Materials that have been quantitatively oxidized at atmospheric pressure below 180 degrees C include neoprene, cellulose, EDTA, tributylphosphate, and nitromethane. More stable compounds such as benzoic acid, polyethylene, oils, and resins have been completely decomposed below 200 degrees C and 10 psig. The process uses dilute nitric acid in a concentrated phosphoric acid media as the main oxidant for the organic compounds. Phosphoric acid allow nitric acid to be retained in solution well above its normal boiling point. The reaction forms NOx vapors which can be reoxidized and recycled using air and water. The addition of 0.001M Pd(II) reduces CO generation to near 1% of the released carbon gases. The advantages of this process are that it is straightforward, uses relatively inexpensive reagents, operates at relatively low temperature and pressure, and produces final solutions which are compatible with stainless steel equipment. For organic wastes, all carbon, hydrogen, and nitrogen are converted to gaseous products. If interfaced with an acid recovery system which converts NOx back to nitric acid, the net oxidizer would be oxygen from air

  11. Modeling the influence of organic acids on soil weathering

    Science.gov (United States)

    Lawrence, Corey R.; Harden, Jennifer W.; Maher, Kate

    2014-01-01

    Biological inputs and organic matter cycling have long been regarded as important factors in the physical and chemical development of soils. In particular, the extent to which low molecular weight organic acids, such as oxalate, influence geochemical reactions has been widely studied. Although the effects of organic acids are diverse, there is strong evidence that organic acids accelerate the dissolution of some minerals. However, the influence of organic acids at the field-scale and over the timescales of soil development has not been evaluated in detail. In this study, a reactive-transport model of soil chemical weathering and pedogenic development was used to quantify the extent to which organic acid cycling controls mineral dissolution rates and long-term patterns of chemical weathering. Specifically, oxalic acid was added to simulations of soil development to investigate a well-studied chronosequence of soils near Santa Cruz, CA. The model formulation includes organic acid input, transport, decomposition, organic-metal aqueous complexation and mineral surface complexation in various combinations. Results suggest that although organic acid reactions accelerate mineral dissolution rates near the soil surface, the net response is an overall decrease in chemical weathering. Model results demonstrate the importance of organic acid input concentrations, fluid flow, decomposition and secondary mineral precipitation rates on the evolution of mineral weathering fronts. In particular, model soil profile evolution is sensitive to kaolinite precipitation and oxalate decomposition rates. The soil profile-scale modeling presented here provides insights into the influence of organic carbon cycling on soil weathering and pedogenesis and supports the need for further field-scale measurements of the flux and speciation of reactive organic compounds.

  12. Chemical effects associated to (n, γ) nuclear reactions in diluted aqueous solutions of liquid or frozen organic halogenides

    International Nuclear Information System (INIS)

    Bermudez Rodriguez, I.M.

    1985-09-01

    Chemical effects associated to nuclear transformation 37 Cl (n, γ) 38 Cl or 127 I (n, γ) 128 I in solid or liquid aqueous solutions of ethyl iodide, trichloro-ethylene, thyroxine or DDT irradiated in a nuclear reactor are studied. The retention of radiohalogen under its initial chemical shape decrease with solute concentration in liquid phase but is almost constant with solute dilution in the solid phase. Potential applications in neutron activation analysis evidencing halogenated molecules in irradiated media are discussed. 57 refs [fr

  13. pH effect on the enthalpy of dilution and volumetric properties of protocatechuic acid at T = 298.15 K

    International Nuclear Information System (INIS)

    Zheng, Yan; Liu, Min; Wang, Yong; Wang, Chunmei; Sun, Dezhi; Wang, Bingquan

    2014-01-01

    Graphical abstract: The dilution thermal power of PCA in potassium phosphate buffer solutions at different pHs and apparent molar volumes were determined in order to investigate the interactions of PCA with the coexistent spicies. - Highlights: • Enthalpies of dilution and apparent molar volumes of PCA in PBS at different pHs were measured. • Enthalpic interaction coefficients, limiting partial molar volumes and experimental slopes of PCA were determined. • The pH dependence of the weak interactions in the investigated system was obtained. • (Solute + solvent) interactions and structure making/breaking ability of solutes in the given system were discussed. - Abstract: The enthalpies of dilution of protocatechuic acid, a natural anti-cancer substance, in sodium phosphate and potassium phosphate buffer solutions with different pH values were measured by using a mixing-flow microcalorimeter at T = 298.15 K. Densities of the pseudo binary system (phosphate buffer + protocatechuic acid) were also measured with a quartz vibrating-tube densimeter. The enthalpic interaction coefficients (h 2 , h 3 and h 4 ) were computed according to the McMillan–Mayer model. Apparent molar volumes of the system were calculated from the data of densities, which have been used to deduce limiting partial molar volumes (V ϕ 0 ) of protocatechuic acid at different pH values. The aim of the experiments and data process is to investigate the interaction between the molecules of the important drug and that of the drug molecule with coexistent species in aqueous solutions as well as the influences on these interactions of such factors as pH and ion strength. Change trends of the enthalpic pair wise interaction coefficient h 2 and V ϕ 0 of protocatechuic acid with pH increasing in the both phosphate buffer solutions were obtained. The thermodynamic properties, h 2 and V ϕ 0 in potassium phosphate buffer solutions were compared with those in sodium phosphate buffer solutions at

  14. Direct Capture of Organic Acids From Fermentation Media Using Ionic Liquids

    Energy Technology Data Exchange (ETDEWEB)

    Klasson, K.T.

    2004-11-03

    Several ionic liquids have been investigated for the extraction of organic acids from fermentation broth. Partitioning of representative organic acids (lactic, acetic, and succinic) between aqueous solution and nine hydrophobic ionic liquids was measured. The extraction efficiencies were strongly dependent on pH of the aqueous phase. Distribution coefficient was very good (approximately 60) at low succinic acid concentrations for one of the ionic liquids (trihexyltetradecylphosphonium methanesulfonate) at neutral pH. However, this ionic liquid had to be diluted with nonanol due to its high viscosity in order to be useful. A diluent (trioctylamine) was also added to this mixture. The results suggest that an extraction system based on ionic liquids may be feasible for succinic acid recovery from fermentation broth and that two ideal extraction stages are needed to reduce the concentration from 33 g/L to 1 g/L of succinic acid. Further studies are needed to evaluate other issues related to practical applications, including ionic liquid loss in the process, toxicity effects of ionic liquids during simultaneous fermentation and extractions.

  15. Technical note: Measurement of mammary plasma flow in sows by downstream dilution of mammary vein infused para-aminohippuric acid

    DEFF Research Database (Denmark)

    Larsen, Uffe Krogh; Storm, Adam Christian; Theil, Peter Kappel

    2016-01-01

    catheter was surgically implanted in the femoral artery, and another 2 were inserted in the right cranial mammary vein of 8 second- and third-parity sows on d 76 ± 2 SEM of gestation. On the 3rd and 17th days in milk, arterial and venous blood samples were drawn in hourly intervals from 0.5 h before until...... 6.5 h after feeding. The MPF in the right cranial mammary vein was measured by downstream dilution of infused pAH (3.0 mmol/h). Total MPF-pAH was calculated assuming that the measured flow constituted the flow from 5 out of 14 suckled glands on the basis of the anatomical structure of the mammary...

  16. Unique Dispersal of the Changjiang-Diluted Water Plume in the East China Sea Revealed from Satellite Monitoring of Colored Dissolved Organic Matter (CDOM)

    OpenAIRE

    Hiroaki Sasaki; Yasushi Gomi; Takamasa Asai; Masashi Shibata; Yoko Kiyomoto; Kazumaro Okamura; Kou Nishiuchi; Toru Hasegawa; Haruya Yamada

    2014-01-01

    The optical properties of colored dissolved organic matter (CDOM) in the Changjiang (Yangtze River) plume water were investigated during the summer of 2009 and 2010. The absorption coefficient of CDOM at 325 nm (aCDOM) increased inversely with decreasing sea-surface salinity (SSS), implying that aCDOM can be used as a natural tracer of Changjiang-diluted water (CDW). This aCDOM vs. SSS relationship, however, differed between 2009 and 2010. For mapping the CDW plume, the aCDOM was retrieved fr...

  17. Dilution of 210Pb by organic sedimentation in lakes of different trophic states, and application to studies of sediment-water interactions

    International Nuclear Information System (INIS)

    Binford, M.W.; Brenner, M.

    1986-01-01

    Lake sediments reflect conditions in the water column and can be used for rapid, integrative measurements of limnological variables. Examination of 210 Pb-dated cores from 12 Florida lakes of widely differing trophic state (expressed as Carlson's trophic state index: TSI) shows that net accumulation rate of organic matter is related to primary productivity in the water column. In 26 other lakes the activity of unsupported 210 Pb g -1 organic matter in surficial sediments is inversely related to trophic state and, therefore, to organic accumulation rate. From this observation, the authors develop a new method that uses fallout 210 Pb as a dilution tracer to calculate net sedimentary accumulation rates of any material in surface mud. They demonstrate strong relationships between net loss rate of biologically important materials (C, N, P, and pigments) and their respective water concentrations (expressed as TSI). Multiple regression models incorporating net sediment accumulation rates of all four variables explain up to 70% of the lake-to-lake variation of TSI. The 210 Pb-dilution method has application for studies for material cycling, paleolimnology, and sediment accumulation processes

  18. Production of Valuables Organic Acids from Organic Wastes with Hydrothermal Treatment Process

    Directory of Open Access Journals (Sweden)

    Muhammad Faisal

    2009-06-01

    Full Text Available This article reports production of valuables organic acids from the hydrothermal treatment of representative organic wastes and compounds (i. e. domestic sludge, proteinaceous, cellulosic and plastic wastes with or without oxidant (H2O2. Organic acids such as acetic, formic, propionic, succinic and lactic acids were obtained in significant amounts. At 623 K (16.5 MPa, acetic acid of about 26 mg/g-dry waste fish entrails was obtained. This increased to 42 mg/g dry waste fish entrails in the presence of H2O2. Experiments on glucose to represent cellulosic wastes were also carried out, getting acetic acid of about 29 mg/g-glucose. The study was extended to terephthalic acid and glyceraldehyde, reaction intermediates of hydrothermal treatment of PET plastic wastes and glucose, respectively. Studies on temperature dependence of formation of organic acids showed thermal stability of acetic acid, whereas, formic acid decomposed readily under hydrothermal conditions. In general, results demonstrated that the presence of oxidants favored formation of organic acids with acetic acid being the major product. Keywords: hydrothermal treatment, organic acids, organic wastes, oxidant, supercritical water oxidation

  19. A Cumulative Spore Killing Approach: Synergistic Sporicidal Activity of Dilute Peracetic Acid and Ethanol at Low pH Against Clostridium difficile and Bacillus subtilis Spores.

    Science.gov (United States)

    Nerandzic, Michelle M; Sankar C, Thriveen; Setlow, Peter; Donskey, Curtis J

    2016-01-01

    Background.  Alcohol-based hand sanitizers are the primary method of hand hygiene in healthcare settings, but they lack activity against bacterial spores produced by pathogens such as Clostridium difficile and Bacillus anthracis. We previously demonstrated that acidification of ethanol induced rapid sporicidal activity, resulting in ethanol formulations with pH 1.5-2 that were as effective as soap and water washing in reducing levels of C difficile spores on hands. We hypothesized that the addition of dilute peracetic acid (PAA) to acidified ethanol would enhance sporicidal activity while allowing elevation of the pH to a level likely to be well tolerated on skin (ie, >3). Methods.  We tested the efficacy of acidified ethanol solutions alone or in combination with PAA against C difficile and Bacillus subtilis spores in vitro and against nontoxigenic C difficile spores on hands of volunteers. Results.  Acidification of ethanol induced rapid sporicidal activity against C difficile and to a lesser extent B subtilis. The addition of dilute PAA to acidified ethanol resulted in synergistic enhancement of sporicidal activity in a dose-dependent fashion in vitro. On hands, the addition of 1200-2000 ppm PAA enhanced the effectiveness of acidified ethanol formulations, resulting in formulations with pH >3 that were as effective as soap and water washing. Conclusions.  Acidification and the addition of dilute PAA induced rapid sporicidal activity in ethanol. Our findings suggest that it may be feasible to develop effective sporicidal ethanol formulations that are safe and tolerable on skin.

  20. Formation, aggregation and reactivity of amorphous ferric oxyhydroxides on dissociation of Fe(III)-organic complexes in dilute aqueous suspensions

    Science.gov (United States)

    Bligh, Mark W.; Waite, T. David

    2010-10-01

    While chemical reactions that take place at the surface of amorphous ferric oxides (AFO) are known to be important in aquatic systems, incorporation of these reactions into kinetic models is hindered by a lack of ability to reliably quantify the reactivity of the surface and the changes in reactivity that occur over time. Long term decreases in the reactivity of iron oxides may be considered to result from changes in the molecular structure of the solid, however, over shorter time scales where substantial aggregation may occur, the mechanisms of reactivity loss are less clear. Precipitation of AFO may be described as a combination of homogeneous and heterogeneous reactions, however, despite its potentially significant role, the latter reaction is usually neglected in kinetic models of aquatic processes. Here, we investigate the role of AFO in scavenging dissolved inorganic ferric (Fe(III)) species (Fe') via the heterogeneous precipitation reaction during the net dissociation of organically complexed Fe(III) in seawater. Using sulfosalicylic acid (SSA) as a model ligand, AFO was shown to play a significant role in inducing the net dissociation of the Fe-SSA complexes with equations describing both the heterogeneous precipitation reaction and the aging of AFO being required to adequately describe the experimental data. An aggregation based mechanism provided a good description of AFO aging over the short time scale of the experiments. The behaviour of AFO described here has implications for the bioavailability of iron in natural systems as a result of reactions involving AFO which are recognised to occur over time scales of minutes, including adsorption of Fe' and AFO dissolution, precipitation and ageing.

  1. Activity coefficients at infinite dilution and physicochemical properties for organic solutes and water in the ionic liquid 1-(2-hydroxyethyl)-3-methylimidazolium trifluorotris(perfluoroethyl)phosphate

    International Nuclear Information System (INIS)

    Marciniak, Andrzej; Wlazło, Michał

    2013-01-01

    Highlights: • γ ∞ and K L for 65 solutes in the IL [C 2 OHmim][FAP] were determined by IGC. • Partial molar thermodynamics functions ΔG 1 E,∞ , ΔH 1 E,∞ and ΔS 1 E,∞ were calculated. • Selectivities and capacities for alkanes/thiophene separation problems were calculated. • LFER system constants as a function of T for [C 2 OHmim][FAP] were calculated. • Results were compared to other ILs based on the same cation and anion. -- Abstract: This work presents new data of activity coefficients at infinite dilution, γ ∞ of different organic solutes and water in the 1-(2-hydroxyethyl)-3-methylimidazolium trifluorotris(perfluoroethyl)phosphate, [C 2 OHmim][FAP] ionic liquid. Values of γ ∞ were determined for 65 organic solutes, including alkanes, alkenes, alkynes, cycloalkanes, aromatic hydrocarbons, alcohols, thiophene, ethers, ketones, esters, 1-nitropropane, aldehydes, acetonitrile and water by inverse gas chromatography within the temperature range from (318.15 to 368.15) K. The basic thermodynamic functions, such as partial molar excess Gibbs energies, ΔG 1 E,∞ , enthalpies, ΔH 1 E,∞ and entropies, ΔS 1 E,∞ at infinite dilution were calculated from the experimental γ ∞ values obtained over the temperature range. Additionally the gas–liquid partition coefficients, K L were determined. Experimental values of gas–liquid partition coefficients were used to determine the coefficients in the Abraham solvation parameter model (LFER). Results are compared to previously investigated ionic liquids with the same [C 2 OHmim] + cation and [FAP] − anion. The selectivity and capacity at infinite dilution for alkanes/thiophene extraction problems were calculated from experimental γ ∞ values to verify the possibility of investigated ionic liquid as an entrainer in liquid–liquid extraction

  2. Effect of acidic seed on biogenic secondary organic aerosol growth

    Science.gov (United States)

    Czoschke, Nadine M.; Jang, Myoseon; Kamens, Richard M.

    Secondary organic aerosol (SOA) growth in the presence of acid aerosols was studied in twin 500 l Teflon bags and in a 4 m flow reactor. In Teflon bags, isoprene, acrolein and α-pinene were all made to react individually with ozone and exposed to either acid or non-acid inorganic seed aerosols to determine the effect of acid-catalyzed heterogeneous reactions on SOA growth. α-Pinene and ozone were made to react in a flow reactor to assess the immediate effect of mixing an acid aerosol with SOA at high and low relative humidity levels. In all cases, exposure to acid seed aerosol increased the amount of SOA mass produced. Fourier transform infrared spectra of the SOA in acid systems confirmed the transformation of carbonyl functional groups through acid-catalyzed heterogeneous reactions when SOAs formed in acidic environments or were exposed to acidic aerosols. Organic products initially produced from ozonation in the gas phase partition onto the inorganic seed aerosol and react heterogeneously with an acid catalyst forming low vapor pressure products. These acid-catalyzed heterogeneous reactions are implicated in generating the increased SOA mass observed in acidic aerosol systems as they transform predominantly gas phase compounds of high volatility into low vapor pressure predominantly particle phase products.

  3. Reactive Distillation for Esterification of Bio-based Organic Acids

    Energy Technology Data Exchange (ETDEWEB)

    Fields, Nathan; Miller, Dennis J.; Asthana, Navinchandra S.; Kolah, Aspi K.; Vu, Dung; Lira, Carl T.

    2008-09-23

    The following is the final report of the three year research program to convert organic acids to their ethyl esters using reactive distillation. This report details the complete technical activities of research completed at Michigan State University for the period of October 1, 2003 to September 30, 2006, covering both reactive distillation research and development and the underlying thermodynamic and kinetic data required for successful and rigorous design of reactive distillation esterification processes. Specifically, this project has led to the development of economical, technically viable processes for ethyl lactate, triethyl citrate and diethyl succinate production, and on a larger scale has added to the overall body of knowledge on applying fermentation based organic acids as platform chemicals in the emerging biorefinery. Organic acid esters constitute an attractive class of biorenewable chemicals that are made from corn or other renewable biomass carbohydrate feedstocks and replace analogous petroleum-based compounds, thus lessening U.S. dependence on foreign petroleum and enhancing overall biorefinery viability through production of value-added chemicals in parallel with biofuels production. Further, many of these ester products are candidates for fuel (particularly biodiesel) components, and thus will serve dual roles as both industrial chemicals and fuel enhancers in the emerging bioeconomy. The technical report from MSU is organized around the ethyl esters of four important biorenewables-based acids: lactic acid, citric acid, succinic acid, and propionic acid. Literature background on esterification and reactive distillation has been provided in Section One. Work on lactic acid is covered in Sections Two through Five, citric acid esterification in Sections Six and Seven, succinic acid in Section Eight, and propionic acid in Section Nine. Section Ten covers modeling of ester and organic acid vapor pressure properties using the SPEAD (Step Potential

  4. Determination of Glyphosate, its Degradation Product Aminomethylphosphonic Acid, and Glufosinate, in Water by Isotope Dilution and Online Solid-Phase Extraction and Liquid Chromatography/Tandem Mass Spectrometry

    Science.gov (United States)

    Meyer, Michael T.; Loftin, Keith A.; Lee, Edward A.; Hinshaw, Gary H.; Dietze, Julie E.; Scribner, Elisabeth A.

    2009-01-01

    The U.S. Geological Survey method (0-2141-09) presented is approved for the determination of glyphosate, its degradation product aminomethylphosphonic acid (AMPA), and glufosinate in water. It was was validated to demonstrate the method detection levels (MDL), compare isotope dilution to standard addition, and evaluate method and compound stability. The original method USGS analytical method 0-2136-01 was developed using liquid chromatography/mass spectrometry and quantitation by standard addition. Lower method detection levels and increased specificity were achieved in the modified method, 0-2141-09, by using liquid chromatography/tandem mass spectrometry (LC/MS/MS). The use of isotope dilution for glyphosate and AMPA and pseudo isotope dilution of glufosinate in place of standard addition was evaluated. Stable-isotope labeled AMPA and glyphosate were used as the isotope dilution standards. In addition, the stability of glyphosate and AMPA was studied in raw filtered and derivatized water samples. The stable-isotope labeled glyphosate and AMPA standards were added to each water sample and the samples then derivatized with 9-fluorenylmethylchloroformate. After derivatization, samples were concentrated using automated online solid-phase extraction (SPE) followed by elution in-line with the LC mobile phase; the compounds separated and then were analyzed by LC/MS/MS using electrospray ionization in negative-ion mode with multiple-reaction monitoring. The deprotonated derivatized parent molecule and two daughter-ion transition pairs were identified and optimized for glyphosate, AMPA, glufosinate, and the glyphosate and AMPA stable-isotope labeled internal standards. Quantitative comparison between standard addition and isotope dilution was conducted using 473 samples analyzed between April 2004 and June 2006. The mean percent difference and relative standard deviation between the two quantitation methods was 7.6 plus or minus 6.30 (n = 179), AMPA 9.6 plus or minus 8

  5. Use of Gelidium amansii as a promising resource for bioethanol: a practical approach for continuous dilute-acid hydrolysis and fermentation.

    Science.gov (United States)

    Park, Jeong-Hoon; Hong, Ji-Yeon; Jang, Hyun Chul; Oh, Seung Geun; Kim, Sang-Hyoun; Yoon, Jeong-Jun; Kim, Yong Jin

    2012-03-01

    A facile continuous method for dilute-acid hydrolysis of the representative red seaweed species, Gelidium amansii was developed and its hydrolysate was subsequently evaluated for fermentability. In the hydrolysis step, the hydrolysates obtained from a batch reactor and a continuous reactor were systematically compared based on fermentable sugar yield and inhibitor formation. There are many advantages to the continuous hydrolysis process. For example, the low melting point of the agar component in G. amansii facilitates improved raw material fluidity in the continuous reactor. In addition, the hydrolysate obtained from the continuous process delivered a high sugar and low inhibitor concentration, thereby leading to both high yield and high final ethanol titer in the fermentation process. Copyright © 2011 Elsevier Ltd. All rights reserved.

  6. Study of corrosion susceptibility of stainless steel-304 and stainless steel-316 under mechanical stress in diluted boiling nitric acid with chlorides

    International Nuclear Information System (INIS)

    Desjardins, D.; Puiggali, M.; El Kheloui, A.; Petit, M.C.; Clement, C.; Berge, J.P.

    1991-01-01

    A detailed study of corrosion of stressed 304 and 316 stainless steels in boiling solutions of diluted nitric acid in presence of chloride is presented. After a chemical study of the electrolyte, the different kinds of corrosion observed are represented on HNO 3 concentration - Cl - concentration diagrams. A more fundamental study based on several electrochemical techniques (forward scan and return potentiodynamic curves, potentiokinetic curves with different scan rates, sample depassivation by rapid straining under potentiostatic control) is carried out. The results allow to confirm the observations and to explain them in terms of competition between anodic dissolution, depassivation, repassivation processes with a precise analyze of the role of the solution and of the mechanical stress [fr

  7. Performance and techno-economic assessment of several solid-liquid separation technologies for processing dilute-acid pretreated corn stover.

    Science.gov (United States)

    Sievers, David A; Tao, Ling; Schell, Daniel J

    2014-09-01

    Solid-liquid separation of pretreated lignocellulosic biomass slurries is a critical unit operation employed in several different processes for production of fuels and chemicals. An effective separation process achieves good recovery of solute (sugars) and efficient dewatering of the biomass slurry. Dilute acid pretreated corn stover slurries were subjected to pressure and vacuum filtration and basket centrifugation to evaluate the technical and economic merits of these technologies. Experimental performance results were used to perform detailed process simulations and economic analysis using a 2000 tonne/day biorefinery model to determine differences between the various filtration methods and their process settings. The filtration processes were able to successfully separate pretreated slurries into liquor and solid fractions with estimated sugar recoveries of at least 95% using a cake washing process. A continuous vacuum belt filter produced the most favorable process economics. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Hydrolysis of Miscanthus for bioethanol production using dilute acid presoaking combined with wet explosion pre-treatment and enzymatic treatment

    DEFF Research Database (Denmark)

    Sørensen, Annette; Teller, Philip Johan; Hilstrøm, Troels

    2008-01-01

    xylose prior to wet explosion. The acid presoaking extracted 63.2% xylose and 5.2% glucose. Direct enzymatic hydrolysis of the presoaked biomass was found to give only low sugar yields of 24-26% glucose. Wet explosion is a pre-treatment method that combines wet-oxidation and steam explosion. The effect...... of wet explosion on non-presoaked and presoaked Miscanthus was investigated using both atmospheric air and hydrogen peroxide as the oxidizing agent. All wet explosion pre-treatments showed to have a disrupting effect on the lignocellulosic biomass, making the sugars accessible for enzymatic hydrolysis......Miscanthus is a high yielding bioenergy crop. In this study we used acid presoaking, wet explosion, and enzymatic hydrolysis to evaluate the combination of the different pre-treatment methods for bioethanol production with Miscanthus. Acid presoaking is primarily carried out in order to remove...

  9. Use of organic acids in acne and skin discolorations therapy

    Directory of Open Access Journals (Sweden)

    Alicja Kapuścińska

    2015-03-01

    Full Text Available Acne is one of the most frequent skin disorders that occurs in puberty, but often adults also have acne. The most important factors responsible for acne are elevated production of sebum by hyperactive sebaceous glands and blockage of the follicle because of hyperkeratosis [14]. The third etiopathogenic factor of acne is excessive microflora reproduction [8]. The most significant bacterium that is responsible for formation of skin lesions is Propionibacterium acnes, a rod-shaped Gram-positive and aerotolerant anaerobic bacterium. It is estimated that P. acnes is responsible for acne in approximately 80% of people aged 11 to 30 [27,40]. Even healed skin lesions can often cause skin discolorations and scar formation [51]. Exfoliating chemical substances that are commonly used in dermatology and cosmetology are organic acids. Exfoliating treatment using organic acids is called “chemical peeling” and consists of controlled application of those substances on the skin [38]. The depth of exfoliation depends on organic acid concentration, type of substance and contact time with the skin [41]. Using exfoliating agents seems to be helpful in excessive keratinization – one of several factors responsible for acne. Moreover, epidermis exfoliation is a popular method of removing skin discoloration [22]. Considering chemical structure, exfoliating substances that are most often used in cosmetology contain alpha-hydroxyacids (glycolic acid, lactic acid, mandelic acid and citric acid, beta-hydroxyacids (salicylic acid and other organic acids, such as trichloroacetic acid and pyruvic acid [47]. In this article, a literature review of use of organic acids in acne and skin discoloration therapy is presented.

  10. Aspartic acid interaction with cobalt(II) in dilute aqueous solution: A {sup 57}Co emission Moessbauer spectroscopic study

    Energy Technology Data Exchange (ETDEWEB)

    Kamnev, Alexander A.; Tugarova, Anna V. [Institute of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Sciences (Russian Federation); Kovacs, Krisztina; Homonnay, Zoltan, E-mail: homonnay@ludens.elte.hu; Kuzmann, Erno; Vertes, Attila [Eoetvoes Lorand University, Institute of Chemistry (Hungary)

    2012-03-15

    Emission ({sup 57}Co) Moessbauer spectra of the aspartic acid-{sup 57}CoCl{sub 2} system were measured at T = 80 K in frozen aqueous solution and in the form of a dried residue of this solution. The Moessbauer spectra, besides a weak contribution from after-effects, showed two Fe{sup 2 + }/Co{sup 2 + } components which were ascribed to octahedrally and tetrahedrally coordinated {sup 57}Co{sup II} microenvironments in the Asp-cobalt(II) complex. This dual coordination mode may be due to the involvement of the second terminal carboxylic group of aspartic acid in the coordination sphere of Co.

  11. Differential Mobility-Mass Spectrometry Double Spike Isotope Dilution Study of Release of β-Methylaminoalanine and Proteinogenic Amino Acids during Biological Sample Hydrolysis.

    Science.gov (United States)

    Beach, Daniel G; Kerrin, Elliott S; Giddings, Sabrina D; Quilliam, Michael A; McCarron, Pearse

    2018-01-08

    The non-protein amino acid β-methylamino-L-alanine (BMAA) has been linked to neurodegenerative disease and reported throughout the environment. Proposed mechanisms of bioaccumulation, trophic transfer and chronic toxicity of BMAA rely on the hypothesis of protein misincorporation. Poorly selective methods for BMAA analysis have led to controversy. Here, a recently reported highly selective method for BMAA quantitation using hydrophilic interaction liquid chromatography-differential mobility spectrometry-tandem mass spectrometry (HILIC-DMS-MS/MS) is expanded to include proteinogenic amino acids from hydrolyzed biological samples. For BMAA quantitation, we present a double spiking isotope dilution approach using D 3 -BMAA and 13 C 15 N 2 -BMAA. These methods were applied to study release of BMAA during acid hydrolysis under a variety of conditions, revealing that the majority of BMAA can be extracted along with only a small proportion of protein. A time course hydrolysis of BMAA from mussel tissue was carried out to assess the recovery of BMAA during sample preparation. The majority of BMAA measured by typical methods was released before a significant proportion of protein was hydrolyzed. Little change was observed in protein hydrolysis beyond typical hydrolysis times but the concentration of BMAA increased linearly. These findings demonstrate protein misincorporation is not the predominant form of BMAA in cycad and shellfish.

  12. Pretreatment of wheat straw by nonionic surfactant-assisted dilute acid for enhancing enzymatic hydrolysis and ethanol production.

    Science.gov (United States)

    Qi, Benkun; Chen, Xiangrong; Wan, Yinhua

    2010-07-01

    Pretreating wheat straw (WS) with combined use of varied sulfuric acid concentration (0-3%, w/v) and Tween 20 concentration (0-1%) was investigated in an attempt to enhance the hydrolysis and fermentability of pretreated WS. Enzymatic hydrolysis yield of glucan and xylan and ethanol production by simultaneous saccharification and fermentation (SSF) of water-insoluble solids (WIS) were significantly affected by the amount of Tween 20 added during acid pretreatment. Any further addition of Tween 20 in either hydrolysis stage or fermentation stage only led to small increase in glucan conversion and ethanol production. Determination of adsorption of cellulases during hydrolysis showed that Tween 20-assisted acid treated straw solution contained more free cellulases than individual acid treated straw solution, indicating that modification of lignin surface by Tween 20 added during pretreatment likely occurred. In addition, the effects of pretreatment conditions on overall recovery of glucose and xylose after pretreatment and enzymatic hydrolysis were also investigated. Copyright 2010 Elsevier Ltd. All rights reserved.

  13. Thermodynamics and activity coefficients at infinite dilution for organic solutes and water in the ionic liquid 1-butyl-1-methylmorpholinium tricyanomethanide

    International Nuclear Information System (INIS)

    Domańska, Urszula; Lukoshko, Elena Vadimovna

    2014-01-01

    Highlights: • Measurements of activity coefficients at infinite dilution using GLC. • Sixty one organic solvents in the ionic liquid 1-butyl-1-methylmorpholinium tricyanomethanide. • High selectivity for heptane/thiophene, or pyridine, or 1-nitropropane. • The excess thermodynamic functions and the gas–liquid partition coefficients were presented. • Possible entrainer for the extraction of sulphur and nitrogen-compounds from alkanes. -- Abstract: The activity coefficients at infinite dilution, γ 13 ∞ , for 61 solutes, including alkanes, cycloalkanes, alkenes, alkynes, aromatic hydrocarbons, alcohols, water, thiophene, ethers, ketones, esters, aldehyde, acetonitrile, pyridine and 1-nitropropane in the ionic liquid (IL) 1-butyl-1-methylmorpholinium tricyanomethanide, [BMMOR][TCM] were determined by gas–liquid chromatography at six temperatures within the range of (318.15 to 368.15) K. The thermodynamic functions at infinite dilution as partial molar excess Gibbs free energy ΔG 1 E,∞ , enthalpy ΔH 1 E,∞ , and entropy term T ref ΔS 1 E,∞ were calculated from the experimental γ 13 ∞ values obtained over the temperature range. The density of [BMMOR][TCM] was measured over the temperature range (288.15 to 368.15) K. The gas–liquid partition coefficient K L was calculated for all solutes. The values of selectivity and capacity for a few separation problems such as hexane/benzene, cyclohexane/benzene, heptane/thiophene at T = 328.15 K were calculated from γ 13 ∞ and compared to literature values for similar ionic liquids, viz. N-methyl-2-pyrrolidinone (NMP), and sulfolane. In comparison with the previously measured values for [BMPYR][TCM], the morpholinium IL presents high selectivity for the separation of aromatic hydrocarbons from aliphatic hydrocarbons, and especially thiophene, or piridine from heptane with a slightly lower capacity. New data show that [BMMOR][TCM] IL may be proposed as an alternative solvent for the separation of

  14. Measurements of activity coefficients at infinite dilution for organic solutes and water in the ionic liquid 1-butyl-1-methylpyrrolidinium tricyanomethanide

    International Nuclear Information System (INIS)

    Domańska, Urszula; Lukoshko, Elena Vadimovna

    2013-01-01

    Highlights: • Measurements of activity coefficients at infinite dilution using GLC. • 62 organic solvents and water in the ionic liquid 1-butyl-1-methylpyrrolidinium tricyanomethanide. • High capacity for thiophene, 1.37 at T = 328.15 K. • Possible entrainer for extraction of sulfur, or nitrogen compounds from fuels. • The excess thermodynamic functions and the gas–liquid partition coefficients were calculated. -- Abstract: The activity coefficients at infinite dilution, γ 13 ∞ , for 62 solutes, including alkanes, cycloalkanes, alkenes, alkynes, aromatic hydrocarbons, alcohols, water, thiophene, ethers, ketones, acetonitrile, pyridine and 1-nitropropane in the ionic liquid 1-butyl-1-methylpyrrolidinium tricyanomethanide, [BMPYR][TCM] were determined by gas–liquid chromatography at six temperatures over the range of (318.15 to 368.15) K. The partial molar excess Gibbs free energy, ΔG 1 E ∞, enthalpy ΔH 1 E ∞, and entropy term T ref ΔS 1 E ,∞ at infinite dilution were calculated from the experimental γ 13 ∞ values obtained over the temperature range. The densities of [BMPYR][TCM] were measured within temperature range from 318.15 K to 368.15 K. The gas–liquid partition coefficients, K L were calculated for all solutes. The values of selectivity for few separation problems as hexane/benzene, cyclohexane/benzene, heptane/thiophene were calculated from γ 13 ∞ and compared to literature values for N-methyl-2-pyrrolidinone (NMP), sulfolane, and other ionic liquids based on [BMPYR] + cation. In comparison with the former measured ILs, [BMPYR][TCM] present quite high selectivity for the separation of aromatic hydrocarbons and aliphatics hydrocarbons, an average capacity for benzene. The data presented here shows that [BMPYR][TCM] ionic liquid can be used as an alternative solvent for the separation of thiophene from the aliphatic hydrocarbons

  15. Impacts of the Changjiang diluted water on sinking processes of particulate organic matters in the East China Sea

    Science.gov (United States)

    Sukigara, Chiho; Mino, Yoshihisa; Tripathy, Sarat Chandra; Ishizaka, Joji; Matsuno, Takeshi

    2017-12-01

    Intensive surveys with repeated CTD and microstructure turbulent observations, water and sediments sampling as well as onboard incubation and sediment trap experiments were conducted to reveal the nitrogen budget in the center of the East China Sea (ECS) during July 2010 and 2011. Low salinity water (Changjiang Diluted Water, CDW) covered the study area in 2010, but not in 2011. Higher chlorophyll a (chl. a) concentration, primary productivity, and downward particle flux in the upper layer were observed in 2010 than those in 2011. Existence of the CDW resulted in a steep pycnocline and an associated subsurface chl. a maximum (SCM) layer directly beneath the CDW. From chemical analyses of particulate carbon and nitrogen contents and isotope ratios, it became apparent that the particles sunk out the euphotic zone in 2010 was primarily originated in the CDW layer and secondly in the SCM layer. Whereas, in 2011, sinking particles were originated in the surface layer but a part of them were decomposed in the bottom of pycnocline. Our findings indicate that the CDW would supply particles into the deep layer and contribute to the downward transport of materials and the efficiency of biological pump in the ECS.

  16. Acoustic properties of organic acid mixtures in water

    Science.gov (United States)

    Macavei, I.; Petrisor, V.; Auslaender, D.

    1974-01-01

    The variation of the rate of propagation of ultrasounds in organic acid mixtures in water points to structural changes caused by interactions that take place under conditions of thermal agitation, at different acid concentrations. At the same time, a difference is found in the changes in velocity as a function of the length of the carbon chain of the acids in the mixture as a result of their effect on the groups of water molecules associated by hydrogen bonds.

  17. Association mapping of main tomato fruit sugars and organic acids

    Directory of Open Access Journals (Sweden)

    Jiantao Zhao

    2016-08-01

    Full Text Available Association mapping has been widely used to map the significant associated loci responsible for natural variation in complex traits and are valuable for crop improvement. Sugars and organic acids are the most important metabolites in tomato fruits. We used a collection of 174 tomato accessions composed of S. lycopersicum (123 accessions and S. lycopersicum var cerasiforme (51 accessions to detect significantly associated loci controlling the variation of main sugars and organic acids. The accessions were genotyped with 182 SSRs spreading over the tomato genome. Association mapping was conducted on the main sugars and organic acids detected by gas chromatography-mass spectrometer (GC-MS over two years using the mixed linear model (MLM. We detected a total of 58 significantly associated loci (P<0.001 for the 17 sugars and organic acids, including fructose, glucose, sucrose, citric acid, malic acid. These results not only co-localized with several reported QTLs, including fru9.1/PV, suc9.1/PV, ca2.1/HS, ca3.1/PV, ca4.1/PV and ca8.1/PV, but also provided a list of candidate significantly associated loci to be functionally validated. These significantly associated loci could be used for deciphering the genetic architecture of tomato fruit sugars and organic acids and for tomato quality breeding.

  18. Separation and recovery of organic acids from fermented kitchen ...

    African Journals Online (AJOL)

    PRECIOUS

    2009-11-02

    Nov 2, 2009 ... Figure 1 shows the recovery process of organic acids from fermen- ted kitchen waste. ... freezing process was carried out using a deep freezer at -30°C for overnight. .... few factors which affect the production of lactic acid in the.

  19. ORGANIC ACIDS CONCENTRATION IN WINE STOCKS AFTER Saccharomyces cerevisiae FERMENTATION

    Directory of Open Access Journals (Sweden)

    V. N. Bayraktar

    2013-04-01

    Full Text Available The biochemical constituents in wine stocks that influence the flavor and quality of wine are investigated in the paper. The tested parameters consist of volume fraction of ethanol, residual sugar, phenolic compounds, tartaric, malic, citric, lactic, acetic acids, titratable acidity and volatile acids. The wine stocks that were received from white and red grape varieties Tairov`s selection were tested. There was a correlation between titratable acidity and volatile acids in the wine stocks from white and red grape varieties. High correlation was also found between lactic and acetic acids, between volatile acids, acetic acid and sugar. It was determined that wine stocks with a high concentration of ethanol originated from those yeast strains of Saccharomyces cerevisiae, in a fermented grape must of high speed of enzyme activity. The taste of wine stocks correlated with the ratio of tartaric to malic acid. Analysis showed significant differences between the varieties of white and red wine stocks in concentrations of organic acids, phenolic compounds, residual sugar, and volume fraction of ethanol. Positive correlation was indicated for both studied groups for volatile acids and acetic acid, tartaric, malic, lactic acids and total sugar. Prospective yeast cultures with high productivity of alcohol (ethanol were selected for winemaking biotechnology.

  20. Metabolic evolution of Escherichia coli strains that produce organic acids

    Science.gov (United States)

    Grabar, Tammy; Gong, Wei; Yocum, R Rogers

    2014-10-28

    This invention relates to the metabolic evolution of a microbial organism previously optimized for producing an organic acid in commercially significant quantities under fermentative conditions using a hexose sugar as sole source of carbon in a minimal mineral medium. As a result of this metabolic evolution, the microbial organism acquires the ability to use pentose sugars derived from cellulosic materials for its growth while retaining the original growth kinetics, the rate of organic acid production and the ability to use hexose sugars as a source of carbon. This invention also discloses the genetic change in the microorganism that confers the ability to use both the hexose and pentose sugars simultaneously in the production of commercially significant quantities of organic acids.

  1. Effect of isothermal dilution on emission factors of organic carbon and n-alkanes in the particle and gas phases of diesel exhaust

    Science.gov (United States)

    Fujitani, Yuji; Saitoh, Katsumi; Fushimi, Akihiro; Takahashi, Katsuyuki; Hasegawa, Shuich; Tanabe, Kiyoshi; Kobayashi, Shinji; Furuyama, Akiko; Hirano, Seishiro; Takami, Akinori

    2012-11-01

    To investigate the effect of isothermal dilution (30 °C) on emission factors (EFs) of semivolatile and nonvolatile compounds of heavy-duty diesel exhaust, we measured EFs for particulate matter (PM), organic carbon (OC), and elemental carbon (EC) in the particle phase, and EFs for n-alkanes in both the particle phase and the gas phase of exhaust produced under high-idle engine operating conditions at dilution ratios (DRs) ranging from 8 to 1027. The EC EFs did not vary with DR, whereas the OC EFs in the particle phase determined at DR = 1027 were 13% of the EFs determined at DR = 8, owing to evaporation of organic compounds. Using partitioning theory and n-alkane EFs measured at DR = 14 and 238, we calculated the distributions of compounds between the particle and gas phases at DR = 1760, which corresponds to the DR for tailpipe emissions as they move from the tailpipe to the roadside atmosphere. The gas-phase EF of a compound with a vapor pressure of 10-7 Pa was 0.01 μg kg-1-fuel at DR = 14, and this value is 1/330 the value derived at DR = 1760. Our results suggest that the EFs of high-volatility compounds in the particle phase will be overestimated and that the EFs of low-volatility compounds in the gas phase will be underestimated if the estimates are derived from data obtained at the low DRs and they are applied to the real world. Therefore, extrapolation from EFs derived at low DR values to EFs at atmospherically relevant DRs will be a source of error in predictions of the concentrations of particulate matter and gas-phase precursors to secondary organic aerosols in air quality models.

  2. A survey of yeast from the Yarrowia clade for lipid production in dilute-acid pretreated lignocellulosic biomass hydrolysate

    Science.gov (United States)

    Yarrowia lipolytica is an oleaginous yeast species that has attracted attention as a model organism for synthesis of single cell oil. Among over 50 isolates of Y. lipolytica identified, only a few of the strains have been studied extensively. Furthermore, 12 other yeast species were recently assigne...

  3. Development of SI-traceable C-peptide certified reference material NMIJ CRM 6901-a using isotope-dilution mass spectrometry-based amino acid analyses.

    Science.gov (United States)

    Kinumi, Tomoya; Goto, Mari; Eyama, Sakae; Kato, Megumi; Kasama, Takeshi; Takatsu, Akiko

    2012-07-01

    A certified reference material (CRM) is a higher-order calibration material used to enable a traceable analysis. This paper describes the development of a C-peptide CRM (NMIJ CRM 6901-a) by the National Metrology Institute of Japan using two independent methods for amino acid analysis based on isotope-dilution mass spectrometry. C-peptide is a 31-mer peptide that is utilized for the evaluation of β-cell function in the pancreas in clinical testing. This CRM is a lyophilized synthetic peptide having the human C-peptide sequence, and contains deamidated and pyroglutamylated forms of C-peptide. By adding water (1.00 ± 0.01) g into the vial containing the CRM, the C-peptide solution in 10 mM phosphate buffer saline (pH 6.6) is reconstituted. We assigned two certified values that represent the concentrations of total C-peptide (mixture of C-peptide, deamidated C-peptide, and pyroglutamylated C-peptide) and C-peptide. The certified concentration of total C-peptide was determined by two amino acid analyses using pre-column derivatization liquid chromatography-mass spectrometry and hydrophilic chromatography-mass spectrometry following acid hydrolysis. The certified concentration of C-peptide was determined by multiplying the concentration of total C-peptide by the ratio of the relative area of C-peptide to that of the total C-peptide measured by liquid chromatography. The certified value of C-peptide (80.7 ± 5.0) mg/L represents the concentration of the specific entity of C-peptide; on the other hand, the certified value of total C-peptide, (81.7 ± 5.1) mg/L can be used for analyses that does not differentiate deamidated and pyroglutamylated C-peptide from C-peptide itself, such as amino acid analyses and immunochemical assays.

  4. Simple and rapid analytical method for detection of amino acids in blood using blood spot on filter paper, fast-GC/MS and isotope dilution technique.

    Science.gov (United States)

    Kawana, Shuichi; Nakagawa, Katsuhiro; Hasegawa, Yuki; Yamaguchi, Seiji

    2010-11-15

    A simple and rapid method for quantitative analysis of amino acids, including valine (Val), leucine (Leu), isoleucine (Ile), methionine (Met) and phenylalanine (Phe), in whole blood has been developed using GC/MS. In this method, whole blood was collected using a filter paper technique, and a 1/8 in. blood spot punch was used for sample preparation. Amino acids were extracted from the sample, and the extracts were purified using cation-exchange resins. The isotope dilution method using ²H₈-Val, ²H₃-Leu, ²H₃-Met and ²H₅-Phe as internal standards was applied. Following propyl chloroformate derivatization, the derivatives were analyzed using fast-GC/MS. The extraction recoveries using these techniques ranged from 69.8% to 87.9%, and analysis time for each sample was approximately 26 min. Calibration curves at concentrations from 0.0 to 1666.7 μmol/l for Val, Leu, Ile and Phe and from 0.0 to 333.3 μmol/l for Met showed good linearity with regression coefficients=1. The method detection limits for Val, Leu, Ile, Met and Phe were 24.2, 16.7, 8.7, 1.5 and 12.9 μmol/l, respectively. This method was applied to blood spot samples obtained from patients with phenylketonuria (PKU), maple syrup urine disease (MSUD), hypermethionine and neonatal intrahepatic cholestasis caused by citrin deficiency (NICCD), and the analysis results showed that the concentrations of amino acids that characterize these diseases were increased. These results indicate that this method provides a simple and rapid procedure for precise determination of amino acids in whole blood. Copyright © 2010 Elsevier B.V. All rights reserved.

  5. Aspartic acid interaction with cobalt(II) in dilute aqueous solution: A 57Co emission Mössbauer spectroscopic study

    International Nuclear Information System (INIS)

    Kamnev, Alexander A.; Tugarova, Anna V.; Kovács, Krisztina; Homonnay, Zoltan; Kuzmann, Erno; Vértes, Attila

    2012-01-01

    Emission ( 57 Co) Mössbauer spectra of the aspartic acid— 57 CoCl 2 system were measured at T = 80 K in frozen aqueous solution and in the form of a dried residue of this solution. The Mössbauer spectra, besides a weak contribution from after-effects, showed two Fe 2 +  /Co 2 +  components which were ascribed to octahedrally and tetrahedrally coordinated 57 Co II microenvironments in the Asp–cobalt(II) complex. This dual coordination mode may be due to the involvement of the second terminal carboxylic group of aspartic acid in the coordination sphere of Co.

  6. Deposition of lignin droplets produced during dilute acid pretreatment of maize stems retards enzymatic hydrolysis of cellulose.

    Science.gov (United States)

    Selig, Michael J; Viamajala, Sridhar; Decker, Stephen R; Tucker, Melvin P; Himmel, Michael E; Vinzant, Todd B

    2007-01-01

    Electron microscopy of lignocellulosic biomass following high-temperature pretreatment revealed the presence of spherical formations on the surface of the residual biomass. The hypothesis that these droplet formations are composed of lignins and possible lignin carbohydrate complexes is being explored. Experiments were conducted to better understand the formation of these "lignin" droplets and the possible implications they might have on the enzymatic saccharification of pretreated biomass. It was demonstrated that these droplets are produced from corn stover during pretreatment under neutral and acidic pH at and above 130 degrees C, and that they can deposit back onto the surface of residual biomass. The deposition of droplets produced under certain pretreatment conditions (acidic pH; T > 150 degrees C) and captured onto pure cellulose was shown to have a negative effect (5-20%) on the enzymatic saccharification of this substrate. It was noted that droplet density (per unit area) was greater and droplet size more variable under conditions where the greatest impact on enzymatic cellulose conversion was observed. These results indicate that this phenomenon has the potential to adversely affect the efficiency of enzymatic conversion in a lignocellulosic biorefinery.

  7. Influence of microwaves on the leaching kinetics of uraninite from a low grade ore in dilute sulfuric acid

    International Nuclear Information System (INIS)

    Madakkaruppan, V.; Pius, Anitha; Sreenivas, T.; Giri, Nitai; Sarbajna, Chanchal

    2016-01-01

    Highlights: • U leaching from a low-grade Si-rich ore studied in H_2SO_4 medium with (MW) irradiation. • MW heating is more efficient in terms of U recovery, kinetics and purity of liquor. • U leachability of 84% obtained in 90 min at 95 °C with 0.38 M H_2SO_4 at 450 mVwith MW heating • Conventional conductive heating gave about 74% leachability with less purity liquor. • U leaching was found follow product layer diffusion as controlling mechanism. - Abstract: This paper describes a study on microwave assisted leaching of uranium from a low-grade ore of Indian origin. The host rock for uranium mineralization is chlorite-biotite-muscovite-quartzo-feldspathic schist. The dominant presence of siliceous minerals determined leaching of uranium values in sulfuric acid medium under oxidizing conditions. Process parametric studies like the effect of sulfuric acid concentration (0.12–0.50 M), redox potential (400–500 mV), particle size (600–300 μm) and temperature (35°–95 °C) indicated that microwave assisted leaching is more efficient in terms of overall uranium dissolution, kinetics and provide relatively less impurities (Si, Al, Mg and Fe) in the leach liquor compared to conventional conductive leaching. The kinetics of leaching followed shrinking core model with product layer diffusion as controlling mechanism.

  8. Influence of microwaves on the leaching kinetics of uraninite from a low grade ore in dilute sulfuric acid

    Energy Technology Data Exchange (ETDEWEB)

    Madakkaruppan, V. [Atomic Minerals Directorate for Exploration and Research, Begumpet, Hyderabad 500016 (India); Pius, Anitha, E-mail: dranithapius@gmail.com [Department of Chemistry, Gandhigram Rural Institute, Gandhigram, Dindigul District, Tamil Nadu 624302 (India); Sreenivas, T.; Giri, Nitai [Mineral Processing Division, Bhabha Atomic Research Center, AMD Complex, Begumpet, Hyderabad 500016 (India); Sarbajna, Chanchal [Atomic Minerals Directorate for Exploration and Research, Begumpet, Hyderabad 500016 (India)

    2016-08-05

    Highlights: • U leaching from a low-grade Si-rich ore studied in H{sub 2}SO{sub 4} medium with (MW) irradiation. • MW heating is more efficient in terms of U recovery, kinetics and purity of liquor. • U leachability of 84% obtained in 90 min at 95 °C with 0.38 M H{sub 2}SO{sub 4} at 450 mVwith MW heating • Conventional conductive heating gave about 74% leachability with less purity liquor. • U leaching was found follow product layer diffusion as controlling mechanism. - Abstract: This paper describes a study on microwave assisted leaching of uranium from a low-grade ore of Indian origin. The host rock for uranium mineralization is chlorite-biotite-muscovite-quartzo-feldspathic schist. The dominant presence of siliceous minerals determined leaching of uranium values in sulfuric acid medium under oxidizing conditions. Process parametric studies like the effect of sulfuric acid concentration (0.12–0.50 M), redox potential (400–500 mV), particle size (600–300 μm) and temperature (35°–95 °C) indicated that microwave assisted leaching is more efficient in terms of overall uranium dissolution, kinetics and provide relatively less impurities (Si, Al, Mg and Fe) in the leach liquor compared to conventional conductive leaching. The kinetics of leaching followed shrinking core model with product layer diffusion as controlling mechanism.

  9. On the solubility of nicotinic acid and isonicotinic acid in water and organic solvents

    International Nuclear Information System (INIS)

    Abraham, Michael H.; Acree, William E.

    2013-01-01

    Highlights: ► Solubilities of nicotinic acid and isonicotinic acids in organicsolvents have been determined. ► Solubilities are used to calculate Abraham descriptors for the two acids. ► These descriptors then yield water-solvent and gas-solvent partitions into numerous solvents. ► The solubility of the neutral acids in water is obtained. ► The method is straightforward and can be applied to any set of compound solubilities. -- Abstract: We have determined the solubility of nicotinic acid in four solvents and the solubility of isonicotinic acid in another four solvents. These results, together with literature data on the solubility of nicotinic acid in five other organic solvents and isonicotinic acid in four other organic solvents, have been analyzed through two linear Gibbs energy relationships in order to extract compound properties, or descriptors, that encode various solute–solvent interactions. The descriptors for nicotinic acid and isonicotinic acid can then be used in known equations for partition of solutes between water and organic solvents to predict partition coefficients and then further solubility in a host of organic solvents, as well as to predict a number of other physicochemical properties

  10. Alleviating soil acidity through plant organic compounds

    Directory of Open Access Journals (Sweden)

    Anderson R. Meda

    2001-06-01

    Full Text Available A laboratory experiment was conducted to evaluate the effects of water soluble plant extracts on soil acidity. The plant materials were: black oat, oil seed radish, white and blue lupin, gray and dwarf mucuna, Crotalaria spectabilis and C. breviflora, millet, pigeon pea, star grass, mato grosso grass, coffee leaves, sugar cane leaves, rice straw, and wheat straw. Plant extracts were added on soil surface in a PVC soil column at a rate of 1.0 ml min-1. Both soil and drainage water were analyzed for pH, Ca, Al, and K. Plant extracts applied on the soil surface increased soil pH, exchangeable Ca ex and Kex and decreased Al ex. Oil seed radish, black oat, and blue lupin were the best and millet the worst materials to alleviate soil acidity. Oil seed radish markedly increased Al in the drainage water. Chemical changes were associated with the concentrations of basic cations in the plant extract: the higher the concentration the greater the effects in alleviating soil acidity.Foram conduzidos experimentos de laboratórios para avaliar os efeitos de extratos de plantas solúveis em água na acidez do solo. Os materiais de plantas foram: aveia preta, nabo, tremoço branco e azul, mucuna cinza e anã, Crotalaria spectabilis e C. breviflora, milheto, guandu, grama estrela, grama mato grosso, folhas de café, folhas de cana-de-açúcar, palhada de arroz e palhada de trigo. Foi utilizado o seguinte procedimento para o extrato da planta solúvel em água: pesar 3g de material de planta, adicionar 150 ml de água, agitar por 8h e filtrar. Os extratos de plantas foram adicionados na superfície do solo em uma coluna de PVC (1 ml min-1. Após, adicionou-se água deionizada em quantidade equivalente a três volumes de poros. Os extratos de plantas aumentaram o pH, Ca e K trocável e diminuíram Al. Nabo, aveia preta e tremoço azul foram os melhores e milheto o pior material para amenizar a acidez do solo. Nabo aumentou Al na água de drenagem. As altera

  11. Study of Acid Hydrolysis on Organic Waste: Understanding The Effect of Delignification and Particle Size

    Directory of Open Access Journals (Sweden)

    Anwar Nadiem

    2018-01-01

    Full Text Available Organic wastes from Swiettenia marcophylla L, Artocarpus heterophyllus L, Mangifera indica L, and Annona muricata L were prepared by grinding into 0.1875, 0.3750, 0.7500 mm of particle size and delignified by 2% NaOH at 80°C for 90 minutes. Acid dilution hydrolysis process with H2SO4 1% was performed at 150°C for 120 minutes in a closed reactor. The effect of particle size and delignification on and reducing sugar concentration were investigated. The result showed (1 leaves that can be used as raw material to produce hydrogen should have 38–49% cellulose and hemicellulose. (2 Reducing sugar concentration increased with particle size reduction and delignification. (3 the best result with the highest reducing sugar concentration was achieved by 0.1875 mm particle size with delignification on Annona muricata L.

  12. Processing of Unsaturated Organic Acid Aerosols by Ozone

    Science.gov (United States)

    Aloisio, S.; Donaldson, D. J.; Eliason, T. L.; Cziczo, D.; Vaida, V.

    2002-05-01

    We present results of in-situ studies of the oxidative "processing" of organic aerosols composed of unsaturated organic compounds. Aerosol samples of 2-octenoic acid and undecylenic acid were exposed to approx. 10 mbar ozone in a room temperature, atmospheric pressure flow tube reactor. In-situ spectroscopic probing of the reaction mixture, as well as GC-MS analysis of the flow tube effluent, shows evidence of efficient oxidation of double bonds in the organic species, with production of gas-phase and aerosol phase ozonolysis products.

  13. Mapping the low salinity Changjiang Diluted Water using satellite-retrieved colored dissolved organic matter (CDOM) in the East China Sea during high river flow season

    Science.gov (United States)

    Sasaki, Hiroaki; Siswanto, Eko; Nishiuchi, Kou; Tanaka, Katsuhisa; Hasegawa, Toru; Ishizaka, Joji

    2008-02-01

    Absorption coefficients of colored dissolved organic matter (CDOM) [a g(λ)] were measured and relationship with salinity was derived in the East China Sea (ECS) during summer when amount of the Changjiang River discharge is large. Low salinity Changjiang Diluted Water (CDW) was observed widely in the shelf region and was considered to be the main origin of CDOM, resulting in a strong relationship between salinity and a g(λ). Error of satellite a g(λ) estimated by the present ocean color algorithm could be corrected by satellite-retrieved chlorophyll data. Satellite-retrieved salinity could be predicted with about +/-1.0 accuracy from satellite a g(λ) and the relation between salinity and a g(λ). Our study suggests that satellite-derived a g(λ) can be an indicator of the low salinity CDW during summer.

  14. Flavor Compounds in Pixian Broad-Bean Paste: Non-Volatile Organic Acids and Amino Acids

    Directory of Open Access Journals (Sweden)

    Hongbin Lin

    2018-05-01

    Full Text Available Non-volatile organic acids and amino acids are important flavor compounds in Pixian broad-bean paste, which is a traditional Chinese seasoning product. In this study, non-volatile organic acids, formed in the broad-bean paste due to the metabolism of large molecular compounds, are qualitatively and quantitatively determined by high-performance liquid chromatography (HPLC. Amino acids, mainly produced by hydrolysis of soybean proteins, were determined by the amino acid automatic analyzer. Results indicated that seven common organic acids and eighteen common amino acids were found in six Pixian broad-bean paste samples. The content of citric acid was found to be the highest in each sample, between 4.1 mg/g to 6.3 mg/g, and malic acid were between 2.1 mg/g to 3.6 mg/g ranked as the second. Moreover, fumaric acid was first detected in fermented bean pastes albeit with a low content. For amino acids, savory with lower sour taste including glutamine (Gln, glutamic acid (Glu, aspartic acid (Asp and asparagines (Asn were the most abundant, noted to be 6.5 mg/g, 4.0 mg/g, 6.4 mg/g, 4.9 mg/g, 6.2 mg/g and 10.2 mg/g, and bitter taste amino acids followed. More importantly, as important flavor materials in Pixian broad-bean paste, these two groups of substances are expected to be used to evaluate and represent the flavor quality of Pixian broad-bean paste. Moreover, the results revealed that citric acid, glutamic acid, methionine and proline were the most important flavor compounds. These findings are agreat contribution for evaluating the quality and further assessment of Pixian broad-bean paste.

  15. Flavor Compounds in Pixian Broad-Bean Paste: Non-Volatile Organic Acids and Amino Acids.

    Science.gov (United States)

    Lin, Hongbin; Yu, Xiaoyu; Fang, Jiaxing; Lu, Yunhao; Liu, Ping; Xing, Yage; Wang, Qin; Che, Zhenming; He, Qiang

    2018-05-29

    Non-volatile organic acids and amino acids are important flavor compounds in Pixian broad-bean paste, which is a traditional Chinese seasoning product. In this study, non-volatile organic acids, formed in the broad-bean paste due to the metabolism of large molecular compounds, are qualitatively and quantitatively determined by high-performance liquid chromatography (HPLC). Amino acids, mainly produced by hydrolysis of soybean proteins, were determined by the amino acid automatic analyzer. Results indicated that seven common organic acids and eighteen common amino acids were found in six Pixian broad-bean paste samples. The content of citric acid was found to be the highest in each sample, between 4.1 mg/g to 6.3 mg/g, and malic acid were between 2.1 mg/g to 3.6 mg/g ranked as the second. Moreover, fumaric acid was first detected in fermented bean pastes albeit with a low content. For amino acids, savory with lower sour taste including glutamine (Gln), glutamic acid (Glu), aspartic acid (Asp) and asparagines (Asn) were the most abundant, noted to be 6.5 mg/g, 4.0 mg/g, 6.4 mg/g, 4.9 mg/g, 6.2 mg/g and 10.2 mg/g, and bitter taste amino acids followed. More importantly, as important flavor materials in Pixian broad-bean paste, these two groups of substances are expected to be used to evaluate and represent the flavor quality of Pixian broad-bean paste. Moreover, the results revealed that citric acid, glutamic acid, methionine and proline were the most important flavor compounds. These findings are agreat contribution for evaluating the quality and further assessment of Pixian broad-bean paste.

  16. Organic acid profile of commercial sour cassava starch

    Directory of Open Access Journals (Sweden)

    DEMIATE I.M.

    1999-01-01

    Full Text Available Organic acids are present in sour cassava starch ("polvilho azedo" and contribute with organoleptic and physical characteristics like aroma, flavor and the exclusive baking property, that differentiate this product from the native cassava starch. Samples of commercial sour cassava starch collected in South and Southeast Brazil were prepared for high performance liquid chromatography (HPLC analysis. The HPLC equipment had a Biorad Aminex HPX-87H column for organic acid analysis and a refractometric detector. Analysis was carried out with 0.005M sulfuric acid as mobile phase, 0.6ml/min flow rate and column temperature of 60° C. The acids quantified were lactic (0.036 to 0.813 g/100g, acetic (0 to 0.068 g/100g, propionic (0 to 0.013 g/100g and butyric (0 to 0.057 g/100g, that are produced during the natural fermentation of cassava starch. Results showed large variation among samples, even within the same region. Some samples exhibited high acid levels, mainly lactic acid, but in these neither propionic nor butyric acids were detected. Absence of butyric acid was not expected because this is an important component of the sour cassava starch aroma, and the lack of this acid may suggest that such samples were produced without the natural fermentation step.

  17. Corrosion of alloy C-22 in organic acid solutions

    International Nuclear Information System (INIS)

    Carranza, Ricardo M.; Rodriguez, Martin A.; Giordano, Celia M.

    2007-01-01

    Electrochemical studies such as cyclic potentiodynamic polarization (CPP) and electrochemical impedance spectroscopy (EIS) were performed to determine the corrosion behavior of Alloy 22 (N06022) in 1M NaCl solutions at various pH values from acidic to neutral at 90 C degrees. All the tested material was wrought Mill Annealed (MA). Tests were also performed in NaCl solutions containing weak organic acids such as oxalic, acetic, citric and picric acids. Results show that the corrosion rate of Alloy 22 was significantly higher in solutions containing oxalic acid than in solutions of pure NaCl at the same pH. Citric and Picric acids showed a slightly higher corrosion rate, and Acetic acid maintained the corrosion rate of pure chloride solutions at the same pH. Organic acids revealed to be weak inhibitors for crevice corrosion. Higher concentration ratios, compared to nitrate ions, were needed to completely inhibit crevice corrosion in chloride solutions. Results are discussed considering acid dissociation constants, buffer capacity and complex formation constants of the different weak acids. (author) [es

  18. Improved ethanol yield and reduced Minimum Ethanol Selling Price (MESP by modifying low severity dilute acid pretreatment with deacetylation and mechanical refining: 1 Experimental

    Directory of Open Access Journals (Sweden)

    Chen Xiaowen

    2012-08-01

    and mechanical refining. The new process shows improved overall ethanol yields compared to traditional dilute acid pretreatment. The experimental results from this work support the techno-economic analysis and calculation of Minimum Ethanol Selling Price (MESP detailed in our companion paper.

  19. Dilute chemical decontamination program review

    International Nuclear Information System (INIS)

    Anstine, L.D.; Blomgren, J.C.; Pettit, P.J.

    1980-01-01

    The objective of the Dilute Chemical Decontamination Program is to develop and evaluate a process which utilizes reagents in dilute concentrations for the decontamination of BWR primary systems and for the maintenance of dose rates on the out-of-core surfaces at acceptable levels. A discussion is presented of the process concept, solvent development, advantages and disadvantages of reagent systems, and VNC loop tests. Based on the work completed to date it is concluded that (1) rapid decontamination of BWRs using dilute reagents is feasible; (2) reasonable reagent conditions for rapid chemical decontamination are: 0.01M oxalic acid + 0.005M citric acid, pH3.0, 90/degree/C, 0.5 to 1.0 ppm dissolved oxygen; (3) control of dissolved oxygen concentration is important, since high levels suppress the rate of decontamination and low levels allow precipitation of ferrous oxalate. 4 refs

  20. Process Design and Economics for the Conversion of Lignocellulosic Biomass to Hydrocarbons: Dilute-Acid and Enzymatic Deconstruction of Biomass to Sugars and Biological Conversion of Sugars to Hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Davis, R.; Tao, L.; Tan, E. C. D.; Biddy, M. J.; Beckham, G. T.; Scarlata, C.; Jacobson, J.; Cafferty, K.; Ross, J.; Lukas, J.; Knorr, D.; Schoen, P.

    2013-10-01

    This report describes one potential conversion process to hydrocarbon products by way of biological conversion of lingnocellulosic-dervied sugars. The process design converts biomass to a hydrocarbon intermediate, a free fatty acid, using dilute-acid pretreatement, enzymatic saccharification, and bioconversion. Ancillary areas--feed handling, hydrolysate conditioning, product recovery and upgrading (hydrotreating) to a final blendstock material, wastewater treatment, lignin combusion, and utilities--are also included in the design.

  1. Quantification of abscisic acid in grapevine leaf (Vitis vinifera) by isotope-dilution liquid chromatography-mass spectrometry.

    Science.gov (United States)

    Vilaró, Francisca; Canela-Xandri, Anna; Canela, Ramon

    2006-09-01

    A specific, sensitive, precise, and accurate method for the determination of abscisic acid (ABA) in grapevine leaf tissues is described. The method employs high-performance liquid chromatography and electrospray ionization-mass spectrometry (LC-ESI-MS) in selected ion monitoring mode (SIM) to analyze ABA using a stable isotope-labeled ABA as an internal standard. Absolute recoveries ranged from 72% to 79% using methanol/water pH 5.5 (50:50 v/v) as an extraction solvent. The best efficiency was obtained when the chromatographic separation was carried out by using a porous graphitic carbon (PGC) column. The statistical evaluation of the method was satisfactory in the work range. A relative standard deviation (RDS) of < 5.5% and < 6.0% was obtained for intra-batch and inter-batch comparisons, respectively. As for accuracy, the relative error (%Er) was between -2.7 and 4.3%, and the relative recovery ranged from 95% to 107%.

  2. Sugars, organic acids, minerals and lipids in jabuticaba

    Directory of Open Access Journals (Sweden)

    Annete de Jesus Boari Lima

    2011-06-01

    Full Text Available The aim of this work was to determine the sugar, organic acid and mineral compositions of the whole fruit and fractions (skin, pulp and seed of the Paulista (Plinia cauliflora and Sabará (Plinia jaboticaba jabuticaba tree genotypes, as well as the oil compositions of their skin and seeds. High levels of sugar, especially fructose, followed by glucose and sucrose, were encountered in the fruit. In the Paulista genotype, higher levels of total and reducing sugars were found in the pulp and skin, which was not observed when comparing the whole fruit of both genotypes. Five organic acids were found in the whole fruit and in the fractions of the two jabuticaba genotypes in quantitative order: citric acid > succinic acid > malic acid > oxalic acid > acetic acid. Potassium was the most abundant mineral found. This fruit was also shown to be rich in magnesium, phosphorus, calcium and copper. The seed oil had nearly the same constitution as the oil extracted from the skin in both genotypes and the major compounds were an unidentified phytosterol, palmitic, linoleic and oleic acids, and squalene.

  3. Chloroacetic acids - Degradation intermediates of organic matter in forest soil

    Czech Academy of Sciences Publication Activity Database

    Matucha, Miroslav; Gryndler, Milan; Schröder, P.; Forczek, Sándor; Uhlířová, H.; Fuksová, Květoslava; Rohlenová, Jana

    2007-01-01

    Roč. 39, č. 1 (2007), s. 382-385 ISSN 0038-0717 R&D Projects: GA ČR GA522/02/0874; GA ČR GA526/05/0636 Institutional research plan: CEZ:AV0Z50380511 Keywords : trichloroacetic acid * dichloroacetic acid * chlorination * soil organic matter Subject RIV: EF - Botanics Impact factor: 2.580, year: 2007

  4. Evaluation of soluble fraction and enzymatic residual fraction of dilute dry acid, ethylenediamine, and steam explosion pretreated corn stover on the enzymatic hydrolysis of cellulose.

    Science.gov (United States)

    Qin, Lei; Liu, Li; Li, Wen-Chao; Zhu, Jia-Qing; Li, Bing-Zhi; Yuan, Ying-Jin

    2016-06-01

    This study is aimed to examine the inhibition of soluble fraction (SF) and enzymatic residual fraction (ERF) in dry dilute acid (DDA), ethylenediamine (EDA) and steam explosion (SE) pretreated corn stover (CS) on the enzymatic digestibility of cellulose. SF of DDA, EDA and SE pretreated CS has high xylose, soluble lignin and xylo-oligomer content, respectively. SF of EDA pretreated CS leads to the highest inhibition, followed by SE and DDA pretreated CS. Inhibition of ERF of DDA and SE pretreated CS is higher than that of EDA pretreated CS. The inhibition degree (A0/A) of SF is 1.76 and 1.21 times to that of ERF for EDA and SE pretreated CS, respectively. The inhibition degree of ERF is 1.05 times to that of SF in DDA pretreated CS. The quantitative analysis shows that SF of EDA pretreated CS, SF and ERF of SE pretreated CS cause significant inhibition during enzymatic hydrolysis. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Integrated Process for Ethanol, Biogas, and Edible Filamentous Fungi-Based Animal Feed Production from Dilute Phosphoric Acid-Pretreated Wheat Straw.

    Science.gov (United States)

    Nair, Ramkumar B; Kabir, Maryam M; Lennartsson, Patrik R; Taherzadeh, Mohammad J; Horváth, Ilona Sárvári

    2018-01-01

    Integration of wheat straw for a biorefinery-based energy generation process by producing ethanol and biogas together with the production of high-protein fungal biomass (suitable for feed application) was the main focus of the present study. An edible ascomycete fungal strain Neurospora intermedia was used for the ethanol fermentation and subsequent biomass production from dilute phosphoric acid (0.7 to 1.2% w/v) pretreated wheat straw. At optimum pretreatment conditions, an ethanol yield of 84 to 90% of the theoretical maximum, based on glucan content of substrate straw, was observed from fungal fermentation post the enzymatic hydrolysis process. The biogas production from the pretreated straw slurry showed an improved methane yield potential up to 162% increase, as compared to that of the untreated straw. Additional biogas production, using the syrup, a waste stream obtained post the ethanol fermentation, resulted in a combined total energy output of 15.8 MJ/kg wheat straw. Moreover, using thin stillage (a waste stream from the first-generation wheat-based ethanol process) as a co-substrate to the biogas process resulted in an additional increase by about 14 to 27% in the total energy output as compared to using only wheat straw-based substrates. ᅟ.

  6. Conditioning of dilute-acid pretreated corn stover hydrolysate liquors by treatment with lime or ammonium hydroxide to improve conversion of sugars to ethanol.

    Science.gov (United States)

    Jennings, Edward W; Schell, Daniel J

    2011-01-01

    Dilute-acid pretreatment of lignocellulosic biomass enhances the ability of enzymes to hydrolyze cellulose to glucose, but produces many toxic compounds that inhibit fermentation of sugars to ethanol. The objective of this study was to compare the effectiveness of treating hydrolysate liquor with Ca(OH)2 and NH4OH for improving ethanol yields. Corn stover was pretreated in a pilot-scale reactor and then the liquor fraction (hydrolysate) was extracted and treated with various amounts of Ca(OH)2 or NH4OH at several temperatures. Glucose and xylose in the treated liquor were fermented to ethanol using a glucose-xylose fermenting bacteria, Zymomonas mobilis 8b. Sugar losses up to 10% occurred during treatment with Ca(OH)2, but these losses were two to fourfold lower with NH4OH treatment. Ethanol yields for NH4OH-treated hydrolysate were 33% greater than those achieved in Ca(OH)2-treated hydrolysate and pH adjustment to either 6.0 or 8.5 with NH4OH prior to fermentation produced equivalent ethanol yields. Copyright © 2010 Elsevier Ltd. All rights reserved.

  7. Process Design and Economics for Biochemical Conversion of Lignocellulosic Biomass to Ethanol: Dilute-Acid Pretreatment and Enzymatic Hydrolysis of Corn Stover

    Energy Technology Data Exchange (ETDEWEB)

    Humbird, D.; Davis, R.; Tao, L.; Kinchin, C.; Hsu, D.; Aden, A.; Schoen, P.; Lukas, J.; Olthof, B.; Worley, M.; Sexton, D.; Dudgeon, D.

    2011-03-01

    This report describes one potential biochemical ethanol conversion process, conceptually based upon core conversion and process integration research at NREL. The overarching process design converts corn stover to ethanol by dilute-acid pretreatment, enzymatic saccharification, and co-fermentation. Building on design reports published in 2002 and 1999, NREL, together with the subcontractor Harris Group Inc., performed a complete review of the process design and economic model for the biomass-to-ethanol process. This update reflects NREL's current vision of the biochemical ethanol process and includes the latest research in the conversion areas (pretreatment, conditioning, saccharification, and fermentation), optimizations in product recovery, and our latest understanding of the ethanol plant's back end (wastewater and utilities). The conceptual design presented here reports ethanol production economics as determined by 2012 conversion targets and 'nth-plant' project costs and financing. For the biorefinery described here, processing 2,205 dry ton/day at 76% theoretical ethanol yield (79 gal/dry ton), the ethanol selling price is $2.15/gal in 2007$.

  8. Direct determination of fatty acid esters of 3-chloro-1, 2-propanediol in edible vegetable oils by isotope dilution - ultra high performance liquid chromatography - triple quadrupole mass spectrometry.

    Science.gov (United States)

    Li, Heli; Chen, Dawei; Miao, Hong; Zhao, Yunfeng; Shen, Jianzhong; Wu, Yongning

    2015-09-04

    A selective and sensitive ultra-high performance liquid chromatography - triple quadrupole mass spectrometry (UHPLC-MS/MS) method coupled with matrix solid phase dispersion (MSPD) extraction was developed for the direct determination of fatty acid esters of 3-chloro-1,2-propanediol (3-MCPD esters) in edible vegetable oils. The method integrated the isotope dilution technique, MSPD extraction and UHPLC - MS/MS analysis with multi-reaction monitoring mode (MRM). Matrix-matched calibration curves showed good linearity within the range of 0.01-10mgL(-1) with the correlation coefficient not less than 0.999. Limits of detection (LODs) and limit of quantification (LOQs) of the 3-MCPD esters fell into the range of 0.0001-0.02mgkg(-1) and 0.0004-0.05mgkg(-1), respectively. The recoveries for the spiked extra virgin olive oils ranged from 94.4% to 108.3%, with the relative standard deviations (RSD) ranging from 0.6% to 10.5%. The method was applied for the oil sample (T2642) of the official Food Analysis Performance Assessment Scheme (FAPAS) in 2014 and other real samples from supermarket, and the results showed that the present method was comparative to the gas chromatography-mass spectrometry (GC-MS) method based on the improved German Society for Fat Science (DGF) standard method C-III 18 (09) except for palm oil. Copyright © 2015. Published by Elsevier B.V.

  9. Fermentation process for the production of organic acids

    Science.gov (United States)

    Hermann, Theron; Reinhardt, James; Yu, Xiaohui; Udani, Russell; Staples, Lauren

    2018-05-01

    This invention relates to improvements in the fermentation process used in the production of organic acids from biological feedstock using bacterial catalysts. The improvements in the fermentation process involve providing a fermentation medium comprising an appropriate form of inorganic carbon, an appropriate amount of aeration and a biocatalyst with an enhanced ability to uptake and assimilate the inorganic carbon into the organic acids. This invention also provides, as a part of an integrated fermentation facility, a novel process for producing a solid source of inorganic carbon by sequestering carbon released from the fermentation in an alkali solution.

  10. Biochar: a green sorbent to sequester acidic organic contaminants

    Science.gov (United States)

    Sigmund, Gabriel; Kah, Melanie; Sun, Huichao; Hofmann, Thilo

    2015-04-01

    Biochar is a carbon rich product of biomass pyrolysis that exhibits a high sorption potential towards a wide variety of inorganic and organic contaminants. Because it is a valuable soil additive and a potential carbon sink that can be produced from renewable resources, biochar has gained growing attention for the development of more sustainable remediation strategies. A lot of research efforts have been dedicated to the sorption of hydrophobic contaminants and metals to biochar. Conversely, the understanding of the sorption of acidic organic contaminants remains limited, and questions remain on the influence of biochar characteristics (e.g. ash content) on the sorption behaviour of acidic organic contaminants. To address this knowledge gap, sorption batch experiments were conducted with a series of structurally similar acidic organic contaminants covering a range of dissociation constant (2,4-D, MCPA, 2,4-DB and triclosan). The sorbents selected for experimentation included a series of 10 biochars covering a range of characteristics, multiwalled carbon nanotubes as model for pure carbonaceous phases, and an activated carbon as benchmark. Overall, sorption coefficient [L/kg] covered six orders of magnitude and generally followed the order 2,4-D pH dependent lipophilicity ratio (i.e. D instead of Kow), ash content and ionic strength are key factors influencing the sorption of acidic organic contaminants to biochars. Overall, the identified factors, as well as the environmental matrix, should be carefully considered when selecting the type of biochar for sequestration purposes.

  11. Effects of gamma radiation from 60Co on dilute aqueous solutions of Linear Alkyl Sulfonate Surfactants and other organic pollutants

    International Nuclear Information System (INIS)

    Rohrer, D.M.

    1975-01-01

    This study is the result of research findings and operational experiences gained by the author in over four years of work associated with the use of 60 Co for the treatment of waste-water. The effects of 60 Co are discussed with regard to radiochemical destruction of specific organic pollutant species. The study deals specifically with the effects of gamma radiation from a 30,000 Ci 60 Co source upon aqueous solutions of Linear Alkyl Sulfonate Surfactants. The new Linear Alkyl Sulfonate (LAS) Surfactants, the major surfactant produced in the United States of America since June 1965, was developed to replace the old Alkyl Benzene Sulfonate (ABS) Surfactants. The reason for the removal of Alkyl Benzene Sulfonate Surfactants was their extreme environmental stability and the associated appearance of foam in waste-water treatment plants and receiving streams. Although the Linear Alkyl Sulfonate Surfactants are considered 'bio-degradable', the time required for 'bio-degradation' is impractical within the present environmental guidelines. This led to research into alternate techniques of treatment for the destruction of Linear Alkyl Sulfonate Surfactants. Consideration is also given to similar effects of gamma radiation upon pesticides and to the practical aspects of the use of gamma radiation for the treatment of waste-water. Included are discussions of the general experimental procedures used, the sources and their calibration, and sampling techniques to ensure the accuracy of the data. (author)

  12. Effect of inorganic salts on the volatility of organic acids.

    Science.gov (United States)

    Häkkinen, Silja A K; McNeill, V Faye; Riipinen, Ilona

    2014-12-02

    Particulate phase reactions between organic and inorganic compounds may significantly alter aerosol chemical properties, for example, by suppressing particle volatility. Here, chemical processing upon drying of aerosols comprised of organic (acetic, oxalic, succinic, or citric) acid/monovalent inorganic salt mixtures was assessed by measuring the evaporation of the organic acid molecules from the mixture using a novel approach combining a chemical ionization mass spectrometer coupled with a heated flow tube inlet (TPD-CIMS) with kinetic model calculations. For reference, the volatility, i.e. saturation vapor pressure and vaporization enthalpy, of the pure succinic and oxalic acids was also determined and found to be in agreement with previous literature. Comparison between the kinetic model and experimental data suggests significant particle phase processing forming low-volatility material such as organic salts. The results were similar for both ammonium sulfate and sodium chloride mixtures, and relatively more processing was observed with low initial aerosol organic molar fractions. The magnitude of low-volatility organic material formation at an atmospherically relevant pH range indicates that the observed phenomenon is not only significant in laboratory conditions but is also of direct atmospheric relevance.

  13. Molecular physiology of weak organic acid stress in Bacillus subtilis

    NARCIS (Netherlands)

    van Beilen, J.W.A.

    2013-01-01

    The mechanism by which weak organic acid (WOA) preservatives inhibit growth of microorganisms may differ between different WOAs and these differences are not well understood. The aim of this thesis has been to obtain a better understanding of the mode of action of these preservatives by which they

  14. Effects of organic acid supplementation on antioxidant capacity and ...

    African Journals Online (AJOL)

    Four commercial organic acids and a reference antibiotic, Neoxyval, were administered to commercial broilers to evaluate the efficacy of these products during pre- and post-challenge with Salmonella enterica subsp. enterica Typhimurium (S. Typhimurium) on selected indicators of their antioxidant status and immune ...

  15. Organic acid production in Aspergillus niger and other filamentous fungi

    NARCIS (Netherlands)

    Odoni, Dorett I.

    2017-01-01

    The aim of the thesis was to increase the understanding of organic acid production in Aspergillus niger and other filamentous fungi, with the ultimate purpose to improve A. niger as biotechnological production host.

    In Chapter 1, the use of microbial

  16. Relationship between plant growth and organic acid exudates from ...

    African Journals Online (AJOL)

    Plant–mycorrhizal interaction is an important association in the ecosystem with significant impacts on the physical, biological and chemical properties of the soil. In the present study, potential relationships that exist between organic acid production by ectomycorrhizal pine seedlings and plant parameters in the absence of ...

  17. Amine-oxide hybrid materials for acid gas separations

    KAUST Repository

    Bollini, Praveen; Didas, Stephanie A.; Jones, Christopher W.

    2011-01-01

    Organic-inorganic hybrid materials based on porous silica materials functionalized with amine-containing organic species are emerging as an important class of materials for the adsorptive separation of acid gases from dilute gas streams

  18. Removal of rhodamine B (a basic dye) and thoron (an acidic dye) from dilute aqueous solutions and wastewater simulants by ion flotation.

    Science.gov (United States)

    Shakir, Kamal; Elkafrawy, Ahmed Faouzy; Ghoneimy, Hussein Fouad; Elrab Beheir, Shokry Gad; Refaat, Mamdoh

    2010-03-01

    The present work deals with removal, by ion flotation, of two dyes: a basic dye (rhodamine B (RB)) and an acidic one (thoron (TH)) from dilute aqueous solutions and simulated wastewaters. These dyes are widely used for analytical and biological staining purposes. Besides, RB is commonly used in dyeing of various industrial products. Therefore, wastewaters emanating from chemical and radiochemical laboratories, and biomedical and biological research laboratories may be contaminated with RB and TH. Ion flotation of these dyes has been investigated over a wide range of pH using the anionic surfactant, sodium lauryl sulfate (NaLS) and the cationic surfactant, cetyltrimethylammonium bromide (CTAB) as collectors. Successful removals could be achieved for RB and TH with the anionic collector, NaLS, and the cationic collector, CTAB, respectively. In addition to the effects of pH and type of collector on the efficiency of removal of each dye, the effects of collector and dye concentrations, frother dosage, ionic strength, bubbling time period and presence of foreign salts were investigated and the optimal removal conditions have been established. Removals exceeding 99.5 % and 99.9% could be achieved for RB and TH, respectively. The results obtained are discussed with respect to dissociation of dye, type of collector, ionic strength and sign and magnitude of charge of added foreign ions. Kinetics of flotation were also studied. Further studies demonstrate that under optimum conditions the developed flotation processes can be applied for the treatment of dye-contaminated wastewaters simulated to those generated at dyeing industries and radiochemical laboratories. Copyright 2009 Elsevier Ltd. All rights reserved.

  19. Activity coefficients at infinite dilution of organic solutes in the ionic liquid 1-octyl-3-methylimidazolium hexafluorophosphate using gas-liquid chromatography at T = (313.15, 323.15, and 333.15) K

    International Nuclear Information System (INIS)

    Olivier, Eugene; Letcher, Trevor M.; Naidoo, Paramespri; Ramjugernath, Deresh

    2010-01-01

    Activity coefficients at infinite dilution were determined for 24 solutes: n-alkanes, alk-1-enes, alk-1-ynes, cycloalkanes, alkylbenzenes and alcohols in the ionic liquid 1-octyl-3-methylimidazolium hexafluorophosphate, [OMIM][PF 6 ], by gas-liquid chromatography at three different temperatures T = (313.15, 323.15, and 333.15) K. The partial molar excess enthalpy values at infinite dilution were calculated from the experimental data over the same temperature range. Capacities and selectivities at infinite dilution for the systems hexane/benzene and methanol/benzene were determined from the experimental data and compared to the literature values for other ionic liquids, as well as for industrial molecular solvents. The influence of the cation and anion of the ionic liquid on the activity coefficient is discussed, as well as the usefulness of [OMIM][PF 6 ] in separating organic liquids.

  20. Acid-base properties of Baltic Sea dissolved organic matter

    Science.gov (United States)

    Hammer, Karoline; Schneider, Bernd; Kuliński, Karol; Schulz-Bull, Detlef E.

    2017-09-01

    Calculations related to the marine CO2 system that are based on alkalinity data may be strongly biased if the contributions of organic compounds are ignored. In coastal seas, concentrations of dissolved organic matter (DOM) are frequently high and alkalinity from inorganic compounds is low. In this study, based on measurements of total alkalinity, total CO2, and pH, we determined the organic alkalinity, Aorg, in water from the central Baltic Sea. The maximum Aorg measured in the surface mixed layer during the spring bloom was > 50 μmol/kg-SW but the Aorg decreased with depth and approached zero below the permanent halocline. This behavior could be attributed to the decreased pH of deeper water layers. The data were used to calculate the bulk dissociation constant, KDOM, for marine DOM and the fraction f of dissolved organic carbon (DOC) that acts as a carrier for acid-base functional groups. The p KDOM (7.27) agreed well with the value (7.34) previously estimated in a preliminary study of organic alkalinity in the Baltic Sea. The fraction of carbon atoms carrying acid-base groups was 17% and was somewhat higher than previously reported (12%). Spike experiments performed using artificial seawater and three different humic/fulvic substances tested whether the acid-base properties of these substances explain the results of our field study. Specifically, Aorg was determined at different concentrations (DOC) of the added humic/fulvic substances. The relationship between Aorg and the DOC concentrations indicated that humic/fulvic substances are more acidic (p KDOM < 6.5) than the bulk DOC natural occurring in the Baltic Sea.

  1. Process Design and Economics for the Conversion of Lignocellulosic Biomass to Hydrocarbons: Dilute-Acid and Enzymatic Deconstruction of Biomass to Sugars and Catalytic Conversion of Sugars to Hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Davis, R. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Tao, L. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Scarlata, C. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Tan, E. C. D. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Ross, J. [Harris Group Inc., New York, NY (United States); Lukas, J. [Harris Group Inc., New York, NY (United States); Sexton, D. [Harris Group Inc., New York, NY (United States)

    2015-03-01

    This report describes one potential conversion process to hydrocarbon products by way of catalytic conversion of lignocellulosic-derived hydrolysate. This model leverages expertise established over time in biomass deconstruction and process integration research at NREL, while adding in new technology areas for sugar purification and catalysis. The overarching process design converts biomass to die die diesel- and naphtha-range fuels using dilute-acid pretreatment, enzymatic saccharification, purifications, and catalytic conversion focused on deoxygenating and oligomerizing biomass hydrolysates.

  2. The Acid-Base Balance Between Organic Acids and Circumneutral Ground Waters in Large Peatlands

    Science.gov (United States)

    Siegel, D. I.; Glaser, P. H.; So, J.

    2006-05-01

    Organic acids supply most of the acidity in the surface waters of bogs in peatlands. Yet, the fundamental geochemical properties of peatland organic acids are still poorly known. To assess the geochemical properties of typical organic acid assemblages in peatlands, we used a triprotic analog model for peat pore waters and surface waters in the Glacial Lake Agassiz Peatlands, optimizing on charge balance and calibrated to estimates of mole site density in DOC and triprotic acid dissociation constants. Before the calibration process, all bog waters and 76% of fen waters had more than +20% charge imbalance. After calibration, most electrochemically balanced within 20%. In the best calibration, the mole site denisty of bog DOC was estimated as ~0.05 mmol/mmol C., approximately 6 times smaller than that for fen DOC or the DOC in the fen deeper fen peats that underlie bogs. The three modeled de-protonation constants were; pKa1 = ~3.0, pKa2 = ~4.5 and pKa3 = ~7.0 for the bog DOC, and; pKa1 = ~5.2, pKa2 =~ 6.5 and pKa3 = ~7.0 for the fen DOC. Bog DOC, behaves as a strong acid despite its small mole site density. The DOC in bog runoff can therefore theoretically acidify the surface waters in adjacent fens wherever these waters do not receive sufficient buffering alkalinity from active groundwater seepage.

  3. Activity coefficients at infinite dilution of organic solutes in the ionic liquid trihexyltetradecylphosphonium bis (trifluoromethylsulfonyl) imide using gas–liquid chromatography at T = (313.15, 333.15, 353.15 and 373.15) K

    International Nuclear Information System (INIS)

    Tumba, Kaniki; Letcher, Trevor M.; Naidoo, Paramespri; Ramjugernath, Deresh

    2013-01-01

    Highlights: • Activity coefficients at infinite dilution measured in the ionic liquid [3C 6 C 14 P][BTI]. • 22 solutes investigated at T = (313.15, 333.15, 353.15, 373.15) K using glc. • Selectivities and capacities for selected separations compared to other IL’s and solvents. -- Abstract: Activity coefficients at infinite dilution for organic solutes, which include n-alkanes, alk-1-enes, alk-1-ynes, cycloalkanes, alkylbenzenes, alcohols and ketones, in the ionic liquid trihexyltetradecylphosphonium bis (trifluoromethylsulfonyl) imide were measured by gas–liquid chromatography using the latter as the stationary phase. This ionic liquid had previously been studied and reported in literature; however due to significant discrepancies in the reported infinite activity coefficient values, there was justification for further study and reporting. The temperature range investigated in this study is significantly wider and at higher temperatures than presented previously in the literature. From the experimental infinite dilution activity coefficient data at the four different temperatures T = (313.15, 333.15, 353.15 and 373.15) K, partial molar excess enthalpies at infinite dilution were calculated. Values of the selectivity for hexane/benzene and methanol/benzene separations were determined from experimental values of the activity coefficients at infinite dilution and these results were compared to literature values for other ionic liquids, as well as for industrial solvents. The capacities were also determined as it gives an indication of the solvent extraction behavior of the ionic liquid

  4. Formation of organic acids from trace carbon in acidic oxidizing media

    International Nuclear Information System (INIS)

    Terrassier, C.

    2003-01-01

    Carbon 14 does not fully desorb as CO 2 during the hot concentrated nitric acid dissolution step of spent nuclear fuel reprocessing: a fraction is entrained in solution into the subsequent process steps as organic species. The work described in this dissertation was undertaken to identify the compounds arising from the dissolution in 3 N nitric acid of uranium carbides (selected as models of the chemical form of carbon 14 in spent fuel) and to understand their formation and dissolution mechanism. The compounds were present at traces in solution, and liquid-solid extraction on a specific stationary phase (porous graphite carbon) was selected to concentrate the monoaromatic poly-carboxylic acids including mellitic acid, which is mentioned in the literature but has not been formally identified. The retention of these species and of oxalic acid - also cited in the literature - was studied on this stationary phase as a function of the mobile phase pH, revealing an ion exchange retention mechanism similar to the one observed for benzyltrimethylammonium polystyrene resins. The desorption step was then optimized by varying the eluent pH and ionic strength. Mass spectrometry analysis of the extracts identified acetic acid, confirmed the presence of mellitic acid, and revealed compounds of high molecular weight (about 200 g/mol); the presence of oxalic acid was confirmed by combining gas chromatography and mass spectrometry. Investigating the dissolution of uranium and zirconium carbides in nitric acid provided considerable data on the reaction and suggested a reaction mechanism. The reaction is self-catalyzing via nitrous acid, and the reaction rate de pends on the acidity and nitrate ion concentration in solution. Two uranium carbide dissolution mechanisms are proposed: one involves uranium at oxidation state +IV in solution, coloring the dissolution solution dark green, and the other assumes that uranium monocarbide is converted to uranium oxide. The carboxylic acid

  5. Nitric-phosphoric acid oxidation of organic waste materials

    International Nuclear Information System (INIS)

    Pierce, R.A.; Smith, J.R.

    1995-01-01

    A wet chemical oxidation technology has been developed to address issues facing defense-related facilities, private industry, and small-volume generators such as university and medical laboratories. Initially tested to destroy and decontaminate a heterogenous mixture of radioactive-contaminated solid waste, the technology can also remediate other hazardous waste forms. The process, unique to Savannah River, offers a valuable alternative to incineration and other high-temperature or high-pressure oxidation processes. The process uses nitric acid in phosphoric acid; phosphoric acid allows nitric acid to be retained in solution well above its normal boiling point. The reaction converts organics to carbon dioxide and water, and generates NO x vapors which can be recycled using air and water. Oxidation is complete in one to three hours. In previous studies, many organic compounds were completely oxidized, within experimental error, at atmospheric pressure below 180 degrees C; more stable compounds were decomposed at 200 degrees C and 170 kPa. Recent studies have evaluated processing parameters and potential throughputs for three primary compounds: EDTA, polyethylene, and cellulose. The study of polyvinylchloride oxidation is incomplete at this time

  6. Profiling of the Contents of Amino Acids, Water-Soluble Vitamins, Minerals, Sugars and Organic Acids in Turkish Hazelnut Varieties

    Directory of Open Access Journals (Sweden)

    Taş Neslihan Göncüoğlu

    2018-09-01

    Full Text Available Proximate composition, profiles of amino acids, sugars, organic acids, vitamins and minerals of fourteen Turkish hazelnut varieties harvested in 2013 and 2014 were investigated. Glutamic acid, arginine and aspartic acid were the most predominant amino acids, representing of about 50% of hazelnut protein. Individual amino acid profiles showed significant differences depending upon the harvest year (p<0.05. Concentration of sucrose was the highest followed by fructose, glucose, stachyose, raffinose and myo-inositol, respectively. Phytic acid was predominant organic acid in all varieties, followed by malic acid. Independent of the variety, hazelnuts were rich in pantothenic acid, nicotinic acid, pyridoxal, biotin, thiamine, nicotinamide. Pantothenic and nicotinic acid were significantly higher in most of the varieties in harvest year 2014. Potassium was the most predominant mineral, followed by magnesium, calcium, sodium, manganese, zinc, iron and copper, respectively.

  7. Progress on Zeolite-membrane-aided Organic Acid Esterification

    Science.gov (United States)

    Makertiharta, I. G. B. N.; Dharmawijaya, P. T.

    2017-07-01

    Esterification is a common route to produce carboxylic acid esters as important intermediates in chemical and pharmaceutical industries. However, the reaction is equilibrium limited and needs to be driven forward by selective removal one of the products. There have been some efforts to selectively remove water from reaction mixture via several separation processes (such as pervaporation and reactive distillation). Integrated pervaporation and esterification has gained increasing attention towards. Inorganic zeolite is the most popular material for pervaporation due to its high chemical resistant and separation performance towards water. Zeolite also has proven to be an effective material in removing water from organic compound. Zeolite can act not only as selective layer but also simultaneously act as a catalyst on promoting the reaction. Hence, there are many configurations in integrating zeolite membrane for esterification reaction. As a selective layer to remove water from reaction mixture, high Si/Al zeolite is preferred to enhance its hydrophilicity. However, low Si/Al zeolite is unstable in acid condition due to dealumination thus eliminate its advantages. As a catalyst, acid zeolites (e.g. H-ZSM-5) provide protons for autoprotolysis of the carboxylic acid similar to other catalyst for esterification (e.g. inorganic acid, and ion exchange resins). There are many studies related to zeolite membrane aided esterification. This paper will give brief information related to zeolite membrane role in esterification and also research trend towards it.

  8. Emulsion Liquid Membrane Technology in Organic Acid Purification

    International Nuclear Information System (INIS)

    Norela Jusoh; Norasikin Othman; Nur Alina Nasruddin

    2016-01-01

    Emulsion Liquid Membrane (ELM) process have shown a great potential in wide application of industrial separations such as in removal of many chemicals, organic compounds, metal ions, pollutants and biomolecules. This system promote many advantages including simple operation, high selectivity, low energy requirement, and single stage extraction and stripping process. One potential application of ELM is in the purification of succinic acid from fermentation broth. This study outline steps for developing emulsion liquid membrane process in purification of succinic acid. The steps include liquid membrane formulation, ELM stability and ELM extraction of succinic acid. Several carrier, diluent and stripping agent was screened to find appropriate membrane formulation. After that, ELM stability was investigated to enhance the recovery of succinic acid. Finally, the performance of ELM was evaluated in the extraction process. Results show that formulated liquid membrane using Amberlite LA2 as carrier, palm oil as diluent and sodium carbonate, Na_2CO_3 as stripping agent provide good performance in purification. On the other hand, the prepared emulsion was observed to be stable up to 1 hour and sufficient for extraction process. In conclusion, ELM has high potential to purify succinic acid from fermentation broth. (author)

  9. Phthalic acid esters found in municipal organic waste

    DEFF Research Database (Denmark)

    Hartmann, Hinrich; Ahring, Birgitte Kiær

    2003-01-01

    Contamination of the organic fraction of municipal solid waste (OFMSW) with xenobiotic compounds and their fate during anaerobic digestion was investigated. The phthalic acid ester di-(2- ethylhexyl)phthalate (DEHP) was identified as the main contaminant in OFMSW in concentrations more than half.......41-0.79 d(-1), which is much higher than in previous investigations. It can be concluded that the higher removal rates are due to the higher temperature and higher initial concentrations per kg dry matter. These results suggest that the limiting factor for DEHP degradation is the bioavailability, which...... is enhanced at higher temperature and higher degradation of solid organic matter, to which the highly hydrophobic DEHP is adsorbed. The investigated reactor configuration with a thermophilic and a hyper-thermophilic treatment is, therefore, a good option for CD combining high rate degradation of organic...

  10. Nickel deficiency disrupts metabolism of ureides, amino acids, and organic acids of young pecan foliage.

    Science.gov (United States)

    Bai, Cheng; Reilly, Charles C; Wood, Bruce W

    2006-02-01

    The existence of nickel (Ni) deficiency is becoming increasingly apparent in crops, especially for ureide-transporting woody perennials, but its physiological role is poorly understood. We evaluated the concentrations of ureides, amino acids, and organic acids in photosynthetic foliar tissue from Ni-sufficient (Ni-S) versus Ni-deficient (Ni-D) pecan (Carya illinoinensis [Wangenh.] K. Koch). Foliage of Ni-D pecan seedlings exhibited metabolic disruption of nitrogen metabolism via ureide catabolism, amino acid metabolism, and ornithine cycle intermediates. Disruption of ureide catabolism in Ni-D foliage resulted in accumulation of xanthine, allantoic acid, ureidoglycolate, and citrulline, but total ureides, urea concentration, and urease activity were reduced. Disruption of amino acid metabolism in Ni-D foliage resulted in accumulation of glycine, valine, isoleucine, tyrosine, tryptophan, arginine, and total free amino acids, and lower concentrations of histidine and glutamic acid. Ni deficiency also disrupted the citric acid cycle, the second stage of respiration, where Ni-D foliage contained very low levels of citrate compared to Ni-S foliage. Disruption of carbon metabolism was also via accumulation of lactic and oxalic acids. The results indicate that mouse-ear, a key morphological symptom, is likely linked to the toxic accumulation of oxalic and lactic acids in the rapidly growing tips and margins of leaflets. Our results support the role of Ni as an essential plant nutrient element. The magnitude of metabolic disruption exhibited in Ni-D pecan is evidence of the existence of unidentified physiological roles for Ni in pecan.

  11. Crystal and molecular structure of eight organic acid-base adducts from 2-methylquinoline and different acids

    Science.gov (United States)

    Zhang, Jing; Jin, Shouwen; Tao, Lin; Liu, Bin; Wang, Daqi

    2014-08-01

    Eight supramolecular complexes with 2-methylquinoline and acidic components as 4-aminobenzoic acid, 2-aminobenzoic acid, salicylic acid, 5-chlorosalicylic acid, 3,5-dinitrosalicylic acid, malic acid, sebacic acid, and 1,5-naphthalenedisulfonic acid were synthesized and characterized by X-ray crystallography, IR, mp, and elemental analysis. All of the complexes are organic salts except compound 2. All supramolecular architectures of 1-8 involve extensive classical hydrogen bonds as well as other noncovalent interactions. The results presented herein indicate that the strength and directionality of the classical hydrogen bonds (ionic or neutral) between acidic components and 2-methylquinoline are sufficient to bring about the formation of binary organic acid-base adducts. The role of weak and strong noncovalent interactions in the crystal packing is ascertained. These weak interactions combined, the complexes 1-8 displayed 2D-3D framework structure.

  12. Butanol production from sweet sorghum bagasse (SSB) with high solids content: part I – comparison of liquid hot water pretreatment with dilute sulfuric acid

    Science.gov (United States)

    In these studies we pretreated sweet sorghum bagasse (SSB) using liquid hot water (LHW) or dilute H2SO4 (2 g·L-1) at 190 deg C for zero min (as soon as temperature reached 190 deg C, cooling was started) to reduce generation of sugar degradation fermentation inhibiting products such as furfural and ...

  13. Simultaneous analysis of amino acid and organic acid by NMR spectrometry, 2

    International Nuclear Information System (INIS)

    Koda, Naoya; Yamaguchi, Shuichi; Mori, Takeshi.

    1987-01-01

    Analysis of urine from patients with inborn error of metabolism were studied by 1 H-nuclear magnetic resonance (NMR) spectrometry. Diseases studied were as follows; phenylketonuria, biotin responsive multiple carboxylase deficiency, non-ketotic hyperglycinemia, 3-ketothiolase deficiency, alkaptonuria, methylmalonic acidemia, isovaleric acidemia, glutaric aciduria, argininosuccinic aciduria and hyperornithinemia. In each disease, specific metabolites in urine were recognized by NMR spectrometry. This method is accomplished within 10 minutes with non-treated small volume of urine and will be successfully available for the screening and/or diagnosis of inherited metabolic diseases of amino acid and organic acid. (author)

  14. The liquid-liquid extraction of chloro-(trichlorostannato)-rhodium(I/III) and -ruthenium (II) complexes from dilute hydrochloric acid into 4-methylpentan-2-one

    International Nuclear Information System (INIS)

    Wyrley-Birch, J.M.

    1984-10-01

    The effect of stannous chloride on the liquid-liquid extraction of rhodium and ruthenium from hydrochloric acid solutions into 4-methyl-pentan-2-one (MIBK)/hexane mixtures was studied in detail. Stannous chloride concentrations were found to considerably increase the efficiency of the extraction of rhodium and ruthenium into the organic phase. Chloro-(trichlorostannato)-rhodium (I/III) complexes were formed at room temperature. The rate of chloro-(trichlorostannato)-ruthenium (II) complex formation was extremely slow at room temperature, but increased on heating of the aqueous solutions. The amount of rhodium and ruthenium extracted into the organic phase depend on the Sn(II):M molar ratio, the HCl, H sup(+) and Cl sup(-) concentrations, as well as the equilibration time. A 119 Sn NMR study of the MIBK extracts, showed that the stoichiometry of the chloro-(trichlorostannato)-rhodium (I/III) complexes extracted into the organic phase was dependent on the Sn(II):Rh(III) molar ratio as well as the HCl, H sup(+) and Cl sup(-) concentrations in the aqueous phase. The predominant species observed in the organic phase from HCl solutions containing Sn(II):Rh(III) ratios >= 5:1, was shown to be an hydrido complex having the form [RhH(SnCl 3 ) 4 Cl] 3 sup(-) or [RhH(SnCl 3 ) 4 ]2 sup(-). An essentially quantitative separation of rhodium and ruthenium was achieved utilising the variation in the rates of rhodium-tin and ruthenium-tin complex formation

  15. Organic Acids as Hetrotrophic Energy Sources in Hydrothermal Systems

    Science.gov (United States)

    Windman, T. O.; Zolotova, N.; Shock, E.

    2004-12-01

    Many thermophilic microbes are heterotrophs, but little is known about the organic compounds present in hydrothermal ecosystems. More is known about what these organisms will metabolize in lab experiments than what they do metabolize in nature. In an effort to bridge this gap, we have begun to incorporate organic analyses into ongoing research on Yellowstone hydrothermal ecosystems. After filtering at least a liter of hot spring water to minimize contamination, samples were collected into sixty-milliliter serum vials containing ultra-pure phosphoric acid, sodium hydroxide, or benzalkonium chloride. Approximately 80 sites were sampled spanning temperatures from 60 to 90°C and pH values from 2 to 9. Analytical data for organic acid anions (including formate, acetate, lactate, and succinate) were obtained by ion chromatography. Preliminary results indicate that concentrations of organic acids anions range from 5 to 300 ppb. These results can be used with other field and lab data (sulfate, sulfide, nitrate, ammonia, bicarbonate, pH, hydrogen) in thermodynamic calculations to evaluate the amounts of energy available in heterotrophic reactions. Preliminary results of such calculations show that sulfate reduction to sulfide coupled to succinate oxidation to bicarbonate yields about 6 kcal per mole of electrons transferred. When formate oxidation to bicarbonate or hydrogen oxidation to water is coupled to sulfate reduction there is less energy available by approximately a factor of two. A comparison with nitrate reduction to ammonia involving succinate and/or formate oxidation reveals several similarities. Using formate to reduce nitrate can yield about as much energy as nitrate reduction with hydrogen (typically 12 to 14 kcal per mole of electrons transferred), but using succinate can yield more than twice as much energy. In fact, reduction of nitrate with succinate can provide more energy than any of the inorganic nitrate reduction reactions involving sulfur, iron

  16. Determination of activity coefficients at infinite dilution of water and organic solutes (polar and non-polar) in the Ammoeng 100 ionic liquid at T = (308.15, 313.5, 323.15, and 333.15) K

    International Nuclear Information System (INIS)

    Reddy, Prashant; Chiyen, Kaleng J.; Deenadayalu, Nirmala; Ramjugernath, Deresh

    2011-01-01

    Highlights: → Activity coefficients at infinite dilution in the ionic liquid Ammoeng 100. → Twenty-seven solutes investigated at T = (308.15, 313.15, 323.15, and 333.15) K. → Ammoeng 100 not suited to aromatic/aliphatic and alkane/alcohol separations. - Abstract: Activity coefficients at infinite dilution (γ 13 ∞ ) have been determined for 27 solutes, viz. water and organic compounds (n-alkanes, cycloalkanes, 1-alkenes, 1-alkynes, aromatics, alcohols, and ketones) in the ionic liquid Ammoeng 100, by gas-liquid chromatography at four different temperatures, T = (308.15, 313.15, 323.15, and 333.15) K. Columns with different phase loadings (20 to 24)% of the ionic liquid in the stationary phase were employed to obtain γ 13 ∞ values at each temperature investigated. Partial molar excess enthalpies at infinite dilution (ΔH 1 E,∞ ) were calculated for the solutes from the temperature dependency relationship of the ln(γ 13 ∞ ) values for the temperature range in this study. The uncertainties in the determinations of the γ 13 ∞ and ΔH 1 E,∞ values are 6% and 10%, respectively. Selectivity values at infinite dilution (S ij ∞ ), have been computed from the γ 13 ∞ values to assess the potential candidacy of the Ammoeng 100 ionic liquid for the separation of alkane/alcohol mixtures. The results from this study have been compared to those available for several ionic liquids from previous investigations.

  17. Activity coefficients at infinite dilution of organic solutes in the ionic liquid trihexyl(tetradecyl)phosphonium tetrafluoroborate using gas-liquid chromatography at T = (313.15, 333.15, 353.15, and 373.15) K

    International Nuclear Information System (INIS)

    Tumba, Kaniki; Reddy, Prashant; Naidoo, Paramespri; Ramjugernath, Deresh

    2011-01-01

    Research highlights: → Activity coefficients at infinite dilution in the ionic liquid [3C 6 C 14 P][BF 4 ]. → Twenty-seven solutes investigated at T = (313.15, 333.15, 353.15, and 373.15) K. → [3C 6 C 14 P][BF 4 ] shows promise for the separation of aromatic and alcohol mixtures. - Abstract: Activity coefficients at infinite dilution have been measured by gas-liquid chromatography for 27 organic solutes (n-alkanes, 1-alkenes, 1-alkynes, cycloalkanes, aromatics, alcohols, and ketones) in the ionic liquid trihexyl(tetradecyl)phosphonium tetrafluoroborate [3C 6 C 14 P][BF 4 ]. The measurements were carried out at four different temperatures viz.T = (313.15, 333.15, 353.15, and 373.15) K. From the experimental data, partial molar excess enthalpy values at infinite dilution were calculated for the experimental temperature range. The selectivity values for the separation of n-hexane/benzene, cyclohexane/benzene, and methanol/benzene mixtures were determined from the experimental infinite dilution activity coefficient values. These values were compared to those available in the literature for other ionic liquids and commercial solvents, so as to assess the feasibility of employing [3C 6 C 14 P][BF 4 ] in solvent-enhanced industrial separations.

  18. Diffusion cell investigations into the acidic degradation of organic coatings

    DEFF Research Database (Denmark)

    Møller, Victor Buhl; Wang, Ting; Dam-Johansen, Kim

    2018-01-01

    Protective organic coatings work by preventing contact between an aggressive environment and a vulnerable substrate. However, the long required lifetime of a barrier coating provides a challenge when attempting to evaluate coating performance. Diffusion cells can be used as a tool to estimate...... coating barrier properties and lifetime. In this work, a diffusion cell array was designed, constructed, and compared to previous designs, with simplicity being the most important design parameter. Sulfuric acid diffusion through five different coatings was monitored using a battery of cells...

  19. Lignocellulosic Biomass to Ethanol Process Design and Economics Utilizing Co-Current Dilute Acid Prehydrolysis and Enzymatic Hydrolysis for Corn Stover

    Energy Technology Data Exchange (ETDEWEB)

    Aden, A.; Ruth, M.; Ibsen, K.; Jechura, J.; Neeves, K.; Sheehan, J.; Wallace, B.; Montague, L.; Slayton, A.; Lukas, J.

    2002-06-01

    This report is an update of NREL's ongoing process design and economic analyses of processes related to developing ethanol from lignocellulosic feedstocks. The U.S. Department of Energy (DOE) is promoting the development of ethanol from lignocellulosic feedstocks as an alternative to conventional petroleum-based transportation fuels. DOE funds both fundamental and applied research in this area and needs a method for predicting cost benefits of many research proposals. To that end, the National Renewable Energy Laboratory (NREL) has modeled many potential process designs and estimated the economics of each process during the last 20 years. This report is an update of the ongoing process design and economic analyses at NREL. We envision updating this process design report at regular intervals; the purpose being to ensure that the process design incorporates all new data from NREL research, DOE funded research and other sources, and that the equipment costs are reasonable and consistent with good engineering practice for plants of this type. For the non-research areas this means using equipment and process approaches as they are currently used in industrial applications. For the last report, published in 1999, NREL performed a complete review and update of the process design and economic model for the biomass-to-ethanol process utilizing co-current dilute acid prehydrolysis with simultaneous saccharification (enzymatic) and co-fermentation. The process design included the core technologies being researched by the DOE: prehydrolysis, simultaneous saccharification and co-fermentation, and cellulase enzyme production. In addition, all ancillary areas--feed handling, product recovery and purification, wastewater treatment (WWT), lignin combustor and boiler-turbogenerator, and utilities--were included. NREL engaged Delta-T Corporation (Delta-T) to assist in the process design evaluation, the process equipment costing, and overall plant integration. The process design

  20. Organic acids in cloud water and rainwater at a mountain site in acid rain areas of South China.

    Science.gov (United States)

    Sun, Xiao; Wang, Yan; Li, Haiyan; Yang, Xueqiao; Sun, Lei; Wang, Xinfeng; Wang, Tao; Wang, Wenxing

    2016-05-01

    To investigate the chemical characteristics of organic acids and to identify their source, cloud water and rainwater samples were collected at Mount Lu, a mountain site located in the acid rain-affected area of south China, from August to September of 2011 and March to May of 2012. The volume-weighted mean (VWM) concentration of organic acids in cloud water was 38.42 μeq/L, ranging from 7.45 to 111.46 μeq/L, contributing to 2.50 % of acidity. In rainwater samples, organic acid concentrations varied from 12.39 to 68.97 μeq/L (VWM of 33.39 μeq/L). Organic acids contributed significant acidity to rainwater, with a value of 17.66 %. Formic acid, acetic acid, and oxalic acid were the most common organic acids in both cloud water and rainwater. Organic acids had an obviously higher concentration in summer than in spring in cloud water, whereas there was much less discrimination in rainwater between the two seasons. The contribution of organic acids to acidity was lower during summer than during spring in both cloud water (2.20 % in summer vs 2.83 % in spring) and rainwater (12.24 % in summer vs 19.89 % in spring). The formic-to-acetic acid ratio (F/A) showed that organic acids were dominated by primary emissions in 71.31 % of the cloud water samples and whole rainwater samples. Positive matrix factorization (PMF) analysis determined four factors as the sources of organic acids in cloud water, including biogenic emissions (61.8 %), anthropogenic emissions (15.28 %), marine emissions (15.07 %) and soil emissions (7.85 %). The findings from this study imply an indispensable role of organic acids in wet deposition, but organic acids may have a limited capacity to increase ecological risks in local environments.

  1. Metal mobilization from metallurgical wastes by soil organic acids.

    Science.gov (United States)

    Potysz, Anna; Grybos, Malgorzata; Kierczak, Jakub; Guibaud, Gilles; Fondaneche, Patrice; Lens, Piet N L; van Hullebusch, Eric D

    2017-07-01

    Three types of Cu-slags differing in chemical and mineralogical composition (historical, shaft furnace, and granulated slags) and a matte from a lead recovery process were studied with respect to their susceptibility to release Cu, Zn and Pb upon exposure to organic acids commonly encountered in soil environments. Leaching experiments (24-960 h) were conducted with: i) humic acid (20 mg/L) at pH t 0  = 4.4, ii) fulvic acid (20 mg/L) at pH t 0  = 4.4, iii) an artificial root exudates (ARE) (17.4 g/L) solution at pH t 0  = 4.4, iv) ARE solution at pH t 0  = 2.9 and v) ultrapure water (pH t 0  = 5.6). The results demonstrated that the ARE contribute the most to the mobilization of metals from all the wastes analyzed, regardless of the initial pH of the solution. For example, up to 14%, 30%, 24% and 5% of Cu is released within 960 h from historical, shaft furnace, granulated slags and lead matte, respectively, when exposed to the artificial root exudates solution (pH 2.9). Humic and fulvic acids were found to have a higher impact on granulated and shaft furnace slags as compared to the ultrapure water control and increased the release of metals by a factor up to 37.5 (Pb) and 20.5 (Cu) for granulated and shaft furnace slags, respectively. Humic and fulvic acids amplified the mobilization of metals by a maximal factor of 13.6 (Pb) and 12.1 (Pb) for historical slag and lead matte, respectively. The studied organic compounds contributed to different release rates of metallic contaminants from individual metallurgical wastes under the conditions tested. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. The role of organic acids exuded from roots in phosphorus nutrition and aluminium tolerance in acidic soils

    Energy Technology Data Exchange (ETDEWEB)

    Hocking, P J; Randall, P J; Delhaize, E [CSIRO Plant Industry, Canberra (Australia); Keerthisinghe, G [International Atomic Energy Agency, Vienna (Austria)

    2000-06-01

    Soil acidity is a major problem of large areas of arable land on a global scale. Many acid soils are low in plant-available phosphorus (P) or are highly P-fixing, resulting in poor plant growth. In addition, aluminium (Al) is soluble in acid soils in the toxic Al{sup 3+} form, which also reduces plant growth. There is considerable evidence that both P deficiency and exposure to Al{sup 3+} stimulate the efflux of organic acids from roots of a range of species. Organic acids such as citrate, malate and oxalate are able to desorb or solubilise fixed soil P, making it available for plant uptake. Organic acids also chelate Al{sup 3+} to render it non-toxic, and are, therefore, involved in Al tolerance mechanisms. In this review, we discuss the literature on the role of organic acids exuded from roots in improving plant P uptake and Al-tolerance in acid soils. Research is now attempting to understand how P deficiency or exposure to Al{sup 3+} activates or induces organic acid efflux at the molecular level, with the aim of improving P acquisition and Al tolerance by conventional plant breeding and by genetic engineering. At the agronomic level, it is desirable that existing crop and pasture plants with enhanced soil-P uptake and tolerance to Al due to organic acid exudation are integrated into farming systems. (author)

  3. The role of organic acids exuded from roots in phosphorus nutrition and aluminium tolerance in acidic soils

    International Nuclear Information System (INIS)

    Hocking, P.J.; Randall, P.J.; Delhaize, E.; Keerthisinghe, G.

    2000-01-01

    Soil acidity is a major problem of large areas of arable land on a global scale. Many acid soils are low in plant-available phosphorus (P) or are highly P-fixing, resulting in poor plant growth. In addition, aluminium (Al) is soluble in acid soils in the toxic Al 3+ form, which also reduces plant growth. There is considerable evidence that both P deficiency and exposure to Al 3+ stimulate the efflux of organic acids from roots of a range of species. Organic acids such as citrate, malate and oxalate are able to desorb or solubilise fixed soil P, making it available for plant uptake. Organic acids also chelate Al 3+ to render it non-toxic, and are, therefore, involved in Al tolerance mechanisms. In this review, we discuss the literature on the role of organic acids exuded from roots in improving plant P uptake and Al-tolerance in acid soils. Research is now attempting to understand how P deficiency or exposure to Al 3+ activates or induces organic acid efflux at the molecular level, with the aim of improving P acquisition and Al tolerance by conventional plant breeding and by genetic engineering. At the agronomic level, it is desirable that existing crop and pasture plants with enhanced soil-P uptake and tolerance to Al due to organic acid exudation are integrated into farming systems. (author)

  4. The influence of organic acids in relation to acid deposition in controlling the acidity of soil and stream waters on a seasonal basis

    International Nuclear Information System (INIS)

    Chapman, Pippa J.; Clark, Joanna M.; Reynolds, Brian; Adamson, John K.

    2008-01-01

    Much uncertainty still exists regarding the relative importance of organic acids in relation to acid deposition in controlling the acidity of soil and surface waters. This paper contributes to this debate by presenting analysis of seasonal variations in atmospheric deposition, soil solution and stream water chemistry for two UK headwater catchments with contrasting soils. Acid neutralising capacity (ANC), dissolved organic carbon (DOC) concentrations and the Na:Cl ratio of soil and stream waters displayed strong seasonal patterns with little seasonal variation observed in soil water pH. These patterns, plus the strong relationships between ANC, Cl and DOC, suggest that cation exchange and seasonal changes in the production of DOC and seasalt deposition are driving a shift in the proportion of acidity attributable to strong acid anions, from atmospheric deposition, during winter to predominantly organic acids in summer. - Seasonal variations in soil solution ANC is controlled by seasonal variations in seasalt deposition and production of dissolved organic acids

  5. Pretreatment of various feedstocks for lactic acid production: detection of sugars, organic acids and furanics in liquid fractions

    NARCIS (Netherlands)

    Harmsen, P.F.H.; Lips, S.J.J.; Bakker, R.R.C.

    2012-01-01

    Barley straw, sugarcane bagasse and empty fruit bunches were pretreated under acid- and alkaline conditions. Solid phase was separated from the liquid phase and the concentration of dissolved monomeric sugars, organic acids and furanics was determined. Acid hydrolysis yielded monomeric xylose

  6. Activity coefficients at infinite dilution measurements for organic solutes and water in the ionic liquid 4-methyl-N-butyl-pyridinium bis(trifluoromethylsulfonyl)-imide

    Energy Technology Data Exchange (ETDEWEB)

    Domanska, Urszula [Physical Chemistry Department, Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw (Poland)], E-mail: ula@ch.pw.edu.pl; Marciniak, Andrzej [Physical Chemistry Department, Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw (Poland)

    2009-12-15

    The activity coefficients at infinite dilution, {gamma}{sub 13}{sup {infinity}} for 36 solutes: alkanes, cycloalkanes, alkenes, alkynes, aromatic hydrocarbons, alcohols, thiophene, tetrahydrofuran, ethers, acetone, and water in the ionic liquid 4-methyl-N-butyl-pyridinium bis(trifluoromethylsulfonyl)-imide [bmPY][NTf{sub 2}] were determined by gas-liquid chromatography at temperatures from 298.15 K to 368.15 K. The partial molar excess enthalpies at infinite dilution values {delta}H{sub 1}{sup E,{infinity}} were calculated from the experimental {gamma}{sub 13}{sup {infinity}} values obtained over the temperature range. The selectivity for different separation problems were calculated from the {gamma}{sub 13}{sup {infinity}} and compared to the literature values for other ionic liquids, N-methyl-2-pyrrolidinone (NMP) and sulfolane.

  7. Activity coefficients at infinite dilution measurements for organic solutes and water in the ionic liquid 4-methyl-N-butyl-pyridinium bis(trifluoromethylsulfonyl)-imide

    International Nuclear Information System (INIS)

    Domanska, Urszula; Marciniak, Andrzej

    2009-01-01

    The activity coefficients at infinite dilution, γ 13 ∞ for 36 solutes: alkanes, cycloalkanes, alkenes, alkynes, aromatic hydrocarbons, alcohols, thiophene, tetrahydrofuran, ethers, acetone, and water in the ionic liquid 4-methyl-N-butyl-pyridinium bis(trifluoromethylsulfonyl)-imide [bmPY][NTf 2 ] were determined by gas-liquid chromatography at temperatures from 298.15 K to 368.15 K. The partial molar excess enthalpies at infinite dilution values ΔH 1 E,∞ were calculated from the experimental γ 13 ∞ values obtained over the temperature range. The selectivity for different separation problems were calculated from the γ 13 ∞ and compared to the literature values for other ionic liquids, N-methyl-2-pyrrolidinone (NMP) and sulfolane.

  8. Activity coefficients at infinite dilution and physicochemical properties for organic solutes and water in the ionic liquid 4-(2-methoxyethyl)-4-methylmorpholinium trifluorotris(perfluoroethyl)phosphate

    International Nuclear Information System (INIS)

    Wlazło, Michał; Marciniak, Andrzej

    2012-01-01

    Highlights: ► The γ 13 ∞ and K L for 62 solutes in the IL [COC 2 mMOR][FAP] were determined by IGC. ► Partial molar excess thermodynamic functions at infinite dilution were calculated. ► The selectivities and capacities for selected separation problems were calculated. ► LFER system constants as a function of T for [COC 2 mMOR][FAP] were calculated. - Abstract: This paper presents new data on activity coefficients at infinite dilution, γ ∞ for 62 different solutes: alkanes, alkenes, alkynes, cycloalkanes, aromatic hydrocarbons, alcohols, thiophene, ethers, ketones, and water in the ionic liquid 4-(2-methoxyethyl)-4-methylmorpholinium trifluorotris(perfluoroethyl)phosphate, [COC 2 mMOR][FAP]. The data were determined by inverse gas chromatography at six temperatures from T = 318.15 K to T = 368.15 K. These values were compared with ionic liquid based on the same cation and bis(trifluoromethylsulfonyl)-amide anion, [COC 2 mMOR][NTf 2 ]. Additionally the partial molar excess Gibbs free energies ΔG 1 E,∞ , enthalpies ΔH 1 E,∞ , and entropies ΔS 1 E,∞ at infinite dilution were calculated from the experimental γ ∞ values obtained over the temperatures range. The selectivities and capacities at infinite dilution for hexane/benzene, cyclohexane/benzene, and heptane/thiophene extraction problems were calculated from the γ ∞ to verify the possibility of investigated ionic liquid as an entrainer in liquid–liquid extraction and desulphurization of fuels. Obtained values were compared with literature data of other ionic liquids based on trifluorotris(perfluoroethyl)phosphate and bis(trifluoromethylsulfonyl)-amide anions and industrial solvents: NMP and sulfolane. Also the Abraham solvation parameter model was used for evaluation of the solvation characteristic of the ionic liquid. Linear free energy relationship (LFER) system constants as a function of temperature were calculated.

  9. Gas-liquid chromatography measurements of activity coefficients at infinite dilution of various organic solutes and water in tri-iso-butylmethylphosphonium tosylate ionic liquid

    International Nuclear Information System (INIS)

    Domanska, Urszula; Paduszynski, Kamil

    2010-01-01

    Activity coefficients at infinite dilution (γ 13 ∞ ) of 33 different solutes (including alkanes, cycloalkanes, alkenes, alkynes, benzene, alkylbenzenes, water, alcohols, MTBE, thiophene and THF) in the ionic liquid tri-iso-butylmethylphosphonium tosylate have been determined by using the GLC method and have been reported over the temperature range (298.15 to 368.15) K. The partial molar excess enthalpies of mixing at infinite dilution have been determined based on temperature dependence of γ 13 ∞ . Selectivity and capacity at infinite dilution has been also calculated for exemplary separation processes in systems n-hexane/benzene and n-hexane/thiophene, to evaluate if the studied ionic liquid is capable to be a good entrainer for these processes, e.g. in the liquid-liquid extraction. The obtained results are promising however the ionic liquid studied shows a lower selectivity than some of imidazolium-based ionic liquids. To our best knowledge, the results indicate that tri-iso-butylmethylphosphonium tosylate is the best for the separation problem of aliphatic hydrocarbons from aromatic hydrocarbons among all of the studied quaternary phosphonium-based ionic liquids.

  10. Activity coefficients at infinite dilution and physicochemical properties for organic solutes and water in the ionic liquid 1-(2-methoxyethyl)-1-methylpiperidinium bis(trifluoromethylsulfonyl)-amide

    International Nuclear Information System (INIS)

    Marciniak, Andrzej; Wlazło, Michał

    2012-01-01

    Highlights: The and KL for 61 solutes in the ionic liquid [COC2mPIP][NTf2] were determined by IGC at different temperatures. ► The partial molar excess Gibbs energies, enthalpies and entropies at infinite dilution were calculated. ► The selectivities for selected compounds which form azeotropic mixtures were calculated and compared to other ILs. ► LFER system constants as a function of temperature for [COC2mPIP][NTf2] were calculated. - Abstract: The activity coefficients at infinite dilution, γ ∞ and gas–liquid partition coefficients, K L for 61 solutes: alkanes, alkenes, alkynes, cycloalkanes, aromatic hydrocarbons, alcohols, thiophene, ethers, ketones, esters, 1-nitropropane, butanal, acetonitrile, and water in the ionic liquid 1-(2-methoxyethyl)-1-methylpiperidinium bis(trifluoromethylsulfonyl)-amide were determined by inverse gas chromatography at the temperatures from (318.15 to 368.15) K. The partial molar excess Gibbs free energies ΔG 1 E,∞ , enthalpies ΔH 1 E,∞ and entropies ΔS 1 E,∞ at infinite dilution were calculated from the experimental γ ∞ values obtained over the temperature range. The selectivities for selected compounds, which form azeotropic mixtures, were calculated from the γ ∞ and compared to the literature values for other ionic liquids based on bis(trifluoromethylsulfonyl)-amide anion.

  11. Sensitive determination of nucleic acids using organic nanoparticle fluorescence probes

    Science.gov (United States)

    Zhou, Yunyou; Bian, Guirong; Wang, Leyu; Dong, Ling; Wang, Lun; Kan, Jian

    2005-06-01

    This paper describes the preparation of organic nanoparticles by reprecipitation method under sonication and vigorous stirring. Transmission electron microscopy (TEM) was used to characterize the size and size distribution of the luminescent nanoparticles. Their average diameter was about 25 nm with a size variation of ±18%. The fluorescence decay lifetime of the nanoparticles also was determined on a self-equipped fluorospectrometer with laser light source. The lifetime (˜0.09 μs) of nanoparticles is about three times long as that of the monomer. The nanoparticles were in abundant of hydrophilic groups, which increased their miscibility in aqueous solution. These organic nanoparticles have high photochemical stability, excellent resistance to chemical degradation and photodegradation, and a good fluorescence quantum yield (25%). The fluorescence can be efficiently quenched by nucleic acids. Based on the fluorescence quenching of nanoparticles, a fluorescence quenching method was developed for determination of microamounts of nucleic acids by using the nanoparticles as a new fluorescent probe. Under optimal conditions, maximum fluorescence quenching is produced, with maximum excitation and emission wavelengths of 345 and 402 nm, respectively. Under optimal conditions, the calibration graphs are linear over the range 0.4-19.0 μg ml -1 for calf thymus DNA (ct-DNA) and 0.3-19.0 μg ml -1 for fish sperm DNA (fs-DNA). The corresponding detection limits are 0.25 μg ml -1 for ct-DNA and 0.17 μg ml -1 for fs-DNA. The relative standard deviation of six replicate measurements is 1.3-2.1%. The method is simple, rapid and sensitive with wide linear range. The recovery and relative standard deviation are very satisfactory.

  12. Mannan-oligosaccharide and organic acids for weaned piglets

    Directory of Open Access Journals (Sweden)

    Marcia de Souza Vieira

    2017-08-01

    Full Text Available This study aimed to evaluate the effect of acetic, propionic, and formic (50% organic acids and mannan-oligosaccharide (50% on growth performance, digestibility, and faecal score in challenged weaned piglets. Twenty male piglets (5.57 ± 0.32 kg of BW; 21-24 days of age were housed individually in metabolic cages for 28 days in an acclimatised room. The treatments were composed of the inclusion (0.1%; n = 10 or not (n = 10 of additive in the diet. The experimental design was completely randomised with two treatments, 10 replicates, and one piglet per replicate. The nutritional matrix was supplemented with 10% of barley and 35.9 to 34.0% of soybean meal in the pre-starter diet (3-14 days post-weaning and the starter diet (15-28 days post-weaning, respectively, to cause an intestinal challenge. Diets did not include any antimicrobial or growth promoters. Weekly, the animal and the leftover diet were weighed to evaluate growth performance. Digestibility was evaluated through total faeces and urine collection. Piglets fed diets with additive had 8.7% greater weight gain (P < 0.05 compared to those piglets in the control treatment in the starter phase. For other growth performance responses there was no treatment effect. Similarly, the inclusion of additive in the piglet diets did not affect the faecal score or the energy and nutrient digestibility. In the starter phase and throughout the experimental period, piglets fed diets with additive had 18.37% and 15.07% greater nitrogen (N intake and 19.53% and 16.05% greater N retention, respectively, compared to piglets in the control treatment (P < 0.05. In conclusion, the addition of additive composed by organic acids and mannan-oligosaccharide does not improve energy and nutrient digestibility but increases the N retention and weight gain in weaned piglets in the starting phase.

  13. Effects of organic acid pickling on the corrosion resistance of magnesium alloy AZ31 sheet

    DEFF Research Database (Denmark)

    Nwaogu, Ugochukwu Chibuzoh; Blawert, C.; Scharnagl, N.

    2010-01-01

    mu m of the contaminated surface was required to reach corrosion rates less than 1 mm/year in salt spray condition. Among the three organic acids examined, acetic acid is the best choice. Oxalic acid can be an alternative while citric acid is not suitable for cleaning AZ31 sheet, because......Organic acids were used to clean AZ31 magnesium alloy sheet and the effect of the cleaning processes on the surface condition and corrosion performance of the alloy was investigated. Organic acid cleanings reduced the surface impurities and enhanced the corrosion resistance. Removal of at least 4...

  14. Production of volatile fatty acid in the rumen and its relationship with their concentration, intake of dry matter and digestible organic matter in buffalo (Bos bubalis) calves

    International Nuclear Information System (INIS)

    Verma, D.N.; Singh, U.B.

    1979-01-01

    The production rates of total volatile fatty acid (TVFA) in the rumen of buffalo (Bos bubalis) calves were estimated using a single injection isotope dilution technique. A series of twelve experiments were done with animals given wheat straw and concentrate mixture. The production rate of TVFA ranged from 19.77 to 24.84 moles/d depending upon the amount of food consumed by the animals. Highly significant correlations were observed between TVFA production and their concentration, dry matter and digestible organic matter intake. (auth.)

  15. Highly thermal-stable and functional cellulose nanocrystals and nanofibrils produced using fully recyclable organic acids

    Science.gov (United States)

    Liheng Chen; Junyong Zhu; Carlos Baez; Peter Kitin; Thomas Elder

    2016-01-01

    Here we report the production of highly thermal stable and functional cellulose nanocrystals (CNC) and nanofibrils (CNF) by hydrolysis using concentrated organic acids. Due to their low water solubility, these solid organic acids can be easily recovered after hydrolysis reactions through crystallization at a lower or ambient temperature. When dicarboxylic acids were...

  16. Recovery of Organic and Amino Acids from Sludge and Fish Waste in Sub Critical Water Conditions

    Directory of Open Access Journals (Sweden)

    Muhammad Faisal

    2011-12-01

    Full Text Available The possibility of organic and amino acid production from the treatment of sludge and fish waste using water at sub critical conditions was investigated. The results indicated that at sub-critical conditions, where the ion product of water went through a maximum, the formation of organic acids was favorable. The presence of oxidant favored formation of acetic and formic acid. Other organic acids of significant amount were propionic, succinic and lactic acids. Depending on the type of wastes, formation of other organic acids was also possible. Knowing the organic acids obtained by hydrolysis and oxidation in sub-critical water of various wastes are useful in designing of applicable waste treatment process, complete degradation of organic wastes into volatile carbon and water, and also on the viewpoint of resource recovery. The production of lactic acid was discussed as well. The results indicated that temperature of 573 K, with the absence of oxidant, yield of lactic acid from fish waste was higher than sewage sludge. The maximum yield of total amino acids (137 mg/g-dry fish from waste fish entrails was obtained at subcritical condition (T = 523 K, P = 4 MPa at reaction time of 60 min by using the batch reactor. The amino acids obtained in this study were mainly alanine and glycine. Keywords:  organic acids, amino acids, sub-critical water, hydrothermal, resources recovery

  17. Activity coefficients at infinite dilution of organic solutes in the ionic liquid, methyl(trioctyl)ammonium thiosalicylate, [N1888][TS] by gas-liquid chromatography at T = (303.15, 313.15, and 323.15) K

    International Nuclear Information System (INIS)

    Reddy, Prashant; Gwala, Nobuhle V.; Deenadayalu, Nirmala; Ramjugernath, Deresh

    2011-01-01

    Research highlights: → Ammonium ionic liquid selectivity value lower than for imidazolium ionic liquid. → Ammonium ionic liquids with smaller alkyl groups have higher selectivity values. → For the same cation the [TS] anion has a higher selectivity than the [NTf 2 ]. - Abstract: In this work, activity coefficients at infinite dilution (γ 13 ∞ ) have been obtained for 19 polar and non-polar organic solutes in the form of n-alkanes, cycloalkanes, 1-alkenes, 1-alkynes, aromatic compounds, and ketones in the ionic liquid methyl(trioctyl)ammonium thiosalicylate by gas-liquid chromatography at three different temperatures, i.e. T = (303.15, 313.15, and 323.15) K. Two columns with different phase loadings of the ionic liquid in the stationary phase (25% and 30%) were employed to obtain γ 13 ∞ values at each temperature investigated. Partial molar excess enthalpies at infinite dilution (ΔH 1 E,∞ ) were calculated for each of the solutes from the temperature dependency of the γ 13 ∞ values for the temperature range in this study. Selectivity values at infinite dilution (S ij ∞ ) were computed from the γ 13 ∞ values to screen the potential candidacy of the ionic liquid for the separation of n-hexane/benzene mixtures. The results from this study have been compared to those available for several other classes of ionic liquids and commercial solvents employed in solvent-enhanced industrial separation processes.

  18. Dynamics of three organic acids (malic, acetic and succinic acid) in sunflower exposed to cadmium and lead.

    Science.gov (United States)

    Niu, Zhixin; Li, Xiaodong; Sun, Lina; Sun, Tieheng

    2013-01-01

    Sunflower (Helianthus annuus L.) has been considered as a good candidate for bioaccumulation of heavy metals. In the present study, sunflower was used to enrich the cadmium and lead in sand culture during 90 days. Biomass, Cd and Pb uptake, three organic acids and pH in cultures were investigated. Results showed that the existence of Cd and Pb showed different interactions on the organic acids exudation. In single Cd treatments, malic and acetic acids in Cd10 showed an incremental tendency with time. In the mixed treatments of Cd and Pb, malic acids increased when 10 and 40 mg x L(-1) Cd were added into Pb50, but acetic acids in Pb50 were inhibited by Cd addition. The Cd10 supplied in Pb10 stimulated the secretion of malic and succinic acids. Moreover, the Cd or Pb uptake in sunflower showed various correlations with pH and some organic acids, which might be due to the fact that the Cd and Pb interfere with the organic acids secretion in rhizosphere of sunflower, and the changes of organic acids altered the form and bioavailability of Cd and Pb in cultures conversely.

  19. Amino acids and hexosamines as indicators of organic matter degradation state in North Sea sediments

    NARCIS (Netherlands)

    Dauwe, B.; Middelburg, J.J.

    1998-01-01

    Sediment cores from six stations in the eastern North Sea were analyzed for protein amino acids, the nonprotein amino acids beta-alanine and gamma-aminobutyric acid and the hexosamines galactosamine and glucosamine, and bulk parameters (organic carbon, nitrogen, total hydrolyzable amino acids and

  20. Determination of organic acids evolution during apple cider fermentation using an improved HPLC analysis method

    NARCIS (Netherlands)

    Zhang, H.; Zhou, F.; Ji, B.; Nout, M.J.R.; Fang, Q.; Zhang, Z.

    2008-01-01

    An efficient method for analyzing ten organic acids in food, namely citric, pyruvic, malic, lactic, succinic, formic, acetic, adipic, propionic and butyric acids, using HPLC was developed. Boric acid was added into the mobile phase to separate lactic and succinic acids, and a post-column buffer

  1. Leaching of organic acids from macromolecular organic matter by non-supercritical CO2

    Science.gov (United States)

    Sauer, P.; Glombitza, C.; Kallmeyer, J.

    2012-04-01

    The storage of CO2 in underground reservoirs is discussed controversly in the scientific literature. The worldwide search for suitable storage formations also considers coal-bearing strata. CO2 is already injected into seams for enhanced recovery of coal bed methane. However, the effects of increased CO2 concentration, especially on organic matter rich formations, are rarely investigated. The injected CO2 will dissolve in the pore water, causing a decrease in pH and resulting in acidic formation waters. Huge amounts of low molecular weight organic acids (LMWOAs) are chemically bound to the macromolecular matrix of sedimentary organic matter and may be liberated by hydrolysis, which is enhanced by the acidic porewater. Recent investigations outlined the importance of LMWOAs as a feedstock for microbial life in the subsurface [1]. Therefore, injection of CO2 into coal formations may result in enhanced nutrient supply for subsurface microbes. To investigate the effect of high concentrations of dissolved CO2 on the release of LMWOAs from coal we developed an inexpensive high-pressure high temperature system that allows manipulating the partial pressure of dissolved gases at pressures and temperatures up to 60 MPa and 120° C, respectively. In a reservoir vessel, gases are added to saturate the extraction medium to the desired level. Inside the extraction vessel hangs a flexible and inert PVDF sleeve (polyvinylidene fluoride, almost impermeable for gases), holding the sample and separating it from the pressure fluid. The flexibility of the sleeve allows for subsampling without loss of pressure. Coal samples from the DEBITS-1 well, Waikato Basin, NZ (R0 = 0.29, TOC = 30%). were extracted at 90° C and 5 MPa, either with pure or CO2-saturated water. Subsamples were taken at different time points during the extraction. The extracted LMWOAs such as formate, acetate and oxalate were analysed by ion chromatography. Yields of LMWOAs were higher with pure water than with CO2

  2. The reliability of grazing rate estimates from dilution experiments: Have we over-estimated rates of organic carbon consumption by microzooplankton?

    Directory of Open Access Journals (Sweden)

    J. R. Dolan,

    2005-01-01

    Full Text Available According to a recent global analysis, microzooplankton grazing is surprisingly invariant, ranging only between 59 and 74% of phytoplankton primary production across systems differing in seasonality, trophic status, latitude, or salinity. Thus an important biological process in the world ocean, the daily consumption of recently fixed carbon, appears nearly constant. We believe this conclusion is an artefact because dilution experiments are 1 prone to providing over-estimates of grazing rates and 2 unlikely to furnish evidence of low grazing rates. In our view the overall average rate of microzooplankton grazing probably does not exceed 50% of primary production and may be even lower in oligotrophic systems.

  3. Volumetric properties of ascorbic acid (vitamin C) and thiamine hydrochloride (vitamin B1) in dilute HCl and in aqueous NaCl solutions at (283.15, 293.15, 298.15, 303.15, 308.15, and 313.15) K

    International Nuclear Information System (INIS)

    Ayranci, Guler; Sahin, Melike; Ayranci, Erol

    2007-01-01

    Apparent molar volumes and apparent molar isentropic compressibilities of ascorbic acid (vitamin C) and thiamine hydrochloride (vitamin B 1 ) were determined from accurately measured density and sound velocity data in water and in aqueous NaCl solutions at (283.15, 293.15, 298.15, 303.15, 308.15, and 313.15) K. These volume and compressibility data were extrapolated to zero concentration using suitable empirical or theoretical equations to determine the corresponding infinite dilution values. Apparent molar expansibilities at infinite dilution were determined from slopes of apparent molar volume vs. temperature plots. Ionization of both ascorbic acid and thiamine hydrochloride were suppressed using sufficiently acidic solutions. Apparent molar volumes at infinite dilution for ascorbic acid and thiamine hydrochloride were found to increase with temperature in acidic solutions and in the presence of co-solute, NaCl. Apparent molar expansibility at infinite dilution were found to be constant over the temperature range studied and were all positive, indicating the hydrophilic character of the two vitamins studied in water and in the presence of co-solute, NaCl. Apparent molar isentropic compressibilities of ascorbic acid at infinite dilution were positive in water and in the presence of co-solute, NaCl, at low molalities. Those of thiamine hydrochloride at infinitive dilution were all negative, consistent with its ionic nature. Transfer apparent molar volumes of vitamins at infinite dilution from water solutions to NaCl solutions at various temperatures were determined. The results were interpreted in terms of complex vitamin-water-co-solute (NaCl) interactions

  4. Effects of organic acids, amino acids and ethanol on the radio-degradation of patulin in an aqueous model system

    International Nuclear Information System (INIS)

    Yun, Hyejeong; Lim, Sangyong; Jo, Cheorun; Chung, Jinwoo; Kim, Soohyun; Kwon, Joong-Ho; Kim, Dongho

    2008-01-01

    The effects of organic acids, amino acids, and ethanol on the radio-degradation of patulin by gamma irradiation in an aqueous model system were investigated. The patulin, dissolved in distilled water at a concentration of 50 ppm, was practically degraded by the gamma irradiation at the dose of 1.0 kGy, while 33% of the patulin remained in apple juice. In the aqueous model system, the radio-degradation of patulin was partially inhibited by the addition of organic acids, amino acids, and ethanol. The proportions of remaining patulin after irradiation with the dose of 1.0 kGy in the 1% solution of malic acid, citric acid, lactic acid, acetic acid, ascorbic acid, and ethanol were 31.4%, 2.3%, 31.2%, 6.1%, 50.8%, and 12.5%, respectively. During 30 days of storage, the remaining patulin was reduced gradually in the solution of ascorbic acid and malic acid compared to being stable in other samples. The amino acids, serine, threonine, and histidine, inhibited the radio-degradation of patulin. In conclusion, it was suggested that 1 kGy of gamma irradiation (recommended radiation doses for radicidation and/or quarantine in fruits) is effective for the reduction of patulin, but the nutritional elements should be considered because the radio-degradation effects are environment dependent

  5. PCI-GC-MS-MS approach for identification of non-amino organic acid and amino acid profiles.

    Science.gov (United States)

    Luan, Hemi; Yang, Lin; Ji, Fenfen; Cai, Zongwei

    2017-03-15

    Alkyl chloroformate have been wildly used for the fast derivatization of metabolites with amino and/or carboxyl groups, coupling of powerful separation and detection systems, such as GC-MS, which allows the comprehensive analysis of non-amino organic acids and amino acids. The reagents involving n-alkyl chloroformate and n-alcohol are generally employed for providing symmetric labeling terminal alkyl chain with the same length. Here, we developed an asymmetric labeling strategy and positive chemical ionization gas chromatography-tandem mass spectrometry (PCI-GC-MS-MS) approach for determination of non-amino organic acids and amino acids, as well as the short chain fatty acids. Carboxylic and amino groups could be selectively labelled by propyl and ethyl groups, respectively. The specific neutral loss of C 3 H 8 O (60Da), C 3 H 5 O 2 (74Da) and C 4 H 8 O 2 (88Da) were useful in the selective identification for qualitative analysis of organic acids and amino acid derivatives. PCI-GC-MS-MS using multiple reaction monitoring (MRM) was applied for semi-quantification of typical non-amino organic acids and amino acids. This method exhibited a wide range of linear range, good regression coefficient (R 2 ) and repeatability. The relative standard deviation (RSD) of targeted metabolites showed excellent intra- and inter-day precision (chloroformate derivatization. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Hybridizing pines with diluted pollen

    Science.gov (United States)

    Robert Z. Callaham

    1967-01-01

    Diluted pollens would have many uses by the tree breeder. Dilutions would be particularly advantageous in making many controlled pollinations with a limited amount of pollen. They also would be useful in artificial mass pollinations of orchards or single trees. Diluted pollens might help overcome troublesome genetic barriers to crossing. Feasibility o,f using diluted...

  7. Low-Vacuum Deposition of Glutamic Acid and Pyroglutamic Acid: A Facile Methodology for Depositing Organic Materials beyond Amino Acids.

    Science.gov (United States)

    Sugimoto, Iwao; Maeda, Shunsaku; Suda, Yoriko; Makihara, Kenji; Takahashi, Kazuhiko

    2014-01-01

    Thin layers of pyroglutamic acid (Pygl) have been deposited by thermal evaporation of the molten L-glutamic acid (L-Glu) through intramolecular lactamization. This deposition was carried out with the versatile handmade low-vacuum coater, which was simply composed of a soldering iron placed in a vacuum degassing resin chamber evacuated by an oil-free diaphragm pump. Molecular structural analyses have revealed that thin solid film evaporated from the molten L-Glu is mainly composed of L-Pygl due to intramolecular lactamization. The major component of the L-Pygl was in β-phase and the minor component was in γ-phase, which would have been generated from partial racemization to DL-Pygl. Electron microscopy revealed that the L-Glu-evaporated film generally consisted of the 20 nm particulates of Pygl, which contained a periodic pattern spacing of 0.2 nm intervals indicating the formation of the single-molecular interval of the crystallized molecular networks. The DL-Pygl-evaporated film was composed of the original DL-Pygl preserving its crystal structures. This methodology is promising for depositing a wide range of the evaporable organic materials beyond amino acids. The quartz crystal resonator coated with the L-Glu-evaporated film exhibited the pressure-sensing capability based on the adsorption-desorption of the surrounding gas at the film surface.

  8. Simultaneous treatment of chlorinated organics and removal of metals and radionuclides with bimetals and complexing acids - application to surfactant solutions

    Energy Technology Data Exchange (ETDEWEB)

    Korte, N.E.; Gu, B. [Oak Ridge National Lab., TN (United States)

    1997-10-01

    Currently available methods for separation and treatment of radioactive mixed waste are typically energy-intensive, and often require high temperatures. Passive methods that operate at ambient temperatures are needed. The purpose of this task is to develop bimetallic substrates, using a base metal such as iron and a promoter metal such as palladium (Pd), to provide a passive, low-energy solution to a substantial portion of DOE`s mixed-waste problem. This technology consists of a porous medium that can simultaneously dechlorinate hazardous organics such as TCE and polychlorinated biphenyls (PCBs) at the same time that it removes metallic and hazardous wastes from a solvent/surfactant solution. The porous medium consists of a bimetallic substrate such as palladized iron (Pd/Fe). Palladium is readily chemically plated on iron and preliminary studies suggest that only 0.05 to 0.1% Pd is needed for an efficient reaction. Thus, the cost of the material is reasonable especially is it is long-lived or can be regenerated. Field implementation would consist of the passage of a surfactant-laden, mixed waste through a column or bed of the bimetallic substrate. The organic component of this mixed waste may contain semivolatile compounds such as PCBs or pesticides and herbicides. The bimetal simultaneously removes radionuclides and metals and degrades halogenated hydrocarbons. Virtually any concentration can be treated. Following reaction of the bimetal with the waste stream, the resulting effluent will consist of an uncontaminated aqueous solution of surfactant or solvent that can be reused. The bimetal would then be rinsed with a dilute mineral acid or a mild complexing acid (e.g., oxalic or citric acid) to regenerate the surface and to remove sorbed metals and non-hazardous organic residue. The latter effluent would be low-level radioactive waste in some cases, but it would now be much easier to manage and be of a lower volume than the original mixed waste.

  9. Changes in Lignin and Polysaccharide Components in 13 Cultivars of Rice Straw following Dilute Acid Pretreatment as Studied by Solution-State 2D 1H-13C NMR

    Science.gov (United States)

    Teramura, Hiroshi; Sasaki, Kengo; Oshima, Tomoko; Aikawa, Shimpei; Matsuda, Fumio; Okamoto, Mami; Shirai, Tomokazu; Kawaguchi, Hideo; Ogino, Chiaki; Yamasaki, Masanori; Kikuchi, Jun; Kondo, Akihiko

    2015-01-01

    A renewable raw material, rice straw is pretreated for biorefinery usage. Solution-state two-dimensional (2D) 1H-13 C hetero-nuclear single quantum coherence (HSQC) nuclear magnetic resonance (NMR) spectroscopy, was used to analyze 13 cultivars of rice straw before and after dilute acid pretreatment, to characterize general changes in the lignin and polysaccharide components. Intensities of most (15 of 16) peaks related to lignin aromatic regions, such as p-coumarate, guaiacyl, syringyl, p-hydroxyphenyl, and cinnamyl alcohol, and methoxyl, increased or remained unchanged after pretreatment. In contrast, intensities of most (11 of 13) peaks related to lignin aliphatic linkages or ferulate decreased. Decreased heterogeneity in the intensities of three peaks related to cellulose components in acid-insoluble residues resulted in similar glucose yield (0.45–0.59 g/g-dry biomass). Starch-derived components showed positive correlations (r = 0.71 to 0.96) with glucose, 5-hydroxymethylfurfural (5-HMF), and formate concentrations in the liquid hydrolysates, and negative correlations (r = –0.95 to –0.97) with xylose concentration and acid-insoluble residue yield. These results showed the fate of lignin and polysaccharide components by pretreatment, suggesting that lignin aromatic regions and cellulose components were retained in the acid insoluble residues and starch-derived components were transformed into glucose, 5-HMF, and formate in the liquid hydrolysate. PMID:26083431

  10. On the microstructure of organic solutions of mono-carboxylic acids: Combined study by infrared spectroscopy, small-angle neutron scattering and molecular dynamics simulations

    Energy Technology Data Exchange (ETDEWEB)

    Eremin, Roman A., E-mail: era@jinr.ru [Joint Institute for Nuclear Research, Dubna 141980 (Russian Federation); Kholmurodov, Kholmirzo T. [Joint Institute for Nuclear Research, Dubna 141980 (Russian Federation); International University “Dubna”, Dubna 141980 (Russian Federation); Petrenko, Viktor I. [Joint Institute for Nuclear Research, Dubna 141980 (Russian Federation); Taras Shevchenko National University of Kyiv, Kyiv 03022 (Ukraine); Rosta, László [Wigner Research Centre for Physics, Hungarian Academy of Sciences, Budapest H-1525 (Hungary); Grigoryeva, Natalia A. [Faculty of Physics, Saint-Petersburg State University, 198504 Saint-Petersburg (Russian Federation); Avdeev, Mikhail V. [Joint Institute for Nuclear Research, Dubna 141980 (Russian Federation)

    2015-11-05

    Highlights: • The model of the scattering particle for a reliable SANS analysis is proposed. • The structural parameters of saturated mono-carboxylic acids in solutions are obtained. • The differences in nematic transitions correlate to solvation peculiarities. - Abstract: The data of infrared spectroscopy (IR), molecular dynamics (MD) simulations and small-angle neutron scattering (SANS) have been combined to conclude about the nanoscale structural organization of organic non-polar solutions of saturated mono-carboxylic acids with different alkyl chain lengths for diluted solutions of saturated myristic (C14) and stearic (C18) acids in benzene and decalin. In particular, the degree of dimerization was found from the IR spectra. The structural anisotropy of the acids and their dimers was used in the treatment of the data of MD simulations to describe the solute–solvent interface in a cylindrical approximation and show its rather strong influence on SANS. The corresponding scattering length density profiles were used to fit the experimental SANS data comprising the information about the acid molecule isomerization. The SANS data from concentrated solutions showed a partial self-assembling of the acids within the nematic transition is different for two solvents due to lyophobic peculiarities.

  11. Gluconeogenesis from labeled carbon: estimating isotope dilution

    International Nuclear Information System (INIS)

    Kelleher, J.K.

    1986-01-01

    To estimate the rate of gluconeogenesis from steady-state incorporation of labeled 3-carbon precursors into glucose, isotope dilution must be considered so that the rate of labeling of glucose can be quantitatively converted to the rate of gluconeogenesis. An expression for the value of this isotope dilution can be derived using mathematical techniques and a model of the tricarboxylic acid (TCA) cycle. The present investigation employs a more complex model than that used in previous studies. This model includes the following pathways that may affect the correction for isotope dilution: 1) flux of 3-carbon precursor to the oxaloacetate pool via acetyl-CoA and the TCA cycle; 2) flux of 4- or 5-carbon compounds into the TCA cycle; 3) reversible flux between oxaloacetate (OAA) and pyruvate and between OAA and fumarate; 4) incomplete equilibrium between OAA pools; and 5) isotope dilution of 3-carbon tracers between the experimentally measured pool and the precursor for the TCA-cycle OAA pool. Experimental tests are outlined which investigators can use to determine whether these pathways are significant in a specific steady-state system. The study indicated that flux through these five pathways can significantly affect the correction for isotope dilution. To correct for the effects of these pathways an alternative method for calculating isotope dilution is proposed using citrate to relate the specific activities of acetyl-CoA and OAA

  12. Pilot-scale recovery of low molecular weight organic acids from ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-11-05

    Nov 5, 2008 ... 2Graduate School of Life Science and Systems Engineering, Kyushu Institute of Technology, 2-4 Hibiniko, Wakamatsu- ... 2000) as well as for the recovery of organic acids from ..... Fellowship from Third World Organization for.

  13. Gangue minerals reactivity in oxidative leaching of uraninite with dilute sulfuric acid from low-grade ores. An approach for better leach liquor purity

    International Nuclear Information System (INIS)

    Madakkaruppan, V.; Chanchal Sarbajna; Pius, Anitha; Sreenivas, T.

    2016-01-01

    This paper presents results of sulfuric acid leaching studies carried out on a low-grade uranium ore with emphasis on attaining maximum uranium leachability with minimum content of detrimental ions like Si, Al, Fe, Mg and P, which originate from reactive gangue minerals like chlorite, biotite and apatite. A 'two-stage leaching' scheme was developed wherein the total reaction time and the pH of the slurry were split such that the initial phase consists of higher acidity with shorter reaction period and the later phase involves reduced acidity and longer reaction time. This modification gives leach liquor of higher purity with good uranium leachability at relatively lower acid consumption. (author)

  14. Quantification of N-acetyl- and N-glycolylneuraminic acids by a stable isotope dilution assay using high-performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Allevi, Pietro; Femia, Eti Alessandra; Costa, Maria Letizia; Cazzola, Roberta; Anastasia, Mario

    2008-11-28

    The present report describes a method for the quantification of N-acetyl- and N-glycolylneuraminic acids without any derivatization, using their (13)C(3)-isotopologues as internal standards and a C(18) reversed-phase column modified by decylboronic acid which allows for the first time a complete chromatographic separation between the two analytes. The method is based on high-performance liquid chromatographic coupled with electrospray ion-trap mass spectrometry. The limit of quantification of the method is 0.1mg/L (2.0ng on column) for both analytes. The calibration curves are linear for both sialic acids over the range of 0.1-80mg/L (2.0-1600ng on column) with a correlation coefficient greater than 0.997. The proposed method was applied to the quantitative determination of sialic acids released from fetuin as a model of glycoproteins.

  15. Toxicity of Select Organic Acids to the Slightly Thermophilic Acidophile Acidithiobaccillus Caldus

    Energy Technology Data Exchange (ETDEWEB)

    John E Aston; William A Apel; Brady D Lee; Brent M Peyton

    2009-02-01

    Acidithiobacillus caldus is a thermophilic acidophile found in commercial biomining, acid mine drainage systems, and natural environments. Previous work has characterized A. caldus as a chemolithotrophic autotroph capable of utilizing reduced sulfur compounds under aerobic conditions. Organic acids are especially toxic to chemolithotrophs in low-pH environments, where they diffuse more readily into the cell and deprotonate within the cytoplasm. In the present study, the toxic effects of oxaloacetate, pyruvate, 2-ketoglutarate, acetate, malate, succinate, and fumarate on A. caldus strain BC13 were examined under batch conditions. All tested organic acids exhibited some inhibitory effect. Oxaloacetate was observed to inhibit growth completely at a concentration of 250 µM, whereas other organic acids were completely inhibitory at concentrations of between 1,000 and 5,000 µM. In these experiments, the measured concentrations of organic acids decreased with time, indicating uptake or assimilation by the cells. Phospholipid fatty acid analyses indicated an effect of organic acids on the cellular envelope. Notable differences included an increase in cyclic fatty acids in the presence of organic acids, indicating possible instability of the cellular envelope. This was supported by field emission scanning-electron micrographs showing blebbing and sluffing in cells grown in the presence of organic acids.

  16. Characteristics of organic acids in the fruit of different pumpkin species.

    Science.gov (United States)

    Nawirska-Olszańska, Agnieszka; Biesiada, Anita; Sokół-Łętowska, Anna; Kucharska, Alicja Z

    2014-04-01

    The aim of the research was to determine the composition of organic acids in fruit of different cultivars of three pumpkin species. The amount of acids immediately after fruit harvest and after 3 months of storage was compared. The content of organic acids in the examined pumpkin cultivars was assayed using the method of high performance liquid chromatography (HPLC). Three organic acids (citric acid, malic acid, and fumaric acid) were identified in the cultivars, whose content considerably varied depending on a cultivar. Three-month storage resulted in decreased content of the acids in the case of cultivars belonging to Cucurbita maxima and Cucurbita pepo species, while a slight increase was recorded for Cucurbita moschata species. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

  17. An interlaboratory comparison of the performance of ethanol-producing micro-organisms in a xylose-rich acid hydrolysate

    Energy Technology Data Exchange (ETDEWEB)

    Hahn-Haegerdal, B. (Dept. of Applied Microbiology, Lund Inst. of Technology/Univ. of Lund (Sweden)); Jeppsson, H. (Dept. of Applied Microbiology, Lund Inst. of Technology/Univ. of Lund (Sweden)); Olsson, L. (Dept. of Applied Microbiology, Lund Inst. of Technology/Univ. of Lund (Sweden)); Mohagheghi, A. (Bioprocess and Fuels Engineering Research Branch, National Renewable Energy Lab., Golden, CO (United States))

    1994-03-01

    A xylose-rich, dilute-acid-pretreated corn-cob hydrolysate was fermented by Escherichia coli ATCC 11303, recombinant (rec) E. coli B (pLOI 297 and KO11), Pichia stipitis (CBS 5773, 6054 and R), Saccharomyces cerevisiae isolate 3 in combination with xylose isomerase, rec S. cerevisiae (TJ1, H550 and H477) and Fusarium oxysporum VTT-D-80134 in an interlaboratory comparison. The micro-organisms were studied according to three different options: (A) fermentation under consistent conditions. (B) fermentation under optimal conditions for the organism, and (C) fermentation under optimal conditions for the organism with detoxification of the hydrolysate. The highest yields of ethanol, 0.24 g/g (A), 0.36 g/g (B) and 0.54 g/g (C), were obtained from rec E. coli B, KO11. P. stipitis and F. oxysporum were sensitive to the inhibitors present in the hydrolysate and produced a maximum yield of 0.34 g/g (C) and 0.04 g/g (B), respectively. The analysis of the corn-cob hydrolysate and aspects of process economy of the different fermentation options (pH, sterilization, nutrient supplementation, adaptation, detoxification) are discussed. (orig.)

  18. Effect of simultaneous cooling on microwave-assisted wet digestion of biological samples with diluted nitric acid and O{sub 2} pressure

    Energy Technology Data Exchange (ETDEWEB)

    Bizzi, Cezar A. [Departamento de Química, Universidade Federal de Santa Maria, Santa Maria, Rio Grande do Sul 97105-900 (Brazil); Nóbrega, Joaquim A. [Departamento de Química, Universidade Federal de São Carlos, São Carlos, São Paulo 13565-905 (Brazil); Barin, Juliano S. [Departamento de Tecnologia e Ciência dos Alimentos, Universidade Federal de Santa Maria, Santa Maria, Rio Grande do Sul 97105-900 (Brazil); Oliveira, Jussiane S.S.; Schmidt, Lucas; Mello, Paola A. [Departamento de Química, Universidade Federal de Santa Maria, Santa Maria, Rio Grande do Sul 97105-900 (Brazil); Flores, Erico M.M., E-mail: ericommf@gmail.br [Departamento de Química, Universidade Federal de Santa Maria, Santa Maria, Rio Grande do Sul 97105-900 (Brazil)

    2014-07-21

    Highlights: • Simultaneously cooling during microwave heating for improving digestion efficiency. • Maximum MW power delivered into cavity, improving the temperature in liquid phase. • Temperature gradient increases regeneration reaction of HNO{sub 3} in O{sub 2} rich atmosphere. • Digestion of several matrices using diluted HNO{sub 3} combined with O{sub 2} pressure. - Abstract: The present work evaluates the influence of vessel cooling simultaneously to microwave-assisted digestion performed in a closed system with diluted HNO{sub 3} under O{sub 2} pressure. The effect of outside air flow-rates (60–190 m{sup 3} h{sup −1}) used for cooling of digestion vessels was evaluated. An improvement in digestion efficiency caused by the reduction of HNO{sub 3} partial pressure was observed when using higher air flow-rate (190 m{sup 3} h{sup −1}), decreasing the residual carbon content for whole milk powder from 21.7 to 9.3% (lowest and highest air flow-rate, respectively). The use of high air flow-rate outside the digestion vessel resulted in a higher temperature gradient between liquid and gas phases inside the digestion vessel and improved the efficiency of sample digestion. Since a more pronounced temperature gradient was obtained, it contributed for increasing the condensation rate and thus allowed a reduction in the HNO{sub 3} partial pressure of the digestion vessel, which improved the regeneration of HNO{sub 3}. An air flow-rate of 190 m{sup 3} h{sup −1} was selected for digestion of animal fat, bovine liver, ground soybean, non fat milk powder, oregano leaves, potato starch and whole milk powder samples, and a standard reference material of apple leaves (NIST 1515), bovine liver (NIST 1577) and whole milk powder (NIST 8435) for further metals determination by inductively coupled plasma atomic emission spectroscopy (ICP-OES). Results were in agreement with certified values and no interferences caused by matrix effects during the determination step

  19. Organic acid excretion in Penicillium ochrochloron increases with ambient pH

    Directory of Open Access Journals (Sweden)

    Pamela eVrabl

    2012-04-01

    Full Text Available Despite being of high biotechnological relevance, many aspects of organic acid excretion in filamentous fungi like the influence of ambient pH are still insufficiently understood. While the excretion of an individual organic acid may peak at a certain pH value, the few available studies investigating a broader range of organic acids indicate that total organic acid excretion rises with increasing external pH.We hypothesized that this phenomenon might be a general response of filamentous fungi to increased ambient pH. If this is the case, the observation should be widely independent of the organism, growth conditions or experimental design and might therefore be a crucial key point in understanding the function and mechanisms of organic acid excretion in filamentous fungi.In this study we explored this hypothesis using ammonium limited chemostat cultivations (pH 2-7, and ammonium or phosphate limited bioreactor batch cultivations (pH 5 and 7. Two strains of Penicillium ochrochloron were investigated differing in the spectrum of excreted organic acids.Confirming our hypothesis, the main result demonstrated that organic acid excretion in P. ochrochloron was enhanced at high external pH levels compared to low pH levels independent of the tested strain, nutrient limitation and cultivation method. We discuss these findings against the background of three hypotheses explaining organic acid excretion in filamentous fungi, i.e. overflow metabolism, charge balance and aggressive acidification hypothesis.

  20. Ice nucleation in sulfuric acid/organic aerosols: implications for cirrus cloud formation

    Directory of Open Access Journals (Sweden)

    M. R. Beaver

    2006-01-01

    Full Text Available Using an aerosol flow tube apparatus, we have studied the effects of aliphatic aldehydes (C3 to C10 and ketones (C3 and C9 on ice nucleation in sulfuric acid aerosols. Mixed aerosols were prepared by combining an organic vapor flow with a flow of sulfuric acid aerosols over a small mixing time (~60 s at room temperature. No acid-catalyzed reactions were observed under these conditions, and physical uptake was responsible for the organic content of the sulfuric acid aerosols. In these experiments, aerosol organic content, determined by a Mie scattering analysis, was found to vary with the partial pressure of organic, the flow tube temperature, and the identity of the organic compound. The physical properties of the organic compounds (primarily the solubility and melting point were found to play a dominant role in determining the inferred mode of nucleation (homogenous or heterogeneous and the specific freezing temperatures observed. Overall, very soluble, low-melting organics, such as acetone and propanal, caused a decrease in aerosol ice nucleation temperatures when compared with aqueous sulfuric acid aerosol. In contrast, sulfuric acid particles exposed to organic compounds of eight carbons and greater, of much lower solubility and higher melting temperatures, nucleate ice at temperatures above aqueous sulfuric acid aerosols. Organic compounds of intermediate carbon chain length, C4-C7, (of intermediate solubility and melting temperatures nucleated ice at the same temperature as aqueous sulfuric acid aerosols. Interpretations and implications of these results for cirrus cloud formation are discussed.

  1. Helium dilution refrigerator

    International Nuclear Information System (INIS)

    1973-01-01

    A new system of continuous heat exchange for a helium dilution refrigerator is proposed. The 3 He effluent tube is concurrent with the affluent mixed helium tube in a vertical downward direction. Heat exchange efficiency is enhanced by placing in series a number of elements with an enlarged surface area

  2. Isotope dilution analysis

    Energy Technology Data Exchange (ETDEWEB)

    Fudge, A.

    1978-12-15

    The following aspects of isotope dilution analysis are covered in this report: fundamental aspects of the technique; elements of interest in the nuclear field, choice and standardization of spike nuclide; pre-treatment to achieve isotopic exchange and chemical separation; sensitivity; selectivity; and accuracy.

  3. Bioethanol production by cashew apple bagasse (Anacardium occidentale L.): comparison of acid diluted and alkali pre-treatments; Producao de bioetanol a partir da fibra do caju (Anacardium occidentale L.): comparacao entre o pre-tratamento acido e alcalino

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Tigressa H.S.; Pinheiro, Alvaro D.T.; Goncalves, Luciana R.B. [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil); Rocha, Maria V.P.; Macedo, Gorete R. de [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)

    2008-07-01

    Due to the growing environmental awareness on the negative impact resulting from utilization of fossil fuels, and in the search for renewable energy sources, biofuels' interest as Bioethanol has rapidly expanded recently. In this context, lignocellulosic compounds have become center of attention as an abundant and economic alternative source of carbohydrates for ethanol production. In this study, cashew's bagasse acid hydrolysis was initially studied for glucose synthesis and its fermentation towards ethanol production. Sulfuric acid concentration, solids concentration and time were some of the factors evaluated. The highest glucose productivity value (162,9 mg.g de bagaco{sup -1}) , was obtained for 0,6 mol.L{sup -1} of sulfuric acid in an autoclave at 121 deg C for 15 min. For the fermentation of the hydrolyzed material by S. cerevisiae containing 16 {+-} 2,0 g.L{sup -1} of glucose metabolic, the yield and productivity obtained were 0,63 g-g glucose{sup -1} and 1,43 g.L{sup -1}h{sup -1} respectively. Ethanol concentration after 6 h of fermentation of this hydrolyzed was 11 g.L{sup -1}. In the best conditions of acid hydrolysis, a second pre-treatment with diluted sulfuric acid was performed to evaluate availability of hemicelluloses at 160 deg C and 180 deg C. For comparative purposes, alkali pre-treatment was evaluated under the conditions of 0,6 mol.L{sup -1}, 30% p/v of bagasse thermically treated at 121 deg C for 15 minutes. However, concentration of sugars was not sufficient for fermentation. Also, nitrogen supplementation of the hydrolyzed fraction did not influence significantly ethanol production. The results demonstrate that the hydrolyzed fraction from the acid pre-treatment of cashew's bagasse could be utilized for ethanol production. (author)

  4. Nitrogen oxide absorption into water and dilute nitric acid in an engineering-scale sieve-plate column: description of a mathematical model and comparison with experimental data

    Energy Technology Data Exchange (ETDEWEB)

    Counce, R M

    1978-09-01

    The study reported here is concerned with the absorption of gaseous NO/sub x/ compounds into water and dilute HNO/sub 3/ in a three-stage sieve-plate column with plates designed for high gas-liquid interfacial area. The performance of the column was measured while several operating parameters were varied. A mechanistic model was developed and presented to explain the observed phenomena. The results of the study indicate the importance of three mechanisms in the absorption of gaseous NO/sub x/ compounds: (a) the absorption of NO/sub 2/*, which results in the production of liquid HNO/sub 3/ and HNO/sub 2/; (b) the dissociation of the liquid HNO/sub 2/ into HNO/sub 3/ and gaseous NO; and (c) the gas-phase oxidation of NO to NO/sub 2/. A useful model was developed to explain the absorption of NO/sub x/ compounds based on the above mechanisms. This model is presented and discussed.

  5. New Data on Joint Extraction of Nitric Acid, Uranium(VI) and Tetravalent Elements by Diluted TBP and New Approach to Modeling of their Distribution

    International Nuclear Information System (INIS)

    Zilberman, B.Ya.; Fedorov, Yu.S.; Puzikov, E.A.; Blazheva, I.V.

    2008-01-01

    HNO 3 and U(IV) extraction by diluted TBP (tributyl phosphate) appeared significantly higher than believed earlier, requiring correction of mathematical model for extraction of all the species. The proposed model of HNO 3 extraction includes its dissolving in the extracted water, as well as its abduction to UO 2 (NO 3 ) 2 (TBP) 2 . Extraction of U(VI) and tetravalent elements is considered as reaction of their hydrated or partially hydrolyzed forms, the latter could be extracted themselves or as neutral forms with water liberation. The equation of element chemical reaction for modeling is determined by the slope of the linear part of the S-shaped curve representing D/S 2 function as a plot of HNO 3 concentration, where D is a distribution coefficient of the micro-component and S is a TBP concentration free of HNO 3 . The description of tetravalent element extraction in U(VI) presence needs the assumption of cation-cation interaction of element hydrolyzed forms with U(VI) in aqueous phase. Zr distribution is affected by micellar effects. (authors)

  6. Synthesis of N,N-Bis(nonaflyl) Squaric Acid Diamide and its Application to Organic Reactions

    International Nuclear Information System (INIS)

    Cheon, Cheol Hong; Yamamoto, Hisashi

    2010-01-01

    We have developed a new strong Brφnsted acid bearing two nonaflyl groups based on the squaric acid scaffold. The Brφnsted acid 2 showed the almost same reactivity as bistriflyl squaramide 1 in Mukaiyama aldol and Michael reactions of benzaldehyde with silyl enol ether. Moreover, the utility of Brφnsted acid 2 could be expanded to carbonyl ene reaction of rac-citronellal. Further application of this new Brφnsted acid to organic reactions and to flow system reactors is currently underway in our laboratory. Brφnsted acid catalysis is one of the growing fields in modern organic synthesis.1 Although several Brφnsted acids, such as urea/thiourea, TADDOL, and phosphoric acid, have been applied to a variety of organic reactions, other Brφnsted acid scaffolds have been much less explored. Recently, Rawal et al have developed a Brφnsted acid catalyst based on squaric acid moiety and successfully applied it as a catalyst for conjugate addition of 1,3-dicarbonyl compounds to nitroolefins. More recently, we have developed a strong Brφnsted acid derived from squaric acid by introducing a strong electron withdrawing trifluoromethanesulfonyl (Tf) group and applied it to Mukaiyama aldol and Michael reaction of a variety of aldehydes, ketones, and α,β-unsaturated ketones. As a continuing effort to develop strong Brφnsted acids based on the squaric acid scaffold, it was expected that replacement of Tf group with a longer perfluoro-alkanesulfonyl group would be able to tune the physical properties, such as solubilities in organic solvents and fluoro-philicity, without loss of reactivity. Herein, we report the development of a new Brφnsted acid based on the squaric acid scaffold carrying two nonafluorobutanesulfonyl (Nf) groups and the preliminary results of its reactivity to various organic reactions

  7. Formic and Acetic Acid Observations over Colorado by Chemical Ionization Mass Spectrometry and Organic Acids' Role in Air Quality

    Science.gov (United States)

    Treadaway, V.; O'Sullivan, D. W.; Heikes, B.; Silwal, I.; McNeill, A.

    2015-12-01

    Formic acid (HFo) and acetic acid (HAc) have both natural and anthropogenic sources and a role in the atmospheric processing of carbon. These organic acids also have an increasing importance in setting the acidity of rain and snow as precipitation nitrate and sulfate concentrations have decreased. Primary emissions for both organic acids include biomass burning, agriculture, and motor vehicle emissions. Secondary production is also a substantial source for both acids especially from biogenic precursors, secondary organic aerosols (SOAs), and photochemical production from volatile organic compounds (VOCs) and oxygenated volatile organic compounds (OVOCs). Chemical transport models underestimate organic acid concentrations and recent research has sought to develop additional production mechanisms. Here we report HFo and HAc measurements during two campaigns over Colorado using the peroxide chemical ionization mass spectrometer (PCIMS). Iodide clusters of both HFo and HAc were recorded at mass-to-charge ratios of 173 and 187, respectively. The PCIMS was flown aboard the NCAR Gulfstream-V platform during the Deep Convective Clouds and Chemistry Experiment (DC3) and aboard the NCAR C-130 during the Front Range Air Pollution and Photochemistry Experiment (FRAPPE). The DC3 observations were made in May and June 2012 extending from the surface to 13 km over the central and eastern United States. FRAPPE observations were made in July and August 2014 from the surface to 7 km over Colorado. DC3 measurements reported here are focused over the Colorado Front Range and complement the FRAPPE observations. DC3 HFo altitude profiles are characterized by a decrease up to 6 km followed by an increase either back to boundary layer mixing ratio values or higher (a "C" shape). Organic acid measurements from both campaigns are interpreted with an emphasis on emission sources (both natural and anthropogenic) over Colorado and in situ photochemical production especially ozone precursors.

  8. Effect of fermentation period on the organic acid and amino acid contents of Ogiri from castor oil bean seeds

    Directory of Open Access Journals (Sweden)

    Ojinnaka, M-T. C.

    2013-01-01

    Full Text Available Aims: To monitor the changes in the concentration of organic acid and amino acid contents during the fermentation of castor oil bean seed into ogiri.Methodology and results: In this study, ogiri, a Nigerian fermented food condiment was prepared from castor oil bean using Bacillus subtilis as a monoculture starter for the production of three different fermented castor oil bean condiment samples: B1 (0% NaCl/lime, B2 (2% NaCl, B3 (3% lime. Variations in the composition of the castor oil bean with fermentation over 96 h periods were evaluated for organic acid and amino acid contents using High Performance Liquid Chromatography. Organic acids were detected in the fermented castor oil bean samples as fermentation period increased to 96 h. Organic acids identified were oxalic, citric, tartaric, malic, succinic, lactic, formic, acetic, propionic and butyric acids. The lactic acid contents in sample B1 (0% NaCl/lime decreased initially and then increased as the fermentation period progressed. The value at 96 h fermentation was 1.336 µg/mL as against 0.775 µg/mL at 0 h fermentation. Sample B3 (3% lime had lactic acid content that increased as fermentation period increased with lactic acid content of 1.298 µg/mL at 96 h fermentation. The acetic acid content of sample B1 increased as fermentation progressed and at 96 h fermentation, its value was 1.204 µg/mL while those of B2 and B3 were 0.677 µg/mL and 1.401 µg/mL respectively. The three fermented castor oil bean samples also contained sufficient amount of amino acids. Sample B1 had the highest values in isoleucine glycine and histidine with values 1.382 µg/mL, 0.814 µg/mL and 1.022 µg/mL respectively while sample B2 had the highest value in leucine content with 0.915 µg/mL at 96 h fermentation, closely followed by sample B3 and B1 with 0.798 µg/mL and 0.205 µg/mL respectively. The results of amino acid analysis indicated a high concentration of all amino acids at 96 h of fermentation

  9. Effects of Organic Acids on Adsorption of Cadmium onto Kaolinite, Goethite, and Bayerite

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Effects of organic acids (oxalic, acetic, and citric) on adsorption characteristics of Cadmium (Cd) on soil clay minerals(kaolinite, goethite, and bayerite) were studied under different concentrations and different pH values. Although the types of organic acids and minerals were different, the effects of the organic acids on the adsorption of Cd on the minerals were similar, i.e., the amount of adsorbed Cd with an initial solution pH of 5.0 and initial Cd concentration of 35 mg L-1increased with increasing concentration of the organic acid in solution at lower concentrations, and decreased at higher concentrations. The percentage of Cd adsorbed on the minerals in the presence of the organic acids increased considerably with increasing pH of the solution. Meanwhile, different Cd adsorption in the presence of the organic acids, due to different properties on both organic acids and clay minerals, on kaolinite, goethite, or bayerite for different pHs or organic acid concentrations was found.

  10. Thermophysical properties of starch and whey protein composite prepared in presence of organic acid and esters

    Science.gov (United States)

    Previously, we prepared starch and protein composite by reactive mixing in presence of various organic acids and found that use of these acid esters resulted in composites with good mechanical properties. In this study, concentration (% w/w) of acid citrates in the starch-protein composites were var...

  11. Acyl Meldrum's acid derivatives: application in organic synthesis

    Science.gov (United States)

    Janikowska, K.; Rachoń, J.; Makowiec, S.

    2014-07-01

    This review is focused on an important class of Meldrum's acid derivatives commonly known as acyl Meldrum's acids. The preparation methods of these compounds are considered including the recently proposed and rather rarely used ones. The chemical properties of acyl Meldrum's acids are described in detail, including thermal stability and reactions with various nucleophiles. The possible mechanisms of these transformations are analyzed. The bibliography includes 134 references.

  12. Phosphorus release from phosphate rock and iron phosphate by low-molecular-weight organic acids.

    Science.gov (United States)

    Xu, Ren-kou; Zhu, Yong-guan; Chittleborough, David

    2004-01-01

    Low-molecular-weight(LMW) organic acids widely exist in soils, particularly in the rhizosphere. A series of batch experiments were carried out to investigate the phosphorus release from rock phosphate and iron phosphate by low-molecular-weight organic acids. Results showed that citric acid had the highest capacity to solubilize P from both rock and iron phosphate. P solubilization from rock phosphate and iron phosphate resulted in net proton consumption. P release from rock phosphate was positively correlated with the pKa values. P release from iron phosphate was positively correlated with Fe-organic acid stability constants except for aromatic acids, but was notcorrelated with pKa. Increase in the concentrations of organic acids enhanced P solubilization from both rock and iron phosphate almost linearly. Addition of phenolic compounds further increased the P release from iron phosphate. Initial solution pH had much more substantial effect on P release from rock phosphate than from iron phosphate.

  13. Preparation of High-purity Indium Oxalate Salt from Indium Scrap by Organic Acids

    International Nuclear Information System (INIS)

    Koo, Su-Jin; Ju, Chang-Sik

    2013-01-01

    Effect of organic acid on the preparation of indium-oxalate salt from indium scraps generated from ITO glass manufacturing process was studied. Effects of parameters, such as type and concentration of organic acids, pH of reactant, temperature, reaction time on indium-oxalate salt preparation were examined. The impurity removal efficiency was similar for both oxalic acid and citric acid, but citric acid did not make organic acid salt with indium. The optimum conditions were 1.5 M oxalic acid, pH 7, 80 .deg. C, and 6 hours. On the other hand, the recoveries increased with pH, but the purity decreased. The indium-oxalate salt purity prepared by two cycles was 99.995% (4N5). The indium-oxalate salt could be converted to indium oxide and indium metal by substitution reaction and calcination

  14. Density and viscosity study of nicotinic acid and nicotinamide in dilute aqueous solutions at and around the temperature of the maximum density of water

    International Nuclear Information System (INIS)

    Dhondge, Sudhakar S.; Dahasahasra, Prachi N.; Paliwal, Lalitmohan J.; Deshmukh, Dinesh W.

    2014-01-01

    Highlights: • Volumetric and transport behaviour of aqueous solutions of important vitamins are reported. • Various interactions of nicotinic acid and nicotinamide with water have been reported. • The temperature dependence of interactions between solute and solvent is discussed. • The study indicates that nicotinamide is more hydrated as compared to nicotinic acid. - Abstract: In the present study, we report experimental densities (ρ) and viscosities (η) of aqueous solutions of nicotinic acid and nicotinamide within the concentration range (0 to 0.1) mol · kg −1 at T = (275.15, 277.15 and 279.15) K. These parameters are then used to obtain thermodynamic and transport functions such as apparent molar volume of solute (V ϕ ), limiting apparent molar volume of solute (V ϕ 0 ), limiting apparent molar expansivity of solute (E ϕ 0 ), coefficient of thermal expansion (α ∗ ), Jones–Dole equation viscosity A, B and D coefficients, temperature derivative of B coefficient i.e. (dB/dT) and hydration number (n H ), etc. The activation parameters of viscous flow for the binary mixtures have been determined and discussed in terms of Eyring’s transition state theory. These significant parameters are helpful to study the structure promoting or destroying tendency of solute and various interactions present in (nicotinic acid + water) and (nicotinamide + water) binary mixtures

  15. Surface coverage and corrosion inhibition effect of Rosmarinus officinalis and zinc oxide on the electrochemical performance of low carbon steel in dilute acid solutions

    Directory of Open Access Journals (Sweden)

    Roland Tolulope Loto

    2018-03-01

    Full Text Available Electrochemical analysis of the corrosion inhibition and surface protection properties of the combined admixture of Rosmarinus officinalis and zinc oxide on low carbon steel in 1 M HCl and H2SO4 solution was studied by potentiodynamic polarization, open circuit potential measurement, optical microscopy and ATR-FTIR spectroscopy. Results obtained confirmed the compound to be more effective in HCl solution, with optimal inhibition efficiencies of 93.26% in HCl and 87.7% in H2SO4 acid solutions with mixed type inhibition behavior in both acids. The compound shifts the corrosion potential values of the steel cathodically in HCl and anodically in H2SO4 signifying specific corrosion inhibition behavior without applied potential. Identified functional groups of alcohols, phenols, 1°, 2° amines, amides, carbonyls (general, esters, saturated aliphatic, carboxylic acids, ethers, aliphatic amines, alkenes, aromatics, alkyl halides and alkynes within the compound completely adsorbed onto the steel forming a protective covering. Thermodynamic calculations showed physisorption molecular interaction with the steel’s surface according to Langmuir and Frumkin adsorption isotherms. Optical microscopy images of the inhibited and uninhibited steels contrast each other with steel specimens from HCl solution showing a better morphology. Keywords: Corrosion, Inhibitor, Adsorption, Steel, Acid

  16. [Roles of organic acid metabolism in plant adaptation to nutrient deficiency and aluminum toxicity stress].

    Science.gov (United States)

    Wang, Jianfei; Shen, Qirong

    2006-11-01

    Organic acids not only act as the intermediates in carbon metabolism, but also exert key roles in the plant adaptation to nutrient deficiency and metal stress and in the plant-microbe interactions at root-soil interface. From the viewpoint of plant nutrition, this paper reviewed the research progress on the formation and physiology of organic acids in plant, and their functions in nitrogen metabolism, phosphorus and iron uptake, aluminum tolerance, and soil ecology. New findings in the membrane transport of organic acids and the biotechnological manipulation of organic acids in transgenic model were also discussed. This novel perspectives of organic acid metabolism and its potential manipulation might present a possibility to understand the fundamental aspects of plant physiology, and lead to the new strategies to obtain crop varieties better adapted to environmental and metal stress.

  17. Multichannel Mars Organic Analyzer (McMOA): Microfluidic Networks for the Automated In Situ Microchip Electrophoretic Analysis of Organic Biomarkers on Mars

    Science.gov (United States)

    Chiesl, T. N.; Benhabib, M.; Stockton, A. M.; Mathies, R. A.

    2010-04-01

    We present the Multichannel Mars Organic Analyzer (McMOA) for the analysis of Amino Acids, PAHs, and Oxidized Carbon. Microfluidic architecures integrating automated metering, mixing, on chip reactions, and serial dilutions are also discussed.

  18. Profile of preoperative fecal organic acids closely predicts the incidence of postoperative infectious complications after major hepatectomy with extrahepatic bile duct resection: Importance of fecal acetic acid plus butyric acid minus lactic acid gap.

    Science.gov (United States)

    Yokoyama, Yukihiro; Mizuno, Takashi; Sugawara, Gen; Asahara, Takashi; Nomoto, Koji; Igami, Tsuyoshi; Ebata, Tomoki; Nagino, Masato

    2017-10-01

    To investigate the association between preoperative fecal organic acid concentrations and the incidence of postoperative infectious complications in patients undergoing major hepatectomy with extrahepatic bile duct resection for biliary malignancies. The fecal samples of 44 patients were collected before undergoing hepatectomy with bile duct resection for biliary malignancies. The concentrations of fecal organic acids, including acetic acid, butyric acid, and lactic acid, and representative fecal bacteria were measured. The perioperative clinical characteristics and the concentrations of fecal organic acids were compared between patients with and without postoperative infectious complications. Among 44 patients, 13 (30%) developed postoperative infectious complications. Patient age and intraoperative bleeding were significantly greater in patients with postoperative infectious complications compared with those without postoperative infectious complications. The concentrations of fecal acetic acid and butyric acid were significantly less, whereas the concentration of fecal lactic acid tended to be greater in the patients with postoperative infectious complications. The calculated gap between the concentrations of fecal acetic acid plus butyric acid minus lactic acid gap was less in the patients with postoperative infectious complications (median 43.5 vs 76.1 μmol/g of feces, P = .011). Multivariate analysis revealed that an acetic acid plus butyric acid minus lactic acid gap acid profile (especially low acetic acid, low butyric acid, and high lactic acid) had a clinically important impact on the incidence of postoperative infectious complications in patients undergoing major hepatectomy with extrahepatic bile duct resection. Copyright © 2017. Published by Elsevier Inc.

  19. Complex forming properties of natural organic acids. Pt. 2

    International Nuclear Information System (INIS)

    Ephraim, J.H.; Mathuthu, A.S.; Marinsky, J.A.

    1990-07-01

    An ultrafiltration technique combined with ion-selective-electrode and atomic absorption methods have been employed to obtain information on the complex forming properties of fulvic acid with iron and calcium. A model for interpreting complexation of metal ions to fulvic acid at any pH, medium ionic strength and metal to fulvic acid ratio developed earlier has been used in an attempt to predict the nature of iron and calcium interaction to Armadale Horizon Bh fulvic acid. Binding of calcium to fulvic acid which is enhanced at pHs greater than 6.0 has reasonably been predicted by the model taking into consideration complications due to the polyelectrolyte nature and the heterogeneity of the fulvic acid. The lack of agreement observed between the model predicted binding behavior and the experimentally observed results for the fulvic acid-iron system has been attributed to the formation of metal-induced aggregation. Reduction of Fe(III) to Fe(II) by the fulvic acid as reported by other workers is corroborated. (orig.)

  20. Chemical constituents of the essential oil and organic acids from longkong (Aglaia dookkoo Griff. fruits

    Directory of Open Access Journals (Sweden)

    Abdulhakim Hamad

    2006-03-01

    Full Text Available The pulp of longkong fruits (Aglaia dookkoo Griff., collected from Narathiwat province, was dried and extracted by steam distillation to obtain the essential oil in 0.48% yield. The GC-MS data showed oleic acid (14.80%, α-copaene (11.15%, germacrene-D (9.16%, δ- cadinene (6.74%, τ -muurolol (6.34%, (+ spathulenol (5.72% and palmitic acid (5.49% as the major constituents. Organic acids were also extracted from dried pulp with methanol using a Soxhlet apparatus to give the crude extract in 36.26% yield. Four organic acids: glycolic, maleic, malic and citric acids were determined by HPLC. Maleic acid (1.23% was the major acid and the others were citric (0.22%, malic (0.15% and glycolic acids (0.14%.

  1. Defects in dilute nitrides

    International Nuclear Information System (INIS)

    Chen, W.M.; Buyanova, I.A.; Tu, C.W.; Yonezu, H.

    2005-01-01

    We provide a brief review our recent results from optically detected magnetic resonance studies of grown-in non-radiative defects in dilute nitrides, i.e. Ga(In)NAs and Ga(Al,In)NP. Defect complexes involving intrinsic defects such as As Ga antisites and Ga i self interstitials were positively identified.Effects of growth conditions, chemical compositions and post-growth treatments on formation of the defects are closely examined. These grown-in defects are shown to play an important role in non-radiative carrier recombination and thus in degrading optical quality of the alloys, harmful to performance of potential optoelectronic and photonic devices based on these dilute nitrides. (author)

  2. Surface coverage and corrosion inhibition effect of Rosmarinus officinalis and zinc oxide on the electrochemical performance of low carbon steel in dilute acid solutions

    Science.gov (United States)

    Loto, Roland Tolulope

    2018-03-01

    Electrochemical analysis of the corrosion inhibition and surface protection properties of the combined admixture of Rosmarinus officinalis and zinc oxide on low carbon steel in 1 M HCl and H2SO4 solution was studied by potentiodynamic polarization, open circuit potential measurement, optical microscopy and ATR-FTIR spectroscopy. Results obtained confirmed the compound to be more effective in HCl solution, with optimal inhibition efficiencies of 93.26% in HCl and 87.7% in H2SO4 acid solutions with mixed type inhibition behavior in both acids. The compound shifts the corrosion potential values of the steel cathodically in HCl and anodically in H2SO4 signifying specific corrosion inhibition behavior without applied potential. Identified functional groups of alcohols, phenols, 1°, 2° amines, amides, carbonyls (general), esters, saturated aliphatic, carboxylic acids, ethers, aliphatic amines, alkenes, aromatics, alkyl halides and alkynes within the compound completely adsorbed onto the steel forming a protective covering. Thermodynamic calculations showed physisorption molecular interaction with the steel's surface according to Langmuir and Frumkin adsorption isotherms. Optical microscopy images of the inhibited and uninhibited steels contrast each other with steel specimens from HCl solution showing a better morphology.

  3. Complex Formation of Selected Radionuclides with Ligands Commonly Found in Ground Water: Low Molecular Organic Acids

    DEFF Research Database (Denmark)

    Jensen, Bror Skytte; Jensen, H.

    1985-01-01

    A general approach to the analysis of potentiometric data on complex formation between cations and polybasic amphoteric acids is described. The method is used for the characterisation of complex formation between Cs+, Sr2+, Co2+, La 3+, and Eu3+ with a α-hydroxy acids, tartaric acid and citric ac......, and with the α-amino acids, aspartic acid and L-cysteine. The cations have been chosen as typical components of reactor waste, and the acids because they are often found as products of microbial activity in pits or wherever organic material decays...

  4. Organic acid production from starchy waste by rumen derived microbial communities

    OpenAIRE

    Ayudthaya, S. P. N.; Van De Weijer, Antonius H. P.; Van Gelder, Antonie H.; Stams, Alfons Johannes Maria; De Vos, Willem M.; Plugge, Caroline M.

    2017-01-01

    Microbiology Centennial Symposium 2017 - Exploring Microbes for the Quality of Life (Book of Abstracts) Converting organic waste to energy carriers and valuable products such as organic acids (OA) using microbial fermentation is one of the sustainable options of renewable energy. Substrate and inoculum are important factors in optimizing the fermentation. In this study, we investigated organic acid production and microbial composition shift during the fermentation of starchy (p...

  5. Fate of trivalent chromium in presence of organic acids - a hydroponic study on soyabean plant using radiotracer

    International Nuclear Information System (INIS)

    Srivastava, Sonal; Prakash, Satya; Srivastava, M.M.

    1999-01-01

    Hydroponic experiments have been conducted to examine the uptake and translocation of root absorbed trivalent chromium in the presence of organic acid supplementation. Statistically significant increase in chromium accumulation in various plant tissues with increasing concentration of organic acids has been observed. Potentiality of organic acids to form labile organically bound Cr III is explored. (author)

  6. Heterogeneous uptake of the C1 to C4 organic acids on a swelling clay mineral

    Directory of Open Access Journals (Sweden)

    M. A. Tolbert

    2007-08-01

    Full Text Available Mineral aerosol is of interest due to its physiochemical impacts on the Earth's atmosphere. However, adsorbed organics could influence the chemical and physical properties of atmospheric mineral particles and alter their impact on the biosphere and climate. In this work, the heterogeneous uptake of a series of small organic acids on the swelling clay, Na-montmorillonite, was studied at 212 K as a function of relative humidity (RH, organic acid pressure and clay mass. A high vacuum chamber equipped with a quadrupole mass spectrometer and a transmission Fourier transform infrared spectrometer was used to detect the gas and condensed phases, respectively. Our results show that while the initial uptake efficiency was found to be independent of organic acid pressure, it increased linearly with increasing clay mass. Thus, the small masses studied allow access to the entire surface area of the clay sample with minimal effects due to surface saturation. Additionally, results from this study show that the initial uptake efficiency for butanoic (butyric acid on the clay increases by an order of magnitude as the RH is raised from 0% to 45% RH at 212 K while the initial uptake efficiency of formic, acetic and propanoic (propionic acids increases only slightly at higher humidities. However, the initial uptake efficiency decreases significantly in a short amount of time due to surface saturation effects. Thus, although the initial uptake efficiencies are appropriate for initial times, the fact that the uptake efficiency will decrease over time as the surface saturates should be considered in atmospheric models. Surface saturation results in sub-monolayer coverage of organic acid on montmorillonite under dry conditions and relevant organic acid pressures that increases with increasing humidity for all organic acids studied. Additionally, the presence of large organic acids may slightly enhance the water content of the clay above 45% RH. Our results indicate

  7. Isolation of living Algae growing in the shells of Molluscs and Barnacles with EDTA (ethylenediaminetetraacetic acid)

    NARCIS (Netherlands)

    Prud’homme van Reine, W.F.; Hoek, van den C.

    1966-01-01

    Several decalcifying mixtures or aqueous solutions of inorganic or organic acids are generally used for releasing algae growing in the shells of molluscs and barnacles, for instance dilute hydrochloric, nitric, citric, or acetic acid (4), a mixture of nitric acid, chromic acid and alcolhol (1),

  8. Evaluation of the organization of the homoionic smectite layers (Na(+) or Ca(2+)) in diluted dispersions using granulometry, microscopy and rheometry.

    Science.gov (United States)

    Paumier, S; Pantet, A; Monnet, P

    2008-09-01

    diluted dispersions.

  9. Improving bioavailability of fruit wastes using organic acid: An exploratory study of biomass pretreatment for fermentation

    International Nuclear Information System (INIS)

    Saha, Shouvik; Kurade, Mayur B.; El-Dalatony, Marwa M.; Chatterjee, Pradip K.; Lee, Dae Sung; Jeon, Byong-Hun

    2016-01-01

    Highlights: • Maximum sugar recovery was achieved with 100 °C/1 h treatment in 0.2 M acetic acid. • C/N ratios (41–47) were retained in all FPWs after the acetic acid treatment. • Combined severity (−0.83) of acetic acid enhanced the bioavailability of the FPWs. • Acetic acid pretreatment is advantageous over mineral acid to curtail sugar loss. • Estimated methane yields are promising for the industrial feasibility. - Abstract: Maximizing the bioavailability of fermentable biomass components is a key challenge in biomass pretreatment due to the loss of sugars during conventional pretreatment approaches. Pretreatment of fruit peels and wastes (FPWs) with dilute acetic acid assisted in maximizing sugar recovery. Optimized conditions (0.2 M acetic acid, 100 °C, 1 h) at 10% substrate loading resulted in enhanced sugar recovery from banana peels (99.9%), pineapple wastes (99.1%), grape pomace (98.8%), and orange peels (97.9%). These high sugar recoveries retained the high C/N ratios (41–47) suitable for effective bioenergy production through the fermentation of these pretreated biomasses. Scanning electron microscopy (SEM) indicated considerable disruption of biomass structural integrity during acetic acid treatment, enhancing the surface area available for better microbial attachment. Fourier transform infrared spectroscopy (FTIR) showed that the acetic acid pretreatment yielded only minor changes to the functional groups in the biomasses, strongly suggesting minimal loss of fermentable sugars. Thus, acetic acid pretreatment aids in enhancing the bioavailability of fermentable sugars from these FPWs biomass, enabling improvements in bioenergy production.

  10. Anaerobic organic acid metabolism of Candida zemplinina in comparison with Saccharomyces wine yeasts.

    Science.gov (United States)

    Magyar, Ildikó; Nyitrai-Sárdy, Diána; Leskó, Annamária; Pomázi, Andrea; Kállay, Miklós

    2014-05-16

    Organic acid production under oxygen-limited conditions has been thoroughly studied in the Saccharomyces species, but practically never investigated in Candida zemplinina, which seems to be an acidogenic species under oxidative laboratory conditions. In this study, several strains of C. zemplinina were tested for organic acid metabolism, in comparison with Saccharomyces cerevisiae, Saccharomyces uvarum and Candida stellata, under fermentative conditions. Only C. stellata produced significantly higher acidity in simple minimal media (SM) with low sugar content and two different nitrogen sources (ammonia or glutamic acid) at low level. However, the acid profile differed largely between the Saccharomyces and Candida species and showed inverse types of N-dependence in some cases. Succinic acid production was strongly enhanced on glutamic acid in Saccharomyces species, but not in Candida species. 2-oxoglutarate production was strongly supported on ammonium nitrogen in Candida species, but remained low in Saccharomyces. Candida species, C. stellata in particular, produced more pyruvic acid regardless of N-sources. From the results, we concluded that the anaerobic organic acid metabolisms of C. zemplinina and C. stellata are different from each other and also from that of the Saccharomyces species. In the formation of succinic acid, the oxidative pathway from glutamic acid seems to play little or no role in C. zemplinina. The reductive branch of the TCA cycle, however, produces acidic intermediates (malic, fumaric, and succinic acid) in a level comparable with the production of the Saccharomyces species. An unidentified organic acid, which was produced on glutamic acid only by the Candida species, needs further investigation. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Organic acids for control of Salmonella in different feed materials

    DEFF Research Database (Denmark)

    Koyuncu, Sevinc; Andersson, Mats Gunnar; Löfström, Charlotta

    2013-01-01

    of FA, propionic acid (PA) and sodium formate (SF) was investigated. Four Salmonella strains isolated from feed were assayed for their acid tolerance. Also, the effect of lower temperatures (5°C and 15°C) compared to room temperature was investigated in rape seed and soybean meal. Results The efficacy...... of acid treatments varied significantly between different feed materials. The strongest reduction was seen in pelleted and compound mash feed (2.5 log10 reduction) followed by rapeseed meal (1 log10 reduction) after 5 days exposure. However, in soybean meal the acid effects were limited (less than 0.5 log......10 reduction) even after several weeks’ exposure. In all experiments the survival curves showed a concave shape, with a fast initial death phase followed by reduction at a slower rate during the remaining time of the experiment. No difference in Salmonella reduction was observed between FA...

  12. Review article Herbal extracts and organic acids as natural feed ...

    African Journals Online (AJOL)

    2013-07-16

    Jul 16, 2013 ... time and improved activity of proteolytic enzymes. ... Modern laboratory techniques enable the isolation and characterization of ..... microbial metabolites such as ammonia and biogenic amines. ..... acid determine their efficacy.

  13. Improvement of gas chromatographic analysis for organic acids and ...

    African Journals Online (AJOL)

    Yomi

    2010-08-27

    Aug 27, 2010 ... and ethanol fermentation by using the anaerobic bacterium. Clostridium ... GC analysis. Standard solution for GC analysis consisted of acetic acid (Sigma-. Aldrich ... Microorganism and inoculum preparation. C. beijerinckii ...

  14. Synthesis of Amino Acid Precursors with Organic Solids in Planetesimals with Liquid Water

    Science.gov (United States)

    Kebukawa, Y; Misawa, S.; Matsukuma, J.; Chan, Q. H. S.; Kobayashi, J.; Tachibana, S.; Zolensky, M. E.

    2017-01-01

    Amino acids are important ingredients of life that would have been delivered to Earth by extraterrestrial sources, e.g., comets and meteorites. Amino acids are found in aqueously altered carbonaceous chondrites in good part in the form of precursors that release amino acids after acid hydrolysis. Meanwhile, most of the organic carbon (greater than 70 weight %) in carbonaceous chondrites exists in the form of solvent insoluble organic matter (IOM) with complex macromolecular structures. Complex macromolecular organic matter can be produced by either photolysis of interstellar ices or aqueous chemistry in planetesimals. We focused on the synthesis of amino acids during aqueous alteration, and demonstrated one-pot synthesis of a complex suite of amino acids simultaneously with IOM via hydrothermal experiments simulating the aqueous processing

  15. The non-participation of organic sulphur in acid mine drainage generation.

    Science.gov (United States)

    Casagrande, D J; Finkelman, R B; Caruccio, F T

    1989-12-01

    Acid mine drainage is commonly associated with land disturbances that encounter and expose iron sulphides to oxidising atmospheric conditions. The attendant acidic conditions solubilise a host of trace metals. Within this flow regime the potential exists to contaminate surface drinking water supplies with a variety of trace materials. Accordingly, in evaluating the applications for mines located in the headwaters of water sheds, the pre-mining prediction of the occurrence of acid mine drainage is of paramount importance.There is general agreement among investigators that coal organic sulphur is a nonparticipant in acid mine drainage generation; however, there is no scientific documentation to support this concensus. Using simulated weathering, kinetic, mass balance, petrographic analysis and a peroxide oxidation procedure, coal organic sulphur is shown to be a nonparticipant in acid mine drainage generation. Calculations for assessing the acid-generating potential of a sedimentary rock should not include organic sulphur content.

  16. Kinetic Modelling and Experimental Studies for the Effects of Fe2+ Ions on Xylan Hydrolysis with Dilute-Acid Pretreatment and Subsequent Enzymatic Hydrolysis

    Directory of Open Access Journals (Sweden)

    Hui Wei

    2018-01-01

    Full Text Available High-temperature (150–170 °C pretreatment of lignocellulosic biomass with mineral acids is well established for xylan breakdown. Fe2+ is known to be a cocatalyst of this process although kinetics of its action remains unknown. The present work addresses the effect of ferrous ion concentration on sugar yield and degradation product formation from corn stover for the entire two-step treatment, including the subsequent enzymatic cellulose hydrolysis. The feedstock was impregnated with 0.5% acid and 0.75 mM iron cocatalyst, which was found to be optimal in preliminary experiments. The detailed kinetic data of acid pretreatment, with and without iron, was satisfactorily modelled with a four-step linear sequence of first-order irreversible reactions accounting for the formation of xylooligomers, xylose and furfural as intermediates to provide the values of Arrhenius activation energy. Based on this kinetic modelling, Fe2+ turned out to accelerate all four reactions, with a significant alteration of the last two steps, that is, xylose degradation. Consistent with this model, the greatest xylan conversion occurred at the highest severity tested under 170 °C/30 min with 0.75 mM Fe2+, with a total of 8% xylan remaining in the pretreated solids, whereas the operational conditions leading to the highest xylose monomer yield, 63%, were milder, 150 °C with 0.75 mM Fe2+ for 20 min. Furthermore, the subsequent enzymatic hydrolysis with the prior addition of 0.75 mM of iron(II increased the glucose production to 56.3% from 46.3% in the control (iron-free acid. The detailed analysis indicated that conducting the process at lower temperatures yet long residence times benefits the yield of sugars. The above kinetic modelling results of Fe2+ accelerating all four reactions are in line with our previous mechanistic research showing that the pretreatment likely targets multiple chemistries in plant cell wall polymer networks, including those represented by the C

  17. Biochemical studies on the effect of fluoride on higher plants. I. Metabolism of carbohydrates, organic acids and amino acids. [Glycine max var. Hawkeye

    Energy Technology Data Exchange (ETDEWEB)

    Yang, S F; Miller, G W

    1963-01-01

    Metabolic processes associated with free sugars, organic acids and amino acids in higher plants subjected to fluoride fumigation were studied quantitatively. Fluoride-fumigated leaves contained more reducing sugars and less sucrose than the normal leaves. This result suggested inhibition of sucrose synthesis by fluoride. Necrotic leaves contained increased total concentrations of organic acids, which were mostly attributable to malic acid, malonic acid and citric acid. The greater increase in malic acid relative to that of citric acid was the reverse of results observed in chlorotic tissue. Necrotic leaves contained enhanced amounts of free amino acids. The greatest increase occurred in the concentration of asparagine and might be related to the increased respiratory rate of necrotic leaves. Pipecolic acid accumulated in large quantities in nicrotic tissue and was not detected in normal leaves. The accumulation of organic acids and amino acids in leaves during fluoride fumigation was evidenced by a lowered respiratory quotient.

  18. Biotechnological Production of Organic Acids from Renewable Resources.

    Science.gov (United States)

    Pleissner, Daniel; Dietz, Donna; van Duuren, Jozef Bernhard Johann Henri; Wittmann, Christoph; Yang, Xiaofeng; Lin, Carol Sze Ki; Venus, Joachim

    2017-03-07

    Biotechnological processes are promising alternatives to petrochemical routes for overcoming the challenges of resource depletion in the future in a sustainable way. The strategies of white biotechnology allow the utilization of inexpensive and renewable resources for the production of a broad range of bio-based compounds. Renewable resources, such as agricultural residues or residues from food production, are produced in large amounts have been shown to be promising carbon and/or nitrogen sources. This chapter focuses on the biotechnological production of lactic acid, acrylic acid, succinic acid, muconic acid, and lactobionic acid from renewable residues, these products being used as monomers for bio-based material and/or as food supplements. These five acids have high economic values and the potential to overcome the "valley of death" between laboratory/pilot scale and commercial/industrial scale. This chapter also provides an overview of the production strategies, including microbial strain development, used to convert renewable resources into value-added products.

  19. Organic Acids Regulation of Chemical-Microbial Phosphorus Transformations in Soils.

    Science.gov (United States)

    Menezes-Blackburn, Daniel; Paredes, Cecilia; Zhang, Hao; Giles, Courtney D; Darch, Tegan; Stutter, Marc; George, Timothy S; Shand, Charles; Lumsdon, David; Cooper, Patricia; Wendler, Renate; Brown, Lawrie; Blackwell, Martin; Wearing, Catherine; Haygarth, Philip M

    2016-11-01

    We have used an integrated approach to study the mobility of inorganic phosphorus (P) from soil solid phase as well as the microbial biomass P and respiration at increasing doses of citric and oxalic acid in two different soils with contrasting agronomic P status. Citric or oxalic acids significantly increased soil solution P concentrations for doses over 2 mmol kg -1 . However, low organic acid doses (<2 mmol kg -1 ) were associated with a steep increase in microbial biomass P, which was not seen for higher doses. In both soils, treatment with the tribasic citric acid led to a greater increase in soil solution P than the dibasic oxalic acid, likely due to the rapid degrading of oxalic acids in soils. After equilibration of soils with citric or oxalic acids, the adsorbed-to-solution distribution coefficient (K d ) and desorption rate constants (k -1 ) decreased whereas an increase in the response time of solution P equilibration (T c ) was observed. The extent of this effect was shown to be both soil and organic acid specific. Our results illustrate the critical thresholds of organic acid concentration necessary to mobilize sorbed and precipitated P, bringing new insight on how the exudation of organic acids regulate chemical-microbial soil phosphorus transformations.

  20. [Effects of low molecular weight organic acids on redox reactions of mercury].

    Science.gov (United States)

    Zhao, Shi-Bo; Sun, Rong-Guo; Wang, Ding-Yong; Wang, Xiao-Wen; Zhang, Cheng

    2014-06-01

    To study the effects of the main component of vegetation root exudates-low molecular weight organic acids on the redox reactions of mercury, laboratory experiments were conducted to investigate the roles of tartaric, citric, and succinic acid in the redox reactions of mercury, and to analyze their interaction mechanism. The results indicated that tartaric acid significantly stimulated the mercury reduction reaction, while citric acid had inhibitory effect. Succinic acid improved the reduction rate at low concentration, and inhibited the reaction at high concentration. The mercury reduction rate by tartaric acid treatment was second-order with respect to Hg2+ concentration, ranging from 0.0014 L x (ng x min)(-1) to 0.005 6 L x (ng x min)(-1). All three organic acids showed a capacity for oxidating Hg(0) in the early stage, but the oxidized Hg(0) was subsequently reduced. The oxidation capacity of the three organic acids was in the order of citric acid > tartaric acid > succinic acid.

  1. Chiral metal-organic frameworks bearing free carboxylic acids for organocatalyst encapsulation.

    Science.gov (United States)

    Liu, Yan; Xi, Xiaobing; Ye, Chengcheng; Gong, Tengfei; Yang, Zhiwei; Cui, Yong

    2014-12-08

    Two chiral carboxylic acid functionalized micro- and mesoporous metal-organic frameworks (MOFs) are constructed by the stepwise assembly of triple-stranded heptametallic helicates with six carboxylic acid groups. The mesoporous MOF with permanent porosity functions as a host for encapsulation of an enantiopure organic amine catalyst by combining carboxylic acids and chiral amines in situ through acid-base interactions. The organocatalyst-loaded framework is shown to be an efficient and recyclable heterogeneous catalyst for the asymmetric direct aldol reactions with significantly enhanced stereoselectivity in relative to the homogeneous organocatalyst. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Cranberry juice and combinations of its organic acids are effective against experimental urinary tract infection

    DEFF Research Database (Denmark)

    Jensen, Heidi Dorthe; Struve, Carsten; Christensen, Søren Brøgger

    2017-01-01

    The antibacterial effect of cranberry juice and the organic acids therein on infection by uro28 pathogenic Escherichia coli was studied in an experimental mouse model of urinary tract infection (UTI). Reduced bacterial counts were found in the bladder (P ... administered singly, did not have any effect in the UTI model. Apparently, the antibacterial effect of the organic acids from cranberry juice on UTI can be obtained by administering a combination of malic acid and either citric or quinic acid. This study show for the first time that cranberry juice reduce E...

  3. Evaluation of different approaches to quantify strong organic acidity and acid-base buffering of organic-rich surface waters in Sweden.

    Science.gov (United States)

    Köhler, Stephan; Hruska, Jakub; Jönsson, Jörgen; Lövgren, Lars; Lofts, Stephen

    2002-11-01

    The role of organic acids in buffering pH in surface waters has been studied using a small brownwater stream (26mg L(-1) TOC) draining a forested catchment in Northern Sweden. Under the conditions of elevated pressure of CO2 stream field pH was changed between 3.5 and 6.1 during the acidification and alkalinization experiment. Acid-base characteristics of the natural organic matter were also determined using a high precision potentiometric method for a concentrated sample from the same stream. We compared the predictions from the Windermere Humic Aqueous Model (WHAM Model V), a model derived from the potentiometric titration (diprotic/monoprotic acid model) and a previously derived triprotic acid model which only uses alkalinity and TOC as input variables. The predicted buffering characteristics of all three models are very similar in the pH range 4.5-7 which suggests that during routine analysis alkalinity and TOC are sufficient to give a good estimate of organic acid anion charge contribution in a large range of surface waters. A slightly adjusted version of WHAM V successfully describes the organic charge contribution in a large number of sampled surface water lakes, which were previously used to calibrate the triprotic model.

  4. Activity coefficients at infinite dilution of organic solutes in the ionic liquid PEG-5 cocomonium methylsulfate at T = (313.15, 323.15, 333.15, and 343.15) K: Experimental results and COSMO-RS predictions

    International Nuclear Information System (INIS)

    Reddy, Prashant; Aslam Siddiqi, M.; Atakan, Burak; Diedenhofen, Michael; Ramjugernath, Deresh

    2013-01-01

    Highlights: ► γ 13 ∞ values reported for 25 organic solutes in the ionic liquid PEG-5 cocomonium methylsulfate. ► Measurements undertaken using the g.l.c. technique at T = (313.15, 323.15, 333.15, and 343.15) K. ► Sound speed, density and refractive index data for ionic liquid PEG-5 cocomonium methylsulfate also reported. ► Measured γ 13 ∞ values compared to COSMO-RS predictions. -- Abstract: Activity coefficients at infinite dilution γ 13 ∞ have been determined for 25 polar and non-polar organic solutes (alkanes, cycloalkanes, alk-1-enes, alk-1-ynes, aromatic compounds, alcohols, and ketones) in the ionic liquid PEG-5 cocomonium methylsulfate with gas–liquid chromatography at four different temperatures, T = (313.15, 323.15, 333.15, and 343.15) K. Packed columns with phase loadings of 0.28 and 0.34 ionic liquid mass fraction in the stationary phase were employed to obtain γ 13 ∞ values at each temperature investigated. Speed of sound, density, and refractive index values have also been measured for the pure ionic liquid at P = 0.1 MPa and T = (303.15, 313.15, 323.15, 333.15, and 343.15) K. The uncertainties in the sound speeds, densities, and refractive indices are estimated to be values of 0.9 m · s −1 , 0.00003 g · cm −3 , and 0.00002, respectively. Partial molar excess enthalpies at infinite dilution ΔH 1 E,∞ were calculated for the solutes from the temperature dependency of the γ 13 ∞ values for the temperature range of this study. The uncertainties in the determinations of γ 13 ∞ and ΔH 1 E,∞ values are 5% and 10%, respectively. Selectivity values at infinite dilution S 12 ∞ for hexane/benzene, cyclohexane/benzene, hexane/hex-1-ene, and hexane/ethanol separations have been calculated. These have been compared against values obtained from COSMO-RS predictions

  5. Top value platform chemicals: bio-based production of organic acids.

    Science.gov (United States)

    Becker, Judith; Lange, Anna; Fabarius, Jonathan; Wittmann, Christoph

    2015-12-01

    Driven by the quest for sustainability, recent years have seen a tremendous progress in bio-based production routes from renewable raw materials to commercial goods. Particularly, the production of organic acids has crystallized as a competitive and fast-evolving field, related to the broad applicability of organic acids for direct use, as polymer building blocks, and as commodity chemicals. Here, we review recent advances in metabolic engineering and industrial market scenarios with focus on organic acids as top value products from biomass, accessible through fermentation and biotransformation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Prediction of acid dissociation constants of organic compounds using group contribution methods

    DEFF Research Database (Denmark)

    Zhou, Teng; Jhamb, Spardha; Liang, Xiaodong

    2018-01-01

    data-points with average absolute error of 0.23; (b) a non-linear GC model for organic compounds using 1622 data-points with average absolute error of 1.18; (c) an artificial neural network (ANN) based GC model for the organic compounds with average absolute error of 0.17. For each of the developed......In this paper, group contribution (GC) property models for the estimation of acid dissociation constants (Ka) of organic compounds are presented. Three GC models are developed to predict the negative logarithm of the acid dissociation constant pKa: (a) a linear GC model for amino acids using 180...

  7. River inputs and organic matter fluxes in the northern Bay of Bengal: Fatty acids

    Digital Repository Service at National Institute of Oceanography (India)

    Reemtsma, T.; Ittekkot, V.; Bartsch, M.; Nair, R.R

    ) 55-71 55 Elsevier Science Publishers B.V., Amsterdam \\[RA\\] River inputs and organic matter fluxes in the northern Bay of Bengal: fatty acids T. Reemtsma a, V. Ittekkot a, M. Bartsch a and R.R. Nair b alnstitut fiir Biogeochemie und Meereschemie..., R.R., 1993. River inputs and organic matter fluxes in the northern Bay of Bengal: fatty acids. Chem. Geol., 103: 55-71. Total particulate matter flux and organic carbon and fatty acid fluxes associated with settling particles collected during...

  8. Liver function and bacteriology of organs in broiler inoculated with nalidixic acid-resistant Salmonella Typhimurium and treated with organic acids

    Directory of Open Access Journals (Sweden)

    Tatiane M. Rocha

    2013-07-01

    Full Text Available AbAns etxrpaecritment was carried out with 630 one-day-old chicks to evaluate the effects of organic acids when birds were experimentally inoculated with Salmonella Typhimurium. Liver damage and the persistence of the bacterium in the organs were evaluated as well. Broilers were distributed in a completely randomised experimental design in a 3×2 factorial arrangement of six treatments with seven replicates of 15 birds each. Birds were inoculated with saline solution or the bacterium via gavage at 1 day of age, or were offered a feed containing or not the organic acid blend for the period of 7 to 14 days of age. A dose of 5.0x102 colony-forming units (CFU/0.5 mL of Salmonella Typhimurium was used for inoculation both via gavage and feed. The parameters evaluated are weight, liver histopathology, liver and serum biochemistry, and bacteriological analyses of the caeca, crop, spleen, and liver and heart pool. At 21 and 28 days of age, the liver of the non-inoculated groups was significantly lighter as compared to the other treatments. Birds fed organic acids presented lower bacterial isolation rates in all organs tested. Birds inoculated in the crop and treated with organic acids presented lower E. coli CFU counts (P<0.05. Birds inoculated with Salmonella presented significant changes (P<0.05 in liver enzymes, as detected by serum biochemistry, and in liver histopathology. It was concluded that organic acids effectively controlled Salmonella Typhimurium and did not cause any liver damage.

  9. The Use of Supported Acidic Ionic Liquids in Organic Synthesis

    Directory of Open Access Journals (Sweden)

    Rita Skoda-Földes

    2014-06-01

    Full Text Available Catalysts obtained by the immobilisation of acidic ionic liquids (ILs on solid supports offer several advantages compared to the use of catalytically active ILs themselves. Immobilisation may result in an increase in the number of accessible active sites of the catalyst and a reduction of the amount of the IL required. The ionic liquid films on the carrier surfaces provide a homogeneous environment for catalytic reactions but the catalyst appears macroscopically as a dry solid, so it can simply be separated from the reaction mixture. As another advantage, it can easily be applied in a continuous fixed bed reactor. In the present review the main synthetic strategies towards the preparation of supported Lewis acidic and Brønsted acidic ILs are summarised. The most important characterisation methods and structural features of the supported ionic liquids are presented. Their efficiency in catalytic reactions is discussed with special emphasis on their recyclability.

  10. Aliphatic, cyclic, and aromatic organic acids, vitamins, and carbohydrates in soil: a review.

    Science.gov (United States)

    Vranova, Valerie; Rejsek, Klement; Formanek, Pavel

    2013-11-10

    Organic acids, vitamins, and carbohydrates represent important organic compounds in soil. Aliphatic, cyclic, and aromatic organic acids play important roles in rhizosphere ecology, pedogenesis, food-web interactions, and decontamination of sites polluted by heavy metals and organic pollutants. Carbohydrates in soils can be used to estimate changes of soil organic matter due to management practices, whereas vitamins may play an important role in soil biological and biochemical processes. The aim of this work is to review current knowledge on aliphatic, cyclic, and aromatic organic acids, vitamins, and carbohydrates in soil and to identify directions for future research. Assessments of organic acids (aliphatic, cyclic, and aromatic) and carbohydrates, including their behaviour, have been reported in many works. However, knowledge on the occurrence and behaviour of D-enantiomers of organic acids, which may be abundant in soil, is currently lacking. Also, identification of the impact and mechanisms of environmental factors, such as soil water content, on carbohydrate status within soil organic matter remains to be determined. Finally, the occurrence of vitamins in soil and their role in biological and biochemical soil processes represent an important direction for future research.

  11. Aliphatic, Cyclic, and Aromatic Organic Acids, Vitamins, and Carbohydrates in Soil: A Review

    Directory of Open Access Journals (Sweden)

    Valerie Vranova

    2013-01-01

    Full Text Available Organic acids, vitamins, and carbohydrates represent important organic compounds in soil. Aliphatic, cyclic, and aromatic organic acids play important roles in rhizosphere ecology, pedogenesis, food-web interactions, and decontamination of sites polluted by heavy metals and organic pollutants. Carbohydrates in soils can be used to estimate changes of soil organic matter due to management practices, whereas vitamins may play an important role in soil biological and biochemical processes. The aim of this work is to review current knowledge on aliphatic, cyclic, and aromatic organic acids, vitamins, and carbohydrates in soil and to identify directions for future research. Assessments of organic acids (aliphatic, cyclic, and aromatic and carbohydrates, including their behaviour, have been reported in many works. However, knowledge on the occurrence and behaviour of D-enantiomers of organic acids, which may be abundant in soil, is currently lacking. Also, identification of the impact and mechanisms of environmental factors, such as soil water content, on carbohydrate status within soil organic matter remains to be determined. Finally, the occurrence of vitamins in soil and their role in biological and biochemical soil processes represent an important direction for future research.

  12. Aliphatic, Cyclic, and Aromatic Organic Acids, Vitamins, and Carbohydrates in Soil: A Review

    Science.gov (United States)

    Vranova, Valerie; Rejsek, Klement; Formanek, Pavel

    2013-01-01

    Organic acids, vitamins, and carbohydrates represent important organic compounds in soil. Aliphatic, cyclic, and aromatic organic acids play important roles in rhizosphere ecology, pedogenesis, food-web interactions, and decontamination of sites polluted by heavy metals and organic pollutants. Carbohydrates in soils can be used to estimate changes of soil organic matter due to management practices, whereas vitamins may play an important role in soil biological and biochemical processes. The aim of this work is to review current knowledge on aliphatic, cyclic, and aromatic organic acids, vitamins, and carbohydrates in soil and to identify directions for future research. Assessments of organic acids (aliphatic, cyclic, and aromatic) and carbohydrates, including their behaviour, have been reported in many works. However, knowledge on the occurrence and behaviour of D-enantiomers of organic acids, which may be abundant in soil, is currently lacking. Also, identification of the impact and mechanisms of environmental factors, such as soil water content, on carbohydrate status within soil organic matter remains to be determined. Finally, the occurrence of vitamins in soil and their role in biological and biochemical soil processes represent an important direction for future research. PMID:24319374

  13. Application of the CPA equation of state to organic acids

    DEFF Research Database (Denmark)

    Derawi, Samer; Zeuthen, Frederik Jacob; Michelsen, Michael Locht

    2004-01-01

    a strong tendency to dimerise in the vapor phase at normal condition resulting in strong non-ideal behavior, even at low pressures. Pure compound parameters have been determined from vapor pressure and liquid density data for the three acids. Among the three tested association schemes (one-site, two......-site, and four-site), only the one-site association scheme describes satisfactorily the association in both the gas and the liquid phase. Second virial coefficients axe predicted well with the proposed one-site model. Excellent binary VLE and acceptable LLE correlations have been obtained for acid + aliphatic...

  14. A new corresponding state-based correlation for the surface tension of organic fatty acids

    Science.gov (United States)

    Zhang, Cuihua; Tian, Jianxiang; Zheng, Mengmeng; Yi, Huili; Zhang, Laibin; Liu, Shuzhen

    2018-01-01

    In this paper, we proposed a new corresponding state-based correlation for organic fatty (aliphatic, carboxylic and polyfunctional) acids. By using the recently published surface tension data of the 99 acids [A. Mulero and I. Cachadiña, J. Phys. Chem. Ref. Data 45 (2016) 033105] and comparing with the recently published other corresponding state correlations, we found that this correlation reproduces the lowest absolute average deviation (AAD) values for 82 acids out of the 99 acids. It can reproduce the surface tension data with AAD less than 10% for 89 out of the 99 acids.

  15. Students' Understanding of Acids/Bases in Organic Chemistry Contexts

    Science.gov (United States)

    Cartrette, David P.; Mayo, Provi M.

    2011-01-01

    Understanding key foundational principles is vital to learning chemistry across different contexts. One such foundational principle is the acid/base behavior of molecules. In the general chemistry sequence, the Bronsted-Lowry theory is stressed, because it lends itself well to studying equilibrium and kinetics. However, the Lewis theory of…

  16. Susceptibility of Campylobacter jejuni to Organic Acids and Monoacylglycerols

    Czech Academy of Sciences Publication Activity Database

    Molatová, Z.; Skřivanová, E.; Macias, B.; McEwan, N. R.; Březina, P.; Marounek, Milan

    2010-01-01

    Roč. 55, č. 3 (2010), s. 215-220 ISSN 0015-5632 R&D Projects: GA ČR GD525/08/H060 Institutional research plan: CEZ:AV0Z50450515 Keywords : CHAIN FATTY-ACIDS * POULTRY * COLONIZATION Subject RIV: EE - Microbiology, Virology Impact factor: 0.977, year: 2010

  17. Improvement of gas chromatographic analysis for organic acids and ...

    African Journals Online (AJOL)

    Yomi

    2010-08-27

    Aug 27, 2010 ... short retention time and fair recognition peak of the compounds were obtained under the ... GC for acid and solvent analysis from ABE fermentation ... FID was kept at 230°C. Nitrogen gas was used as a carrier gas at a.

  18. Organ- and species-specific biological activity of rosmarinic acid

    NARCIS (Netherlands)

    Iswandana, R.; Pham, B.T.; van Haaften, W.T.; Luangmonkong, T.; Oosterhuis, D.; Mutsaers, H.A.M.; Olinga, P.

    2016-01-01

    Rosmarinic acid (RA), a compound found in several plant species, has beneficial properties, including anti-inflammatory and antibacterial effects. We investigated the toxicity, anti-inflammatory, and antifibrotic effects of RA using precision-cut liver slices (PCLS) and precision-cut intestinal

  19. The Effects of Dilute Sulfuric Acid on Sheet Resistance and Transmittance in Poly(3,4-thylenedioxythiophene: Poly(styrenesulfonate Films

    Directory of Open Access Journals (Sweden)

    Teen-Hang Meen

    2013-01-01

    Full Text Available The conductivity of poly(3,4-thylenedioxythiophene: poly(styrenesulfonate (PEDOT: PSS films by adding various molar concentrations of sulfuric acid (H2SO4 was improved and studied in this paper. The sheet resistance of the doped PEDOT: PSS film was enhanced with increasing the ratio of H2SO4, but it drops after the maximum sheet resistance. The reason for this phenomenon is resulting from the fact that the H2SO4 preferentially react with the sorbitol which is so-called the pinacol rearrangement. The nonconductive anions of some PSS− were substituted by the conductive anions of hydrogen sulfate (HSO4- when the residual H2SO4 reacted with PSS. In addition to the substitution reaction, PEDOT chains were increasingly aggregated with increasing the ratio of H2SO4. After doped H2SO4, the sheet resistance of H2SO4-doped PEDOT: PSS film is improved nearly 36%; the surface roughness is reduced from 1.268 nm to 0.822 nm and the transmittance is up to 91.9% in the visible wavelength range from 400 to 700 nm.

  20. UTILIZATION OF OIL PALM EMPTY FRUIT BUNCH (OPEFB FOR BIOETHANOL PRODUCTION THROUGH ALKALI AND DILUTE ACID PRETREATMENT AND SIMULTANEOUS SACCHARIFICATION AND FERMENTATION

    Directory of Open Access Journals (Sweden)

    Yanni Sudiyani

    2010-07-01

    Full Text Available Lignocellulosic biomass is a potential alternative source of bioethanol for energy. The lignocellulosics are abundantly available in Indonesia. Most of them are wastes of agriculture, plantation and forestry. Among those wastes, oil palm empty fruit bunch (OP EFB is one of a potential lignocellulosics to be converted to bioethanol. This EFB, which is wastes in oil palm factories, is quite abundant (around 25 million tons/year and also has high content of cellulose (41-47%. The conversion of OPEFB to ethanol basically consists of three steps which are pretreatment, hydrolysis of cellulose and hemicellulose to simple sugars (hexoses and pentoses, and fermentation of simple sugars to ethanol. Acid and alkali pretreatments are considered the simplest methods and are potentially could be applied in the next couple of years. However, there are still some problems that have to be overcome to make the methods economically feasible. The high price of cellulose enzyme that is needed in the hydrolysis step is one of factors that cause the cost of EFB conversion is still high. Thus, the search of potential local microbes that could produce cellulase is crucial. Besides that, it is also important to explore fermenting microbes that could ferment six carbon sugars from cellulose as well as five carbon sugars from hemicellulose, so that the conversion of lignocellulosics, particularly EFB, would be more efficient. Keywords: OPEFB, lignocellulosics, pretreatment, fermentation, ethanol

  1. A quantitative study of eicosapentaenoic acid (EPA) production by Nannochloropsis gaditana for aquaculture as a function of dilution rate, temperature and average irradiance.

    Science.gov (United States)

    Camacho-Rodríguez, J; González-Céspedes, A M; Cerón-García, M C; Fernández-Sevilla, J M; Acién-Fernández, F G; Molina-Grima, E

    2014-03-01

    Different pilot-scale outdoor photobioreactors using medium recycling were operated in a greenhouse under different environmental conditions and the growth rates (0.1 to 0.5 day(-1)) obtained evaluated in order to compare them with traditional systems used in aquaculture. The annualized volumetric growth rate for Nannochloropsis gaditana was 0.26 g l(-1) day(-1) (peak 0.4 g l(-1) day(-1)) at 0.4 day(-1) in a 5-cm wide flat-panel bioreactor (FP-PBR). The biomass productivity achieved in this reactor was 10-fold higher than in traditional reactors, reaching values of 28 % and 45 % dry weight (d.w.) of lipids and proteins, respectively, with a 4.3 % (d.w.) content of eicosapentaenoic acid (EPA). A model for predicting EPA productivity from N. gaditana cultures that takes into account the existence of photolimitation and photoinhibition of growth under outdoor conditions is presented. The effect of temperature and average irradiance on EPA content is also studied. The maximum EPA productivity attained is 30 mg l(-1) day(-1).

  2. Recombinant cells and organisms having persistent nonstandard amino acid dependence and methods of making them

    Science.gov (United States)

    Church, George M.; Mandell, Daniel J.; Lajoie, Marc J.

    2017-12-05

    Recombinant cells and recombinant organisms persistently expressing nonstandard amino acids (NSAAs) are provided. Methods of making recombinant cells and recombinant organisms dependent on persistently expressing NSAAs for survival are also provided. These methods may be used to make safe recombinant cells and recombinant organisms and/or to provide a selective pressure to maintain one or more reassigned codon functions in recombinant cells and recombinant organisms.

  3. Modeling the acid-base chemistry of organic solutes in Adirondack, New York, lakes

    Science.gov (United States)

    Driscoll, Charles T.; Lehtinen, Michael D.; Sullivan, Timothy J.

    1994-02-01

    Data from the large and diverse Adirondack Lake Survey were used to calibrate four simple organic acid analog models in an effort to quantify the influence of naturally occurring organic acids on lake water pH and acid-neutralizing capacity (ANC). The organic acid analog models were calibrated to observations of pH, dissolved organic carbon (DOC), and organic anion (An-) concentrations from a reduced data set representing 1128 individual lake samples, expressed as 41 observations of mean pH, in intervals of 0.1 pH units from pH 3.9 to 7.0. Of the four organic analog approaches examined, including the Oliver et al. (1983) model, as well as monoprotic, diprotic, and triprotic representations, the triprotic analog model yielded the best fit (r2 = 0.92) to the observed data. Moreover, the triprotic model was qualitatively consistent with observed patterns of change in organic solute charge density as a function of pH. A low calibrated value for the first H+ dissociation constant (pKal = 2.62) and the observation that organic anion concentrations were significant even at very low pH (acidic functional groups. Inclusion of organic acidity in model calculations resulted in good agreement between measured and predicted values of lake water pH and ANC. Assessments to project the response of surface waters to future changes in atmospheric deposition, through the use of acidification models, will need to include representations of organic acids in model structure to make accurate predictions of pH and ANC.

  4. Organic carbon and humic acids in sediments of the Arabian Sea and factors governing their distribution

    Digital Repository Service at National Institute of Oceanography (India)

    Sardessai, S.

    acids are enriched on the slope compared to the inner and outer shelf. While upwelling, primary productivity and redox conditions at the bottom are known to influence organic matter accumulation in sediments, bacterial population and sediment texture...

  5. Enzymatic regulation of organic acid metabolism in an alkali-tolerant ...

    African Journals Online (AJOL)

    Tuoyo Aghomotsegin

    2016-10-05

    Oct 5, 2016 ... seedlings of C. virgata were treated with varying salt and alkali stress. First, the composition and .... mechanisms of organic acid accumulation in C. virgata ..... dehydrogenase and ferredoxin-dependent glutamate synthase in.

  6. Effect of organic acids traces on the carbon steel corrosion behavior

    International Nuclear Information System (INIS)

    Stefanescu, D.; Radulescu; Mogosan, S.

    2009-01-01

    There are many different ways in which organic matter may get in water-steam cycles. One important pathway is constituted by organic matter admitted into the system by chemical make-up water under standard operation conditions (without inverse osmosis). The high molecular weight organic matter, in particularly polysaccharides are broken in organic acids, in particular acetic and formic acid. This paper presents an overview of the investigations undertaken referring to the behavior SA106 gr. B mild steel in secondary circuit aqueous environment contaminated with formic and acetic acid traces. The samples were filmed in static autoclaves in operation conditions of secondary circuit, in contaminated environment and after that they were investigated using metallographic microscopy and SEM. In addition, an electrochemical technique videlicet impedance spectroscopy (EIS) was used to investigate the corrosion behavior of SA106 gr. B carbon steel in secondary circuit medium contaminated with formic and acetic acid traces. (authors)

  7. Production of starch with antioxidative activity by baking starch with organic acids.

    Science.gov (United States)

    Miwa, Shoji; Nakamura, Megumi; Okuno, Michiko; Miyazaki, Hisako; Watanabe, Jun; Ishikawa-Takano, Yuko; Miura, Makoto; Takase, Nao; Hayakawa, Sachio; Kobayashi, Shoichi

    2011-01-01

    A starch ingredient with antioxidative activity, as measured by the DPPH method, was produced by baking corn starch with an organic acid; it has been named ANOX sugar (antioxidative sugar). The baking temperature and time were fixed at 170 °C and 60 min, and the organic acid used was selected from preliminary trials of various kinds of acid. The phytic acid ANOX sugar preparation showed the highest antioxidative activity, but the color of the preparation was almost black; we therefore selected L-tartaric acid which had the second highest antioxidative activity. The antioxidative activity of the L-tartaric acid ANOX sugar preparation was stable against temperature, light, and enzyme treatments (α-amylase and glucoamylase). However, the activity was not stable against variations in water content and pH value. The antioxidative activity of ANOX sugar was stabilized by treating with boiled water or nitrogen gas, or by pH adjustment.

  8. Crystal structures of seven molecular salts derived from benzylamine and organic acidic components

    Science.gov (United States)

    Wen, Xianhong; Jin, Xiunan; Lv, Chengcai; Jin, Shouwen; Zheng, Xiuqing; Liu, Bin; Wang, Daqi; Guo, Ming; Xu, Weiqiang

    2017-07-01

    Cocrystallization of the commonly available organic amine, benzylamine, with a series of organic acids gave a total of seven molecular salts with the compositions: (benzylamine): (p-toluenesulfonic acid) (1) [(HL)+ · (tsa-)], (benzylamine): (o-nitrobenzoic acid) (2) [(HL+) · (onba)-], (benzylamine): (3,4-methylenedioxybenzoic acid) (3) [(HL+) · (mdba-)], (benzylamine): (mandelic acid) (4) [(HL+) · (mda-)], (benzylamine): (5-bromosalicylic acid)2(5) [(HL+) · (bsac-) · (Hbsac)], (benzylamine): (m-phthalic acid) (6) [(HL+) · (Hmpta-)], and (benzylamine)2: (trimesic acid) (7) [(HL+)2 · (Htma2-)]. The seven salts have been characterised by X-ray diffraction technique, IR, and elemental analysis, and the melting points of all the salts were also reported. And their structural and supramolecular aspects are fully analyzed. The result reveals that among the seven investigated crystals the NH2 groups in the benzylamine moieties are protonated when the organic acids are deprotonated, and the crystal packing is interpreted in terms of the strong charge-assisted Nsbnd H⋯O hydrogen bond formation between the ammonium and the deprotonated acidic groups. Except the Nsbnd H⋯O hydrogen bond, the Osbnd H⋯O hydrogen bonds (charge assisted or neutral) were also found at the salts 4-7. Further analysis of the crystal packing of the salts indicated that a different family of additional CHsbnd O/CH2sbnd O, CHsbnd π/CH2sbnd π, Osbnd O, and Osbnd Cπ associations contribute to the stabilization and expansion of the total high-dimensional (2D-3D) framework structures. For the coexistence of the various weak nonbonding interactions these structures adopted homo or hetero supramolecular synthons or both. Some classical supramolecular synthons, such as R42(8), R43(10) and R44(12), usually observed in organic solids of organic acids with amine, were again shown to be involved in constructing most of these hydrogen bonding networks.

  9. Organic acid production from potato starch waste fermentation by rumen microbial communities from Dutch and Thai dairy cows

    NARCIS (Netherlands)

    Palakawong Na Ayudthaya, Susakul; De Weijer, Van Antonius H.P.; Gelder, Van Antonie H.; Stams, Alfons J.M.; Vos, De Willem M.; Plugge, Caroline M.

    2018-01-01

    Background: Exploring different microbial sources for biotechnological production of organic acids is important. Dutch and Thai cow rumen samples were used as inocula to produce organic acid from starch waste in anaerobic reactors. Organic acid production profiles were determined and microbial

  10. Influence of electron beam irradiation in the organic acids profile of Portuguese chestnuts (Castanea sativa Mill.)

    OpenAIRE

    Carocho, Márcio; Antonio, Amilcar L.; Barros, Lillian; Barreira, João C.M.; Bento, Albino; Rafalski, Andrzej; Ferreira, Isabel C.F.R.

    2013-01-01

    Organic acids are primary metabolites that play important roles in plant metabolism and confer distinct flavors in fruits. Their consumption is beneficial for humans, namely against certain illnesses. The food industry uses them as preservatives and flavor enhancers. In fruits conservation and transport, organic acids should be preserved at all costs in order to maintain physical quality and pleasant flavors until they reach the consumer. In 2010, due to European legislation, meth...

  11. Comparison of cultivable acetic acid bacterial microbiota in organic and conventional apple cider vinegar

    OpenAIRE

    Mori Štornik, Aleksandra; Skok, Barbara; Trček, Janja

    2017-01-01

    Organic apple cider vinegar is produced from apples that go through very restricted treatment in orchard. During the first stage of the process, the sugars from apples are fermented by yeasts to cider. The produced ethanol is used as a substrate by acetic acid bacteria in a second separated bioprocess. In both, the organic and conventional apple cider vinegars the ethanol oxidation to acetic acid is initiated by native microbiota that survived alcohol fermentation. We compared the cultivable ...

  12. Effectiveness of Hand Sanitizers with and without Organic Acids for Removal of Rhinovirus from Hands ▿

    Science.gov (United States)

    Turner, Ronald B.; Fuls, Janice L.; Rodgers, Nancy D.

    2010-01-01

    These studies evaluated the effectiveness of ethanol hand sanitizers with or without organic acids to remove detectable rhinovirus from the hands and prevent experimental rhinovirus infection. Ethanol hand sanitizers were significantly more effective than hand washing with soap and water. The addition of organic acids to the ethanol provided residual virucidal activity that persisted for at least 4 h. Whether these treatments will reduce rhinovirus infection in the natural setting remains to be determined. PMID:20047916

  13. The use of Syrian bentonite to remove organics and other ions from commercial Syrian phosphoric acid

    International Nuclear Information System (INIS)

    Khorfan, S.; Abdulbaki, M.; Zein, A.

    2006-01-01

    Using of activated carbon to remove organic matter from phosphoric acid in uranium and P 2 O 5 extraction units has high cost. A new study was conducted to establish a new material instead of activated carbon. Experiments were carried out on removing organic matter by adsorption on Syrian bentonite. The experiments of the removal of humic acid by Syrian bentonite gave good results and showed that the chemical and thermal activation of bentonite increased the adsorption efficiency. (Authors)

  14. The use of Syrian bentonite to remove organics and other ions from commercial Syrian phosphoric acid

    International Nuclear Information System (INIS)

    Khorfan, S.; Abdulbaki, M.; Zein, A.

    2005-03-01

    Using of activated carbon to remove organic matter from phosphoric acid in uranium and P 2 O 5 extraction units has high cost. A new study was conducted to establish a new material instead of activated carbon. Experiments were carried out on removing organic matter by adsorption on Syrian bentonite. The experiments of the removal of humic acid by Syrian bentonite gave good results and showed that the chemical and thermal activation of bentonite increased the adsorption efficiency. (Authors)

  15. Comprehensive profiling of mercapturic acid metabolites from dietary acrylamide as short-term exposure biomarkers for evaluation of toxicokinetics in rats and daily internal exposure in humans using isotope dilution ultra-high performance liquid chromatography tandem mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yu [Department of Food Science and Nutrition, College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, Zhejiang (China); Zhejiang Key Laboratory for Agro-Food Processing, Zhejiang R & D Center for Food Technology and Equipment, Fuli Institute of Food Science, Zhejiang University, Hangzhou 310058, Zhejiang (China); Wang, Qiao; Cheng, Jun [Department of Food Science and Nutrition, College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, Zhejiang (China); Zhang, Jingshun; Xu, Jiaojiao [Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou 310051, Zhejiang (China); Ren, Yiping, E-mail: renyiping@263.net [Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou 310051, Zhejiang (China)

    2015-09-24

    Mercapturic acid metabolites from dietary acrylamide are important short-term exposure biomarkers for evaluating the in vivo toxicity of acrylamide. Most of studies have focused on the measurement of two metabolites, N-acetyl-S-(2-carbamoylethyl)-L-cysteine (AAMA) and N-acetyl-S-(2-carbamoyl-2-hydroxyethyl)-L-cysteine (GAMA). Thus, the comprehensive profile of acrylamide urinary metabolites cannot be fully understood. We developed an isotope dilution ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) method for the simultaneous determination of all four mercapturic acid adducts of acrylamide and its primary metabolite glycidamide under the electroscopy ionization negative (ESI-) mode in the present study. The limit of detection (LOD) and limit of quantification (LOQ) of the analytes ranged 0.1–0.3 ng/mL and 0.4–1.0 ng/mL, respectively. The recovery rates with low, intermediate and high spiking levels were calculated as 95.5%–105.4%, 98.2%–114.0% and 92.2%–108.9%, respectively. Acceptable within-laboratory reproducibility (RSD < 7.0%) substantially supported the use of current method for robust analysis. Rapid pretreatment procedures and short run time (8 min per sample) ensured good efficiency of metabolism profiling, indicating a wide application for investigating short-term internal exposure of dietary acrylamide. Our proposed UHPLC-MS/MS method was successfully applied to the toxicokinetic study of acrylamide in rats. Meanwhile, results of human urine analysis indicated that the levels of N-acetyl-S-(2-carbamoylethyl)-L-cysteine-sulfoxide (AAMA-sul), which did not appear in the mercapturic acid metabolites in rodents, were more than the sum of GAMA and N-acetyl-S-(1-carbamoyl-2-hydroxyethyl)-L-cysteine (iso-GAMA). Thus, AAMA-sul may alternatively become a specific biomarker for investigating the acrylamide exposure in humans. Current proposed method provides a substantial methodology support for comprehensive

  16. Comprehensive profiling of mercapturic acid metabolites from dietary acrylamide as short-term exposure biomarkers for evaluation of toxicokinetics in rats and daily internal exposure in humans using isotope dilution ultra-high performance liquid chromatography tandem mass spectrometry

    International Nuclear Information System (INIS)

    Zhang, Yu; Wang, Qiao; Cheng, Jun; Zhang, Jingshun; Xu, Jiaojiao; Ren, Yiping

    2015-01-01

    Mercapturic acid metabolites from dietary acrylamide are important short-term exposure biomarkers for evaluating the in vivo toxicity of acrylamide. Most of studies have focused on the measurement of two metabolites, N-acetyl-S-(2-carbamoylethyl)-L-cysteine (AAMA) and N-acetyl-S-(2-carbamoyl-2-hydroxyethyl)-L-cysteine (GAMA). Thus, the comprehensive profile of acrylamide urinary metabolites cannot be fully understood. We developed an isotope dilution ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) method for the simultaneous determination of all four mercapturic acid adducts of acrylamide and its primary metabolite glycidamide under the electroscopy ionization negative (ESI-) mode in the present study. The limit of detection (LOD) and limit of quantification (LOQ) of the analytes ranged 0.1–0.3 ng/mL and 0.4–1.0 ng/mL, respectively. The recovery rates with low, intermediate and high spiking levels were calculated as 95.5%–105.4%, 98.2%–114.0% and 92.2%–108.9%, respectively. Acceptable within-laboratory reproducibility (RSD < 7.0%) substantially supported the use of current method for robust analysis. Rapid pretreatment procedures and short run time (8 min per sample) ensured good efficiency of metabolism profiling, indicating a wide application for investigating short-term internal exposure of dietary acrylamide. Our proposed UHPLC-MS/MS method was successfully applied to the toxicokinetic study of acrylamide in rats. Meanwhile, results of human urine analysis indicated that the levels of N-acetyl-S-(2-carbamoylethyl)-L-cysteine-sulfoxide (AAMA-sul), which did not appear in the mercapturic acid metabolites in rodents, were more than the sum of GAMA and N-acetyl-S-(1-carbamoyl-2-hydroxyethyl)-L-cysteine (iso-GAMA). Thus, AAMA-sul may alternatively become a specific biomarker for investigating the acrylamide exposure in humans. Current proposed method provides a substantial methodology support for comprehensive

  17. An estimation of influence of humic acid and organic matter originated from bentonite on samarium solubility

    International Nuclear Information System (INIS)

    Kanaji, Mariko; Sato, Haruo; Sasahira, Akira

    1999-10-01

    Organic acids in groundwater are considered to form complexes and increase the solubility of radionuclides released from vitrified waste in a high-level radioactive waste (HLW) repository. To investigate whether the solubility of samarium (Sm) is influenced by organic substances, we measured Sm solubility in the presence of different organic substances and compared those values with results from thermodynamic predictions. Humic acid (Aldrich) is commercially available and soluble organic matter originated from bentonite were used as organic substances in this study. Consequently, the solubility of Sm showed a tendency to apparently increase with increasing the concentration of humic acid, but in the presence of carbonate, thermodynamic predictions suggested that the dominant species are carbonate complexes and that the effect of organic substances are less than that of carbonate. Based on total organic carbon (TOC), the increase of Sm solubility measured with humic acid (Aldrich) was more significant than that in the case with soluble organic matter originated from bentonite. Since bentonite is presumed to include also simple organic matters of which stability constant for forming complexes is low, the effect of soluble organic matter originated from bentonite on the solubility of Sm is considered to be less effective than that of humic acid (Aldrich). Experimental values were compared with model prediction, proposed by Kim, based on data measured in a low pH region. Tentatively we calculated the increase in Sm solubility assuming complexation with humic acid. Trial calculations were carried out on the premise that the complexation reaction of metal ion with humic acid is based on neutralization process by 1-1 complexation. In this process, it was assumed that one metal ion coordinates with one unit of complexation sites which number of proton exchange sites is equal to ionic charge. Consequently, Kim's model indicated that carbonate complexes should be dominant

  18. Quantitative analysis of the modes of growth inhibition by weak organic acids in Saccharomyces cerevisiae

    NARCIS (Netherlands)

    Ullah, A.; Orij, R.; Brul, S.; Smits, G.J.

    2012-01-01

    Weak organic acids are naturally occurring compounds that are commercially used as preservatives in the food and beverage industries. They extend the shelf life of food products by inhibiting microbial growth. There are a number of theories that explain the antifungal properties of these weak acids,

  19. Renal response to acute acid loading--an organ physiological approach

    DEFF Research Database (Denmark)

    Osther, P J; Engel, K; Kildeberg, P

    2004-01-01

    , as the extracellular acid-base status would be expected to be the key physiological trigger for renal NAE. The object of this study was to investigate the renal response to acute non-carbonic acid loading using a quantitative organ physiological approach. MATERIAL AND METHODS: Five-h NH4Cl loading studies were...

  20. Hygroscopic behavior of atmospheric aerosols containing nitrate salts and water-soluble organic acids

    Science.gov (United States)

    Jing, Bo; Wang, Zhen; Tan, Fang; Guo, Yucong; Tong, Shengrui; Wang, Weigang; Zhang, Yunhong; Ge, Maofa

    2018-04-01

    While nitrate salts have critical impacts on environmental effects of atmospheric aerosols, the effects of coexisting species on hygroscopicity of nitrate salts remain uncertain. The hygroscopic behaviors of nitrate salt aerosols (NH4NO3, NaNO3, Ca(NO3)2) and their internal mixtures with water-soluble organic acids were determined using a hygroscopicity tandem differential mobility analyzer (HTDMA). The nitrate salt / organic acid mixed aerosols exhibit varying phase behavior and hygroscopic growth depending upon the type of components in the particles. Whereas pure nitrate salt particles show continuous water uptake with increasing relative humidity (RH), the deliquescence transition is still observed for ammonium nitrate particles internally mixed with organic acids such as oxalic acid and succinic acid with a high deliquescence point. The hygroscopicity of submicron aerosols containing sodium nitrate and an organic acid is also characterized by continuous growth, indicating that sodium nitrate tends to exist in a liquid-like state under dry conditions. It is observed that in contrast to the pure components, the water uptake is hindered at low and moderate RH for calcium nitrate particles containing malonic acid or phthalic acid, suggesting the potential effects of mass transfer limitation in highly viscous mixed systems. Our findings improve fundamental understanding of the phase behavior and water uptake of nitrate-salt-containing aerosols in the atmospheric environment.

  1. Light-enhanced acid catalysis over a metal-organic framework.

    Science.gov (United States)

    Xu, Caiyun; Sun, Keju; Zhou, Yu-Xiao; Ma, Xiao; Jiang, Hai-Long

    2018-03-06

    A Brønsted acid-functionalized metal-organic framework (MOF), MIL-101-SO 3 H, was prepared for acid-engaged esterification reactions. Strikingly, for the first time, the MOF exhibits significantly light-enhanced activity and possesses excellent activity and recyclability, with even higher activity than H 2 SO 4 under light irradiation.

  2. Hygroscopic behavior of atmospheric aerosols containing nitrate salts and water-soluble organic acids

    Directory of Open Access Journals (Sweden)

    B. Jing

    2018-04-01

    Full Text Available While nitrate salts have critical impacts on environmental effects of atmospheric aerosols, the effects of coexisting species on hygroscopicity of nitrate salts remain uncertain. The hygroscopic behaviors of nitrate salt aerosols (NH4NO3, NaNO3, Ca(NO32 and their internal mixtures with water-soluble organic acids were determined using a hygroscopicity tandem differential mobility analyzer (HTDMA. The nitrate salt ∕ organic acid mixed aerosols exhibit varying phase behavior and hygroscopic growth depending upon the type of components in the particles. Whereas pure nitrate salt particles show continuous water uptake with increasing relative humidity (RH, the deliquescence transition is still observed for ammonium nitrate particles internally mixed with organic acids such as oxalic acid and succinic acid with a high deliquescence point. The hygroscopicity of submicron aerosols containing sodium nitrate and an organic acid is also characterized by continuous growth, indicating that sodium nitrate tends to exist in a liquid-like state under dry conditions. It is observed that in contrast to the pure components, the water uptake is hindered at low and moderate RH for calcium nitrate particles containing malonic acid or phthalic acid, suggesting the potential effects of mass transfer limitation in highly viscous mixed systems. Our findings improve fundamental understanding of the phase behavior and water uptake of nitrate-salt-containing aerosols in the atmospheric environment.

  3. Organic acids as analytical reagent: Part 1. Estimation of zirconium by gallic acid

    International Nuclear Information System (INIS)

    Pande, C.S.; Singh, A.K.; Kumar, Ashok

    1975-01-01

    Gallic acid has been found to be a selective reagent for the estimation of zirconium. The acid gives crystalline precipitate at pH of 4.8. The precipitate is ignited and weighed as ZrO 2 . Cations like Ca +2 , Ba +2 , Sr +2 , Mn +2 , Co +2 , Ni +2 , Fe +3 do not interfere in the estimation. (author)

  4. The development of quantitative determination method of organic acids in complex poly herbal extraction

    Directory of Open Access Journals (Sweden)

    I. L. Dyachok

    2016-08-01

    Full Text Available Aim. The development of sensible, economical and expressive method of quantitative determination of organic acids in complex poly herbal extraction counted on izovaleric acid with the use of digital technologies. Materials and methods. Model complex poly herbal extraction of sedative action was chosen as a research object. Extraction is composed of these medical plants: Valeriana officinalis L., Crataégus, Melissa officinalis L., Hypericum, Mentha piperita L., Húmulus lúpulus, Viburnum. Based on chemical composition of plant components, we consider that main pharmacologically active compounds, which can be found in complex poly herbal extraction are: polyphenolic substances (flavonoids, which are contained in Crataégus, Viburnum, Hypericum, Mentha piperita L., Húmulus lúpulus; also organic acids, including izovaleric acid, which are contained in Valeriana officinalis L., Mentha piperita L., Melissa officinalis L., Viburnum; the aminoacid are contained in Valeriana officinalis L. For the determination of organic acids content in low concentration we applied instrumental method of analysis, namely conductometry titration which consisted in the dependences of water solution conductivity of complex poly herbal extraction on composition of organic acids. Result. The got analytical dependences, which describes tangent lines to the conductometry curve before and after the point of equivalence, allow to determine the volume of solution expended on titration and carry out procedure of quantitative determination of organic acids in the digital mode. Conclusion. The proposed method enables to determine the point of equivalence and carry out quantitative determination of organic acids counted on izovaleric acid with the use of digital technologies, that allows to computerize the method on the whole.

  5. Nickel Deficiency Disrupts Metabolism of Ureides, Amino Acids, and Organic Acids of Young Pecan Foliage[OA

    Science.gov (United States)

    Bai, Cheng; Reilly, Charles C.; Wood, Bruce W.

    2006-01-01

    The existence of nickel (Ni) deficiency is becoming increasingly apparent in crops, especially for ureide-transporting woody perennials, but its physiological role is poorly understood. We evaluated the concentrations of ureides, amino acids, and organic acids in photosynthetic foliar tissue from Ni-sufficient (Ni-S) versus Ni-deficient (Ni-D) pecan (Carya illinoinensis [Wangenh.] K. Koch). Foliage of Ni-D pecan seedlings exhibited metabolic disruption of nitrogen metabolism via ureide catabolism, amino acid metabolism, and ornithine cycle intermediates. Disruption of ureide catabolism in Ni-D foliage resulted in accumulation of xanthine, allantoic acid, ureidoglycolate, and citrulline, but total ureides, urea concentration, and urease activity were reduced. Disruption of amino acid metabolism in Ni-D foliage resulted in accumulation of glycine, valine, isoleucine, tyrosine, tryptophan, arginine, and total free amino acids, and lower concentrations of histidine and glutamic acid. Ni deficiency also disrupted the citric acid cycle, the second stage of respiration, where Ni-D foliage contained very low levels of citrate compared to Ni-S foliage. Disruption of carbon metabolism was also via accumulation of lactic and oxalic acids. The results indicate that mouse-ear, a key morphological symptom, is likely linked to the toxic accumulation of oxalic and lactic acids in the rapidly growing tips and margins of leaflets. Our results support the role of Ni as an essential plant nutrient element. The magnitude of metabolic disruption exhibited in Ni-D pecan is evidence of the existence of unidentified physiological roles for Ni in pecan. PMID:16415214

  6. Molecular polarizability of organic molecules and their complexes. Communication LIV. Molar volumes of polyaryl organoelement compounds in solutions, extrapolated to infinite dilution, and steric structure of the molecules

    International Nuclear Information System (INIS)

    Bulgarevich, S.B.; Burdastykh, T.V.

    2008-01-01

    Molar volumes in various solvents were determined for organic derivatives of silicon, phosphorus, arsenic, sulfur, and tellurium, containing aryl nuclei capable to internal rotation about single bonds between them and bridging groups. Additive analysis of the molar volumes of these compounds showed that the aryl nuclei are acoplanar with respect to the bridging groups. Most probable is a conrotatory mutual orientation of the aromatic rings. Molar volumes were also determined for a series of compounds with two bridging groups, which can serve as models of an extreme case of mutual proximity of aryl ring planes in diaryl systems with one bridging group. A possibility for considerably simplifying the methods for determination of dipole moments and Kerr constants for compounds whose molar volumes can be calculated by our developed additive scheme is demonstrated [ru

  7. Verification of Organic Feed Identity by Fatty Acid Fingerprinting

    NARCIS (Netherlands)

    Tres, A.; Ruth, van S.M.

    2011-01-01

    The origin and authenticity of feed for laying hens is an important and fraud-susceptible aspect in the production of organic eggs. Chemical fingerprinting in combination with chemometric methods is increasingly used in conjunction with administrative controls to verify and safeguard the

  8. Halogenated methanesulfonic acids: A new class of organic micropollutants in the water cycle.

    Science.gov (United States)

    Zahn, Daniel; Frömel, Tobias; Knepper, Thomas P

    2016-09-15

    Mobile and persistent organic micropollutants may impact raw and drinking waters and are thus of concern for human health. To identify such possible substances of concern nineteen water samples from five European countries (France, Switzerland, The Netherlands, Spain and Germany) and different compartments of the water cycle (urban effluent, surface water, ground water and drinking water) were enriched with mixed-mode solid phase extraction. Hydrophilic interaction liquid chromatography - high resolution mass spectrometry non-target screening of these samples led to the detection and structural elucidation of seven novel organic micropollutants. One structure could already be confirmed by a reference standard (trifluoromethanesulfonic acid) and six were tentatively identified based on experimental evidence (chloromethanesulfonic acid, dichloromethanesulfonic acid, trichloromethanesulfonic acid, bromomethanesulfonic acid, dibromomethanesulfonic acid and bromochloromethanesulfonic acid). Approximated concentrations for these substances show that trifluoromethanesulfonic acid, a chemical registered under the European Union regulation REACH with a production volume of more than 100 t/a, is able to spread along the water cycle and may be present in concentrations up to the μg/L range. Chlorinated and brominated methanesulfonic acids were predominantly detected together which indicates a common source and first experimental evidence points towards water disinfection as a potential origin. Halogenated methanesulfonic acids were detected in drinking waters and thus may be new substances of concern. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Acid-resistant organic coatings for the chemical industry: a review

    DEFF Research Database (Denmark)

    Møller, Victor Buhl; Dam-Johansen, Kim; Frankær, Sarah Maria Grundahl

    2017-01-01

    Industries that work with acidic chemicals in their processes need to make choices on how to properly contain the substances and avoid rapid corrosion of equipment. Certain organic coatings and linings can be used in such environments, either to protect vulnerable construction materials, or......, in combination with fiber reinforcement, to replace them. However, degradation mechanisms of organic coatings in acid service are not thoroughly understood and relevant quantitative investigations are scarce. This review describes the uses and limitations of acid-resistant coatings in the chemical industry...

  10. Composition and content analysis of sugars and organic acids for 45 grape cultivars from northeast region of china

    International Nuclear Information System (INIS)

    Zaozhu, G.N.; Jia, Z.; Zhihu, R.; Zuhui, Z.; Quan, G.; Hongyan, G.; Xiuwu, G.

    2017-01-01

    The qualitative and quantitative analysis of sugars and acids of grape cultivars from northeast region of China was carried out for quality evaluation and variety improvement of grape. Analysis of major sugars and organic acids for 45 grape berries was carried out using High Performance Liquid Chromatography (HPLC). The result showed that glucose and fructose were the major sugars, beside that, some grape cultivars also contained sucrose. The quantity of glucose and fructose was almost equal in most of grape berries. A significant positive correlation existed between them, glucose content ranged from 53.24 mg/ml to 124.18mg/ml and fructose content ranged from 48.39 mg/ml to118.84 mg/ml. Tartaric acid, malic acid, citric acid and oxalic acid were organic acids and tartaric acid was the main constituent in most grape berries and its concentration was higher than the other organic acids. However, in some grape cultivars, malic acid and citric acid were two highest organic acids while oxalic acid content was the lowest and even in some cultivars it could not be detected. Tartaric acid ranged from 1.28mg/ml to 6.82 mg/ml, malic acid ranged from 0.09mg/ml to 3.95 mg/ml, citric acid ranged from 0.08mg/ml to 4.43 mg/ml, oxalic acid ranged from mg/ml to 0.370 mg/ml. Thirty-four grape cultivars out of 45 cultivars accounted more than 50% tartic acid of the total organic acid contents. However, in cultivars Bixiang Wuhe and Shennong Jinhuanghou citric acid was the main organic acid. Malic acid and citric acid were significantly positively related with total acid. In 43 grape cultivars, the soluble sugars were glucose and fructose. Besides glucose and fructose, sucrose was also observed in cultivars of LN33 and Cayuga white. (author)

  11. Acid-Base Learning Outcomes for Students in an Introductory Organic Chemistry Course

    Science.gov (United States)

    Stoyanovich, Carlee; Gandhi, Aneri; Flynn, Alison B.

    2015-01-01

    An outcome-based approach to teaching and learning focuses on what the student demonstrably knows and can do after instruction, rather than on what the instructor teaches. This outcome-focused approach can then guide the alignment of teaching strategies, learning activities, and assessment. In organic chemistry, mastery of organic acid-base…

  12. Design of homo-organic acid producing strains using multi-objective optimization

    DEFF Research Database (Denmark)

    Kim, Tae Yong; Park, Jong Myoung; Kim, Hyun Uk

    2015-01-01

    Production of homo-organic acids without byproducts is an important challenge in bioprocess engineering to minimize operation cost for separation processes. In this study, we used multi-objective optimization to design Escherichia coli strains with the goals of maximally producing target organic ...

  13. Organic acids as analytical reagent: Part 1. Estimation of zirconium by gallic acid

    Energy Technology Data Exchange (ETDEWEB)

    Pande, C S; Singh, A K; Kumar, Ashok [Lucknow Univ. (India). Dept. of Chemistry

    1975-07-01

    Gallic acid has been found to be a selective reagent for the estimation of zirconium. The acid gives a crystalline precipitate at pH of 4.8 which is ignited and weighed as ZrO/sub 2/. Cations like Ca/sup +2/, Ba/sup +2/, Sr/sup +2/, Mn/sup +2/, Co/sup +2/, Ni/sup +2/, Fe/sup +3/ do not interfere in the estimation.

  14. Gene deletion of cytosolic ATP: citrate lyase leads to altered organic acid production in Aspergillus niger

    DEFF Research Database (Denmark)

    Meijer, Susan Lisette; Nielsen, Michael Lynge; Olsson, Lisbeth

    2009-01-01

    With the availability of the genome sequence of the filamentous fungus Aspergillus niger, the use of targeted genetic modifications has become feasible. This, together with the fact that A. niger is well established industrially, makes this fungus an attractive micro-organism for creating a cell...... factory platform for production of chemicals. Using molecular biology techniques, this study focused on metabolic engineering of A. niger to manipulate its organic acid production in the direction of succinic acid. The gene target for complete gene deletion was cytosolic ATP: citrate lyase (acl), which...... the acl gene. Additionally, the total amount of organic acids produced in the deletion strain was significantly increased. Genome-scale stoichiometric metabolic model predictions can be used for identifying gene targets. Deletion of the acl led to increased succinic acid production by A. niger....

  15. Optimisation of a wet FGD pilot plant using fine limestone and organic acids

    DEFF Research Database (Denmark)

    Frandsen, Jan; Kiil, Søren; Johnsson, Jan Erik

    2001-01-01

    , but the residual limestone content in the gypsum increased to somewhere between 19 and 30 wt%, making this pH range unsuitable for use in a full-scale plant. The investigations have shown that both the addition of organic acids and the use of a limestone with a fine PSD can be used to optimise wet FGD plants. (C......The effects of adding an organic acid or using a limestone with a fine particle size distribution (PSD) have been examined in a wet flue gas desulphurisation (FGD) pilot plant. Optimisation of the plant with respect to the degree of desulphurisation and the residual limestone content of the gypsum...... has been the aim of the work. In contrast to earlier investigations with organic acids, all essential process parameters (i.e. gas phase concentration profiles of SO(2), slurry pH profiles. and residual limestone in the gypsum) were considered. Slurry concentrations of adipic acid in the range of 0...

  16. Side-by-side comparison of techniques for analyzing organic acids, total organic carbon, and anions. Final report

    International Nuclear Information System (INIS)

    Byers, W.A.; Richards, J.; Silva, H.; Miller, M.R.; Palino, G.F.; Wall, P.S.

    1986-09-01

    The objective of this project was to compare the organic acids sampling and analysis methods of Westinghouse and NWT Corporation. Sampling was performed at three sites, chosen to represent units with high, intermediate and low levels of organic contamination. To check the precision of each method, concurrent sampling was employed. To check the accuracy of each method, additions of standard organic solutions were made at one of the sites. Inorganic anions were also analyzed at each site by each contractor. Theoretical values of cation conductivity were calculated from organic and inorganic analytical data and compared to values measured onsite at the time of sampling. Total organic carbon (TOC) analyses were performed to evaluate different instruments and sampling techniques, as well as provide additional information on the relationship between TOC and organic acids concentrations. It was concluded that either of the organic acid sampling/analysis techniques used by the contractors can produce reliable results. TOC samples lose organics content with storage time and should be analyzed no later than one week after they are taken; if at all possible, they should be stored in a refrigerated condition. State-of-the art techniques for TOC sampling and analysis can produce results varying by 20 to 50 ppB for levels in the range of 50 to 120 ppB; any proposed limits for TOC should be reviewed in that light. Results of anion analyses are quite sensitive to sampling and analytical techniques. Reasonable agreement between calculated and measured values of cation conductivity suggests that both contractors had accurately determined all major anionic species

  17. Speleothem records of acid sulphate deposition and organic carbon mobilisation

    Science.gov (United States)

    Wynn, Peter; Fairchild, Ian; Bourdin, Clement; Baldini, James; Muller, Wolfgang; Hartland, Adam; Bartlett, Rebecca

    2017-04-01

    Dramatic increases in measured surface water DOC in recent decades have been variously attributed to either temperature rise, or destabilisation of long-term soil carbon pools following sulphur peak emissions status. However, whilst both drivers of DOC dynamics are plausible, they remain difficult to test due to the restricted nature of the available records of riverine DOC flux (1978 to present), and the limited availability of SO2 emissions inventory data at the regional scale. Speleothems offer long term records of both sulphur and carbon. New techniques to extract sulphur concentrations and isotopes from speleothem calcite have enabled archives of pollution history and environmental acidification to be reconstructed. Due to the large dynamic range in sulphur isotopic values from end member sources (marine aerosol +21 ‰ to continental biogenic emissions -30 ‰) and limited environmental fractionation under oxidising conditions, sulphur isotopes form an ideal tracer of industrial pollution and environmental acidification in the palaeo-record. We couple this acidification history to the carbon record, using organic matter fluorescence and trace metals. Trace metal ratios and abundance can be used to infer the type and size of organic ligand and are therefore sensitive to changes in temperature as a driver of organic carbon processing and biodegradation. This allows fluorescent properties and ratios of trace metals in speleothem carbonate to be used to represent both the flux of organic carbon into the cave as well as the degradation pathway. Here we present some of the first results of this work, exploring sulphur acidification as a mechanistic control on carbon solubility and export throughout the twentieth century.

  18. Protein haze formation in wines revisited. The stabilising effect of organic acids

    OpenAIRE

    Batista, L.; Monteiro, L.; Loureiro, V.; Teixeira, A.R.; Ferreira, R.B.

    2010-01-01

    The effect on the wine protein haze potential of five organic acids commonly encountered in wines (L(+)- tartaric, L( )-malic, citric, succinic and gluconic acids) was assessed. All five acids, tested at 20 mM, reduced dramatically the haze potential of proteins, either in wine or dissolved in water, throughout the range of pH values typical of wines (i.e., from 2.8 through 3.8). Subtle differences among the acid effects did not correlate with the number of their carboxyl groups, ...

  19. The drying method affects the organic acid content of alfalfa forages

    Directory of Open Access Journals (Sweden)

    P. Pezzi

    2011-03-01

    Full Text Available Malic acid (the main organic acid contained in alfalfa; Callaway et al., 1997 is an important metabolite for ruminal microbial population since it improves the uptake of lactic acid by Selenomonas ruminantium (Evans and Martin, 1997 and Megasphaera elsdenii (Rossi and Piva, 1999. Several studies have shown the effect of adding malic acid to the diet of steers and dairy cows on ruminal fermentation (Martin et al., 1999; Martin et al., 2000 and animal performances (Krummrey et al., 1979; Stallcup, 1979; Kung et al., 1982. Aim of this study was the evaluation of the influence of drying method.......

  20. Effect of organic acids on biofilm formation and quorum signaling of pathogens from fresh fruits and vegetables.

    Science.gov (United States)

    Amrutha, Balagopal; Sundar, Kothandapani; Shetty, Prathapkumar Halady

    2017-10-01

    Organic acids are known to be used as food preservatives due to their antimicrobial potential. This study evaluated the ability of three organic acids, namely, acetic acid, citric acid and lactic acid to manage E. coli and Salmonella sp. from fresh fruits and vegetables. Effect of these organic acids on biofilm forming ability and anti-quorum potential was also investigated. The effect of organic acids on inactivation of E. coli and Salmonella sp. on the surface of a selected vegetable (cucumber) was determined. The minimum inhibitory concentration of the organic acids were found to be 1.5, 2 and 0.2% in E. coli while it was observed to be 1, 1.5 and 1% in Salmonella sp. for acetic, citric and lactic acids respectively. Maximum inhibition of biofilm formation was recorded at 39.13% with lactic acid in E. coli and a minimum of 22.53% with citric acid in Salmonella sp. EPS production was affected in E. coli with lactic acid showing reduction by 13.42% while citric acid and acetic acid exhibited only 6.25% and 10.89% respectively. Swimming and swarming patterns in E. coli was notably affected by both acetic and lactic acids. Lactic and acetic acids showed higher anti-quorum sensing (QS) potential when compared to citric acid. 2% lactic acid showed a maximum inhibition of violacein production by 37.7%. Organic acids can therefore be used as potential quorum quenching agents in food industry. 2% lactic acid treatment on cucumber demonstrated that it was effective in inactivating E. coli and Salmonella sp. There was 1 log reduction in microbial count over a period of 6 days after the lactic acid treatment. Thus, organic acids can act as effective potential sanitizers in reducing the microbial load associated with fresh fruits and vegetables. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Use of organic acids to inactivate Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes on organic fresh apples and lettuce.

    Science.gov (United States)

    Park, Sang-Hyun; Choi, Mi-Ran; Park, Jeong-Woong; Park, Ki-Hwan; Chung, Myung-Sub; Ryu, Sangryeol; Kang, Dong-Hyun

    2011-08-01

    This study was undertaken to investigate the antimicrobial effect of organic acids against Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes on whole red organic apples and lettuce. Several studies have been conducted to evaluate organic acids as sanitizers. However, no studies have compared antimicrobial effects of various organic acids on organic fresh produce, including evaluation of color changes of produce. Apples and lettuce were inoculated with a cocktail of 3 strains each of 3 foodborne pathogens provided above and treated with 1% and 2% organic acids (propionic, acetic, lactic, malic, and citric acid) for 0, 0.5, 1, 5, and 10 min. With increasing treatment time and acid concentration, organic acid treatments showed significant reduction compared to the control treatment (distilled water), and differences in antimicrobial effects between organic acids were observed. After 10 min of treatment with 1% and 2% organic acids in apples, propionic (0.92 to 2.75 log reduction), acetic (0.52 to 2.78 log reduction), lactic (1.69 to >3.42 log reduction), malic (1.48 to >3.42 log reduction), and citric acid (1.52 to >3.42 log reduction) exhibited significant (P acid (1.85 to 2.86 log reduction) showed significant (P acids treatment were not significant during storage. It is suggested that organic acids have a potential as sanitizers for organic fresh produce. These data may help the organic produce industry provide safe fresh produce for consumers. © 2011 Institute of Food Technologists®

  2. Uric Acid Spherulites in the Reflector Layer of Firefly Light Organ

    Science.gov (United States)

    Goh, King-Siang; Sheu, Hwo-Shuenn; Hua, Tzu-En; Kang, Mei-Hua; Li, Chia-Wei

    2013-01-01

    Background In firefly light organs, reflector layer is a specialized tissue which is believed to play a key role for increasing the bioluminescence intensity through reflection. However, the nature of this unique tissue remains elusive. In this report, we investigated the role, fine structure and nature of the reflector layer in the light organ of adult Luciola cerata. Principal Findings Our results indicated that the reflector layer is capable of reflecting bioluminescence, and contains abundant uric acid. Electron microscopy (EM) demonstrated that the cytosol of the reflector layer's cells is filled with densely packed spherical granules, which should be the uric acid granules. These granules are highly regular in size (∼700 nm in diameter), and exhibit a radial internal structure. X-ray diffraction (XRD) analyses revealed that an intense single peak pattern with a d-spacing value of 0.320 nm is specifically detected in the light organ, and is highly similar to the diffraction peak pattern and d-spacing value of needle-formed crystals of monosodium urate monohydrate. However, the molar ratio evaluation of uric acid to various cations (K+, Na+, Ca2+ and Mg2+) in the light organ deduced that only a few uric acid molecules were in the form of urate salts. Thus, non-salt uric acid should be the source of the diffraction signal detected in the light organ. Conclusions In the light organ, the intense single peak diffraction signal might come from a unique needle-like uric acid form, which is different from other known structures of non-salt uric acid form. The finding of a radial structure in the granules of reflector layer implies that the spherical uric acid granules might be formed by the radial arrangement of needle-formed packing matter. PMID:23441187

  3. Role of Organic Acids in Bioformation of Kaolinite: Results of Laboratory Experiments

    Science.gov (United States)

    Bontognali, T. R. R.; Vasconcelos, C.; McKenzie, J. A.

    2012-04-01

    Clay minerals and other solid silica phases have a broad distribution in the geological record and greatly affect fundamental physicochemical properties of sedimentary rocks, including porosity. An increasing number of studies suggests that microbial activity and microbially produced organic acids might play an important role in authigenic clay mineral formation, at low temperatures and under neutral pH conditions. In particular, early laboratory experiments (Linares and Huertas, 1971) reported the precipitation of kaolinite in solutions of SiO2 and Al2O3 with different molar ratios SiO2/Al2O3, together with fulvic acid (a non-characterized mixture of many different acids containing carboxyl and phenolate groups) that was extracted from peat soil. Despite many attempts, these experiments could not be reproduced until recently. Fiore et al. (2011) hypothesized that the non-sterile fulvic acid might have contained microbes that participated in the formation of kaolinite. Using solutions saturated with Si and Al and containing oxalate and/or mixed microbial culture extracted from peat-moss soil, they performed incubation experiments, which produced kaolinite exclusively in solutions containing oxalate and microbes. We proposed to test the role of specific organic acids for kaolinite formation, conducting laboratory experiments at 25˚C, with solutions of sodium silicate, aluminum chloride and various organic compounds (i.e. EDTA, citric acid, succinic acid and oxalic acid). Specific organic acids may stabilize aluminum in octahedral coordination positions, which is crucial for the initial nucleation step. In our experiments, a poorly crystalline mineral that is possibly a kaolinite precursor formed exclusively in the presence of succinic acid. In experiments with other organic compounds, no incorporation of Al was observed, and amorphous silica was the only precipitated phase. In natural environments, succinic acid is produced by a large variety of microbes as an

  4. Capillary electrophoresis method for the analysis of organic acids and amino acids in the presence of strongly alternating concentrations of aqueous lactic acid.

    Science.gov (United States)

    Laube, Hendrik; Boden, Jana; Schneider, Roland

    2017-07-01

    During the production of bio-based bulk chemicals, such as lactic acid (LA), organic impurities have to be removed to produce a ready-to-market product. A capillary electrophoresis method for the simultaneous detection of LA and organic impurities in less than 10 min was developed. LA and organic impurities were detected using a direct UV detection method with micellar background electrolyte, which consisted of borate and sodium dodecyl sulfate. We investigated the effects of electrolyte composition and temperature on the speed, sensitivity, and robustness of the separation. A few validation parameters, such as linearity, limit of detection, and internal and external standards, were evaluated under optimized conditions. The method was applied for the detection of LA and organic impurities, including tyrosine, phenylalanine, and pyroglutamic acid, in samples from a continuous LA fermentation process from post-extraction tapioca starch and yeast extract.

  5. Simultaneous analysis of amino acid and organic acid by NMR spectrometry, 2. Diagnostic aids for inborn error of metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Koda, Naoya; Yamaguchi, Shuichi; Mori, Takeshi.

    1987-09-01

    Analysis of urine from patients with inborn error of metabolism were studied by /sup 1/H-nuclear magnetic resonance (NMR) spectrometry. Diseases studied were as follows; phenylketonuria, biotin responsive multiple carboxylase deficiency, non-ketotic hyperglycinemia, 3-ketothiolase deficiency, alkaptonuria, methylmalonic acidemia, isovaleric acidemia, glutaric aciduria, argininosuccinic aciduria and hyperornithinemia. In each disease, specific metabolites in urine were recognized by NMR spectrometry. This method is accomplished within 10 minutes with non-treated small volume of urine and will be successfully available for the screening andor diagnosis of inherited metabolic diseases of amino acid and organic acid.

  6. Extraction and characterisation of aqueous organic acids from natural waters

    International Nuclear Information System (INIS)

    Smith, B.; Moody, P.M.; Higgo, J.J.W.

    1993-01-01

    Humic and fulvic acids were extracted from large volumes of groundwater associated with the Broubster and Needle's Eye natural analogue sites, and the BGS research site at Drigg in Cumbria. Extractions were performed by both batchwise extraction and radial flow chromatography using DEAE-cellulose. Retained humic substances were eluted using NaOH and separated into humic and fulvic components by acidification to pH 1. After separation the humic component was purified by repetitive precipitation and dissolution whilst the fulvic component was purified by absorption chromatography. The resulting humic substances were shown to be of high purity with respect to metallic elements, with less than 1% of available sites being occupied. During elution the association of trace elements with humic substances was monitored and a high degree of association between humic substances, U and the Rare Earth Elements was noted. (author)

  7. Transport and cycling of iron and hydrogen peroxide in a freshwater stream: Influence of organic acids

    Science.gov (United States)

    Scott, Durelle T.; Runkel, Robert L.; McKnight, Diane M.; Voelker, Bettina M.; Kimball, Briant A.; Carraway, Elizabeth R.

    2003-01-01

    An in-stream injection of two dissolved organic acids (phthalic and aspartic acids) was performed in an acidic mountain stream to assess the effects of organic acids on Fe photoreduction and H2O2 cycling. Results indicate that the fate of Fe is dependent on a net balance of oxidative and reductive processes, which can vary over a distance of several meters due to changes in incident light and other factors. Solution phase photoreduction rates were high in sunlit reaches and were enhanced by the organic acid addition but were also limited by the amount of ferric iron present in the water column. Fe oxide photoreduction from the streambed and colloids within the water column resulted in an increase in the diurnal load of total filterable Fe within the experimental reach, which also responded to increases in light and organic acids. Our results also suggest that Fe(II) oxidation increased in response to the organic acids, with the result of offsetting the increase in Fe(II) from photoreductive processes. Fe(II) was rapidly oxidized to Fe(III) after sunset and during the day within a well-shaded reach, presumably through microbial oxidation. H2O 2, a product of dissolved organic matter photolysis, increased downstream to maximum concentrations of 0.25 ??M midday. Kinetic calculations show that the buildup of H2O2 is controlled by reaction with Fe(III), but this has only a small effect on Fe(II) because of the small formation rates of H2O2 compared to those of Fe(II). The results demonstrate the importance of incorporating the effects of light and dissolved organic carbon into Fe reactive transport models to further our understanding of the fate of Fe in streams and lakes.

  8. Diversity of lactic acid bacteria on organic flours and application of isolates in sourdough fermentation

    OpenAIRE

    Stanzer, Damir; Ivanuša, Ines; Kazazić, Snježana; Hanousek Čiča, Karla; Mrvčić, Jasna

    2017-01-01

    Organic farming preserves biodiversity and organic products can be the source of many microbial species. The species diversity in organically grown wheat, spelt and rye was investigated in order to find strains suitable for sourdough fermentation. Colonies representing various morphological appearances were isolated and catalase-negative colonies were identified by mass spectrometer Microflex LT ™ MALDI-TOF. The fermentation products (lactic, acetic, formic and phenyllactic acid) were determi...

  9. Predicting nitrogen and acidity effects on long-term dynamics of dissolved organic matter

    OpenAIRE

    Rowe, E.C.; Tipping, E.; Posch, M.; Oulehle, Filip; Cooper, D.M.; Jones, T.G.; Burden, A.; Hall, J.; Evans, C.D.

    2014-01-01

    Increases in dissolved organic carbon (DOC) fluxes may relate to changes in sulphur and nitrogen pollution. We integrated existing models of vegetation growth and soil organic matter turnover, acid-base dynamics, and organic matter mobility, to form the ‘MADOC’ model. After calibrating parameters governing interactions between pH and DOC dissolution using control treatments on two field experiments, MADOC reproduced responses of pH and DOC to additions of acidifying and alkalising solutions. ...

  10. Enhancing Skin Permeation of Biphenylacetic Acid (BPA) Using Salt Formation with Organic and Alkali Metal Bases

    OpenAIRE

    PAWAR, Vijay; NAIK, Prashant; GIRIDHAR, Rajani; YADAV, Mange Ram

    2014-01-01

    In the present study, a series of organic and alkali metal salts of biphenylacetic acid (BPA) have been prepared and evaluated in vitro for percutaneous drug delivery. The physicochemical properties of BPA salts were determined using solubility measurements, DSC, and IR. The DSC thermogram and FTIR spectra confirmed the salt formation with organic and alkali metal bases. Among the series, salts with organic amines (ethanolamine, diethanolamine, triethanol-amine, and diethylamine) had lowered ...

  11. [Pollution characteristics of organic acids in atmospheric particles during haze periods in autumn in Guangzhou].

    Science.gov (United States)

    Tan, Ji-hua; Zhao, Jing-ping; Duan, Jing-chun; Ma, Yong-liang; He, Ke-bin; Yang, Fu-mo

    2013-05-01

    Total suspended particles (TSP), collected during a typical haze period in Guangzhou, were analyzed for the fatty acids (C12-C30) and low molecular weight dicarboxylic acids (C3-C9) using gas chromatography/mass spectrometry (GC/MS). The results showed that the concentration of total fatty and carboxylic acids was pretty high during the haze episode. The ratios of fatty acids and carboxylic acids in haze to those in normal days were 1.9 and 2.5, respectively. During the episode of the increasing pollution, the fatty acids and carboxylic acids at night (653 ng x m(-3)) was higher than that (487 ng x m(-3)) in days. After that, the level of fatty acids and carboxylic acids in days (412 ng x m(-3)) was higher than that (336 ng x m(-3)) at night. In general, the time-series of fatty acids and carboxylic acids was similar to that of the air particle and carbonaceous species, however, the trend of the ratio of fatty acids and carboxylic acids to organic carbon was opposite to that of air particle and carbonaceous species. This ratio decreased with the increase of the concentration of air particle and after the night of 27th, the ratio increased with the decrease in the concentration of air particle. The results showed that haze pollution had a significant inhibitory effect on the enrichment of fatty and carboxylic acids. Based on the ratio of malonate to succinate (C3/C4), it could be found that primary sources contribute more to the atmospheric fatty and carboxylic acids during the autumn haze pollution periods in Guangzhou.

  12. Inhibitory Effects of Caffeic Acid, a Coffee-Related Organic Acid, on the Propagation of Hepatitis C Virus.

    Science.gov (United States)

    Tanida, Isei; Shirasago, Yoshitaka; Suzuki, Ryosuke; Abe, Ryo; Wakita, Takaji; Hanada, Kentaro; Fukasawa, Masayoshi

    2015-01-01

    Multipurpose cohort studies have demonstrated that coffee consumption reduces the risk of hepatocellular carcinoma (HCC). Given that one of the main causes of HCC is hepatitis C virus (HCV) infection, we examined the effect of caffeic acid, a major organic acid derived from coffee, on the propagation of HCV using an in vitro naïve HCV particle-infection and production system within human hepatoma-derived Huh-7.5.1-8 cells. When cells were treated with 1% coffee extract or 0.1% caffeic acid for 1-h post HCV infection, the amount of HCV particles released into the medium at 3 and 4 days post-infection considerably decreased. In addition, HCV-infected cells cultured with 0.001% caffeic acid for 4 days, also released less HCV particles into the medium. Caffeic acid treatment inhibited the initial stage of HCV infection (i.e., between virion entry and the translation of the RNA genome) in both HCV genotypes 1b and 2a. These results suggest that the treatment of cells with caffeic acid may inhibit HCV propagation.

  13. Role of Organic Solutes in the Chemistry Of Acid-Impacted Bog Waters of the Western Czech Republic

    Science.gov (United States)

    HrušKa, Jakub; Johnson, Chris E.; KráM, Pavel

    1996-04-01

    In many regions, naturally occurring organic acid anions can effectively buffer mineral acid inputs from atmospheric deposition, moderating their effect on surface water pH. We studied the effect of chronically high inputs of acid rain on the chemistry of three brown-water streams in the western Czech Republic. The dissolved organic acids in the streams were similar in character to those of other systems in Europe and North America. The site densities (the carboxyl group content per mass of C) were similar to values reported from Fenno-Scandia, and the relationship between the apparent pKa and pH conformed to those from two North American studies. Sulfate and organic acid anions (OA-) were the dominant anions in all three streams, yet despite high dissolved organic carbon and total organic acid concentrations, OA - comprised only 21-32% of total anion charge. This pattern was due to very high sulfate concentrations and, in two of the streams, a low degree of dissociation of the organic acids, probably the results of high long-term inputs of strong acids. Stream water pH was highly correlated to sulfate concentration, but uncorrelated with OA-, suggesting that free acidity is controlled by strong mineral acids rather than organic acids. Thus future reductions in strong acid inputs should result in increased pH and a return to organic control over acid-base chemistry.

  14. An overview the boron dilution issue in PWRs

    International Nuclear Information System (INIS)

    Hyvaerinen, J.

    1994-01-01

    The presentation is an overview of boron (boric acid) dilution in pressurized water reactors (PWRs). Boric acid has been widely used in PWRs as a dissolved poison, as one of the main reactivity controlling means, for a long time, from nearly but not quite from the beginning of the design, construction and operation of PWRs in the present-day sense. The specific safety issue, namely the risk of uncontrolled reactivity insertion due to inadvertent boron dilution, is discussed first, followed by a brief look on the history of boron usage in PWRs. A discussion of boron dilution phenomenology is presented next in general terms. Some particular concerns that boron dilution phenomena arouse in the minds of a regulator will also be presented before concluding with a brief look on the future of dissolved poisons. (11 refs.)

  15. Ascorbic acid metabolism in the organism under the lack of oxygen supply to the tissues

    Directory of Open Access Journals (Sweden)

    Sergiy Petrov

    2017-06-01

    Full Text Available The number and ratios of the metabolites of vitamin C - ascorbic, dehydroascorbic and diketogulonic acids were studied under the action of closed space hypoxia, acute blood loss and during sleep – the conditions associated with various oxygen saturation of the organism. It was found that in case of closed space hypoxia, the level of ascorbic and diketogulonic acid decreased with a simultaneous increase in the content of dehydroascorbic acid in the heart and brain. Acute blood loss resulted in decrease in the level of all metabolites of ascorbic acid. During sleep, the level of ascorbic acid metabolites increased. The ratio of vitamin-active metabolites to vitamin-inactive form of ascorbic acid in case of closed space hypoxia and acute blood loss decreased, and during sleep – it did not change significantly.

  16. The Role of Organic Acids on the Release of Phosphorus and Zinc in a Calcareous Soil

    Directory of Open Access Journals (Sweden)

    Sareh Nezami

    2017-02-01

    Full Text Available Introduction: Phosphorus (P and zinc (Zn fixation by soil minerals and their precipitation is one of the major constraints for crop production in calcareous soils. Recent Studies show that root exudates are effective for the extraction of the large amounts of nutrients in calcareous soils. A part of the root exudations are Low Molecular Weight Organic Acids (LMWOAs. LMWOAs are involved in the nutrients availability and uptake by plants, nutrients detoxification, minerals weathering and microbial proliferation in the soil. At nutrients deficiency conditions citric and oxalic acids are released by plants root in large quantities and increase nutrient solubility like P, Zn, Fe, Mn and Cu in the rhizosphere. These components are the large portion of the carbon source in the soil after exudations are mineralized by microorganisms, quickly. In addition, soil surface sorption can affect their half-life and other behaviors in the soil. In order to study the effect of oxalic and citric organic acids on the extraction of phosphorus and zinc from a calcareous soil, an experiment was conducted. Materials and Methods: Studied soil was calcareous and had P and Zn deficiency. Soil sample was collected from A horizon (0-30 cm of Damavand region. 3 g of dried soil sample was extracted with 30 ml of oxalic and citric acids extraction solutions at different concentrations (0.1, 1 and 10 mM and different time periods (10, 60, 180 and 360 minutes on an orbital shaker at 200 rev min-1.The soil extracts then centrifuged for 10 minutes (16000g. After filtering, the pH of the extractions was recorded and then phosphorus, calcium and zinc amounts were determined. Soil extraction with distilled water was used as control. Each treatment was performed in 3 replications. Statistical analysis was performed with ANOVA test followed by the Bonferroni method significant level adjustments due to multiple comparisons. Results and Discussion: The results of variance analysis showed

  17. Nutritional value of organic acid lime juice (Citrus latifolia T., cv. Tahiti

    Directory of Open Access Journals (Sweden)

    Carolina Netto Rangel

    2011-12-01

    Full Text Available Acid lime can be used as fresh fruit or as juice to increase the flavor of drinks. Therefore, it is necessary to analyze organic acid lime nutritional composition in order to evaluate if there are important differences among those conventionally produced. No significant differences in total titrable acidity, pH, ascorbic acid, sucrose, calcium, and zinc were found between the acid lime juice from organic biodynamic crops and conventional crops. However, the organic biodynamic fruits presented higher peel percentage than the conventional ones leading to lower juice yield. On the other hand, fructose, glucose, total soluble solids contents, potassium, manganese, iron, and copper were higher in the conventional samples. These results indicated few nutritional differences between organic and conventional acid lime juices in some constituents. Nevertheless, fruit juice from biodynamic crops could be a good choice since it is free from pesticides and other agents that cause problems to human health maintaining the levels similar to those of important nutritional compounds.

  18. Fructose decomposition kinetics in organic acids-enriched high temperature liquid water

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yinghua; Lu, Xiuyang; Yuan, Lei; Liu, Xin [Department of Chemical and Biochemical Engineering, Zhejiang University, Zheda Road 38, Hangzhou 310027, Zhejiang (China)

    2009-09-15

    Biomass continues to be an important candidate as a renewable resource for energy, chemicals, and feedstock. Decomposition of biomass in high temperature liquid water is a promising technique for producing industrially important chemicals such as 5-hydroxymethylfurfural (5-HMF), furfural, levulinic acid with high efficiency. Hexose, which is the hydrolysis product of cellulose, will be one of the most important starting chemicals in the coming society that is highly dependent on biomass. Taking fructose as a model compound, its decomposition kinetics in organic acids-enriched high temperature liquid water was studied in the temperature range from 180 C to 220 C under the pressure of 10 MPa to further improve reaction rate and selectivity of the decomposition reactions. The results showed that the reaction rate is greatly enhanced with the addition of organic acids, especially formic acid. The effects of temperature, residence time, organic acids and their concentrations on the conversion of fructose and yield of 5-HMF were investigated. The evaluated apparent activation energies of fructose decomposition are 126.8 {+-} 3.3 kJ mol{sup -1} without any catalyst, 112.0 {+-} 13.7 kJ mol{sup -1} catalyzed with formic acid, and 125.6 {+-} 3.8 kJ mol{sup -1} catalyzed with acetic acid, respectively, which shows no significant difference. (author)

  19. Study of organic acids in Schisandrae Chinensis Fructus after vinegar processing.

    Science.gov (United States)

    Yin, Fangzhou; Dai, Hui; Li, Lin; Lu, Tuling; Li, Weidong; Cai, Baochang; Yin, Wu

    2017-10-01

    The ripened fruit of Schisandrae Chinensis Fructus has unique medical properties in Chinese medicine. It is commonly used after vinegar steaming. Vinegar steaming changes the color of Schisandrae Chinensis Fructus from red to black and enhances its acidic and astringent properties. Lignans are the well-investigated components in this herb. However, Schisandrae Chinensis Fructus is acidic in the theory of Chinese medicine, and whether vinegar processing changes its organic acid components remains largely unknown. In this study, the organic acids in this herb were derived by the method of methyl esterification, and further analyzed by gas chromatography with mass spectrometry. A total of 39 organic acid compounds were identified. Interestingly, Schisandrae Chinensis Fructus after vinegar processing showed a significant increase in the content of levulinic acid as compared to the unprocessed ones. Pharmacological experiments demonstrated that levulinic acid inhibited the contractility of isolated intestine and had an inhibitory effect on the excessive hyperfunction of small intestinal propulsion. Moreover, the extracts of vinegar-processed Schisandrae Chinensis Fructus had a stronger inhibitory on the excessive hyperfunction of small intestinal propulsion than that of unprocessed ones. Taken together, this study offers novel insight into the effect of Schisandrae Chinensis Fructus after vinegar processing. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Inhibition Effect of Deanol on Mild Steel Corrosion in Dilute ...

    African Journals Online (AJOL)

    NICOLAAS

    2014-06-23

    Jun 23, 2014 ... The influence of deanol on the corrosion behaviour of mild steel in dilute sulphuric acid with sodium ... the formation of a complex precipitate of protective film, which ... silicon carbide abrasive papers of 80, 120, 220, 800 and 1000 grit ...... ions in sulphuric acid on the corrosion behaviour of stainless steel,.

  1. Intestinal tract is an important organ for lowering serum uric acid in rats

    Science.gov (United States)

    Gao, Zhiyi; Li, Yue; Gao, Tao; Duan, Jinlian; Yang, Rong; Dong, Xianxiang; Zhang, Lumei

    2017-01-01

    The kidney was recognized as a dominant organ for uric acid excretion. The main aim of the study demonstrated intestinal tract was an even more important organ for serum uric acid (SUA) lowering. Sprague-Dawley rats were treated normally or with antibiotics, uric acid, adenine, or inosine of the same molar dose orally or intraperitoneally for 5 days. Rat’s intestinal tract was equally divided into 20 segments except the cecum. Uric acid in serum and intestinal segment juice was assayed. Total RNA in the initial intestinal tract and at the end ileum was extracted and sequenced. Protein expression of xanthine dehydrogenase (XDH) and urate oxidase (UOX) was tested by Western blot analysis. The effect of oral UOX in lowering SUA was investigated in model rats treated with adenine and an inhibitor of uric oxidase for 5 days. SUA in the normal rats was 20.93±6.98 μg/ml, and total uric acid in the intestinal juice was 308.27±16.37 μg, which is two times more than the total SUA. The uric acid was very low in stomach juice, and attained maximum in the juice of the first segment (duodenum) and then declined all the way till the intestinal end. The level of uric acid in the initial intestinal tissue was very high, where XDH and most of the proteins associated with bicarbonate secretion were up-regulated. In addition, SUA was decreased by oral UOX in model rats. The results suggested that intestinal juice was an important pool for uric acid, and intestinal tract was an important organ for SUA lowering. The uric acid distribution was associated with uric acid synthesis and secretion in the upper intestinal tract, and reclamation in the lower. PMID:29267361

  2. Intestinal tract is an important organ for lowering serum uric acid in rats.

    Science.gov (United States)

    Yun, Yu; Yin, Hua; Gao, Zhiyi; Li, Yue; Gao, Tao; Duan, Jinlian; Yang, Rong; Dong, Xianxiang; Zhang, Lumei; Duan, Weigang

    2017-01-01

    The kidney was recognized as a dominant organ for uric acid excretion. The main aim of the study demonstrated intestinal tract was an even more important organ for serum uric acid (SUA) lowering. Sprague-Dawley rats were treated normally or with antibiotics, uric acid, adenine, or inosine of the same molar dose orally or intraperitoneally for 5 days. Rat's intestinal tract was equally divided into 20 segments except the cecum. Uric acid in serum and intestinal segment juice was assayed. Total RNA in the initial intestinal tract and at the end ileum was extracted and sequenced. Protein expression of xanthine dehydrogenase (XDH) and urate oxidase (UOX) was tested by Western blot analysis. The effect of oral UOX in lowering SUA was investigated in model rats treated with adenine and an inhibitor of uric oxidase for 5 days. SUA in the normal rats was 20.93±6.98 μg/ml, and total uric acid in the intestinal juice was 308.27±16.37 μg, which is two times more than the total SUA. The uric acid was very low in stomach juice, and attained maximum in the juice of the first segment (duodenum) and then declined all the way till the intestinal end. The level of uric acid in the initial intestinal tissue was very high, where XDH and most of the proteins associated with bicarbonate secretion were up-regulated. In addition, SUA was decreased by oral UOX in model rats. The results suggested that intestinal juice was an important pool for uric acid, and intestinal tract was an important organ for SUA lowering. The uric acid distribution was associated with uric acid synthesis and secretion in the upper intestinal tract, and reclamation in the lower.

  3. Changes in sugars, organic acids and amino acids in medlar (Mespilus germanica L.) during fruit development and maturation

    Czech Academy of Sciences Publication Activity Database

    Glew, R. H.; Ayaz, F. A.; Sanz, C.; VanderJagt, D. J.; Huang, H. S.; Chuang, L. T.; Strnad, Miroslav

    2003-01-01

    Roč. 83, č. 3 (2003), s. 363-369 ISSN 0308-8146 R&D Projects: GA AV ČR IBS5038351 Grant - others:Scientific and Research Council of Turkey(TR) TUBITAK-NATO Institutional research plan: CEZ:AV0Z5038910 Keywords : Medlar (Mespilus germanica L.) * Sugar * Organic acid Subject RIV: EF - Botanics Impact factor: 1.204, year: 2003

  4. Contribution of sulfuric acid and oxidized organic compounds to particle formation and growth

    Directory of Open Access Journals (Sweden)

    F. Riccobono

    2012-10-01

    Full Text Available Lack of knowledge about the mechanisms underlying new particle formation and their subsequent growth is one of the main causes for the large uncertainty in estimating the radiative forcing of atmospheric aerosols in global models. We performed chamber experiments designed to study the contributions of sulfuric acid and organic vapors to the formation and early growth of nucleated particles. Distinct experiments in the presence of two different organic precursors (1,3,5-trimethylbenzene and α-pinene showed the ability of these compounds to reproduce the formation rates observed in the low troposphere. These results were obtained measuring the sulfuric acid concentrations with two chemical ionization mass spectrometers confirming the results of a previous study which modeled the sulfuric acid concentrations in presence of 1,3,5-trimethylbenzene.

    New analysis methods were applied to the data collected with a condensation particle counter battery and a scanning mobility particle sizer, allowing the assessment of the size resolved growth rates of freshly nucleated particles. The effect of organic vapors on particle growth was investigated by means of the growth rate enhancement factor (Γ, defined as the ratio between the measured growth rate in the presence of α-pinene and the kinetically limited growth rate of the sulfuric acid and water system. The observed Γ values indicate that the growth is already dominated by organic compounds at particle diameters of 2 nm. Both the absolute growth rates and Γ showed a strong dependence on particle size, supporting the nano-Köhler theory. Moreover, the separation of the contributions from sulfuric acid and organic compounds to particle growth reveals that the organic contribution seems to be enhanced by the sulfuric acid concentration. Finally, the size resolved growth analysis indicates that both condensation of oxidized organic compounds and reactive uptake contribute to particle growth.

  5. Molecular understanding of atmospheric particle formation from sulfuric acid and large oxidized organic molecules

    CERN Document Server

    Schobesberger, Siegfried; Bianchi, Federico; Lönn, Gustaf; Ehn, Mikael; Lehtipalo, Katrianne; Dommen, Josef; Ehrhart, Sebastian; Ortega, Ismael K; Franchin, Alessandro; Nieminen, Tuomo; Riccobono, Francesco; Hutterli, Manuel; Duplissy, Jonathan; Almeida, João; Amorim, Antonio; Breitenlechner, Martin; Downard, Andrew J; Dunne, Eimear M; Flagan, Richard C; Kajos, Maija; Keskinen, Helmi; Kirkby, Jasper; Kupc, Agnieszka; Kürten, Andreas; Kurtén, Theo; Laaksonen, Ari; Mathot, Serge; Onnela, Antti; Praplan, Arnaud P; Rondo, Linda; Santos, Filipe D; Schallhart, Simon; Schnitzhofer, Ralf; Sipilä, Mikko; Tomé, António; Tsagkogeorgas, Georgios; Vehkamäki, Hanna; Wimmer, Daniela; Baltensperger, Urs; Carslaw, Kenneth S; Curtius, Joachim; Hansel, Armin; Petäjä, Tuukka; Kulmala, Markku; Donahue, Neil M; Worsnop, Douglas R

    2013-01-01

    Atmospheric aerosols formed by nucleation of vapors affect radiative forcing and therefore climate. However, the underlying mechanisms of nucleation remain unclear, particularly the involvement of organic compounds. Here, we present high-resolution mass spectra of ion clusters observed during new particle formation experiments performed at the Cosmics Leaving Outdoor Droplets chamber at the European Organization for Nuclear Research. The experiments involved sulfuric acid vapor and different stabilizing species, including ammonia and dimethylamine, as well as oxidation products of pinanediol, a surrogate for organic vapors formed from monoterpenes. A striking resemblance is revealed between the mass spectra from the chamber experiments with oxidized organics and ambient data obtained during new particle formation events at the Hyytiälä boreal forest research station. We observe that large oxidized organic compounds, arising from the oxidation of monoterpenes, cluster directly with single sulfuric acid molec...

  6. Influence of containing of asphaltenes and naphthenic acids over organic deposition inhibitor performance

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Geiza E.; Mansur, Claudia R.E.; Pires, Renata V.; Passos, Leonardo B.; Lucas, Elizabete F. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Inst. de Macromoleculas; Alvares, Dellyo R.S.; Gonzalez, Gaspar [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES)

    2004-07-01

    Organic deposition is a serious problem confronted by the petroleum industry in Brazil and worldwide. Among the main petroleum components that may cause deposition problems are waxes and asphaltenes. This work aims at evaluating the influence of petroleum fractions (asphaltenes and naphthenic acids) on the organic deposition phenomenon as well as on organic deposition inhibitors performance. The influence of the organic fractions was evaluated by their ability to change wax crystals, to lower the pour point and to alter the initial wax appearance temperature. The efficiency of the additives was tested by pour point measurements. The results show that asphaltenes seem to act as organic deposition inhibitors, while naphthenic acids do not significantly change the system. Moreover, employing both of them produces no synergic effect. Among polymeric inhibitors, all of the chemically modified EVA copolymer presented better results than the non-modified commercial EVA copolymer. The best result was observed for EVA28C{sub 16}. (author)

  7. Metabolic engineering of Escherichia coli for biotechnological production of high-value organic acids and alcohols

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Chao; Cao, Yujin; Zou, Huibin; Xian, Mo [Chinese Academy of Sciences, Qingdao (China). Key Lab. of Biofuels

    2011-02-15

    Confronted with the gradual and inescapable exhaustion of the earth's fossil energy resources, the bio-based process to produce platform chemicals from renewable carbohydrates is attracting growing interest. Escherichia coli has been chosen as a workhouse for the production of many valuable chemicals due to its clear genetic background, convenient to be genetically modified and good growth properties with low nutrient requirements. Rational strain development of E. coli achieved by metabolic engineering strategies has provided new processes for efficiently biotechnological production of various high-value chemical building blocks. Compared to previous reviews, this review focuses on recent advances in metabolic engineering of the industrial model bacteria E. coli that lead to efficient recombinant biocatalysts for the production of high-value organic acids like succinic acid, lactic acid, 3-hydroxypropanoic acid and glucaric acid as well as alcohols like 1,3-propanediol, xylitol, mannitol, and glycerol with the discussion of the future research in this area. Besides, this review also discusses several platform chemicals, including fumaric acid, aspartic acid, glutamic acid, sorbitol, itaconic acid, and 2,5-furan dicarboxylic acid, which have not been produced by E. coli until now. (orig.)

  8. /sup 1/H-NMR urinalysis. Simultaneous screening of inborn errors of metabolism of amino acid and organic acid disorders

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Hideaki; Yamaguchi, Shuichi

    1988-02-01

    In an effort to examine the usefulness of /sup 1/H-nuclear magnetic resonance (NMR) urinalysis in the diagnosis of congenital metabolic disorders, 70 kinds of urinary metabolites were analysed in relation to the diagnosis of inborn errors of amino acid and organic acid disorders. Homogated decoupling (HMG) method failed to analyze six metabolites within the undetectable range. When non-decoupling method (NON), in which the materials are dissolved in dimethyl sulfoxide, was used, the identification of signals became possible. The combination of HMG and NON methods was, therefore, considered to identify all of the metabolites. When the urine samples, which were obtained from patients with hyperglycerolemia, hyperornithinemia, glutaric acidemia type II, or glycerol kinase deficiency, were analysed by using both HMG and NON methods, abnormally increased urinary metabolites were detected. /sup 1/H-NMR urinalysis, if used in the combination of HMG and NON methods, may allow simultanenous screening of inborn errors of metabolism of amino acid and organic acid disorders. (Namekawa, K.).

  9. Surface complexation modeling of uranium (Vi) retained onto zirconium diphosphate in presence of organic acids

    International Nuclear Information System (INIS)

    Almazan T, M. G.; Garcia G, N.; Ordonez R, E.

    2010-10-01

    In the field of nuclear waste disposal, predictions regarding radionuclide migration through the geosphere, have to take account the effects of natural organic matter. This work presents an investigation of interaction mechanisms between U (Vi) and zirconium diphosphate (ZrP 2 O 7 ) in presence of organic acids (citric acid and oxalic acid). The retention reactions were previously examined using a batch equilibrium method. Previous results showed that U (Vi) retention was more efficient when citric acid or oxalic acid was present in solid surface at lower ph values. In order to determine the retention equilibria for both systems studied, a phosphorescence spectroscopy study was carried out. The experimental data were then fitted using the Constant Capacitance Model included in the FITEQL4.0 code. Previous results concerning surface characterization of ZrP 2 O 7 (surface sites density and surface acidity constants) were used to constraint the modeling. The best fit for U (Vi)/citric acid/ZrP 2 O 7 and U (Vi)/oxalic acid/ZrP 2 O 7 systems considered the formation of a ternary surface complex. (Author)

  10. Antimony leaching release from brake pads: Effect of pH, temperature and organic acids.

    Science.gov (United States)

    Hu, Xingyun; He, Mengchang; Li, Sisi

    2015-03-01

    Metals from automotive brake pads pollute water, soils and the ambient air. The environmental effect on water of antimony (Sb) contained in brake pads has been largely untested. The content of Sb in one abandoned brake pad reached up to 1.62×10(4) mg/kg. Effects of initial pH, temperature and four organic acids (acetic acid, oxalic acid, citric acid and humic acid) on Sb release from brake pads were studied using batch reactors. Approximately 30% (97 mg/L) of the total Sb contained in the brake pads was released in alkaline aqueous solution and at higher temperature after 30 days of leaching. The organic acids tested restrained Sb release, especially acetic acid and oxalic acid. The pH-dependent concentration change of Sb in aqueous solution was best fitted by a logarithmic function. In addition, Sb contained in topsoil from land where brake pads were discarded (average 9×10(3) mg/kg) was 3000 times that in uncontaminated soils (2.7±1 mg/kg) in the same areas. Because potentially high amounts of Sb may be released from brake pads, it is important that producers and environmental authorities take precautions. Copyright © 2015. Published by Elsevier B.V.

  11. The response of quartz crystals coated with thin fatty acid film to organic gases

    CERN Document Server

    Jin, C N; Kim, K H; Kwon, Y S

    1999-01-01

    We tried to apply a quartz crystal as a sensor by using the resonant frequency and the resistance properties of quartz crystals. Four kinds of fatty acids that have the same head groups were coated on the surfaces of the quartz crystals, and the shift of the resonant frequency and the resistance were observed based on the lengths of the tail groups. Myristic acid (C sub 1 sub 4), palmitic acid (C sub 1 sub 6), stearic acid (C sub 1 sub 8), and arachidic acid (C sub 2 sub 0) were deposited on the surfaces of quartz crystals by using the Langmuir-Blodgett (LB) method. As a result, the resonant frequency change was more sensitive to high molecular-weight fatty acids than to low molecular-weight ones. We also observed the effect of temperature on stearic acid LB films, and the response properties of quartz crystals coated with stearic-acid LB films to organic gases were investigated. As a result, the sensitivity of quartz crystals to organic gases was higher for higher molecular-weight gas, and we found that quar...

  12. Organic acid formation in steam–water cycles: Influence of temperature, retention time, heating rate and O2

    International Nuclear Information System (INIS)

    Moed, D.H.; Verliefde, A.R.D.; Heijman, S.G.J.; Rietveld, L.C.

    2014-01-01

    Organic carbon breaks down in boilers by hydrothermolysis, leading to the formation of organic acid anions, which are suspected to cause corrosion of steam–water cycle components. Prediction of the identity and quantity of these anions, based on feedwater organic carbon concentrations, has not been attempted, making it hard to establish a well-founded organic carbon guideline. By using a batch-reactor and flow reactor, the influence of temperature (276–352 °C), retention time (1–25 min), concentration (150–2400 ppb) and an oxygen scavenger (carbohydrazide) on organic acid anion formation from organic carbon was investigated. By comparing this to data gathered at a case-study site, the validity of setups was tested as well. The flow reactor provided results more representative for steam–water cycles than the batch reactor. It was found that lower heating rates give more organic acid anions as degradation products of organic carbon, both in quantity and species variety. The thermal stability of the organic acid anions is key. As boiler temperature increases, acetate becomes the dominant degradation product, due to its thermal stability. Shorter retention times lead to more variety and quantity of organic acid anions, due to a lack of time for the thermally less stable ones to degrade. Reducing conditions (or the absence of oxygen) increase the thermal stability of organic acid anions. As the feedwater organic carbon concentration decreases, there are relatively more organic acid anions formed. - Highlights: •Formation of organic acids from hydrothermolysis of organic carbon has been investigated. •The lower the temperature, the higher the variety of organic acid anions. •At the higher tested temperatures (331–352 °C) acetate is the dominant degradation product. •At longer retention times acetate is the dominant degradation product. •There is no linear relation between the organic carbon concentration and formed organic acids

  13. Distribution equilibria of Eu(III) in the system: bis(2-ethylhexyl)phosphoric acid organic diluent-NaCl, lactic acid, polyaminocarboxylic acid, water

    International Nuclear Information System (INIS)

    Danesi, P.R.; Cianetti, C.; Horwitz, E.P.

    1982-01-01

    The distribution equilibria of Eu 3+ between aqueous phases containing lactic acid and N'-(2hydroxyethyl)ethylenediamine-N,N,N'-triacetic acid (HEDTA) or diethylenetriamine-N,N,N',N',N''-penetaacetic acid (DTPA) at constant ionic strength (μ = 1.0), and n-dodecane solutions of HDEHP have been studied. The formation constants of the simple Eu-lactate complexes and Eu-lactate-HEDTA mixed complex were evaluated from the k/sub d/ data. The conclusion is reached that no lactic acid is coextracted into the organic phase at tracer metal concentrations. The separation factors between Eu 3+ , Pm 3+ , and Am 3+ have been evaluated in the presence of HEDTA

  14. Solvent extraction of hafnium(IV) by dinonylnaphthalene sulfonic acid from mixed aqueous-organic media

    International Nuclear Information System (INIS)

    Hala, J.; Piperkovova, H.

    1979-01-01

    The extraction of hafnium(IV) by heptane and toluene solutions of dinonylnaphthalene sulfonic acid (HD) from mixed aqueous-organic solutions has been studied. Alcohols, ketones, carboxylic acids, cyclic ethers, dimethylsulfoxide and dimethylformamide were used as the organic component of the mixed phase. Methanol, ethanol, formic acid and dioxane increased the extractability of Hf(IV) whereas other solvents showed only an antagonistic effect. The results were discussed from the point of view of the changes in micellar structure of HD, and compared with the uptake of Hf(IV) by resinous cation exchangers. The solubilization by HD of alcohols, carboxylic acids and dimethylsulfoxide was demonstrated by using the corresponding 14 C and 35 S labelled compounds. (author)

  15. Organic acids and aldehydes in rainwater in a northwest region of Spain

    Energy Technology Data Exchange (ETDEWEB)

    Pena, R.M.; Garcia, S.; Herrero, C. [Universidad de Santiago de Compostela, Lugo (Spain). Departamento de Quimica Analitica, Nutricion y Bromatologia

    2002-11-01

    During a 1 year period, measurements of carboxylic acids and aldehydes were carried out in rainwater samples collected at nine different sites in NW Spain surrounding a thermal power plant in order to determine concentration levels and sources. In addition, certain major ions (Cl{sup -}, NO{sub 3}{sup -}, SO{sub 4}{sup 2-}, Na{sup +}, NH{sub 4}{sup +}, K{sup +}, Mg{sup 2+}, Ca{sup 2+}) were also determined. Aldehyde and carboxylic acid concentration patterns and their effects on rainwater composition concerning temporal, seasonal and spatial variations were evaluated. Among carboxylic acids, formic and acetic were predominant (VWA 7.0 and 8.3 {mu}M), while formaldehyde and acroleine were the dominant aldehydes (VWA 0.42 and 1.25 {mu}M). Carboxylic acids were estimated to account for 27.5% of the total free acidity (TFA), whereas sulphuric and nitric acid accounted for 46.2% and 26.2%, respectively. Oxalic acid was demonstrated to be an important contributing compound to the acidification in rainwater representing 7.1% of the TFA. The concentration of aldehydes and carboxylic acids, which originated mainly from biogenic emissions in the area studied, was strongly dependent on the season of the year (growing and non-growing). The ratios of formic to acetic acids are considerably different in the two seasons suggesting that there exist distinct sources in both growing and non-growing seasons. Principal component analysis was applied in order to elucidate the sources of aldehydes and organic acids in rainwater. The prevalence of natural vegetative origins for both of these compounds versus anthropogenic emissions was demonstrated and the importance of the oxidation of aldehydes as a relevant source of organic acids was also established. (author)

  16. Sugars and organic acids in plum fruit affected by Plum pox virus.

    Science.gov (United States)

    Usenik, Valentina; Marn, Mojca Virscek

    2017-05-01

    Plum pox virus (PPV) causes severe economic losses in stone fruit production, but little is known about its effect on plum fruit composition. In this study, the influence of PPV on sugars and organic acids was evaluated in a susceptible plum (Prunus domestica L.) cultivar. PPV infection significantly affected the content and composition of sugars and organic acids. The composition of necrotic tissue was modified the most. A short-time infected tree yielded fruit with similar sugar composition to fruit from a healthy tree, but the decline of organic acids was faster. Prematurely ripened symptomatic fruit had reduced fruit weight and low sugar content. Infected trees of the studied cultivar produce fruit of inferior quality. Fruits are not suitable for processing, especially when most of them exhibit visual symptoms of PPV infection. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  17. Improving Phosphorus Availability in an Acid Soil Using Organic Amendments Produced from Agroindustrial Wastes

    OpenAIRE

    Ch’ng, Huck Ywih; Ahmed, Osumanu Haruna; Majid, Nik Muhamad Ab.

    2014-01-01

    In acid soils, soluble inorganic phosphorus is fixed by aluminium and iron. To overcome this problem, acid soils are limed to fix aluminium and iron but this practice is not economical. The practice is also not environmentally friendly. This study was conducted to improve phosphorus availability using organic amendments (biochar and compost produced from chicken litter and pineapple leaves, resp.) to fix aluminium and iron instead of phosphorus. Amending soil with biochar or compost or a mixt...

  18. Investigation of the atmospheric behavior of dicarboxylic acids and other polar organic aerosol constituents

    International Nuclear Information System (INIS)

    Limbeck, A.

    2001-05-01

    The objective of the present work was to improve the present knowledge about the atmospheric behavior of polar organic aerosol constituents with special respect to dicarboxylic acids. To enable the simultaneous determination of polar organic compounds in atmospheric samples like aerosol or precipitation samples (atmospheric hydrometeors) a new GCMS method was developed. Almost all classes of oxygenated organic compounds like mono- and dicarboxylic acids, aldehydes, alcohols or polar aromatic compounds like phthalates could be determined with only one sample preparation scheme. The separation into two classes of organic compounds with different polarity was performed using solid phase extraction. After a sample pre-treatment of the derived fractions, including esterification of the acids and extraction with cyclohexane, the samples were analyzed with a GCMS system. The new method was applied for the analysis of simultaneously collected interstitial aerosol and cloud water samples from a continental background site in Central Europe (Sonnblick Observatory, located at 3106-m elevation in the Austrian Alps). In all samples a large variety of mono- and dicarboxylic acids were identified and quantified, together with some aldehydes, alcohols and aromatic compounds. Using the obtained data set, for the first time in-cloud scavenging efficiencies for dicarboxylic acids, monocarboxylic acids, and other polar organic compounds were calculated. The results were compared to sulfate, which exhibited an average scavenging efficiency of 0.94. In the last part of the present work the results from laboratory and field investigations conducted with the intention to yield an improved sampling technique for the correction of the positive sampling artifact (adsorption of gas phase organics onto the filter substrate) were presented. (author)

  19. [Effects of simulated acid rain on decomposition of soil organic carbon and crop straw].

    Science.gov (United States)

    Zhu, Xue-Zhu; Huang, Yao; Yang, Xin-Zhong

    2009-02-01

    To evaluate the effects of acid rain on the organic carbon decomposition in different acidity soils, a 40-day incubation test was conducted with the paddy soils of pH 5.48, 6.70 and 8.18. The soils were amended with 0 and 15 g x kg(-1) of rice straw, adjusted to the moisture content of 400 g x kg(-1) air-dried soil by using simulated rain of pH 6.0, 4.5, and 3.0, and incubated at 20 degrees C. The results showed that straw, acid rain, and soil co-affected the CO2 emission from soil system. The amendment of straw increased the soil CO2 emission rate significantly. Acid rain had no significant effects on soil organic carbon decomposition, but significantly affected the straw decomposition in soil. When treated with pH 3.0 acid rain, the amount of decomposed straw over 40-day incubation in acid (pH 5.48) and alkaline (pH 8.18) soils was 8% higher, while that in neutral soil (pH 6.70) was 15% lower, compared to the treatment of pH 6.0 rain. In the treatment of pH 3.0 acid rain, the decomposition rate of soil organic C in acid (pH 5.48) soil was 43% and 50% (P pH 6.70) and alkaline (pH 8.18) soils, while the decomposition rate of straw in neutral soil was 17% and 16% (P < 0.05) lower than that in acid and alkaline soils, respectively.

  20. Quantification of organic acids in beer by nuclear magnetic resonance (NMR)-based methods

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, J.E.A. [CICECO-Department of Chemistry, University of Aveiro, Campus de Santiago, 3810-193 Aveiro (Portugal); Erny, G.L. [CESAM - Department of Chemistry, University of Aveiro, Campus de Santiago, 3810-193 Aveiro (Portugal); Barros, A.S. [QOPNAA-Department of Chemistry, University of Aveiro, Campus de Santiago, 3810-193 Aveiro (Portugal); Esteves, V.I. [CESAM - Department of Chemistry, University of Aveiro, Campus de Santiago, 3810-193 Aveiro (Portugal); Brandao, T.; Ferreira, A.A. [UNICER, Bebidas de Portugal, Leca do Balio, 4466-955 S. Mamede de Infesta (Portugal); Cabrita, E. [Department of Chemistry, New University of Lisbon, 2825-114 Caparica (Portugal); Gil, A.M., E-mail: agil@ua.pt [CICECO-Department of Chemistry, University of Aveiro, Campus de Santiago, 3810-193 Aveiro (Portugal)

    2010-08-03

    The organic acids present in beer provide important information on the product's quality and history, determining organoleptic properties and being useful indicators of fermentation performance. NMR spectroscopy may be used for rapid quantification of organic acids in beer and different NMR-based methodologies are hereby compared for the six main acids found in beer (acetic, citric, lactic, malic, pyruvic and succinic). The use of partial least squares (PLS) regression enables faster quantification, compared to traditional integration methods, and the performance of PLS models built using different reference methods (capillary electrophoresis (CE), both with direct and indirect UV detection, and enzymatic essays) was investigated. The best multivariate models were obtained using CE/indirect detection and enzymatic essays as reference and their response was compared with NMR integration, either using an internal reference or an electrical reference signal (Electronic REference To access In vivo Concentrations, ERETIC). NMR integration results generally agree with those obtained by PLS, with some overestimation for malic and pyruvic acids, probably due to peak overlap and subsequent integral errors, and an apparent relative underestimation for citric acid. Overall, these results make the PLS-NMR method an interesting choice for organic acid quantification in beer.

  1. Quantification of organic acids in beer by nuclear magnetic resonance (NMR)-based methods

    International Nuclear Information System (INIS)

    Rodrigues, J.E.A.; Erny, G.L.; Barros, A.S.; Esteves, V.I.; Brandao, T.; Ferreira, A.A.; Cabrita, E.; Gil, A.M.

    2010-01-01

    The organic acids present in beer provide important information on the product's quality and history, determining organoleptic properties and being useful indicators of fermentation performance. NMR spectroscopy may be used for rapid quantification of organic acids in beer and different NMR-based methodologies are hereby compared for the six main acids found in beer (acetic, citric, lactic, malic, pyruvic and succinic). The use of partial least squares (PLS) regression enables faster quantification, compared to traditional integration methods, and the performance of PLS models built using different reference methods (capillary electrophoresis (CE), both with direct and indirect UV detection, and enzymatic essays) was investigated. The best multivariate models were obtained using CE/indirect detection and enzymatic essays as reference and their response was compared with NMR integration, either using an internal reference or an electrical reference signal (Electronic REference To access In vivo Concentrations, ERETIC). NMR integration results generally agree with those obtained by PLS, with some overestimation for malic and pyruvic acids, probably due to peak overlap and subsequent integral errors, and an apparent relative underestimation for citric acid. Overall, these results make the PLS-NMR method an interesting choice for organic acid quantification in beer.

  2. Volatility of Organic Aerosol: Evaporation of Ammonium Sulfate/Succinic Acid Aqueous Solution Droplets

    Science.gov (United States)

    2013-01-01

    Condensation and evaporation modify the properties and effects of atmospheric aerosol particles. We studied the evaporation of aqueous succinic acid and succinic acid/ammonium sulfate droplets to obtain insights on the effect of ammonium sulfate on the gas/particle partitioning of atmospheric organic acids. Droplet evaporation in a laminar flow tube was measured in a Tandem Differential Mobility Analyzer setup. A wide range of droplet compositions was investigated, and for some of the experiments the composition was tracked using an Aerosol Mass Spectrometer. The measured evaporation was compared to model predictions where the ammonium sulfate was assumed not to directly affect succinic acid evaporation. The model captured the evaporation rates for droplets with large organic content but overestimated the droplet size change when the molar concentration of succinic acid was similar to or lower than that of ammonium sulfate, suggesting that ammonium sulfate enhances the partitioning of dicarboxylic acids to aqueous particles more than currently expected from simple mixture thermodynamics. If extrapolated to the real atmosphere, these results imply enhanced partitioning of secondary organic compounds to particulate phase in environments dominated by inorganic aerosol. PMID:24107221

  3. Changes of organic acid exudation and rhizosphere pH in rice plants under chromium stress

    International Nuclear Information System (INIS)

    Zeng Fanrong; Chen Song; Miao Ying; Wu Feibo; Zhang Guoping

    2008-01-01

    The effect of chromium (Cr) stress on the changes of rhizosphere pH, organic acid exudation, and Cr accumulation in plants was studied using two rice genotypes differing in grain Cr accumulation. The results showed that rhizosphere pH increased with increasing level of Cr in the culture solution and with an extended time of Cr exposure. Among the six organic acids examined in this experiment, oxalic and malic acid contents were relatively higher, and had a significant positive correlation with the rhizosphere pH, indicating that they play an important role in changing rhizosphere pH. The Cr content in roots was significantly higher than that in stems and leaves. Cr accumulation in plants was significantly and positively correlated with rhizosphere pH, and the exudation of oxalic, malic and citric acids, suggesting that an increase in rhizosphere pH, and exudation of oxalic, malic and citric acid enhances Cr accumulation in rice plants. - Rhizosphere pH and organic acid exudation of rice roots are markedly affected by chromium level in culture solution

  4. Seasonal measurements of organic acid fluxes over a ponderosa pine forest

    Science.gov (United States)

    Fulgham, S. R.; Brophy, P.; Link, M.; Ortega, J. V.; Farmer, D.

    2016-12-01

    The biosphere acts as both a source and a sink of oxidized organic compounds. Ignoring dry deposition leads to overestimation of secondary organic aerosols by aerosol models, while ignoring emission sources underestimates the budget of organic acids. Developing parameterizations for oxidized organic dry deposition and emission requires observational constraints. Although biosphere parameters are impacted by seasonal variability, most reactive, trace-gas exchange measurements are made for only short periods of time in the main growing season. Here we make fast (5 - 10 Hz) and sensitive (e.g. 0.73 ppt mean limit of detection for formic acid with 10 s averaging) eddy covariance measurements of gas-phase organic acids and other oxidized organic species with a high resolution Time-of-Flight Chemical Ionization Mass Spectrometer with acetate and iodide reagent ions. Measurements were made in 4 - 6 week campaigns over five seasons from summer 2015 to fall 2016 as part of the Seasonal Particles in Forests Flux studY (SPIFFY) at the Manitou Experimental Forest Observatory near Woodland Park, Colorado. Permeation tubes were used for online calibration of carboxylic acids including formic (C1), propionic (C3), butyric (C4), methacrylic (CH2C(CH3)COOH), valeric (C5), and heptanoic (C7) acids. Average daytime mixing ratios for formic acid were 100 ± 100 ppt in winter and 1500 ± 1000 ppt in summer 2016. Upward fluxes of formic acid were observed throughout the experiment, daytime averages and standard deviations ranging from 1900 ± 1000 ppt cm s-1 in winter to 170 ± 130 ppt cm s-1 in spring. Propionic (22 ± 22 ppt cm s-1), butyric (17 ± 16 ppt cm s-1), and methacrylic (3.5 ± 6.1 ppt cm s-1) acids exhibit a mix of upward, near-zero, and downward fluxes. Fluxes were exponentially correlated to temperature, suggesting an ecosystem-scale source of these acids. We also measure exchange velocities of a broad suite of other oxidized organic compounds (31.99 m/z to 311.523 m/z in

  5. Selective removal of phosphate for analysis of organic acids in complex samples.

    Science.gov (United States)

    Deshmukh, Sandeep; Frolov, Andrej; Marcillo, Andrea; Birkemeyer, Claudia

    2015-04-03

    Accurate quantitation of compounds in samples of biological origin is often hampered by matrix interferences one of which occurs in GC-MS analysis from the presence of highly abundant phosphate. Consequently, high concentrations of phosphate need to be removed before sample analysis. Within this context, we screened 17 anion exchange solid-phase extraction (SPE) materials for selective phosphate removal using different protocols to meet the challenge of simultaneous recovery of six common organic acids in aqueous samples prior to derivatization for GC-MS analysis. Up to 75% recovery was achieved for the most organic acids, only the low pKa tartaric and citric acids were badly recovered. Compared to the traditional approach of phosphate removal by precipitation, SPE had a broader compatibility with common detection methods and performed more selectively among the organic acids under investigation. Based on the results of this study, it is recommended that phosphate removal strategies during the analysis of biologically relevant small molecular weight organic acids consider the respective pKa of the anticipated analytes and the detection method of choice. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Prolonged acid rain facilitates soil organic carbon accumulation in a mature forest in Southern China.

    Science.gov (United States)

    Wu, Jianping; Liang, Guohua; Hui, Dafeng; Deng, Qi; Xiong, Xin; Qiu, Qingyan; Liu, Juxiu; Chu, Guowei; Zhou, Guoyi; Zhang, Deqiang

    2016-02-15

    With the continuing increase in anthropogenic activities, acid rain remains a serious environmental threat, especially in the fast developing areas such as southern China. To detect how prolonged deposition of acid rain would influence soil organic carbon accumulation in mature subtropical forests, we conducted a field experiment with simulated acid rain (SAR) treatments in a monsoon evergreen broadleaf forest at Dinghushan National Nature Reserve in southern China. Four levels of SAR treatments were set by irrigating plants with water of different pH values: CK (the control, local lake water, pH ≈ 4.5), T1 (water pH=4.0), T2 (water pH=3.5), and T3 (water pH=3.0). Results showed reduced pH measurements in the topsoil exposed to simulated acid rains due to soil acidification. Soil respiration, soil microbial biomass and litter decomposition rates were significantly decreased by the SAR treatments. As a result, T3 treatment significantly increased the total organic carbon by 24.5% in the topsoil compared to the control. Furthermore, surface soil became more stable as more recalcitrant organic matter was generated under the SAR treatments. Our results suggest that prolonged acid rain exposure may have the potential to facilitate soil organic carbon accumulation in the subtropical forest in southern China. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Effects of organic solvents on hyaluronic acid nanoparticles obtained by precipitation and chemical crosslinking.

    Science.gov (United States)

    Bicudo, Rafaela Costa Souza; Santana, Maria Helena Andrade

    2012-03-01

    Hyaluronic acid is a hydrophilic mucopolysaccharide composed of alternating units of D-glucuronic acid and N-acetylglucosamine. It is used in many medical, pharmaceutical, and cosmetic applications, as sponges, films, or particle formulations. Hyaluronic acid nanoparticles can be synthesized free of oil and surfactants by nanoprecipitation in organic solvents, followed by chemical crosslinking. The organic solvent plays an important role in particles size and structure. Therefore, this study aimed to investigate the influence of acetone, ethanol, and isopropyl alcohol on the synthesis and physico-chemical properties of hyaluronic acid nanoparticles. Particles were crosslinked with adipic hydrazide and chloride carbodiimide under controlled conditions. The nanoparticles obtained with all three studied solvents were moderately electrostatically stable. Experiments with acetone produced the smallest particle size (120.44 nm) and polydispersity (0.27). The size and polydispersity of hyaluronic acid nanoparticles correlated with the surface tension between water and the organic solvents, not with the thermodynamic affinity of water for the organic solvents.

  8. Synthesis and stability of strongly acidic benzamide derivatives

    DEFF Research Database (Denmark)

    Diness, Frederik; Bjerrum, Niels J.; Begtrup, Mikael

    2018-01-01

    Reactivity studies of strong organic acids based on the replacement of one or both of the oxygens in benzoic acids with the trifluoromethanesulfonamide group are reported. Novel derivatives of these types of acids were synthesized in good yields. The generated N-triflylbenzamides were further...... functionalized through cross-coupling and nucleophilic aromatic substitution reactions. All compounds were stable in dilute aqueous solutions. Studies of stability under acidic and basic conditions are also reported....

  9. Biotechnological production of caffeic acid derivatives from cell and organ cultures of Echinacea species.

    Science.gov (United States)

    Murthy, Hosakatte Niranjana; Kim, Yun-Soo; Park, So-Young; Paek, Kee-Yoeup

    2014-09-01

    Caffeic acid derivatives (CADs) are a group of bioactive compounds which are produced in Echinacea species especially Echinacea purpurea, Echinacea angustifolia, and Echinacea pallida. Echinacea is a popular herbal medicine used in the treatment of common cold and it is also a prominent dietary supplement used throughout the world. Caffeic acid, chlorogenic acid (5-O-caffeoylquinic acid), caftaric acid (2-O-caffeoyltartaric acid), cichoric acid (2, 3-O-dicaffeoyltartaric acid), cynarin, and echinacoside are some of the important CADs which have varied pharmacological activities. The concentrations of these bioactive compounds are species specific and also they vary considerably with the cultivated Echinacea species due to geographical location, stage of development, time of harvest, and growth conditions. Due to these reasons, plant cell and organ cultures have become attractive alternative for the production of biomass and caffeic acid derivatives. Adventitious and hairy roots have been induced in E. pupurea and E. angustifolia, and suspension cultures have been established from flask to bioreactor scale for the production of biomass and CADs. Tremendous progress has been made in this area; various bioprocess methods and strategies have been developed for constant high-quality productivity of biomass and secondary products. This review is aimed to discuss biotechnological methods and approaches employed for the sustainable production of CADs.

  10. Selection of organic acid leaching reagent for recovery of zinc and manganese from zinc-carbon and alkaline spent batteries

    Science.gov (United States)

    Yuliusman; Amiliana, R. A.; Wulandari, P. T.; Ramadhan, I. T.; Kusumadewi, F. A.

    2018-03-01

    Zinc-carbon and alkaline batteries are often used in electronic equipment that requires small quantities of power. The waste from these batteries contains valuable metals, such as zinc and manganese, that are needed in many industries and can pollute the environment if not treated properly. This paper concerns the recovery of zinc and manganese metals from zinc-carbon and alkaline spent batteries with leaching method and using organic acid as the environmental friendly leaching reagent. Three different organic acids, namely citric acid, malic acid and aspartic acid, were used as leaching reagents and compared with sulfuric acid as non-organic acid reagents that often used for leaching. The presence of hydrogen peroxide as manganese reducers was investigated for both organic and non-organic leaching reagents. The result showed that citric acid can recover 64.37% Zinc and 51.32% Manganese, while malic acid and aspartic acid could recover less than these. Hydrogen peroxide gave the significant effect for leaching manganese with non-organic acid, but not with organic acid.

  11. On-line analysis of ETA and organic acids in secondary systems of PWR plants

    International Nuclear Information System (INIS)

    Kurashina, Masahiko; Uzawa, Hideo; Utagawa, Koya; Takaku, Hiroshi

    2005-01-01

    To reduce the iron concentration in the secondary water of plants with pressurized water reactors (PWRs), ethanolamine (ETA) is used as an alkalizing agent in the secondary cycle. An on-line ion chromatography (IC) monitoring system for monitoring concentrations of ETA and anions of organic acids was developed, its performance was evaluated, and verification tests were conducted at an actual PWR plant. It was demonstrated that the concentration of both ETA and anions of organic acids may be successfully monitored by IC in PWR secondary cycle streams alkalized by ETA. (orig.)

  12. Thermally induced processes in mixtures of aluminum with organic acids after plastic deformations under high pressure

    Science.gov (United States)

    Zhorin, V. A.; Kiselev, M. R.; Roldugin, V. I.

    2017-11-01

    DSC is used to measure the thermal effects of processes in mixtures of solid organic dibasic acids with powdered aluminum, subjected to plastic deformation under pressures in the range of 0.5-4.0 GPa using an anvil-type high-pressure setup. Analysis of thermograms obtained for the samples after plastic deformation suggests a correlation between the exothermal peaks observed around the temperatures of degradation of the acids and the thermally induced chemical reactions between products of acid degradation and freshly formed surfaces of aluminum particles. The release of heat in the mixtures begins at 30-40°C. The thermal effects in the mixtures of different acids change according to the order of acid reactivity in solutions. The extreme baric dependences of enthalpies of thermal effects are associated with the rearrangement of the electron subsystem of aluminum upon plastic deformation at high pressures.

  13. Activity coefficients at infinite dilution of organic solutes in the ionic liquid 1-ethyl-3-methylimidazolium trifluoromethanesulfonate using gas-liquid chromatography at T = (313.15, 323.15, and 333.15) K

    International Nuclear Information System (INIS)

    Olivier, Eugene; Letcher, Trevor M.; Naidoo, Paramespri; Ramjugernath, Deresh

    2010-01-01

    Activity coefficients at infinite dilution were determined for 24 solutes (n-alkanes, alk-1-enes, alk-1-ynes, cycloalkanes, alkylbenzenes, and alcohols) in the ionic liquid 1-ethyl-3-methylimidazolium trifluoromethanesulfonate by gas-liquid chromatography at three different temperatures T = (313.15, 323.15, 333.15) K. The partial molar excess enthalpy values at infinite dilution were calculated from the experimental results over the same temperature range. Selectivities and capacities at infinite dilution for the hexane/benzene and methanol/benzene separation problems were calculated from experimental infinite dilution activity coefficient values. The activity coefficients, enthalpies, selectivities, and capacities are discussed and compared to literature values for other ionic liquids, as well as industrial molecular solvents.

  14. One-pot synthesis of amino acid precursors with insoluble organic matter in planetesimals with aqueous activity

    Science.gov (United States)

    Kebukawa, Yoko; Chan, Queenie H. S.; Tachibana, Shogo; Kobayashi, Kensei; Zolensky, Michael E.

    2017-01-01

    The exogenous delivery of organic molecules could have played an important role in the emergence of life on the early Earth. Carbonaceous chondrites are known to contain indigenous amino acids as well as various organic compounds and complex macromolecular materials, such as the so-called insoluble organic matter (IOM), but the origins of the organic matter are still subject to debate. We report that the water-soluble amino acid precursors are synthesized from formaldehyde, glycolaldehyde, and ammonia with the presence of liquid water, simultaneously with macromolecular organic solids similar to the chondritic IOM. Amino acid products from hydrothermal experiments after acid hydrolysis include α-, β-, and γ-amino acids up to five carbons, for which relative abundances are similar to those extracted from carbonaceous chondrites. One-pot aqueous processing from simple ubiquitous molecules can thus produce a wide variety of meteoritic organic matter from amino acid precursors to macromolecular IOM in chondrite parent bodies. PMID:28345041

  15. Process for recovery of uranium from wet process phosphoric acid

    International Nuclear Information System (INIS)

    Wiewiorowski, T.K.; Thornsberry, W.L. Jr.

    1978-01-01

    Process is claimed for the recovery of uranium from wet process phosphoric acid solution in which an organic extractant, containing uranium values and dissolved iron impurities and comprising a dialkylphosphoric acid and a trialkylphosphine oxide dissolved in a water immiscible organic solvent, is contacted with a substantially iron-free dilute aqueous phosphoric acid to remove said iron impurities. The removed impurities are bled from the system by feeding the resulting iron-loaded phosphoric acid to a secondary countercurrent uranium extraction operation from which they leave as part of the uranium-depleted acid raffinate. Also, process for recovering uranium in which the extractant, after it has been stripped of uranium values by aqueous ammonium carbonate, is contacted with a dilute aqueous acid selected from the group consisting of H 2 SO 4 , HCl, HNO 3 and iron-free H 3 PO 4 to improve the extraction efficiency of the organic extractant

  16. Enhancement in extraction rates by addition of organic acids to aqueous phase in solvent extraction of rare earth metals in presence of diethylenetriaminepentaacetic acid

    International Nuclear Information System (INIS)

    Matsuyama, Hideto; Azis, A.; Fujita, Mamoru; Teramoto, Masaaki.

    1996-01-01

    It is well known that the selectivity of rare earth metals by solvent extraction is increased by the addition of a chelating agent such as diethylenetriaminepentaacetic acid (DTPA) in the aqueous phase. One of the disadvantages of this method is the decrease in extraction rates due to complexation in the aqueous phase. In this paper, further addition of organic acids to the aqueous phase was examined for the purpose of enhancing the extraction rates in solvent extraction with DTPA. The addition of several kind of organic acids such as formic acid, acetic acid, malonic acid, lactic acid and citric acid was investigated for a Er/Y separation system. A remarkable enhancement in extraction rates was observed with a slight decrease in the selectivity by the addition of citric acid or lactic acid. Extraction rates in the presence of both DTPA and citric acid increased with the increase in citric acid concentration and with the increase in proton concentration. A 150 times enhancement in extraction rates was found in the low proton concentration condition. In order to analyze the extraction rates and selectivities obtained, mass transfer equations were presented by considering both the dissociation reaction of rare earth metal-DTPA complexes and the complex formation between rare earth metal and organic acid in the aqueous phase. The experimental data were analyzed by these equations. (author)

  17. Features of obtaining malt with use of aqueous solutions of organic acids

    Directory of Open Access Journals (Sweden)

    O. Pivovarov

    2017-12-01

    Full Text Available Recently, the traditional formulations of essential food products are actively including malt – a valuable dietary product rich in extractives and hydrolytic enzymes, obtained by germination in artificially created conditions. Containing a full set of essential amino acids and a high saccharifying ability of malt, obtained from grain cereals, determines its wide use in the production of beer, alcohol, mono- and poly-malt extracts, bakery products, special types of flour, food additives, cereals, non-alcoholic beverages, lactic acid products and, in particular, in the production of natural coffee substitutes. However, the classical germination technology, which includes 2-3 days of soaking and 5-8 days of germination due to the considerable duration and laboriousness of the process, does not meet the requirements of modern technology and the constantly growing rates of industrial production, so this problem requires finding new and improving existing scientific and technical solutions. The features of malt production using organic acids of different concentrations are presented. The malt production technology has been analyzed and investigated. It includes washing, disinfection, air and water soaking of grains, germination and drying. The feature of the technology under investigation is using of aqueous solutions of butadiene, 3-pyridinecarboxylic acid and pteroylglutamic acid. The results of the inquiry of the effect of these organic acids on energy and the ability of germination of the grain are presented. The optimal values of concentrations of active substances in solutions are revealed. The influence of organic acids on the absorption of grain moisture has been investigated. It has been established that in comparison with the classical technology, the use of these acids as a growth stimulator can reduce the overall length of the reproduction process of the material from 1.5 to 2 times and increase the yield of flour grains in the batch of

  18. Effect of organic solvents on dissolution process of mechano-chemically activated molybdenum by inorganic acid solutions

    International Nuclear Information System (INIS)

    Shevtsova, I.Ya.; Chernyak, A.S.; Khal'zov, A.A.

    1992-01-01

    The process of chemical dissolution of mechanochemically activated and nonactivated molybdenite by inorganic acid solutions in certain organic solvents of different nature was considered. It is shown that the highest extraction of molybdenum in solution is achieved in the presence of nitric acid. The dissociation constant of the acid used in the given organic solvent does not affect molybdenite solubility. When dissolving molybdenite by solutions of nitric acid in carbonic acids, alcohols and esters, the solubility of the concentrate depends on the length of hydrocarbon chain of the organic solvent and dispersion degree of mineral source material

  19. EFFECT OF THE USE OF MOS AND ORGANIC ACIDS IN PERFORMANCE PIGLETS

    Directory of Open Access Journals (Sweden)

    L. Vargas

    2017-02-01

    Full Text Available The production chain of swine has been developed to meet the consumer market , seeking a more lean meat and produced cleanly. Faced with this demand , key areas of swine as genetics, nutrition , health , ambience , animal welfare, management of costs and environmental management are increasingly studied and debated to the organs concerned . Have advances in the field of nutrition has also contributed to a cleaner animal production through the use of enhancers efficiency as prebiotics and organic acids in the diets of pigs as potential substitutes for conventional growth promoters . The mannan oligosaccharides ( MOS along with organic acids , are able to maintain the integrity of the digestive tract , by benefiting the multiplication of beneficial bacteria and also in the specific case of MOS , act as adsorbents of pathogenic bacteria , preventing their adhesion in the intestinal epithelium and causing their elimination . Since these effects improve the absorption of nutrients with gains in production rates . Given the above , the objective of this study is to evaluate the effects of MOS and organic acid in the performance parameters of piglets during 15-30 Kg The experiment will be conducted in the UEP on Swine Campuses Two Neighbors - UTFPR . Crusaders 18 pigs with an initial average weight of 15kg with 50 days of age , distributed in a completely randomized design with two treatments will be used : T1 - basal ration T2 - ration + 0.2% MOS + organic acid , with 3 replications and 3 animals per experimental unit . The parameters evaluated were weight gain , feed intake , feed conversion , stool consistency and feed cost per kg of produced pig . There was no difference ( P > 0.05 on growth performance and fecal consistency between treatments . However , the cost per kg pig was highest in treatment 2 (with additives compared to Treatment 1 (control. In the conditions of the present study was conducted , it can be concluded that the use of MOS and

  20. Lewis Acid-Base Chemistry of 7-Azaisoindigo-Based Organic Semiconductors.

    Science.gov (United States)

    Randell, Nicholas M; Fransishyn, Kyle M; Kelly, Timothy L

    2017-07-26

    Low-band-gap organic semiconductors are important in a variety of organic electronics applications, such as organic photovoltaic devices, photodetectors, and field effect transistors. Building on our previous work, which introduced 7-azaisoindigo as an electron-deficient building block for the synthesis of donor-acceptor organic semiconductors, we demonstrate how Lewis acids can be used to further tune the energies of the frontier molecular orbitals. Coordination of a Lewis acid to the pyridinic nitrogen of 7-azaisoindigo greatly diminishes the electron density in the azaisoindigo π-system, resulting in a substantial reduction in the lowest unoccupied molecular orbital (LUMO) energy. This results in a smaller highest occupied molecular orbital-LUMO gap and shifts the lowest-energy electronic transition well into the near-infrared region. Both H + and BF 3 are shown to coordinate to azaisoindigo and affect the energy of the S 0 → S 1 transition. A combination of time-dependent density functional theory and UV/vis and 1 H NMR spectroscopic titrations reveal that when two azaisoindigo groups are present and high concentrations of acid are used, both pyridinic nitrogens bind Lewis acids. Importantly, we demonstrate that this acid-base chemistry can be carried out at the solid-vapor interface by exposing thin films of aza-substituted organic semiconductors to vapor-phase BF 3 ·Et 2 O. This suggests the possibility of using the BF 3 -bound 7-azaisoindigo-based semiconductors as n-type materials in various organic electronic applications.

  1. Omega-9 Oleic Acid Induces Fatty Acid Oxidation and Decreases Organ Dysfunction and Mortality in Experimental Sepsis.

    Directory of Open Access Journals (Sweden)

    Cassiano Felippe Gonçalves-de-Albuquerque

    Full Text Available Sepsis is characterized by inflammatory and metabolic alterations, which lead to massive cytokine production, oxidative stress and organ dysfunction. In severe systemic inflammatory response syndrome, plasma non-esterified fatty acids (NEFA are increased. Several NEFA are deleterious to cells, activate Toll-like receptors and inhibit Na+/K+-ATPase, causing lung injury. A Mediterranean diet rich in olive oil is beneficial. The main component of olive oil is omega-9 oleic acid (OA, a monounsaturated fatty acid (MUFA. We analyzed the effect of OA supplementation on sepsis. OA ameliorated clinical symptoms, increased the survival rate, prevented liver and kidney injury and decreased NEFA plasma levels in mice subjected to cecal ligation and puncture (CLP. OA did not alter food intake and weight gain but diminished reactive oxygen species (ROS production and NEFA plasma levels. Carnitine palmitoyltransferase IA (CPT1A mRNA levels were increased, while uncoupling protein 2 (UCP2 liver expression was enhanced in mice treated with OA. OA also inhibited the decrease in 5' AMP-activated protein kinase (AMPK expression and increased the enzyme expression in the liver of OA-treated mice compared to septic animals. We showed that OA pretreatment decreased NEFA concentration and increased CPT1A and UCP2 and AMPK levels, decreasing ROS production. We suggest that OA has a beneficial role in sepsis by decreasing metabolic dysfunction, supporting the benefits of diets high in monounsaturated fatty acids (MUFA.

  2. Sulfation of metal-organic framework: Opportunities for acid catalysis and proton conductivity

    Energy Technology Data Exchange (ETDEWEB)

    Goesten, M.G.; Stavitski, E.; Juan-Alcaniz, J.; Ramos-Fernandez, E.V.; Sai Sankar Gupta, K.B.; van Bekkum, H.; Gascon, J. and Kapteijn, F.

    2011-05-24

    A new post-functionalization method for metal-organic frameworks (MOFs) has been developed to introduce acidity for catalysis. Upon treatment with a mixture of triflic anhydride and sulfuric acid, chemically stable MOF structures MIL-101(Cr) and MIL-53(Al) can be sulfated, resulting in a Broensted sulfoxy acid group attached to up to 50% of the aromatic terephthalate linkers of the structure. The sulfated samples have been extensively characterized by solid-state NMR, XANES, and FTIR spectroscopy. The functionalized acidic frameworks show catalytic activity similar to that of acidic polymers like Nafion{reg_sign} display in the esterification of n-butanol with acetic acid (TOF {approx} 1 min{sup -1} {at} 343 K). Water adsorbs strongly up to 4 molecules per sulfoxy acid group, and an additional 2 molecules are taken up at lower temperatures in the 1-D pore channels of S-MIL-53(Al). The high water content and Broensted acidity provide the structure S-MIL-53(Al) a high proton conductivity up to moderate temperatures.

  3. Influence of rice straw-derived dissolved organic matter on lactic acid fermentation by Rhizopus oryzae.

    Science.gov (United States)

    Chen, Xingxuan; Wang, Xiahui; Xue, Yiyun; Zhang, Tian-Ao; Li, Yuhao; Hu, Jiajun; Tsang, Yiu Fai; Zhang, Hongsheng; Gao, Min-Tian

    2018-01-31

    Rice straw can be used as carbon sources for lactic acid fermentation. However, only a small amount of lactic acid is produced even though Rhizopus oryzae can consume glucose in rice straw-derived hydrolysates. This study correlated the inhibitory effect of rice straw with rice straw-derived dissolved organic matter (DOM). Lactic acid fermentations with and without DOM were conducted to investigate the effect of DOM on lactic acid fermentation by R. oryzae. Fermentation using control medium with DOM showed a similar trend to fermentation with rice straw-derived hydrolysates, showing that DOM contained the major inhibitor of rice straw. DOM assay indicated that it mainly consisted of polyphenols and polysaccharides. The addition of polyphenols and polysaccharides derived from rice straw confirmed that lactic acid fermentation was promoted by polysaccharides and significantly inhibited by polyphenols. The removal of polyphenols also improved lactic acid production. However, the loss of polysaccharides during the removal of polyphenols resulted in low glucose consumption. This study is the first to investigate the effects of rice straw-derived DOM on lactic acid fermentation by R. oryzae. The results may provide a theoretical basis for identifying inhibitors and promoters associated with lactic acid fermentation and for establishing suitable pretreatment methods. Copyright © 2018 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  4. Organics Characterization Of DWPF Alternative Reductant Simulants, Glycolic Acid, And Antifoam 747

    Energy Technology Data Exchange (ETDEWEB)

    White, T. L. [Savannah River Site (SRS), Aiken, SC (United States); Wiedenman, B. J. [Savannah River Site (SRS), Aiken, SC (United States); Lambert, D. P. [Savannah River Site (SRS), Aiken, SC (United States); Crump, S. L. [Savannah River Site (SRS), Aiken, SC (United States); Fondeur, F. F. [Savannah River Site (SRS), Aiken, SC (United States); Papathanassiu, A. E. [Catholic University of America Vitreous State Laboratory, Washington, DC (United States); Kot, W. K. [Catholic University of America Vitreous State Laboratory, Washington, DC (United States); Pegg, I. L. [Catholic University of America Vitreous State Laboratory, Washington, DC (United States)

    2013-10-01

    The present study examines the fate of glycolic acid and other organics added in the Chemical Processing Cell (CPC) of the Defense Waste Processing Facility (DWPF) as part of the glycolic alternate flowsheet. Adoption of this flowsheet is expected to provide certain benefits in terms of a reduction in the processing time, a decrease in hydrogen generation, simplification of chemical storage and handling issues, and an improvement in the processing characteristics of the waste stream including an increase in the amount of nitrate allowed in the CPC process. Understanding the fate of organics in this flowsheet is imperative because tank farm waste processed in the CPC is eventually immobilized by vitrification; thus, the type and amount of organics present in the melter feed may affect optimal melt processing and the quality of the final glass product as well as alter flammability calculations on the DWPF melter off gas. To evaluate the fate of the organic compounds added as the part of the glycolic flowsheet, mainly glycolic acid and antifoam 747, samples of simulated waste that was processed using the DWPF CPC protocol for tank farm sludge feed were generated and analyzed for organic compounds using a variety of analytical techniques at the Savannah River National Laboratory (SRNL). These techniques included Ion Chromatography (IC), Gas Chromatography-Mass Spectrometry (GC-MS), Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES), and Nuclear Magnetic Resonance (NMR) Spectroscopy. A set of samples were also sent to the Catholic University of America Vitreous State Laboratory (VSL) for analysis by NMR Spectroscopy at the University of Maryland, College Park. Analytical methods developed and executed at SRNL collectively showed that glycolic acid was the most prevalent organic compound in the supernatants of Slurry Mix Evaporator (SME) products examined. Furthermore, the studies suggested that commercially available glycolic acid contained minor amounts

  5. Organics Characterization Of DWPF Alternative Reductant Simulants, Glycolic Acid, And Antifoam 747

    International Nuclear Information System (INIS)

    White, T. L.; Wiedenman, B. J.; Lambert, D. P.; Crump, S. L.; Fondeur, F. F.; Papathanassiu, A. E.; Kot, W. K.; Pegg, I. L.

    2013-01-01

    The present study examines the fate of glycolic acid and other organics added in the Chemical Processing Cell (CPC) of the Defense Waste Processing Facility (DWPF) as part of the glycolic alternate flowsheet. Adoption of this flowsheet is expected to provide certain benefits in terms of a reduction in the processing time, a decrease in hydrogen generation, simplification of chemical storage and handling issues, and an improvement in the processing characteristics of the waste stream including an increase in the amount of nitrate allowed in the CPC process. Understanding the fate of organics in this flowsheet is imperative because tank farm waste processed in the CPC is eventually immobilized by vitrification; thus, the type and amount of organics present in the melter feed may affect optimal melt processing and the quality of the final glass product as well as alter flammability calculations on the DWPF melter off gas. To evaluate the fate of the organic compounds added as the part of the glycolic flowsheet, mainly glycolic acid and antifoam 747, samples of simulated waste that was processed using the DWPF CPC protocol for tank farm sludge feed were generated and analyzed for organic compounds using a variety of analytical techniques at the Savannah River National Laboratory (SRNL). These techniques included Ion Chromatography (IC), Gas Chromatography-Mass Spectrometry (GC-MS), Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES), and Nuclear Magnetic Resonance (NMR) Spectroscopy. A set of samples were also sent to the Catholic University of America Vitreous State Laboratory (VSL) for analysis by NMR Spectroscopy at the University of Maryland, College Park. Analytical methods developed and executed at SRNL collectively showed that glycolic acid was the most prevalent organic compound in the supernatants of Slurry Mix Evaporator (SME) products examined. Furthermore, the studies suggested that commercially available glycolic acid contained minor amounts

  6. Sustainable carbon sources for microbial organic acid production with filamentous fungi.

    Science.gov (United States)

    Dörsam, Stefan; Fesseler, Jana; Gorte, Olga; Hahn, Thomas; Zibek, Susanne; Syldatk, Christoph; Ochsenreither, Katrin

    2017-01-01

    The organic acid producer Aspergillus oryzae and Rhizopus delemar are able to convert several alternative carbon sources to malic and fumaric acid. Thus, carbohydrate hydrolysates from lignocellulose separation are likely suitable as substrate for organic acid production with these fungi. Before lignocellulose hydrolysate fractions were tested as substrates, experiments with several mono- and disaccharides, possibly present in pretreated biomass, were conducted for their suitability for malic acid production with A. oryzae. This includes levoglucosan, glucose, galactose, mannose, arabinose, xylose, ribose, and cellobiose as well as cheap and easy available sugars, e.g., fructose and maltose. A. oryzae is able to convert every sugar investigated to malate, albeit with different yields. Based on the promising results from the pure sugar conversion experiments, fractions of the organosolv process from beechwood ( Fagus sylvatica ) and Miscanthus giganteus were further analyzed as carbon source for cultivation and fermentation with A. oryzae for malic acid and R. delemar for fumaric acid production. The highest malic acid concentration of 37.9 ± 2.6 g/L could be reached using beechwood cellulose fraction as carbon source in bioreactor fermentation with A. oryzae and 16.2 ± 0.2 g/L fumaric acid with R. delemar . We showed in this study that the range of convertible sugars for A. oryzae is even higher than known before. We approved the suitability of fiber/cellulose hydrolysate obtained from the organosolv process as carbon source for A. oryzae in shake flasks as well as in a small-scale bioreactor. The more challenging hemicellulose fraction of F. sylvatica was also positively evaluated for malic acid production with A. oryzae .

  7. Uptake of Alkylamines on Dicarboxylic Acids Relevant to Secondary Organic Aerosol Formation

    Science.gov (United States)

    Marrero-Ortiz, W.; Secrest, J.; Zhang, R.

    2017-12-01

    Aerosols play a critical role in climate directly by scattering and absorbing solar radiation, and indirectly by functioning as cloud condensation nuclei (CCN); both represent the largest uncertainties in climate predictions. New particle formation contributes significantly to CCN production; however, the mechanisms related to particle nucleation and growth processes are not well understood. Organic acids are atmospherically abundant, and their neutralization by low molecular weight amines may result in the formation of stable low volatility aminium salt products contributing to the growth of secondary organic aerosols and even the alteration of the aerosol properties. The acid-base neutralization of particle phase succinic acid and tartaric acid by low molecular weight aliphatic amines, i.e. methylamine, dimethylamine, and trimethylamine, has been investigated by employing a low-pressure fast flow reactor at 298K with an ion drift - chemical ionization mass spectrometer (ID-CIMS). The heterogeneous uptake is time dependent and influenced by organic acids functionality, alkylamines basicity, and steric effect. The implications of our results to atmospheric nanoparticle growth will be discussed.

  8. Heat shock and salicylic acid on postharvest preservation of organic strawberries

    Directory of Open Access Journals (Sweden)

    Sidiane Coltro

    2014-06-01

    Full Text Available Heat shock and salicylic acid have been studied on shelf-life extension of fruits. The benefits of these techniques have been related to their effect on inducing physiological defense responses against the oxidative stress and pathogen development. The objective of this study was to evaluate the effect of heat shock and salicylic acid on the postharvest preservation and contents of total phenolics, anthocyanins, ascorbic acid, fresh weight loss and microbiological quality of organic strawberries cv. Dover. Strawberries produced organically and stored at 5 ºC were subjected to heat shock (45 ºC ± 3 ºC for 3 h, application of salicylic acid (soaking in 2.0 mmol L-1 solution, heat shock in combination with salicylic acid and control. After treatment, the fruits were packed and stored in a climatic chamber at 5 ºC ± 2 ºC. At 1, 7 and 14 days, the experimental units were removed from refrigeration and kept at room temperature of approximately 20 ºC for two days. There was no effect of treatments on fresh weight loss, incidence of pathogens or chemical variations in strawberry fruits during the storage period. In natural conditions, organically grown strawberries remained in good condition for sale up to seven days of storage in all treatments.

  9. Drip irrigation emitter clogging in Dutch greenhouses as affected by methane and organic acids

    NARCIS (Netherlands)

    Kreij, de C.; Burg, van der A.M.M.; Runia, W.T.

    2003-01-01

    It is believed that the serious clogging of drip irrigation emitters in the Dutch greenhouse industry is caused by methane-oxidising bacteria and/or organic acids used as anti-clogging agents. In this study greenhouses with moderate to severe emitter clogging have been examined. High methane

  10. Determination of alcohols, ethers and organic acids in irradiated sweet potato wine by capillary gas chromatography

    International Nuclear Information System (INIS)

    Zhou Yingcai; Yuan Bihuai; Xu Peishu; Wang Xiuying

    1986-01-01

    Alcohols, ethers and organic acids in irradiated sweet potato wine have been determined with capillary GC. The results show that the contents of some components have changed after irradiation, but no new species are formed. The G values of the changed components have been calculated

  11. Synthesis, characterization and crystal structures of new organic compounds containing cyanoacrylic acid

    Czech Academy of Sciences Publication Activity Database

    Khalaji, A.D.; Mogheiseh, M.; Eigner, Václav; Dušek, Michal; Chow, T.J.; Maddahi, E.

    2015-01-01

    Roč. 1098, Oct (2015), s. 318-323 ISSN 0022-2860 R&D Projects: GA ČR(CZ) GA14-03276S Institutional support: RVO:68378271 Keywords : organic compounds * cyanoacrylic acid * single-crystal structure analysis * dye-sensitized solar cells * density functional theory Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.780, year: 2015

  12. Volatile fatty acids production from sewage organic matter by combined bioflocculation and anaerobic fermentation

    NARCIS (Netherlands)

    Khiewwijit, R.; Keesman, K.J.; Rijnaarts, H.H.M.; Temmink, B.G.

    2014-01-01

    This work aims at exploring the feasibility of a combined process bioflocculation to concentrate sewage organic matter and anaerobic fermentation to produce volatile fatty acids (VFA). Bioflocculation, using a high-loaded aerobic membrane bioreactor (HL-MBR), was operated at an HRT of 1 h and an SRT

  13. Aggregation behavior of cholic acid derivatives in organic solvents and in water

    NARCIS (Netherlands)

    Willemen, H.M.

    2002-01-01

    In this thesis various cholic acid derivatives are reported that display aggregation in water or in organic solvents. Spontaneous aggregation of single molecules into larger, ordered structures occurs at the borderline of solubility. Amphiphilic compounds, or surfactants, which possess a

  14. Functional genomics for food microbiology: Molecular mechanisms of weak organic acid preservative adaptation in yeast

    NARCIS (Netherlands)

    Brul, S.; Kallemeijn, W.; Smits, G.

    2008-01-01

    The recent era of genomics has offered tremendous possibilities to biology. This concise review describes the possibilities of applying (functional) genomics studies to the field of microbial food stability. In doing so, the studies on weak-organic-acid stress response in yeast are discussed by way

  15. A Green Polymerization of Aspartic Acid for the Undergraduate Organic Laboratory

    Science.gov (United States)

    Bennett, George D.

    2005-01-01

    The green polymerization of aspartic acid carried out during an organic-inorganic synthesis laboratory course for undergraduate students is described. The procedure is based on work by Donlar Corporation, a Peru, Illinois-based company that won a Green Chemistry Challenge Award in 1996 in the Small Business category for preparing thermal…

  16. Influence of aluminum on growth, mineral nutrition and organic acid exudation of rambutan (Nephelium lappaceum)

    Science.gov (United States)

    A randomized complete block design experiment with six aluminum (Al) concentrations was carried out to evaluate the effect of aluminum on nutrient content, plant growth, dry matter production and