bluuebunny/crossref_metadata_2025_split huggingface dataset:
Anaerobic filters for municipal wastewater treatment
Authors: Viraraghavan T. , Landine R. C. , Pyke S. R. 
Published: July 2010

AbstractFour laboratory reactors (two downflow rock, one downflow wood, and one horizontal flow rock) were operated at 35–38°C for an initial period of six months and later at 23‐27°C, with primary clarifier effluent (PCE) from a municipal wastewater treatment plant as the feed to the reactors. A pilot‐scale rock medium reactor located at a municipal wastewater treatment plant was operated at 24–28°C initially in the downflow mode and later at 18‐20°C in the upflow mode with PCE as feed. The laboratory study showed that PCE can be successfully treated using both downflow and horizontal flow anaerobic filters, with similar performance under both flow modes.Bench‐scale filters obtained better BOD and SS removals compared to the pilot‐scale filter.
Substrate sequestration and product inhibition in enzymic reactors: Analytical model and experimental studies
Authors: Raul Avrom Z. , Ilan Ehud , Lotan Noah 
Published: July 2010

AbstractThe adverse influence that substrate sequestration exerts on the performance of a continuously operated, plug‐flow enzymic reactor was studied both experimentally and theoretically. Thus, glutathione‐S‐transferase was immobilized on activated agarose, and its performance in a packed‐bed reactor, both in the presence and in the absence of bovine serum albumin as sequestrator, was investigated. In parallel, an analytical model was developed, accounting for the behavior of systems which obey Michaelis—Menten kinetics, and which involve substrate sequestration and product inhibition. Substrate conversion in the reactor was found to decrease as sequestrator concentration and/or substrate—sequestrator association constant increased.
The use of vegetable oils to recover compounds from aqueous solutions
Authors: Welsh Frank W. , Williams Ross E. 
Published: July 2010

AbstractCorn oil, canola oil, olive oil, sunflower oil, peanut oil and soyabean oil were tested as extractants for the recovery of organic compounds from aqueous solution. Short chain aliphatic alcohols and acids were poorly recovered (Kd < 1.0) while most esters, aldehydes and aromatic compounds tested were satisfactorily recovered (Kd > 2.0) from aqueous solution by vegetable oils. Kd is defined as the ratio of the concentration of the dissolved substance in the extractant to that in the aqueous phase. The exception was caffeine which was poorly extracted from water. The type of oil used appeared to have limited effect on Kd. Increasing the reaction temperature resulted in increased Kd for most readily extractable compounds. Acidulated fatty acid was also tested as an extractant. Although it generally resulted in a greater Kd than the oils or hexane control, acidulated fatty acid was less desirable as an extractant because it tended to create an emulsion with the aqueous phase under the test conditions.
The effect of lauric acid shock loads on the biological and physical performance of granular sludge in UASB reactors digesting acetate
Authors: Rinzema Arjen , Alphenaar Arne , Lettinga Gatze 
Published: July 2010

AbstractThe specific activity of acetotrophic methanogens and the physical behaviour of granular sludge in laboratory‐scale upflow anaerobic sludge bed (UASB) reactors subjected to shock loads of lauric acid in the absence and presence of calcium were studied. In the absence of calcium, lauric acid completely inhibited acetotrophic methanogens above a threshold level of 100 mg C12:0dm−3, whereas no inhibition occurred below this threshold concentration. Addition of an equivalent amount of calcium to wastewater containing lauric acid prevented inhibition of acetotrophic methanogens at least up to 1500 mg C12:0dm−3. Addition of less than an equivalent amount of calcium apparently removed more than a stoichiometric amount of lauric acid: 50 % inhibition occurred at approximately 700 mg ‘free’ or excess C12:0dm−3. The results indicate that complete sludge wash‐out from conventional UASB reactors is likely to occur within 2‐8 h if the system is overloaded with an influent containing more than 100 mg C12:0dm−3. Calcium did not prevent wash‐out.
Inequivalent quadrupolar couplings of the deuterium‐exchanged nitrogen in micellar liquid crystals
Authors: Huque Entazul M. 
Published: July 2010

AbstractIn deuterium NMR, two inequivalent quadrupolar couplings of the deuterium‐exchanged nitrogen in a hydrocarbon chain near a chiral carbon atom have been observed in the nematic and cholesteric mesophases. The two quadrupolar doublets arise from the ND segments of the amphiphile and are interpreted as being due to the intramolecular motion in the amphiphile chain about the C—N bond. Different peak intensity of the two doublets suggests that one conformation is more stable than the other.
Study of cyclodextrin production using cyclodextrin glycosyltransferase immobilized on chitosan
Authors: Yang Chin‐Ping , Su Chein‐Shyong 
Published: July 2010

AbstractCyclodextrin glycosyltransferase (CGTase EC.3.2.1.19) was immobilized on chitosan through covalent bonding using glutaratdehyde. Various characteristics of immobilized CGTase (ICGTase) such as the pH—activity curve, the temperature—activity curve, pH and thermal stability, batch re‐usability and continuous operation stability were evaluated. Among them, the pH optimum and temperature optimum of CGTase were shifted from pH 7.5 and 55°C to pH 8.5 and 60°C after immobilization. No increase of pH stability was observed, whereas the thermal stability of ICGTase was superior to that of free CGTase. ICGTase retained 83 % of relative activity in converting liquefied starch (5% (w/v)) to cyclodextrins (CDs) under the conditions of four times of repeated use of 23 h conversion by the batch system at 55°C and pH 8.5. The half‐life of ICGTase under the same conditions by the continuous operation system was about 6 days. About 46 % of the liquefied potato starch solution (5 % (w/v)) was converted to CDs by ICGTase. Addition of ethanol in starch solution was found to increase the formation of β‐CD, and 58‐3 % yield of CDs was obtained by the addition of 16 % (v/v) ethanol in starch. The kinetic constants Km and Vmax of ICGTase and free CGTase were also examined.
Kinetics of hydrogenation of D‐glucose to sorbitol
Authors: Verma Rohit , Gehlawat Jagdish K. 
Published: July 2010

AbstractThe kinetics of the heterogeneous reaction between hydrogen and aqueous solutions of D‐glucose to produce sorbitol were studied in a high pressure Parr reactor. Raney‐Ni was used as catalyst. The reaction between hydrogen and D‐glucose was found to be very slow. In the agitated slurry reactor the diffusional aspects were completely eliminated and the reaction followed homogeneous kinetics. It was found to be first order with respect to both hydrogen and D‐glucose. The values of the pseudo‐first‐order rate constants were found to be 1.5 × 10−4 and 6.4 × 10−4s−1 at 398 and 435 K, respectively. The activation energy was found to be 64.8 kJ mol−1.
Continuous simultaneous saccharification and fermentation of raw starch in a membrane reactor
Authors: Matsumura Masatoshi , Hirata June 
Published: July 2010

AbstractA kinetic model for simultaneous saccharification and fermentation (SSF) of raw starch is proposed. The model includes the effect of ethanol on an active site for saccharification and the decay of a raw starch affinity site. The kinetic parameters were determined by using the experimental results of a batch saccharification and a long‐term repeated‐batch SSF of raw sweet potato starch. From analysis of the experimental results it is concluded that two subsites took part in ethanol inhibition, and that the inactivation of the raw starch affinity site was induced by adsorption of glucoamylase onto raw starch. The proposed kinetic model successfully predicted the progress of continuous SSF in a membrane reactor.
Determination of starch and maltose using immobilized amyloglucosidase and a glucose electrode in a flow injection system
Authors: Gorton Lo , Appelqvist Roger , Johansson Gillis , Scheller Frieder , Kirstein Dieter 
Published: July 2010

AbstractMaltose and starch were hydrolysed to glucose by immobilized amyloglucosidase in a packed‐bed reactor and then measured by a glucose oxidase electrode in a flow injection analysis manifold. The steady‐state signals for both maltose and starch were constant for reactor residence times between 24 and 73 s. They were reduced on addition of mutarotase by c. 10 % with maltose and by c. 20 % with starch. The steady‐state value for glucose in the presence of mutarotase coincided with that for equivalent amounts of both maltose and starch according to Zulkowski, indicating a 100 % conversion im the amyloglucosidase reactor. For 40‐μm3 samples, linear response curves were obtained over 100‐fold range of concentration. The maximum injection rate corresponded to 30 samples h−1.
Recovery of biosurfactants by ultrafiltration
Authors: Mulligan Catherine N. , Gibbs Bernard F. 
Published: July 2010

AbstractUltrafiltration was used in a one‐step method to purify and concentrate biosurfactants—surfactin and rhamnolipids—from culture supernatant fluids. The ability of surfactant molecules to form micelles at concentrations above the critical micelle concentration allows these aggregates to be retained by relatively high molecular weight cut‐off membranes. Lower molecular weight impurities such as salts, free amino acids, peptides and small proteins are easily removed. Various molecular weight cut‐off membranes were examined for the retention of surfactin and rhamnolipids (mol. wts 1036 and 802 respectively). Amicon XM 50 was the superior membrane for retention of surfactin and a 160‐fold purification was rapidly achieved. The YM 10 membrane was the most appropriate for rhamnolipid recovery. Ultrafiltration can play an important role in biosurfactant purification as large volumes of media can be processed rapidly at extremely low cost.
Recovery of uranium by tannin immobilized on matrices which have amino group
Authors: Nakajima Akira , Sakaguchi Takashi 
Published: July 2010

AbstractTannin, which contains polyhydroxy groups, has a high affinity for uranium. Various tannin–protein complexes were prepared to develop new adsorbents for uranium recovery from seawater. Albumin tannate has a high ability to adsorb uranium from seawater. Tannin was immobilized on matrices which have multiple active amino groups, such as aminopolystyrene and poly(vinyl‐4,6‐diamino‐s‐triazine)—poly VT. Of these complexes, tannin immobilized on poly VT adsorbed uranium most efficiently from seawater and highly selectively from a solution containing various heavy metals; the uranium adsorption was very rapid and was pH dependent. This adsorbent therefore appears to have potential for use in a commercial process for uranium recovery from seawater or from uranium‐containing waste water.
Synthesis of 9,10‐Bis‐hetaryl anthracenes and their application on polyester fibres as disperse dyes
Authors: Rangnekar D. W. , Rajadhyaksha D. D. 
Published: July 2010

Abstract9,10‐Dibromoanthracene (2) obtained from anthracene by bromination was reacted with cuprous cyanide in refluxing DMF to obtain 9,10‐dicyanoanthracene (3). The key intermediate (3) was condensed with orthophenylenediamine (4a), ortho‐aminophenol (4b) and dicyanodiamine (6) to give 9,10‐bis(benzimidazol‐2‐yl)anthracene (5a), 9,10‐bis(benzoxazol‐2‐yl)anthracene (5b) and 9,10‐bis(4,6‐diamino‐S‐triazin‐2‐yl)anthracene (5c), respectively. The spectral properties of 5a‐5c were studied. These compounds, when applied as disperse dyes on polyester fibres, gave excellent results.
Kinetics and mechanism of homogeneous catalytic hydroxylation of maleic acid by hydrogen peroxide. Part I: Formal kinetics
Authors: Oludipe John O. , Koiki Kolawole K. , Litvintsev Igor Yu. , Sapunov Valentin N. 
Published: July 2010

AbstractThe kinetics of maleic acid hydroxylation by H2O2 in the presence of a homogeneous catalyst have been studied. A rate equation for the consumption of H2O2 has been obtained. The retardation of the reaction resulting from catalyst deactivation was observed. The fall in the activity of catalyst during the course of the reaction has been associated with the formation of a complex between the former and the reaction product.
Landfill co‐disposal of phenol‐bearing wastewaters: Organic load considerations
Authors: Watson‐craik Irene A. , Senior Eric 
Published: July 2010

AbstractA multi‐stage model, operated with single elution, was used to investigate the effects of organic loadings on the attenuation of a model phenolic wastewater in domestic refuse. Although 100% dissimilation of influent phenol (2–5 mmol dm−3) was recorded at a dilution rate of 0.007 h−1, partial inhibition of both phenol degradation and species competing with methanogens for a common electron donor(s) was apparent at concentrations ±4 mmol dm−3. On extended perfusion with 8 mmol phenol dm−3, the progressive inhibition of phenol dissimilation was not obviated by nutrient supplementation. Simultaneous degradation of the catabolic intermediate, hexanoic acid, and elevated methane release rates suggested that the transformation of phenol to hexanoate was rate limiting.
Comparison of oxygen supply methods for cultures of shear‐stress sensitive organisms including animal cell culture
Authors: Mano Takashi , Kimura Tatsuro , Lijima Shinji , Takahashi Katsuroku , Takeuchi Hiroshi , Kobayashi Takeshi 
Published: July 2010

AbstractIn animal cell culture, oxygen supply sometimes limits cell growth. Therefore, four oxygen supply methods (free surface aeration, porous Teflon tubing, perfluorocarbon addition and external aerator) were compared in terms of oxygen transfer rate for suspension culture of animal cells. Oxygen transfer rate with the free surface aeration was dependent on the vertical position of the impeller and the stirred Reynolds number for h/HL >0.35, but no effect of the impeller position was observed for h/HL < 0.35. The relationship between the Reynolds and Sherwood numbers could be expressed by simple correlations. These correlations could also be applied to oxygen transfer using porous Teflon tubing. When oxygen was supplied with perfluorocarbon saturated with air, the overall mass transfer coefficient KL was estimated to be about 9.0 × 10−3 cm s−1, which was five‐fold greater than that of the surface aeration. Maximum cell densities which would be supported by four methods were calculated from values of KLa for different sizes of fermentor assuming that oxygen supply would be the rate‐limiting factor in animal cell culture.
Performance analysis of an immobilized yeast packed‐bed reactor for ethanol fermentation
Authors: Ching Chi‐Bun , Teo Wah‐Koon , Chu Khim‐Hoong 
Published: July 2010

AbstractThe performance of an immobilized packed‐bed bioreactor for continuous ethanol fermentation was evaluated. Immobilized yeasts were prepared by entrapment in calcium alginate gel. An axial dispersed plug flow model incorporating the effects of substrate and product inhibition on fermentation kinetics was developed. The model equations were solved by the method of orthogonal collocation and the suitability of the reactor model to predict the conversions obtained in this biocatalytic reaction system was assessed.
The surface activity of triisooctylamine and the mechanism of palladium (II) extraction by dihexyl sulphide in the presence of triisooctylamine
Authors: Szymanowski J. , Bauer D. , Cote G. , Prochaska K. 
Published: July 2010

AbstractThe interfacial activities of triisooctylamine, dihexyl sulphide and dodecylmethyl sulphide were studied and used to discuss the mechanism of palladium (II) extraction from acidic chloride solutions by a mixture of dialkyl sulphide with triisooctylamine. The surface excess isotherms were computed and amine association was considered. The extraction occurs probably according to a complex interfacial‐bulk mechanism in which the reaction between palladium and protonated amine occurs mainly in the bulk of the aqueous phase but the intermediate complex R3NHPdCl3 adsorbs at the interface and reacts with dialkylsulphide in the limiting step.
An investigation of engineering parameters for the use of immobilized biomass particles in biosorption
Authors: Tsezos Marios , Deutschmann Ake A. 
Published: July 2010

AbstractImmobilized, inactive mycelia of Rhizopus arrhizus are preferential to native biomass for use in the biosorption of metal ions. Refinement of a proprietary immobilization technique previously developed at McMaster University enabled production of particles of immobilized Rhizopus arrhizus biomass having a 12–23% wt of polymer additive. The effects of production stage parameters on the intrinsic uptake capacity of the immobilized biomass were examined. Kinetic experiments showed the following trends: a decrease in the weight percent of the added polymer leads to an increase in the apparent uranium uptake capacity of the immobilized biomass particles far a given contact time. A decrease in the particle size improved the kinetics of metal uptake and led to an increase in the apparent uranium uptake capacity for the same contact time. An increase in the initial concentration of the uranium solution caused equilibrium conditions to be attained faster.
1,5‐Dihydroxy‐4,8‐diamino‐ and 1,8‐dihydroxy‐4,5‐diaminoanthraquinone‐β‐ethers and thioethers. Blue dyes for synthetic polymer fibres
Authors: Peters Arnold T. 
Published: July 2010

AbstractCondensation of mono‐ and di‐bromo‐derivatives of 1,5‐dihydroxy‐4,8‐diaminoanthraquinone and of 1,8‐dihydroxy‐4,5‐diaminoanthraquinone with phenols and thiols afforded the corresponding β‐ethers and thioethers. These compounds coloured polyester in bright reddish‐blue to greenish‐blue hues of generally good fastness to light and sublimation. The colour of the dyes is discussed with respect to the nature and orientation of the β‐substituent.
High selective production of tetrahydrofurfuryl alcohol: Catalytic hydrogenation of furfural and furfuryl alcohol
Authors: Merat Nadine , Godawa Christine , Gaset Antoine 
Published: July 2010

AbstractTetrahydrofurfuryl alcohol could be obtained by catalytic hydrogenation of either furfural or furfuryl alcohol using Pd‐, Ru‐, Rh‐ and Ni‐supported catalysts as well as their mixtures with a Cu‐supported catalyst. In the case of furfural hydrogenation, the best results (97 % yield, 100 % conversion, 98 % selectivity) were obtained in the presence of Ni and Cu. However, this catalytic mixture could not be recycled. In the case of furfuryl alcohol hydrogenation, Ni‐supported catalysts were the most active. Nickel‐onsilica‐alumina catalyst containing 59 % of metal lead to the best results (98–99 % yield, selectivity and conversion >99 %). Moreover, it could be recycled. Hydrogenation of furfuryl alcohol in the presence of this catalyst was the best procedure for the production of tetrahydrofurfuryl alcohol.
Dispersed‐phase holdup and mass transfer in a rotating disc contactor with perforated skirts
Authors: Kawase Yoshinori 
Published: July 2010

AbstractDispersed‐phase holdup and extraction efficiency were measured in a pilot‐plant scale rotating disc contactor (RDC) with perforated skirts (RDCS) with kerosene‐o‐cresol‐water system. The data for the RDCS were examined using the data in this work and the available correlations proposed for the plain RDC. A comparison between the data measured in the RDCS and those in the RDC indicated that the RDCS has rather better extraction efficiency compared with the RDC.
The influence of physicochemical properties of ZSM‐5 on catalytic dewaxing
Authors: Sivasanker S. , Waghmare K. J. , Reddy K. M. , Kothasthane A. N. , Ratnasamy P. 
Published: July 2010

AbstractA decrease in the crystallite size increases the activity as well as the selectivity and reduces the deactivation of ZSM‐5 zeolites in the dewaxing of petroleum fractions. Isomorphous replacement of Al3+ by Fe3+ reduces the dewaxing activity but enhances the yield of dewaxed oil and gasoline at the expense of C1‐C4 gases. Within limits, the Si/Al ratio does not affect the performance of ZSM‐5 zeolite in the hydrodewaxing process.
Study of the mechanism of pore diffusion in batch adsorption systems
Authors: McKay Gordon , Al‐Duri Bushra 
Published: July 2010

AbstractIn this study the film‐pore diffusion model was applied to describe system transport kinetics of three basic dye‐carbon systems, namely Basic Blue 69, Basic Red 22 and Basic Yellow 21. The mass transfer parameters evaluated were the external mass transfer coefficient kf (cm s−1) and the effective diffusivity Deff (cm2 s−1).A single kf value was sufficient to describe each dye system: these were 0.15 × 10−2, 0.20 × 10−2 and 0.50 × 10−2 cm s−1 for BB69, BR22 and BY21, respectively. The effective diffusivity was found to have values much larger than those of pore diffusivities calculated from liquid diffusivities and its value decreased with increasing initial dye concentration. This was attributed to the effect of surface diffusion, hence pore diffusivity was exchanged by the effective pore diffusivity in the model.The present model was solved by the exponential curve fit technique; results were expressed in the form of experimental and theoretical Sherwood Numbers compared in terms of the residual.
Lightfastness modelling of azo dyes bearing heteroaromatic substituents
Authors: Carpignano Rosarina , Savarino Piero , Viscardi Guido , Barni Ermanno , Baroni Massimo , Clementi Sergio , Cruciani Gabriele 
Published: July 2010

AbstractLightfastness for a number of azo dyes bearing heteroaromatic substituents was modelled by the partial least squares method (PLS) in terms of structural descriptors, involving the principal properties of usual substituents, and the chemical shifts of the heteroaromatic moieties. The model permits the prediction of possible structures, with higher values of the technological property, worthy of synthesis.
Hydrocarbon conversions with some intermetallic catalysts
Authors: Bahia A. , Brown J. M. , Caga I. T. , Harris I. R. , King C. E. , Winterbottom J. M. 
Published: July 2010

AbstractThe intermetallic pseudo‐binary alloys of the general type ZrRh3‐xPdx and ZrRh3‐xRux (0 < × < 3) have been prepared by argon arc melting and melt quenching of the constituent elements.The alloys were powdered and employed as catalysts for (i) hydrogenation of oct‐1‐yne in the liquid phase at 101.32 kPa total pressure and 70°C, (ii) hydrogenation of buta‐1,3‐diene in the gas phase at 101.32 kPa total pressure in the temperature range 45–225°C, and (iii) hydrogenolysis of n‐pentane in the gas phase at 101.32 kPa total pressure and in the temperature range 200–400°C.Activity and selectivity measurements were made with respect to (i) alkene formation for the hydrogenation reactions, and (ii) C2 + C3‐alkane formation for the hydrogenolysis reaction. The activity of the alloy series appears to correlate to some degree with the electronic properties and hydrogen sorption capacity of the intermetallic alloys. Auger electron spectroscopy measurements revealed that for ZrRh3‐xPdx alloys both the surface and bulk compositions were in good agreement; this behaviour is contrasted briefly with that of CeRh3‐xPdx alloys which, unlike ZrRh3‐x alloys, suffered significant oxygen interaction in the surface and sub‐surface layers, although this did not affect Rh:Pd ratios.Catalysts that were active for hydrogenation were inactive for hydrogenolysis and vice versa. However, selectivity values for the hydrogenation reactions generally reflected the behaviour of the predominant noble transition metal. Again, the behaviour of ZrRh3‐xPdx and CeRh3‐x alloys is contrasted, since the latter were more selective for butene formation from buta‐1,3‐diene, and attributed to the oxygen Contamination of the surface. Further more, the selectivity of both ZrPd and CePd, for 1‐octyne and butu‐l j‐dene hydrogenation was significantly greater than that of palladium by virtue of the fact that the intermetallics were found to be largely inactive for alkene hydrogenation.