bluuebunny/crossref_metadata_2025_split huggingface dataset:
Alternating aerobic and anoxic digestion of waste activated sludge
Authors: Hao Oliver J. , Kim Michael H. , Al‐Ghusain Ibrahim 
Published: July 2010

AbstractNitrate generated in situ due to nitrification in an aerobic digester was utilized through endogenous nitrate respiration (ENR). This was done by alternating aerobic/anoxic (A/A) cycles. The destruction of volatile suspended solids (VSS) in the A/A system was the same as compared to a controlled‐aerobic digester. Approximately 33% of total nitrogen was removed in the A/A system of which 27% was due to ENR during anoxic cycles.During each anoxic cycle, nitrate reduction was found to be a zero order reaction with respect to nitrate. The specific ENR rates decreased significantly with digestion time due to changes in VSS. Both pH and alkalinity increased during anoxic cycles resulting in enhanced VSS decay and complete nitrification under subsequent aerobic conditions.The energy savings associated with the A/A system and the use of the specific ENR rates are discussed.
Simulation of batch and continuous reactors with co‐immobilized yeast and β‐galactosidase
Authors: Axelsson Anders , Zacchi Guido 
Published: July 2010

AbstractA reaction‐diffusion model was used to simulate a co‐immobilized system utilizing the numerical method of orthogonal collocation. The production of ethanol from deproteinized whey using β‐galactosidase co‐immobilized with Saccharomyces cerevisiae in calcium alginate gel beads was chosen as a model system. Calculated concentrations of lactose, glucose, galactose and ethanol were compared with experimental data for a batch reactor and a continuous horizontal packed‐bed reactor.The mathematical model has been used to analyse the influence of internal and external mass transfer for the continuous reactor. The external mass transfer was shown to be of minor importance.The introduction of baffles decreased the backmixing in the horizontal packed‐bed reactor. Internal mass transfer was found to be the main cause of the reduction in the apparent reaction rate. Thus, much of the expected increase in reaction rate is diminished by mass transfer hindrance when the cell concentration is increased.
The loss of substrate from a vial during freeze‐drying using escherichia coli as a trace organism
Authors: Adams Gerald D. J. 
Published: July 2010

AbstractThe potential for ablation during product freeze‐drying has been assessed using a defined area surrounding the processed vial. This technique has enabled media formulations to be compared. The paper suggests ways in which the mini‐chambers may be used to investigate the extent of ablation and methods for reducing contamination of a freeze‐drier by ablation.
Examination of boron content and properties of magnesium oxide obtained from sea water
Authors: Petric N. , Petric B. , Martinac V. 
Published: July 2010

AbstractThe potentiometric method was used to determine the boron content in magnesium oxide obtained from sea water by sub‐stoichiometric precipitation (where precipitation of magnesium hydroxide took place with 80% of the stoichiometric quantity of the dolomite lime) and by over‐stoichiometric precipitation (which took place with 120% of the stoichiometric quantity of the dolomite lime); the analyses depend on the method of rinsing the product obtained.The following were examined: the influence of pH of the rinsing solution, duration of stirring and contact of the suspension, influence of the quantity of the rinsing agent, and the method of precipitate separation in sub‐stoichiometric precipitation. It has been proved that the use of the appropriate rinsing method in the case of sub‐stoichiometric precipitation leads to results almost identical to those obtained for over‐stoichiometric precipitation, which is rather important if one bears in mind the advantages of this precipitation method.Individual samples of magnesium oxide obtained from sea water by sub‐ and over‐stoichiometric precipitation were then sintered. This paper lists densities of samples sintered and presents their photomicrographs.
Production and consumption of sorbitol and fructose by saccharomyces cerevisiae ATCC 36859
Authors: Duvnjak Z. , Turcott G. , Duan Z. D. 
Published: July 2010

AbstractThe production and consumption of sorbitol by Saccharomyces cerevisiae ATCC 36859 have been studied in this work. The results showed that the strain produced ethanol and sorbitol in a fructose medium, but it generated only ethanol while growing in a glucose medium. When the strain was pregrown on fructose and transferred to a sorbitol medium, it consumed that polyol and produced ethanol and fructose. It did not grow on sorbitol when it was transferred from a glucose medium. During the growth of the strain in a glucose‐fructose medium, the sorbitol production started some time after the consumption of glucose. Both glucose and ethanol affected the production of sorbitol. Comparing the strain with a wild S. cerevisiae, it was found that the latter one did not produce sorbitol when it grew either on glucose or fructose. Furthermore, the wild strain grew well on sorbitol, regardless of whether it was pregrown on glucose or fructose but it did not produce fructose.
Biodegradation of black liquor hydroxyacids by micrococcus lylae
Authors: Pekarovičová Alexandra , Mikulášová Mária , Černáková L'udmila 
Published: July 2010

AbstractEight bacterial strains utilizing glucoisosaccharinic acid (GISA), which is one of the main components of sulphate black liquor hydroxyacids, were isolated from the environment of a sulphate pulp mill. The best GISA‐utilizing bacterium was isolated from soil and it was identified as Micrococcus lylae. The growth of M. lylae on GISA in the pH range 5.0–9.0 was studied, optimum growth and utilization of GISA being observed at pH 8.0. M. lylae also utilized D,L‐lactic acid and black liquor separated from the lignin.
A packed‐column bioreactor for phenol degradation: Model and experimental verification
Authors: Quail Beverly E. , Hill Gordon A. 
Published: July 2010

AbstractPseudomonas putida (ATCC 17484) has been grown in a pure culture, slime layer inside a continuous packed‐column bioreactor. The bioreactor has been characterized in terms of liquid holdup, dispersion, air stripping, fixed biomass concentration, and degradation rate capabilities. The experimental data has been used to develop a predictive model using mechanistic equations for the operation of packed columns and the biokinetics of pure culture phenol degradation.The liquid holdup, dispersion and liquid‐to‐air mass transfer coefficients were found to be correlated by power law equations commonly used for packed column absorption and stripping equipment. The microorganisms developed a uniform slime layer over the 3‐mm diameter glass spheres, measured to be 200 μm thick. Phenol inlet concentrations of 500 ppm were degraded 100% and at rates up to 1.2 × 10−3 kg m−3 s−1. These results compare favorably with the best biodegradation results reported elsewhere in the literature for other bioreactor designs. The packed‐column bioreactor has the advantages of no moving parts and the need for minimum aeration (air fluxes less than 0.001 ms−1), thereby reducing volatile stripping losses.A computer model of the bioreactor was found to predict accurately the experimental trend in biodegradation capacities and rates with liquid flux. It is shown to be a useful model for studying design parameter changes or for determining scale‐up characteristics due to its simplicity and mechanistic basis.
Cationic azomethine disperse dyes: Synthesis, antifungal activity and tinctorial properties of N‐arylideneamino p‐substituted pyridinium salts as possible dyes for synthetic fibres
Authors: Hanna M. A. , Girges M. M. , Gawinecki R. 
Published: July 2010

AbstractIn a four‐step synthesis, a series of N‐arylideneamino p‐substituted pyridinium salt derivatives were prepared for use as cationic azomethine disperse dyes for polyester and polyacrylonitrile fibres. The effect of different substituents, in both of homo‐ and heterocyclic ring systems, on position of maximum absorbance in UV‐vis spectra was used to explain the different hues of the prepared dyes. Besides, showing promising tinctorial properties, the synthesised dyes revealed fungicidal activity against Aspergillus niger. The structure of the hitherto prepared dyes was inferred by elemental and spectral data.
The Use of a Mathematical Model for the Study of the Important Parameters in Immobilized Biomass Biosorption
Authors: Tsezos Marios , Deutschmann Ake A. 
Published: July 2010

AbstractIt has been shown that the immobilized, inactive mycelia of Rhizopus arrhizus are preferential to native biomass for use in the biosorption of metal ions. A kinetic mass transfer model for the description of the biosorption of metal ions by immobilized biomass from aqueous solution in a batch reactor, has been developed. The present work examines in detail the ability of this kinetic model to describe well the response of the biosorption system to changes caused by variations in the experimental conditions and the properties of the immobilized biomass as well as the parametric sensitivity of the model to process related parameters. It was shown that the immobilized biomass particle size, the initial solute concentration, the maximum immobilized biomass uptake capacity and mass transport coefficients are significant parameters that affect the model results.
Kinetic Model for Oxidative Dehydrogenation of n‐Butanol over Copper‐Barium Catalyst
Authors: Shiau Ching‐Yeh , Liaw Shin‐Tsi 
Published: July 2010

AbstractKinetics for oxidative dehydrogenation of n‐butanol over copper‐barium catalyst was investigated in a fixed‐bed reactor. The effects of oxygen addition, temperature, initial partial pressure, and time factor on the conversion were studied. The results show that the catalyst is quite active and selective for the dehydrogenation of n‐butanol and will become more active when a small amount of oxygen is added in the feed stream. A partial redox model including a pair of redox reaction steps parallel with a direct dehydrogenation reaction step was developed. The rate constants for the three reaction steps were evaluated. The model can predict the experimental data quite well, with a standard deviation less than ±5%.
The Production of the Enzyme Dextransucrase using Unaerated Continuous Fermentations
Authors: Pennell R. D. , Barker P. E. 
Published: July 2010

AbstractFollowing the successful production of dextransucrase with activities greater than 21.9 U cm%−3, using the fed‐batch fermentation technique, the process was then studied in the continuous mode. The organism Leuconostoc mesenteroides NRRL B512 (F) was cultured in an unaerated nutritious medium, containing sucrose, with similarly composed medium used as the feed. Using this method of operation, it was possible to produce approximately 5 U cm%−3 of dextransucrase continuously.Various factors were found to affect dextransucrase production. The sterilization cycle of the feed medium was found to be very important, with temperatures of 125°C causing medium degradation and, hence, a loss in activity. The sucrose concentration of the feed medium and the degree of mixing of the fermentation were also found to be important parameters in this process.
The Effect of Nickel on the Conversion of Amorphous Iron(III) Hydroxide into more Crystalline Iron Oxides in Alkaline Media
Authors: Cornell R. M. , Schneider W. , Giovanoli R. 
Published: July 2010

AbstractThe effect of nickel (Ni) on the transformation of amorphous iron(III) hydroxide into more crystalline iron oxides has been followed using X‐ray powder diffraction and chemical analysis. One aim of this study was to determine the fate of Ni that had been co‐precipitated with amorphous iron(III) hydroxide as the amorphous phase recrystallised.Ni/amorphous iron(III) hydroxide co‐precipitates transformed into Ni substituted α‐FeOOH or α‐Fe2O3, NiFe2O4 and α‐3Ni(OH)2.2H2O in alkaline media. The type of reaction products formed depended on the concentration of Ni in the system and on the pH.Ni retarded the crystallisation of amorphous iron(III) hydroxide by stabilising the co‐precipitate both against dissolution leading to α‐FeOOH and against the internal rearrangement process which leads to α‐Fe2O3.Chemical analysis showed that Ni was incorporated into the structure of α‐FeOOH to a maximum level of 5.5 mol% and into the structure of α‐Fe2O3 to up to 7 mol%. Excess Ni was adsorbed on the surface of the iron oxide or taken up by NiFe2O4 or the pure Ni phase. The b0 dimension of the unit cell increased from 0.9960 nm for α‐FeOOH to 0.9965 nm for α‐FeOOH with 5.5 mol% Ni substitution. The same maximum level of Ni could be incorporated in the α‐FeOOH structure in the presence of either Mn (up to 8 mol%) or Co (up to 7 mol%).
Biobleaching of Pulp and Paper Mill Effluents by Phanerochaete chrysosporium
Authors: Mittar Dev , Khanna P. K. , Marwaha S. S. , Kennedy J. F. 
Published: July 2010

AbstractThe potential of white rot fungi, namely, Polyporus versicolor FRI 165, Polyporus hirsutus FRI 534, Polyporus hirsutus FRI 2862, Phanerochaete chrysosporium BKMF 1767 and Sporotrichum pulverulentum for the reduction of colour of pretreated pulp and paper mill effluents under sterilised and unsterilised conditions has been evaluated. Of these, P. chrysosporium BKMF 1767 cultured under sterilised conditions supported maximum colour reduction after 7 days of growth. The optimisation of the process parameters showed that the addition of nutrient sails in selective combination marginally improved the colour reduction. The 7‐day‐old growth of culture at 20% (v/v) inoculum concentration resulted in maximum decolourisation (69.6%) of the effluent with pH adjusted to 4.5 at 40°C along with more than 50% reduction in biological oxygen demand (BOD) and chemical oxygen demand (COD). The irradiation of the effluent with UV light had apparently no effect on the colour, BOD and COD reduction by P. chrysosporium.
Photocatalytic Cyanide Oxidation from Aqueous Copper Cyanide Solutions over TiO2 and ZnO
Authors: Peral JosÉ , Domenech Xavier 
Published: July 2010

AbstractThe elimination of cyanide from aqueous copper cyanide solutions by oxidation under UV illumination using titanium oxide (TiO2) and zinc oxide (ZnO) as catalyst has been investigated. The study has been carried out by determining the yield of cyanide elimination at different irradiation times, initial cyanide concentrations and pH. It has been observed that cyanide is photo‐oxidised with higher yields in presence than in absence of copper in solution when TiO2 is used as photocatalyst, while the opposite behaviour is reported when ZnO is the photocatalyst employed. This fact is related with the feasibility in which copper species are able to react with photogenerated electrons in the conduction band of the TiO2 particles. Finally, the elimination of cyanide, both free and complexed, from a sample of an electroplating bath has also been studied. The results show that the photocatalytic method is very efficient in the elimination of cyanide in aqueous dilute solutions.
Synthesis of 5,5′‐Oxydimethylenebis (2‐furfural) by Thermal Dehydration of 5‐Hydroxymethyl‐2‐furfural in the Presence of Dimethylsulfoxide
Authors: Larousse Christian , Rigal Luc , Gaset Antoine 
Published: July 2010

AbstractA new method for the synthesis of 5,5′‐oxydimethylenebis (2‐furfural) by thermal dehydration of 5‐hydroxymethyl‐2‐furfural in the presence of dimethyl‐sulfoxide is described. Optimum conditions are studied by experimental design. Reaction media present a high concentration of HMF. Reaction is supposed to be rapid. Yields reach 55% with a 84% selectivity.
Adaptive linear quadratic gaussian (LQG) control of a bioreactor
Authors: Roux G. , Dahhou B. , Najim K. , Queinnec I. 
Published: July 2010

AbstractThe paper deals with the modelling and adaptive control of a continuous‐flow fermentation process for the production of alcohol.The fermenter model has been developed from mass balance and leads to nonlinear differential equations. In practice, control strategies are difficult to derive using this non‐linear model. The dilution rate and the substrate concentration have been considered as control and controlled variables, respectively.The adaptive control algorithm implemented is based on the linear quadratic control approach, where the associated Riccati equation is iterated until the system closed‐loop poles belong to a restricted stability domain which is included in the unit circle.A single input/output model is used for control purposes. The model parameters are estimated on‐line using a robust identification algorithm which includes: data normalization, time‐varying forgetting factor, covariance matrix factorization, etc. Experimental results show the performance of this adaptive scheme and its ability to control biotechnological processes.
Synthesis and anti‐inflammatory activity of some novel 1,3,4‐oxadiazole derivatives
Authors: El‐Samii Z. K. Abd 
Published: July 2010

AbstractSome novel 1,3,4‐oxadiazoline and 1,3,4‐oxadiazole derivatives have been synthesized from 3‐hydroxy‐5,6‐diphenyl‐1,2,4‐triazine. Illucidation of the structures of the isolated products has been proved in the light of their elemental analysis, spectroscopic data and unambiguous synthesis in certain cases. Some derivatives have shown promising anti‐inflammatory activity in comparison to phenylbutazone.
Bioconversion of hemicelluloses of rice hull black liquor into single‐cell protein
Authors: Hussein Assem M. , El‐Saied Houssni , Yasin Mohamed H. 
Published: July 2010

AbstractRice hulls were treated using several sodium hydroxide concentrations and temperatures. The black liquor contents of silica, lignin and hemicelluloses increased with increase in temperature or sodium hydroxide concentration. Hexoses constituted the major part and pentoses the minor part of the black liquor hemicelluloses. The ratio of pentoses to hexoses increased slightly with the increase of treatment variables.The pentose content of the black liquor consisted of arabinose and xylose, while the hexose composition was mannose, galactose, rhamnose and glucose. On increasing the alkali concentration, the xylose and mannose concentrations increased greatly, while galactose and glucose increased only slightly.Using 10 soil samples several isolates of fungi and actinomycetes were obtained. These were identified as five species of the genus Aspergillus, three species of Paecilomyces, two species of Penicillium, one species each of Alternaria, Trichoderma, Chaetomium and Actinopolyspora. These fungi were cultivated on black liquor basal salts medium. The highest bioconversion rate of black liquor hemicelluloses into biomass and single‐cell proteins was achieved by Aspergillus terreus, followed by Paecilomyces simplicissima then Actinopolyspora sp.
Removal of congo red from aqueous solutions by biogas waste slurry
Authors: Namasivayam C. , Yamuna R. T. 
Published: July 2010

AbstractRemoval of Congo Red was carried out using biogas waste slurry as adsorbent at different concentrations of dye, adsorbent dosage, agitation time and pH. The process follows the first‐order rate expression. The equilibrium data fit well in the Freundlich model of adsorption. Maximum removal of dye, 95%, was observed in the pH range 2.3–9.4. Desorption of Congo Red showed that it is solubilised in 50% acetic acid to the extent of 6% and the remainder appears to be chemically complexed irreversibly to the adsorbent. Low desorption of dye from the adsorbent surface in water indicates that the process may not be, essentially, a reversible one.
Kinetics and stability of a chromobacterium viscosum lipase in reversed micellar and aqueous media
Authors: Prazeres D. M. F. , Garcia F. A. P. , Cabral J. M. S. 
Published: July 2010

AbstractThe lipolytic activity of Chromobacterium viscosum lipase B (EC 3.1.1.3.; triacylglycerol hydrolase) solubilized both in water and AOT/isooctane reversed micelles has been investigated using triolein as a substrate. The influence of relevant parameters in the catalytic activity such as temperature, pH, surfactant and substrate concentrations, and water content was tested and compared in both media. A study of stability of the lipase was carried out, with particular reference to the influence of pH.Three major effects of the encapsulation of the lipase in the micelles were observed: increased activity (up to 7 times higher than in water), greater stability, specially at pH 7, and higher resistance to thermal deactivation.
Studying production of lovage essential oils in a hydrodistillation pilot unit equipped with a cohobation system
Authors: Perineau Francis , Ganou Leguet , Vilarem Gérard 
Published: July 2010

AbstractThe hydrodistillation procedure for a unit equipped with a cohobation system is presented. The production of lovage root essential oil and the difficult recovery of the phthalide content (60–85%) is studied. The general mechanism and the role of parameters involved in the extraction and co‐distillation step (plant matter/water ratio, loading ratio) then in the water/essential oil separation step (pH, condensation temperature) are investigated. This study takes into account the quantitative results (yield of essential oil, productivity) and the qualitative ones (composition of recovered essential oils). Optimal distillation conditions with respect to the energy consumption are proposed.
Study of the poisoning of γ‐Al2O3 by alkali metals addition
Authors: Cortez Gilberto García , de Miguel Sergio R. , Scelza Osvaldo A. , Castro Alberto A. 
Published: July 2010

AbstractThe effect of alkali metal addition to alumina on the acid characteristics and on the isopropanol dehydration capacity was analyzed. It was found that the incidence on the catalytic and acid properties of the alkali metal doped alumina depended on the ionic radii of the added element. Thus, K produces a higher poisoning of the acid function than Na and Li. Catalytic results can be interpreted in terms of a modification of the acid sites distribution by the alkali metal addition, the stronger acid sites being mainly affected.
Ethanol dehydration by extractive distillation
Authors: Meirelles Antonio , Weiss Siegfried , Herfurth Herbert 
Published: July 2010

AbstractExperiments and process simulation enable favourable operating conditions to be determined for the extractive distillation of ethanol—water, with ethylene glycol as a solvent. The solvent molar rate to feed molar rate ratio S/F = 0·6 and the reflux ratio R = 0·5 were determined in order to achieve at least 99·5 mole % purity of ethanol. Other parameters examined include feed concentration, purity of solvent, and number of plates.Extractive distillation can be used to achieve high purity of ethanol at low energy consumption and under simple operating conditions.
Hydrolysis of Fe(OH)SO4 in the presence of metallic iron
Authors: Mahapatra Sipra , Prasad Turaga P. 
Published: July 2010

AbstractHydrolysis of Fe(OH)SO4 was carried out in the presence of metallic iron in order to prevent the formation of iron(III) oxides with strongly bonded sulphate. Under the conditions of the experiment, the products were found to be mixtures of ϵ‐Fe2O3 and α‐FeOOH. The occluded sulphate, if any, could be easily washed out with water. The hydrolysis reaction passes through an equilibrium state before coming to completion. The entropy with enthalpy of the hydrolysis corresponding to the equilibrium state were found to be 4 e.u. and 0·5 kJ/mol, respectively. The activation energy of the hydrolysis reaction was found to be 21 kJ/mol.