bluuebunny/crossref_metadata_2025_split huggingface dataset:
Removal of phosphate by foam‐immobilized Phormidium laminosum in batch and continuous‐flow bioreactors
Authors: Garbisu Carlos , Hall David O. , Serra Juan L. 
Published: July 2010

AbstractFree‐living and polyvinyl foam‐immobilized cells of Phormidium laminosum were studied for their phosphate uptake characteristics. Initial phosphate uptake rates yielded hyperbolic curves when plotted against the external phosphate concentration, indicating the existence of a saturatable transport system. The phosphate uptake rates of N‐starved free‐living cyano‐bacteria were also examined and showed that N‐starvation led to lower uptake rates. The addition of nitrate to N‐starved cyanobacteria markedly increased phosphate uptake.Phosphate uptake by free and immobilized cyanobacteria was inhibited in the dark and stimulated by the presence of calcium ions or bicarbonate. No phosphate uptake was observed when a chelating agent, such as ethylenediaminetetraacetic acid (EDTA), was added to the cultures.Several bioreactors were established for initial studies in using immobilized cyanobacteria for the removal of phosphate from water. Three different types of batch fluidized‐bed, as well as two continuous‐flow bioreactors (i.e. fluidized‐ and packed‐bed), were examined. Although cyanobacteria immobilized on the polymer foams did not show high phosphate uptake efficiencies, simultaneous removal of nitrate and phosphate from water by means of N‐starved immobilized cyano‐bacteria appeared to be a promising possibility for future development.
Biotechnology and pollution monitoring: Use of molecular biomarkers in the aquatic environment
Authors: Livingstone David R. 
Published: July 2010

AbstractMetals and organic contaminants, present in the water‐column, sediment or food, are readily accumulated by aquatic organisms. Exposure to and toxic effects of contaminants can be measured in terms of the biochemical responses of the organisms—so‐called molecular biomarkers. The applications, advantages and limitations of such diagnostic and prognostic tests are discussed. The hepatic biotransformation enzyme cytochrome P4501A in fish and other vertebrates is specifically induced by organic contaminants such as aromatic hydrocarbons, PCBs and dioxins, and is used as a biomarker of exposure to organic pollution. Its induction is involved in chemical carcinogenesis via catalysis of the covalent binding of organic contaminants to DNA (DNA‐adducts). P4501A‐induction, measured as enzyme activity, enzyme amount, or mRNA, has been successively used in many field studies, involving some 27 fish species, in USA and Europe. Metallothioneins (MTs) bind and are specifically induced by metals such as Cd, Hg, Ag and Cu, and are used in both vertebrates and invertebrates as a biomarker for metal exposure. Bulky, hydrophobic DNA‐adducts are used as a biomarker for organic contaminant damage. MTs (measured at protein and mRNA levels) and DNA‐adducts (32P‐postlabelling method) have been applied less extensively in the field than P4501A, but the results are similarly encouraging. Biomarkers should be used as part of an integrated programme of pollution monitoring, involving also general measurements of biological damage and animal health, and analysis of chemical contaminants in the biota and environment. Commercial availability of antibodies and mRNA probes will accelerate the widespread application of these molecular biomarkers.
Synthesis of monodispersed micaceous iron oxide by the oxidation of iron with oxygen under hydrothermal conditions
Authors: Uchida Satoshi , Sato Tsugio , Okuwaki Akitsugu 
Published: July 2010

AbstractThe oxidation behavior of iron powder with oxygen was investigated in 5–25 m NaOH solutions at 5 MPa of oxygen partial pressure and 130–290°C, where m = mol(kg H2O)−1. Monodispersed micaceous iron oxide, α‐Fe2O3, was synthesized by the oxidation of iron powder with 5 MPa of oxygen in 10–16 m NaOH solutions at 250–270°C. The diameter of micaceous iron oxide greatly changed depending on the reaction conditions such as the temperature, reaction time and concentrations of NaOH and coexisting ions.
Design and operation of rotating‐disk foam‐breakers fitted to tower fermenters
Authors: Takesono Satoshi , Onodera Masayuki , Yamagiwa Kazuaki , Ohkawa Akira 
Published: July 2010

AbstractThe design and operation of rotating‐disk mechanical foam‐breakers (MFRDs) fitted to tower fermenters, i.e. bubble columns (BCs), treating various foaming liquids were studied. The foam‐breaking behaviour of MFRDs fitted to BCs and the foaming behaviour of BCs were investigated respectively from the changes in the required critical disk rotational speed Nc and those in liquid hold‐up in the foam, øL. The effects of operating conditions on Nc and øL were evaluated quantitatively. On the basis of their results, the empirical equations for predicting Nc and øL in foam‐breaking regions, useful for the design and operation of MFRDs fitted to BCs, were obtained. The level of the required foam‐breaking power Pkc of MFRDs was also clarified in relation to the level of øL which reflects the foaming intensity of BCs and is related to the difficulty of foam‐breaking.
Optimization of the synthesis of furanic polyols from hemicellulose hydrolyzates leading to a route to l‐arabinose as a by‐product
Authors: Bonzon Valérie , El‐Mahdi Halima , Rigal Luc , Borredon Marie‐Elisabeth 
Published: July 2010

AbstractExtending the synthesis of furanic polyols to mixtures of sugars representative of hemicellulose hydrolyzates leads to important yields of furanic polyols of glucose and xylose together with high yields of unreacted L‐arabinose.
Microencapsulation of silicone oils within polyamide—polyethylenimine membranes as oxygen carriers for bioreactor oxygenation
Authors: Poncelet Denis , Leung Ricky , Centomo Liana , Neufeld Ronald J. 
Published: July 2010

AbstractSilicone oils were microencapsulated within polyamide (nylon) membranes cross‐linked with polyethylenimine. Solubility of oxygen within the silicones, whether encapsulated or not, was approximately 6 mmol dm−3, representing solubilities approximately 20‐fold higher than that of oxygen in water. The response time of oxygen transfer from the microencapsulated oxygen carrier was less than 2.5 s; a more precise measurement was limited by the response time characteristics of the oxygen probe. Assuming that the bioreactor volume consists of 10–20% (v/v) microencapsulated silicone oil, this represents an enhancement of the oxygen reservoir by a factor ranging from 4 to 7 and improvement in oxygen transfer rates greater than 15‐fold due to the greatly increased specific surface area in comparison to conventional bubble aeration. Circulation of oxygenated silicone oils encapsulated within inert polymeric membranes may provide an efficient alternative to bioreactor oxygenation with shear sensitive cell systems, or in fermentations with high oxygen requirements.
Photodecomposition of 2,4‐dichlorophenoxyacetic acid: Influence of pH
Authors: Chamarro Esther , Esplugas Santiago 
Published: July 2010

AbstractThe photodecomposition of 2,4‐dichlorophenoxyacetic acid (2,4‐D) in aqueous solutions has been studied by using ultraviolet radiation in an annular batch reactor. The dark reactions were negligible. For short irradiation times, a first order reaction was found with respect to the absorbed radiation and a simple mechanism of this reaction at initial times has been proposed. pH influences the reaction rate only for long times of irradiation, possibly due to the formation of humic acids in the reaction medium.
Mass transfer and reaction of trimethylamine in a three‐phase biological reactor
Authors: Partidário P. J. , Carrondo M. J. T. 
Published: July 2010

AbstractA model system, consisting of a mixed culture of microorganisms, was used to study the performance of a bench‐scale packed bed bubble column (PBC) bioreactor treating trimethylamine. Three mesophilic bacterial strains were selected, mixed and acclimatized to grow with trimethylamine as the sole carbon source; degradation kinetic constants were determined for a bacterial suspension system. Gas transfer to the liquid phase was modelled in order to characterize solute transport and availability into the biofilm. The overall performance of the system is discussed based on mass transfer considerations.
Uptake and recovery of gold by immobilized persimmon tannin
Authors: Nakajima Akira , Sakaguchi Takashi 
Published: July 2010

AbstractSome attempts were made to recover gold from aqueous systems using immobilized persimmon tannin. This adsorbent adsorbed gold from solutions containing hydrogen tetrachloroaurate(III) with high efficiency, whereas there was minimal adsorption from solutions containing gold(I) sodium thiomalate and sodium dicyanoaurate(I). The adsorption of gold was rapid, and was affected by the pH of the solution, temperature, external gold concentration and amount of adsorbent. Adsorbed gold was easily desorbed with 1 mol dm−3 thiourea solution, indicating that immobilized persimmon tannin can be repeatedly re‐used for the recovery of gold using adsorption‐desorption cycles.
Xylanase production by Bacillus polymyxa
Authors: Piñaga F. , Peña J. L. , Vallés S. 
Published: July 2010

AbstractBacillus polymyxa produced high levels (12–13 U cm−3) of extracellular xylanases when grown in a complex medium containing yeast extract and oat spelt xylan as nitrogen and carbon sources respectively. Substantially lower yields of enzyme were produced during growth on the monosaccharides glucose, arabinose and xylose. Meagre growth occurred when ammonium sulphate, instead of yeast extract, was used as nitrogen source. When assayed in culture broth supernatants, xylanase showed an optimum activity in 48°C and at pH values in the range 5.0–6.5. Under such conditions, the half‐life of this xylanase preparation was 8 h. Mn2+ showed a strong inhibitory effect on the enzyme, but inhibition by EDTA (27% w/v) suggested dependence on a metallic ion. SDS‐PAGE and zymogram overlay showed that up to five separate xylanases in the range of 20 to 116 kDa were produced.
Synthesis of some new heterocyclic systems derived from 2‐acetylbenzimidazole
Authors: Hozien Zeinab A. 
Published: July 2010

AbstractThe named compound was reacted with thiosemicarbazide and/or semicarbazide to produce the corresponding condensation products II and V respectively. Reaction of II with chloroacetic acid in ethanol containing anhydrous sodium acetate yielded III. Condensation of III with aromatic aldehydes yielded the corresponding arylidene derivatives (IV). Oxidation of the semicarbazone V with selenium dioxide gave 2‐(1,2,3‐selenadiazole‐4‐yl)benzimidazole (VIa, b) while with thionyl chloride it gave 2‐(1,2,3‐thiadiazole‐4‐yl)benzimidazole (VIIa, b). The chalcones of 2‐acetyl and/or 1‐methyl‐2‐acetylbenzimidazole were condensed with hydrazine hydrate, phenylhydrazine and/or hydroxylamine to produce 2‐(5‐aryl‐1(H)‐pyrazolin‐3‐yl)‐, 2‐(5‐aryl‐1‐phenyl‐2‐pyrazolin‐3‐yl)‐ and 2‐(5‐aryl‐2‐isoxazolin‐3‐yl)benzimidazole (IX, X, XI) respectively.
Analysis of niobium, tantalum and titanium extracted from tantalite and columbite chlorination
Authors: Ruiz María Del C. , González Jorge A. , Olsina Roberto A. 
Published: July 2010

AbstractSeveral analytical methodologies have been developed for determining niobium, tantalum and titanium concentrations in the products of columbite‐tantalite chlorination from the San Luis Province (Argentina). The ore mixed with carbon was attacked with gaseous chlorine in different working conditions. Volatile products were dissolved in concentrated hydrochloric acid after being condensed when coming out of the reactor. The results obtained from molecular absorptiometry in the UV‐visible region of the spectrum, combined with previous separation of the elements studied, were satisfactory. X‐ray fluorescence, carried out on solutions from the dissolution of previously separated oxides gave results in agreement with those obtained by absorptiometry, the former methodology being more versatile than the latter. In all cases analytical results were compared with standards and the errors produced are reported.
Adsorption of disperse dye by powdered activated carbon
Authors: Lin Sheng H. 
Published: July 2010

AbstractThe purpose of this laboratory study is to investigate the effectiveness of powered activated carbon (PAC) on the removal of chemical oxygen demand (COD) and color of disperse dye and the effect of PAC particle size on the treatment efficiency. The adsorption isotherm parameters for the Langmuir, Freundlich and BET model are determined using the adsorption data. It has been found that the multilayer BET isotherm yields significantly better fit to the observed data than the monolayer ones. A simplified mass transfer model is proposed in the present work also for estimating the external mass transfer coefficient using the initial adsorption data at low PAC dosage.
Sodium inhibition and sulphate reduction in the anaerobic treatment of mussel processing wastewaters
Authors: Soto Manuel , Méndez Ramón , Lema Juan M. 
Published: July 2010

AbstractAn anaerobic filter treating high saline wastewaters from a sea food processing industry was subjected to sodium and sulphate shocks. Sodium concentrations ranging from 5 to 12 g dm−3 had no significant influence on the methane production rate, with maximum value of 15 kg COD m−3 day−1. The sulphate‐reducing capacity of the filter was estimated at 2.2 kg SO42‐ m−3 day−1. When using propionic or acetic acid as substrates, the sulphate‐reducing activities were 0.021 and 0.006 g SO42‐ g−1 VSS day−1 respectively. Determination of the methanogenic activity of the sludges indicated that sodium concentrations of 14 g dm−3 caused a 50% inhibition of the methanogenic activity from the anaerobic filter. However, when using the anaerobic filter effluent as the assay medium, the sodium concentration giving the same percent inhibition was 17.7 g dm−3, indicating a beneficial effect probably due to the antagonism caused by the presence of other sea salts. The sludge showed a higher tolerance to sodium toxicity than that reported in previous literature, which can be explained as a consequence of sludge adaptation.
Novel dyes and intermediates for synthetic‐polymer fibres: Synthesis and dyeing performance of 1‐aryl‐5‐hetarylphenylazo‐4‐hydroxypyrazole derivatives and their isomeric 1‐hetarylphenyl‐5‐arylazo analogues as disperse dyes for polyester fibre
Authors: Hanna M. A. 
Published: July 2010

AbstractIn a multi‐step synthesis, a series of 5‐arylazo‐4‐hydroxy‐1‐(substituted imidazol‐5‐on‐2‐ylphenyl)pyrazole‐3‐carboxanilide dyes (VIIIa—i), their isomeric 4‐hydroxy‐1‐phenyl‐5‐(substituted imidazol‐5‐on‐2‐ylphenylazo)pyrazole‐3‐carboxanilide analogues (XIIa—i) and a related series of 4‐hydroxy‐1‐phenyl‐5‐(substituted oxazol‐5‐on‐2‐ylphenylazo)pyrazole‐3‐carboxanilide derivatives (XIa—h) were prepared with a view to evaluating and comparing the assessment of their dyeing performance on synthetic polymer fibres. Fastness ratings were generally good, particularly for the imidazolonylphenylazo series (XIIa—i). Substituents of the latter type are of greater value in attaining optimum light fastness in these dyestuffs. The structures of the synthesized dyes were inferred from elemental and spectral data and, whenever possible, by alternative synthetic routes.
Immobilization studies of an industrial penicillin acylase preparation on a silica carrier
Authors: Fonseca L. P. , Cardoso J. P. , Cabral J. M. S. 
Published: July 2010

AbstractPenicillin acylase (EC 3.5.1.11) was immobilized by covalent binding on a silica gel carrier activated by silanization. High immobilization yields, operational stability, enzyme loading and support reutilization capacity were obtained. The effects of several variables on the activation of the support and on the immobilization method were studied.Other supports and immobilization methods were assessed for the immobilization of penicillin acylase and compared with the basic process used.Activity versus temperature, pH, buffer molarity and penicillin concentration profiles were determined and compared for the free, crosslinked and covalently‐bound silica carrier penicillin acylase preparations.The hydrolysis performance of the latter preparation was assessed in a batch basket reactor and the time course of the hydrolysis reaction modelled by a two parameter model equation.The operational stabilities of penicillin acylase coupled covalently to the silica gel support and immobilized by a crosslinking procedure using glutaraldehyde were also compared.
Macro‐scale modelling of substrate removal kinetics in multicomponent fixed‐film systems
Authors: Tanik A. , Orhon D. , San H. A. 
Published: July 2010

AbstractDesign of aerobic fixed‐film systems is generally performed using a traditional chemical reactor theory which accounts for changes in both substrate and biomass concentration. As most of these systems do not behave as ideal reactors, the theoretical evidence clearly shows that the variation and impact of biomass cannot be accounted for by a single reactor concept. Refinements reported in the literature concerning the fate of soluble substrate are modified in this study to also include the variation of biomass viability for different substrate concentration along the aerobic reactor. Evaluations show that a multi‐stage modelling biofilm performance is likely to be a much more reliable predictive tool for removal efficiencies.
Use of red mud for toxic metals removal: The case of nickel
Authors: Zouboulis Anastasios I. , Kydros Konstantinos A. 
Published: July 2010

AbstractThe presence of red mud was found to remove effectively nickel ions from dilute aqueous solutions (50 mg dm−3). Red mud, being an industrial solid by‐product/waste from alumina production during bauxite processing, was found to act simultaneously as an alkalinity regulator, causing precipitation of nickel as the insoluble hydroxide, as an adsorbent of the formed nickel hydroxide and as a flocculant of the resultant fine particulate matter. Sedimentation was subsequently considered as a possible solid/liquid separation technique. Various parameters, such as dispersion pH, red mud and nickel concentrations and ζ‐potential, were examined and promising results were obtained.
Application of ‘forward mixing’ model to the low interfacial tension system n‐butanol—succinic acid—water in rotating disc contactor liquid extraction columns
Authors: Korchinsky Walter J. , Bastani Daryoush 
Published: July 2010

AbstractPreviously published techniques for acquisition of experimental data, with dispersed phase hold‐up, drop size distributions and solute concentration profiles measured for all runs, and for generation of the relevant ‘forward mixing’ model parameters, have been applied to the low interfacial tension, high dispersed phase viscosity, system n‐butanol—succinic acid—water. The data, and generated parameter values, were consistent with previous data for toluene—acetone—water, with the main exception being the change in distribution of mass transfer resistances predicted by the Handlos—Baron model. Though overall mass transfer coefficients generated were of the same order as for the toluene—acetone—water system, the dominant resistance was predicted to be in the dispersed, rather than the continuous, phase. The influence of dispersed phase viscosity is incorrectly predicted by the Handlos—Baron model, which must be modified, or replaced, to correctly predict this influence. Data on other systems, with viscosity intermediate between the two systems used to date, are to be obtained. Continuous phase axial mixing influences are much higher than predicted by published correlations.
Application of five‐state structured models for growth and secondary metabolite production in cultures of Nicotiana tabacum
Authors: Shibasaki Naomi , Yonemoto Toshikuni , Tadaki Teiriki 
Published: July 2010

AbstractA new structured model was constructed and applied to batch suspension cultures of Nicotiana tabacum in an airlift bioreactor with a draught tube. This model was developed by modifying the structured model proposed by Bailey and Nicholson1,2 for cultures of Catharanthus roseus cells. In this model, a plant cell was considered to consist of a vacuole and non‐vacuole. A secondary metabolite was also assumed to be synthesized by viable cells and stored at a constant concentration in the vacuole. Parameters for the model equations were estimated based upon experimental data using numerical optimization techniques. The simulated results using these parameters showed that the present model was superior to the earlier model for describing growth and product synthesis during all culture periods for the tobacco cell cultures.
Adsorption of disperse dye by various adsorbents
Authors: Lin Sheng H. 
Published: July 2010

AbstractLaboratory investigations of C.I. Disperse Red 60 adsorption on molecular sieves, activated alumina, granular activated carbon (GAC), diatomite and sawdust were conducted in this study. The effectiveness of those adsorbents for pollutant removal and color reduction of disperse dye was examined and compared with that of powdered activated carbon (PAC). It was found that the activated alumina has only 61% COD removal efficiency in comparison with that of PAC while those of molecular sieves, GAC and diatomite are much lower. In terms of color removal, activated alumina and molecular sieves are as effective as PAC while GAC, diatomite and sawdust are much less effective. The monolayer Langmuir isotherm was found to represent well the measured adsorption data and the constant parameters of the adsorption isotherm were determined for all adsorbents. The simplified mass transfer model proposed previously was also used for estimating the mass transfer coefficients using the initial adsorption data for several adsorbents.
An automatic dehydrogenase‐based flow‐injection system: Application for the continuous determination of glucose and lactate in mammalian cell‐cultures
Authors: Becker T. , Schuhmann W. , Betken R. , Schmidt H.‐L. , Leible M. , Albrecht A. 
Published: July 2010

AbstractA concept for the development of an automatic flow‐injection analyzer with integrated dehydrogenase columns and its application in the control of industrial processes is presented. The system is based upon a kernel consisting of a nested‐loop injection unit, pumps for the filling of the injection loops and the transport of buffer and valves for switching on the one hand between sample and standard solutions and on the other hand between different enzyme columns. A Microsoft Windows 3.x application ‘WIN‐FIA’ controls interactively the whole system and can be easily adapted to a specific solution of an analytical problem. As an example, the flow‐injection system was used for the continuous determination of glucose and lactate, using glucose dehydrogenase (GDH) and lactate dehydrogenase (LDH) as indicator enzymes, in a mammalian cell‐culture fermentation process. The resulting concentration values are in good agreement with those obtained by discontinuously taken standard spectrophotometric enzyme assays.
Vegetable composts for sea water uranium extraction
Authors: Marzotto Armando , Montoneri Enzo , Savarino Piero , Viscardi Guido , Croatto Ugo 
Published: July 2010

AbstractComposting wood or crop residues by the addition of tanneries sludge as nitrogen supplement yields products having lower polysaccharides and protein content, but higher relative concentration of lignin material than the starting mixture. When used as sea water uranium adsorbents, the compost products exhibit higher uranium uptake (3.0–100 μg g−1) than parent ligno‐cellulosic materials (0.3–9 μg g−1), thus achieving over 104‐fold uranium concentration relative to sea water. An additional distinguishing feature is the strong pH effect observed on uptake by products. The results are consistent with the expected change of parent lignin to lignin‐humus in the compost product.