bluuebunny/crossref_metadata_2025_split huggingface dataset:
Experimental and simulation studies on intermittent aeration in an oxidation ditch
Authors: Terashima Yutaka , Ozaki Hiroaki , Hashim Mohd A. 
Published: July 2010

AbstractThe simultaneous removal of nitrogen and organic substances can be enhanced by establishing an anoxic stage through intermittent aeration in the oxidation ditch system. In this study, investigations on substrate removal and the optimal operating conditions of a laboratory‐scale oxidation ditch system with intermittent aeration were carried out using synthetic wastewater. Up to 96% of the carbonaceous substances and 93% of total nitrogen were removed. A theoretical model developed for this system gave good agreement with the experimental data.
Interfacial mass transfer in extraction of amino acid by aliquat 336 in organic phase
Authors: Uddin Mohammad S. , Hidajat Kus , Lim Bee‐Gim , Ching Chi‐Bun 
Published: July 2010

AbstractReactive extraction of L‐phenylalanine from alkaline aqueous solution into xylene in the presence of tri‐octyl‐methyl‐ammonium chloride (ALIQUAT 336) as complexing agent was studied using a stirred transfer cell. The study investigated the effects of carrier concentration and temperature on mass transfer rates. Transfer rate across the interface in the presence of surfactant molecules was also studied. A two‐film model was proposed by considering film mass transfer resistances at the aqueous and organic phases. The model predicted adequately the experimental time‐concentration data at different carrier concentrations and temperatures. The model was modified to take into account the presence of surfactant in the organic phase.
Thermodynamics and kinetics of lipase catalysed hydrolysis of oleyl oleate
Authors: Rostrup‐Nielsen Thomas , Pedersen Lars Saaby , Villadsen John 
Published: July 2010

AbstractThe kinetics of enzymatic hydrolysis of oleyl oleate in the boundary layer between stagnant organic and aqueous phases was studied using a commercial lipase preparation which was dissolved in the aqueous phase. Three aspects of the reaction were investigated. (1) The hydrolysis equilibrium in the organic phase cannot be expressed in terms of the concentrations of ester, alcohol and organic acid alone since the activity of the organic compounds changes dramatically with conversion, i.e. with the water content in the organic phase. An empirical correlation that accounts for the water activity and the unknown activity coefficients of the organic compounds is determined. (2) The influence of the interfacial area was examined, and it was found that the amount of ester converted per unit area of interface is independent of the available interfacial area and of the amount of ester. (3) The inhibition of the reaction by the hydrolysis products and by n‐alkanes was measured. Both acid and alcohol inhibit the hydrolysis reaction while the influence of long‐chained alkanes is very small.It is concluded that the reaction rate is determined by the interfacial concentrations, and that these concentrations differ from the bulk concentrations because of the different surface affinities of the components.
A convenient preparative method of unsymmetrical ketones and aliphatic aldehydes by thermolysis of homoallylic alcohols
Authors: Inaba Teruhiko , Sakamoto Masami , Watanabe Shoji , Takahashi Ikufumi , Fujita Tsutomu 
Published: July 2010

AbstractThe thermolyses of various homoallylic alcohols, which are prepared from 1‐alken‐4‐ones (B) by Grignard reaction or reduction, afforded unsymmetrical ketones or aliphatic aldehydes in good yields. For example, the reaction of methylmagnesium iodide with 1‐nonen‐4‐one (1) gave 4‐methyl‐1‐nonen‐4‐ol (2) in 87% yield. The thermolysis of (2) at the temperature of 753 K gave 2‐heptanone (3) in 92% yield. By use of this method, we obtained a variety of 1‐alken‐5‐ones (J) which can be used as important intermediates of the preparation for dihydrojasmone or cis‐jasmone.
Liquid‐phase oxidation of anthracene in acetic acid with an oxygen/Nitric acid system
Authors: Das C. K. , Das N. S. 
Published: July 2010

AbstractOxidation of anthracene in acetic acid by the oxygen/nitric acid system has been studied and an attempt has been made to ascertain a practical limit of the amount of solvent keeping the commercial prospects in view. The effects of other reaction parameters such as flow rate, amount of nitric acid and water, residence time, etc., have been investigated. While opting for a solvent/substrate ratio of 10, the optimum conversion of anthracene to anthraquinone free from nitro‐compounds has been found to be 91% with purity of 98.7%, acceptable to dye‐stuff industries.
Studies on the synthesis of norbornadiene
Authors: Sen A. K. , Kumar Ramesh , Lal Darshan , Srivastava A. K. 
Published: July 2010

AbstractThe dimers and trimers of norbornadiene have a unique polycyclic strained structure and are of great practical value. A systematic study of the synthesis of norbornadiene from dicyclopentadiene and acetylene under pressure has been carried out. The effects of various operating parameters on product distribution have been determined. The optimum conditions for the synthesis are: (i) temperature, 290°C; (ii) residence period, 16 min; (iii) mole ratio of C2H2:N2: dicyclopentadiene, 1:1:0.4; and (iv) initial pressure at ambient temperature, 8.894 × 105 nm−2. Under these conditions the conversion of norbornadiene is 41.74% on the basis of dicyclopentadiene consumed. The loss of dicyclopentadiene due to polymerisation has been estimated from its balance.A kinetic study of the synthesis from cyclopentadiene has also been carried out.
Enzymatic saccharification of canola meal
Authors: Gattinger Loni D. , Duvnjak Zdravko , Khan Waheed A. 
Published: July 2010

AbstractFor the enzymatic saccharification of canola meal by enzyme preparations from Trichoderma reesei as well as by commercially available hemicellulase and multienzyme preparations, a pretreatment consisting of autoclaving is necessary. These enzyme preparations hydrolysed over 20% (w/w) of pretreated canola meal, which constitutes over 70% saccharification of the total polysaccharides present in canola meal. The results show that saccharification of canola meal is mainly brought about by hemicellulases capable of degrading arabinogalactan, arabinoglucan, galactan and galactomannan, while cellulases and xylanases play a minor role. These hemicellulases were found to be more stable at 50°C than cellulases or xylanases. This pretreatment also released water‐soluble polysaccharides consisting mainly of arabinose and glucose. Trichoderma reesei was unable to produce enzymes capable of hydrolysing this polysaccharide when cultivated on canola meal as substrate.
Design and operation of anaerobic digesters using multi‐objective optimization criteria
Authors: Videla Sebastian , Chamy Rolando , Navarrete Eduardo , Lema Juan M. 
Published: July 2010

AbstractA methane fermentation system can be considered as a multi‐objective optimization problem characterized by conflicting objectives such as investment cost, net biogas production and chemical oxygen demand (COD) removal. To this end, a k‐objective ‐constraint method was used to determine the optimal design and operation parameters of a continuously stirred anaerobic digester. This equipment treats leachates from the controlled solid urban wastes landfill at Garraf (Barcelona, Spain), which receives 5–6 × 105 tonnes of wastes per year. The optimal solutions were generated for two design criteria: (a) reduction of cost to a minimum and (b) maximization of net energy production with at least 75% removal of COD. The preferred solution was obtained by using the non‐inferior solution set.
Development of a chromatographic process for largescale purification of staphylococcal enterotoxin B
Authors: Johansson Hans J. , Pettersson Torbjörn N. , Berglöf Jan H. 
Published: July 2010

AbstractA process for large‐scale purification of staphylococcal enterotoxin B (SEB) is presented. The process consists of three chromatographic steps. The first two steps are based on ion‐exchange chromatography and the final one on gel filtration.Diluted culture supernatant (2000 dm3) with a SEB content of 0.4 mg dm−3 were processed and purified. SEB was obtained in 1.5 dm3 of 0.1 mol dm−3 ammonium hydrogen carbonate buffer, pH 8.0. The final product produced a single band on SDS polyacrylamide gel electrophoresis and a single peak when subjected to analytical gel filtration. The overall recovery was 74%.
Synthesis and biological activity of some 5‐substituted aminomethyl‐8‐hydroxyquinoline‐7‐sulphonic acids
Authors: Yanni A. S. , Mohharam A. M. 
Published: July 2010

Abstract5‐Aryl (or alkyl)‐8‐hydroxyquinoline‐7‐sulphonic acids have been prepared by the Mannich reaction of 8‐hydroxyquinoline‐7‐sulphonic acid with primary and secondary amines. Their bactericidal activities have been determined.
Studies on amalgam electrodes. The reaction of but‐1‐yn‐3‐ol at copper amalgam
Authors: Lee J. B. , Boardman W. , Edwards G. S. 
Published: July 2010

AbstractThe copper amalgam electrode can be used for clean oxidative coupling of but‐1‐yn‐3‐ol in good yield. An electrochemically generated intermediate can be further coupled in a solution process by aeration of the electrolyte giving increased yields. Addition of pyridine depresses coulombic yields in the electrochemical system, although it increases the rate of the purely chemical process.
Separation and concentration processes of solutions of Co(II), Ni(II), Cr(III), Fe(III) and Mn(II) by extraction with toluene‐dissolved rosin
Authors: Gomez S. Jimenez , Valdivia L. M. Lopez , Iglesias C. Gonzalez , Selas M. I. Rico 
Published: July 2010

AbstractThe extraction and stripping of Co(II), Ni(II), Cr(III) and Fe(III) from aqueous solutions by rosin dissolved in toluene has been investigated. Results obtained show that rosin is better extractant than abietic or n‐lauric acids under comparable conditions.From these results, and the data of Mn(II) solvent extraction studied previously under the same conditions, a separation and concentration process for these five cations in aqueous solutions has been designed. Saturated solutions of Fe(III), Cr(III), Mn(II) and finally Co(II) and Ni(II) have been obtained successively by extraction and stripping, by addition of ammonium hydroxide to obtain the appropriate pH value, and by modifying adequately the organic phase/aqueous phase volume ratio.
Synthesis of arylazopyrazolo[1,5‐a]pyrimidines and their application to synthetic fibres
Authors: Rangnekar Dinesh W. , Puro Sanjay S. 
Published: July 2010

Abstract4‐Phenyl‐5‐aminopyrazole 2 obtained from phenylcyanoacetaldehyde 1 and hydrazine hydrate reacted with diethyl malonate to give 3‐phenyl‐5,7‐dioxopyrazolo[1,5‐a]pyrimidine 3, used as the key compound in the synthesis of arylazo dyes. The key compound 3 was coupled with various aryldiazonium salts 4 to yield 3‐phenyl‐7‐hydroxy‐6‐arylazopyrazolo[1,5‐a]pyrimid‐5‐ones 5. The resulting arylazo dyes (5) were refluxed in phosphorus oxychloride to give 3‐phenyl‐5,7‐dichloro‐6‐arylazo‐pyrazolo[1,5‐a]pyrimidines 6, which subsequently reacted with refluxing morpholine and piperidine to yield 3‐phenyl‐5,7‐bis(morpholino and piperidino)‐6‐aryiazopyrazolo[1,5‐a]pyrimidines 7. The arylazo dyes 5 and 7 were applied to polyester fibres as disperse dyes and the arylazo dyes 6 were applied to polyamide fibres as disperse reactive dyes. The spectral and dyeing properties of the dyes were studied.
Biosorption of Radionuclides by Fungal Biomass
Authors: White Christopher , Gadd Geoffrey M. 
Published: July 2010

AbstractFour kinds of bioreactor were evaluated for thorium removal by fungal biomass. Static‐bed or stirred‐bed bioreactors did not give satisfactory thorium removal probably because of poor mixing. An air‐lift bioreactor removed approximately 90–95% of the thorium supplied over extended time periods and exhibited a well‐defined breakthrough point after biosorbent saturation. The air‐lift bioreactor promoted efficient circulation and effective contact between the thorium solution and the mycelial pellets. Of several fungal species tested, Rhizopus arrhizus and Aspergillus niger were the most effective biosorbents with loading capacities of 0.5 and 0.6 mmol g−1 respectively (116 and 138 mg g−1) at an inflow thorium concentration of 3 mmol dm−3. The efficiency of thorium biosorption by A. niger was markedly reduced in the presence of other inorganic solutes while thorium biosorption by R. arrhizus was relatively unaffected. Air‐lift bioreactors containing R. arrhizus biomass could effectively remove thorium from acidic solution (1 mol dm−3 HNO3) over a wide range of initial thorium concentrations (0.1–3 mmol dm−3). The biotechnological application and significance of these results are discussed in the wider context of fungal biosorption of radionuclides.
Recovery of Metal Ions by Microfungal Filters
Authors: Wales David S. , Sagar Brian F. 
Published: July 2010

AbstractMany microfungi contain chitin/chitosan as an integral part of the cell wall structure. The binding of toxic and heavy metal ions by chitosan or partly deacetylated chitin is a direct consequence of the base strength of the primary amine group and is most effective for those metals that form complexes with ammonia. Of the microfungi studied, hyphae from Mucor mucedo and Rhizomucor miehei, after treatment with hydroxide to expose the chitin/chitosan, were found to be most effective in the capture of metal ions. Chemically treated mycelia have so far been shown to bind silver, zinc, lead, copper, nickel, cobalt, cadmium, iron and chromium, with the efficiency of metal‐ion binding apparently being inversely proportional to the valency state of the metal ions to be bound.Wet‐laid papers produced from mixed slurries of treated mycelia and various conventional paper‐making and textile fibres have exceptionally good tensile‐ and bursting‐strength properties, particularly in the wet state. Papers containing 1 g treated mycelia removed up to 90% of various metal ions in solution (50 cm3, 7–5 mmol dm−3) with flow rates of 0.5 cm3 cm−2 min−1. However, the total metal‐ion binding capacities of single‐thickness microfungal papers are limited under constant flow conditions. The total volume flowing through the system before metal‐ion breakthrough occurs increases in direct proportion to the number of sheets of microfungal paper but the concomitant reduction in flow rates becomes a limiting factor. Mycelia‐containing structures that allow efficient metal‐ion binding at commercially acceptable flow rates are currently being investigated.
Review of biotechnology applications to nuclear waste treatment
Authors: Ashley Nicholas V. , Roach Daniel J. W. 
Published: July 2010

AbstractThis paper gives an overview of the feasibility of the application of biotechnology to nuclear waste treatment. The contents are based on a report which PA Technology carried out for the Department of the Environment (DoE Reference: DoE/RW/88.008 Sector No 2.3).Many living and dead organisms accumulate heavy metals and radionuclides. The controlled use of this phenomenon forms the basis for the application of biotechnology to the removal of radionuclides from nuclear waste streams. Indeed, biotechnology offers a series of new opportunities for removal of radionuclides from dilute aqueous process effluents. Such technology is already used for heavy metal removal on a commercial basis and could be optimised for radionuclide removal.An overview of biotechnology areas, namely the use of biopolymers and biosorption using biomass applicable to the removal of radionuclides from industrial nuclear effluents is given. The potential of biomagnetic separation technology, genetic engineering and monoclonal antibody technology is also to be examined. The most appropriate technologies to develop for radionuclide removal in the short term appear to be those based on biosorption of radionuclides by biomass and the use of modified and unmodified biopolymers in the medium term.
Metal recovery using chitosan
Authors: Onsosyen Edvar , Skaugrud Osyvind 
Published: July 2010

AbstractChitosan is a natural polycationic polymer which possesses valuable properties as a metal recovering and water purifying agent. Applications are—waste water treatment for heavy metal and radio isotope removal and valuable metal recovery,—potable water purification for reduction of unwanted metals,—agriculture—controlled release of trace metals essential to plant growth,—food—complex binding of iron in precooked food to reduce ‘warmed‐over flavour’.The interactions of metals with chitosan are complex, probably simultaneously dominated by adsorption, ion‐exchange and chelation. To study this it is of utmost importance to work with well characterized chitosans. This has been a problem as available characterizing methodology is limited.Degree of polymerization and deacetylation and the distribution of acetyl groups along the polymer chain is of crucial importance for chitosan metal interacting characteristics. Making chemical derivatives is a way to alter the metal interacting characteristics of chitosan.Chitosan possesses general coagulant/flocculant characteristics towards bio‐molecules and surfaces.
Contribution of endo‐ and exocellular glucose oxidase to gluconic acid production at increased dissolved oxygen concentrations
Authors: Traeger M. , Qazi G. N. , Onken U. , Chopra C. L. 
Published: July 2010

AbstractFor gluconic acid fermentation with Aspergillus niger oxygen‐enriched air was used to increase dissolved oxygen concentration during the production phase from c. 30% to 100% saturation related to air at 1 bar. At the highest dissolved oxygen concentration the activity of glucose oxidase increased more than three‐fold. At the same time, the gluconic acid production rate increased by a factor of two. During the fermentations, glucose oxidase was present endocellularly as well as exocellularly; the presence of this enzyme in the broth was due to a controlled secretion. It was found that the two fractions of the enzyme showed different activities in their contribution to overall acid production. Due to a limitation of oxygen diffusion into the mycelial pellets, activity of endocellular enzyme was reduced by 50–80%. However, since the major part of the enzyme was present in the pellets the action of endocellular glucose oxidase is not negligible. This latter factor must be taken into consideration when optimizing bioreactor design.
Conversion of methanol on silicoaluminophosphate—formation of hexamethylbenzene and olefins
Authors: Das Jagannath , Bhattacharya Anjana , Goswami Tarun K. , Roy Sisir K. 
Published: July 2010

AbstractThe catalytic conversion of methanol over new generation molecular sieve silicoaluminophosphate of type 5 (SAPO‐5) has been studied. The formation of gaseous, liquid and solid hydrocarbons have been observed. While the gaseous hydrocarbon contains 32·5–56·7 wt% of olefins, the liquid product comprises hydrocarbons in the boiling range 98°C‐320°C as determined by gas chromatographic distillation technique. The solid hydrocarbon was identified as hexamethylbenzene by physical, chemical and spectral analysis.
Optimal feed temperature for an immobilized enzyme packed‐bed reactor
Authors: Lin Sheng H. 
Published: July 2010

AbstractOptimal feed temperature was determined for a nonisothermal immobilized enzymatic reaction with enzyme deactivation in a packed‐bed reactor. The optimal feed temperature was obtained by maximizing the average substrate conversion over a given reaction period. Simulation showed the optimal feed temperature to be strongly dependent on the flow dispersion, the reaction activation energy, the corresponding enzyme inactivation energy and the heat of reaction. It was also observed that in a plug flow reactor the enzyme reaction generally exhibited a lower optimal feed temperature and higher substrate conversion than in a continuously stirred tank reactor.
One‐step oxidation of cyclohexane to adipic acid
Authors: Kulsrestha Girendra N. , Shankar Uma , Sharma Jaipal S. , Singh Jasvinder 
Published: July 2010

AbstractLiquid‐phase oxidation of cyclohexane with Co(III) catalyst and gaseous oxygen was found to be influenced by reaction temperature, catalyst concentration and the duration. Maximum adipic acid product selectivity (77%) with about 85% cyclohexane conversion was attained at 100°C using catalyst: cyclohexane molar ratio 0·08. Under these conditions more than 80% cyclohexane was converted in the first hour, although selectivity to adipic acid continued to increase for the next 5 h. Cyclohexyl acetate and cyclohexyl monoadipate were identified as important intermediates. This study supports the mechanism proposed by Schultz, J. G. D. and Opchenko, A., J. Org. Chem., 38 (21) (1973) 3729.
Preparation of battery‐grade manganese dioxide through disproportionation of partially oxidised hydrous manganese oxide in dilute sulphuric acid
Authors: Kanungo S. B. 
Published: July 2010

AbstractManganese hydroxide was precipitated from MnSO4 and NH4OH at controlled pH, partially oxidised by aeration and finally calcined at 573–623 K to yield manganese oxide with oxidation state between +3 and +4. When the calcined oxide was leached in dilute sulphuric acid, MnO2 of high electrochemical activity was obtained. In order to improve the bulk or packing density of the product various oxidants were added during the aerial oxidation of the Mn(OH)2 slurry and also during the leaching in dilute H2SO4. It was observed that the best results were obtained when active MnO2 was added during the aerial oxidation of Mn(OH)2 slurry.
The production of propionic acid from sugars by fermentation through lactic acid as an intermediate
Authors: Tyree Ralph W. , Clausen Edgar C. , Gaddy James L. 
Published: July 2010

AbstractAs an alternative to propionic acid production from sugars by species of propionibacteria, propionic acid may be produced from sugars through lactate as an intermediate. Propionibacteria are actually able to utilize lactate as a substrate much more rapidly than glucose. In this study, Lactobacillus xylosus and Propionibacterium shermanii were utilized to convert glucose and xylose to propionate through lactate as an intermediate. Pure culture batch studies were carried out to obtain fermentation parameters for the two cultures. The pure cultures were then combined in a mixed culture series arrangement designed to prevent nutrient limitation. Finally, propionic acid production from lactate was demonstrated in a cross‐linked immobilized cell reactor using lactate added to the medium and produced by L. xylosus in a continuous stirred tank reactor. Productivities of 14 g dm−3 h−1 at a 9 min residence time (2·1 g dm−3 propionate) and 2 g dm−3 h−1 at a 9·9 h residence time (19·7 g dm−3 propionate) were obtained without pH control.
A high containment polymodal pilot‐plant fermenter—design concepts
Authors: Hambleton Peter , Griffiths J. Bryan , Cameron D. Ross , Melling Jack 
Published: July 2010

AbstractA 225 dm3 pilot‐plant bioreactor system has been designed and constructed that is suitable for biohazardous fermentations. The design enables operation at containment levels above the requirements of good industrial large‐scale practice (GILSP) without secondary containment of the whole plant. The main biosafety features of the systems include the use of steam barriers on O‐ring seals, supply lines and stirrer seals, multiple O‐ring seals, piping of condensate lines and pressure relief systems to a ‘kill tank’, double filtration of inlet and off gases and a mobile isolation unit that allows localised containment of sample valve and probe entry ports. The fermenter can, with minor modifications, be operated as a bottom‐ or top‐stirred reactor for the culture of microbial or animal cells, or as an airlift reactor. The design offers considerable flexibility that could prove cost‐effective for process development and production.The relevance of the various design features to enable bioreactor operations at pilot‐plant scale to be carried out in compliance with current guidelines for large‐scale culture of recombinant microorganisms and microbial pathogens is discussed.