bluuebunny/crossref_metadata_2025_split huggingface dataset:
Styrene degradation along the bed height of perlite biofilter
Authors: Paca Jan , Koutsky Bohumil , Maryska Martin , Halecky Martin 
Published: September 2002

AbstractThe whole bed height of a biofilter was divided into four individual reactor stages in series. This configuration permits a measurement of the leachate pH of each stage individually and minimizes interstage mixing of the immobilized culture. The extent to which the residence time of pollutant in the filter bed influenced biodegradation characteristics and the composition of immobilized culture under conditions of a constant loading rate was studied using a perlite biofilter having an internal diameter of 50 mm and the bed height of each stage being 27 cm. The residence time of pollutant in the bed had no influence on the removal efficiency and the elimination capacity of the whole biofilter although some changes of these parameters in the individual stages were observed. The biofilter achieved an elimination capacity of 140 gm−3 h−1 at removal efficiencies greater than 90%. Degradation activity decreased the pH value of the leachate to 3.5–3.0. Microbial analyses showed that styrene was degraded by eukaryotic cells at low pH values. At pH values above 4.0 prokaryotes were also present in the mixed culture.© 2001 Society of Chemical Industry
Neutralization of acid mine drainage by Turkish lignitic fly ashes; role of organic additives in the fixation of toxic elements
Authors: Polat Mehmet , Guler Erkan , Akar Gul , Mordogan Hasan , Ipekoglu Uner , Cohen Haim 
Published: September 2002

AbstractLignitic fly ashes from two power plants in western Turkey were employed to neutralize the Acid Mine Drainage (AMD) effluents originating from a pyritic ore from northern Turkey. The AMD was rich in heavy metals with a pH of about 2. The fly ash samples, on the other hand, showed strong alkalinity when mixed with water. The product was an aggregate with basic reactivity in most cases. The fly ashes were able to neutralize large amounts of AMD. When the aggregate was placed in water, notable leaching of toxic metals into solution was observed. When an organic additive, waste motor oil in this case, was added during the mixing step, the leaching of metals into water from the resulting aggregate was practically zero.© 2002 Society of Chemical Industry
Selective synthesis of zeolite briquettes from conformed ashes
Authors: García‐Martínez J , Cazorla‐Amorós D , Linares‐Solano A 
Published: September 2002

AbstractThe present study is devoted to the transformation of conformed ashes to zeolites by hydrothermal synthesis. A wide range of experimental conditions was tested to prepare selectively zeolites with different structures. Four different zeolites were synthesised: Na‐P1, analcime, cancrinite and sodalite. Stabilisation of the cancrinite phase was achieved by modification of the silica/alumina ratio of the synthesis mixture. The transformation is not restricted to the external surface of the conformed ashes, on the contrary, different techniques have shown that a homogeneous transformation is produced and its yield does not decrease due to the use of a preconformed material. The main contribution of the proposed method is that the final zeolitic material is already compacted and does not require any conformation step or the use of a binder.© 2002 Society of Chemical Industry
Binders based on cement/glassy combustion residues for the stabilisation/solidification of industrial wastes
Authors: Irabien Angel , Fernández Olmo Iñaki , Andrés Ana 
Published: September 2002

AbstractStabilisation/solidification (S/S) of industrial wastes is a widespread technology, which is commonly applied to the technical management of industrial wastes. One of the main drawbacks of the technology is the use of valuable raw materials. This technology has been adopted as one of the BAT technologies (US EPA) for the management of some industrial wastes. Taking into account that cement/glassy combustion residues have been assumed to be one of the possibilities for the design of environmentally friendly construction materials, the evaluation of new formulations to reduce the amount of cement in S/S processes is discussed. Nearly 600 cement/coal fly ash/waste products, extracted from a cement/waste database named MONOLITH, have been analysed, taking into account the main technical and environmental properties of the wastes treated by these binders.© 2002 Society of Chemical Industry
Modelling of the glass phase in fly ashes using network connectivity theory
Authors: Towler Mark R , Stanton Kenneth T , Mooney Patrick , Hill Robert G , Moreno Natalia , Querol Xavier 
Published: September 2002

AbstractThe amorphous phase of fly ash dominates degradation behaviour because glass has a higher potential energy than the equivalent crystal structure and the variation of bond angles and distances in a glass make the bond breakage easier. It would be advantageous to predict the presence and subsequent degradability of glass on the basis of the solid‐state chemistry of the fly ash. To this end, and inorganic polymer model was applied to a selection of European fly ashes to determine the value known as cross‐link density (CLD). A cross‐link density value of less than two implies that the material is amorphous in nature and the lower the CLD below two, the greater the reactivity and solubility of the glass. Applying this model may facilitate the selection of the most suitable fly ash for a particular recycling application where glass reactivity or dissolution rates are important. To check the applicability of the model to the glass phase of fly ashes, CLD calculations have been performed by removing the contribution to the ash composition from the known crystal phases. The model would be then expected to give a maximum CLD value of two for all the materials. While this approach has been applied successfully to synthetic glasses and glass‐ceramics in the past, only very limited applicability has been found with fly ashes. This is believed to be due to the inherent heterogeneity of the glass phase in fly ash.© 2002 Society of Chemical Industry
Utilisation of zeolitised coal fly ash as immobilising agent of a metallurgical waste
Authors: Fernández‐Pereira Constantino , Galiano Yolanda Luna , Rodríguez‐Piñero Miguel Angel , Vale José , Querol Xavier 
Published: September 2002

AbstractIn the work described in this paper, partially zeolitised coal fly ash from a Spanish power station has been studied as the immobilising agent of an arc furnace dust waste (s‐WA). s‐WA is a dust coming from the collecting systems of particulate material in a carbon–steel electric arc furnace (EAF). The hazardous metals normally found in this kind of waste are lead, cadmium, and chromium. In addition, the dust usually has a high zinc content resulting from the use of galvanised scrap. Because of its heavy metal content, s‐WA is classified as hazardous waste, according to Spanish regulations. Different zeolitisation procedures, depending on the treatment of the fly ash with NaOH and KOH alkaline solutions, using reflux heating and different times of attack were tested. The zeolitised products were studied using XRD in order to characterise the solid phases produced. The solidification/stabilisation (S/S) trials of s‐WA were carried out using the zeolitised ashes, as well as the original coal fly ash, in mixtures containing 20% (w/w) of ordinary Portland cement. To evaluate the efficiency of the immobilisation process, some specific criteria were defined, with regard to some physical (compressive strength) and chemical (pH and metal concentrations in TCLP leachates) characterists of the S/S solids. Finally, comparisons among the stabilising mixtures were made and the role of the zeolitisation of fly ash in the S/S process was evaluated.© 2002 Society of Chemical Industry
Municipal waste incinerator fly ash: supercritical fluid extraction of metals
Authors: Kersch Christof , Kraan Martijn van der , Woerlee Geert F , Witkamp Geert J 
Published: September 2002

AbstractThe amount of residues such as fly ash from municipal waste incinerators and coal‐fired power plants is growing. Fly ash is usually contaminated with toxic heavy metals that leach out on contact with water and pollute the groundwater. Therefore, isolated and expensive disposal of the ash is required. Reuse of ash as a filler for cement or pavements only allows minimum leachability of metals and maximum leaching values of various metals from reused fly ash are prescribed by national legislation. Supercritical‐fluid extraction (SFE) offers a method to reduce the metal content so that leachability is reduced and the demands of legislation are observed. This paper presents results of metal extraction from municipal waste incinerator ash using supercritical CO2. Initial experiments with a 12 dm3 rotating extraction vessel and constant solvent flow showed extraction efficiencies of between 10% and 52%. The influences of complexing‐agent concentration and process time are studied on divalent metals such as Zn2+, Pb2+, Cu2+, Sb2+, Ni2+, and Cd2+.© 2002 Society of Chemical Industry
Loss on ignition and carbon content in pulverized fuel ashes (PFA): two crucial parameters for quality control
Authors: Payá J , Monzó J , Borrachero M V , Amahjour F , Peris‐Mora E 
Published: September 2002

AbstractLoss on ignition (LOI) is one of the selected chemical parameters for characterizing the quality of pulverized fuel ashes (PFA). However, this parameter does not represent the unburned carbon in ashes because of the presence of several other compounds which also decompose on heating. In order to evaluate the carbon content in PFA, several thermal analysis methods have been proposed. Thermogravimetric experiments using active/inert atmospheres, high resolution thermogravimetric procedures, and single differential thermal analysis experiments are proposed as new tools for evaluating the presence of unburned carbon and other materials that are also present in PFA, such as calcium carbonate and calcium hydroxide.© 2002 Society of Chemical Industry
Factory‐scale proving trials using combined mixtures of three by‐product wastes (including incinerated sewage sludge ash) in clay building bricks
Authors: Anderson Michael , Elliott Mark , Hickson Celia 
Published: September 2002

AbstractThis paper reports the results of a series of factory trials which has been recently completed involving Staffordshire University, a major United Kingdom water company and a commercial brick manufacturer, which demonstrate the practical possibilities of incorporating three by‐product wastes, waterworks sludge, incinerated sewage sludge ash and carpet yarn, into the commercial brick‐manufacturing process as a sustainable alternative to their current disposal route of landfill. An initial laboratory development programme primarily involving waterworks sludge or water treatment residue (WTR) confirmed the technical feasibility of its use in brick‐making as an alternative disposal route. However, owing to the very high water content of this waste when freshly produced, ranging between 85 and 70% depending on individual sources, its introduction into the commercial brick‐making processes was identified as likely to present practical difficulties. Consequently, to overcome this problem the reported work describes a successful way in which the handling of WTR was improved by pre‐mixing it with the two other by‐products that jointly possess water‐absorbing properties and the ability of improving the unfired strength of the experimental products. This investigation then progressed from the laboratory to full‐scale brickworks trials encompassing the manufacture of >300 000 experimental bricks. This work programme also included emission monitoring during the firing process, together with full physical testing of the experimental products for direct comparison with the standard commercial products manufactured at the collaborating brick factory.© 2002 Society of Chemical Industry
Application of zeolitic material synthesised from fly ash to the decontamination of waste water and flue gas
Authors: Querol X , Moreno N , Umaña J C , Juan R , Hernández S , Fernandez‐Pereira C , Ayora C , Janssen M , García‐Martínez J , Linares‐Solano A , Cazorla‐Amoros D 
Published: September 2002

AbstractZeolitic material was synthesised from fly ash using two different conversion methodologies. The two conversion products obtained were: (a) impure zeolitic material obtained by direct conversion from different Spanish fly ashes, and (b) a high purity 4A–X zeolite blend synthesised from the silica extracts obtained from the Meirama fly ash (NW Spain). The zeolitic material was tested for potential application as an ion exchanger to decontaminate waters containing high concentrations of ammonium and heavy metals. Preliminary results show high cation uptake efficiencies (up to 4.7 meq g−1) which allowed fast decontamination of different types of industrial or acidic mine waste waters. The CO2, SO2 and NH3 sorption capacity of several zeolitic products was also determined and very promising results were obtained for the A4–X blend. Sorption capacity values of up to 74, 297, and 111 mg g−1 for CO2, SO2 and NH3 respectively were obtained for the zeolitic material synthesised from silica extracts from fly ash and a high‐aluminate waste water.© 2002 Society of Chemical Industry
Zeolite synthesis from coal fly ash by hydrothermal reaction using various alkali sources
Authors: Murayama Norihiro , Yamamoto Hideki , Shibata Junji 
Published: September 2002

AbstractThe main objective of this study was to investigate the reaction mechanism of zeolitization from coal fly ash by alkali hydrothermal treatment. The hydrothermal synthesis of zeolites was carried out using various alkali sources. The changes in the various properties, such as crystal structure, surface texture and cation exchange capacity, of the products and the amounts of Si4+ and Al3+ dissolved in the alkaline solution were investigated during the hydrothermal reaction. The mechanism of zeolite crystallization and the role of various alkali sources on the synthesis reaction were considered.© 2002 Society of Chemical Industry
Operating and scale‐up factors for the electrolytic removal of algae from eutrophied lakewater
Authors: Alfafara Catalino G , Nakano Kazunori , Nomura Nakao , Igarashi Takeshi , Matsumura Masatoshi 
Published: September 2002

AbstractElectrolytic removal of algae was conducted in batch and continuous reactors to investigate operating factors affecting removal efficiency and to explore engineering relationships which could be useful for operation and scale‐up. The system integrated both electro‐flocculation and electro‐flotation mechanisms by using polyvalent metal anodes and inert metal cathodes. Batch reactor studies confirmed that high electrical input power or higher electrical current achieved higher and faster removal efficiencies. Natural liquid circulation was observed during electrolytic operation and increased with higher electrical power. However, a small degree of external mixing may be useful at lower electrical power input. Electro‐flotation alone could not achieve complete algae removal (maximum efficiency 40–50%), and showed the importance of algal floc formation for the complete removal of algae. In continuous electrolysis experiments, the ratio of the volumetric current intensity (amperes dm−3) and the chlorophyll a loading (mg dm−3 h−1) was found to be a useful operating and scale‐up factor to balance high algal removal efficiency with minimum release of excess aluminum. This ratio was eventually found to be just the charge dose or the amount of coulombs required to remove a unit mass of chlorophyll a. The optimum charge dose was determined and used to relate the operating current and electrolysis time of a continuous process.© 2002 Society of Chemical Industry
Extraction separation of Ir(III) and Rh(III) with Cyanex 923 from chloride media: a possible recovery from spent autocatalysts
Authors: Chavan Devendra V , Dhadke Purushottam M 
Published: September 2002

AbstractLiquid–liquid extraction of Ir(III) and Rh(III) with Cyanex 923 from aqueous hydrochloric acid media has been studied. Quantitative extraction of Ir(III) was observed in the range of 5.0–8.0 mol dm−3 HCl with 0.1 mol dm−3 Cyanex 923, while Rh(III) was extracted quantitatively in the range of 1.0–2.0 mol dm−3 HCl with 0.05 mol dm−3 Cyanex 923 in toluene along with 0.2 mol dm−3 SnCl2. The Ir(III) was back extracted with 4.0 mol dm−3 HNO3 quantitatively from the organic phase while Rh(III) was stripped with 3.0 mol dm−3 HNO3. The extraction of Rh(III) with Cyanex 923 was not quantitative without use of SnCl2. However in the extraction of Ir(III) a negative trend was observed in the presence of SnCl2. Varying the temperature of extraction showed that the extraction reactions of both the metal ions are exothermic in nature, and the stoichiometric ratio of Ir(III)/Rh(III) to Cyanex 923 in organic phase was found to be 1:3. The methods developed were applied to the recovery of these metal ions from a synthetic solution of similar composition to that from leaching of spent autocatalysts in 6.0 mol dm−3 HCl.© 2002 Society of Chemical Industry
Anaerobic degradation: the effect of the combined treatment of substrates on the refractory fraction
Authors: Fueyo Gema , Gutierrez Antonio , Berrueta José 
Published: September 2002

AbstractThe anaerobic digestion of landfill leachates mixed with domestic sewage was studied using a batch reactor at laboratory scale. Batch assays were carried out with different proportions of leachate in the feed: 100, 70, 50 and 30% by volume, with and without adjustment of pH, in order to determine the percentage of acidification and methanization, COD removal, anaerobic biodegradability and biomass growth yield. The main effect of the mixing with sewage was a synergistic improvement of the anaerobic treatment of leachates, but in different ways; the greatest improvement in COD removal was obtained when the proportion of leachate in the feed was 70%, but the highest degree of anaerobic biodegradability was obtained with 30% of leachate in the feed. The kinetics of these assays was studied and the experimental data were fitted to a modification of the equation of Chen and Hashimoto. A new concept of ‘non‐biodegradable fraction’ is proposed.© 2002 Society of Chemical Industry
Unstructured model for seed cultures without pH control of Lactobacillus helveticus growing on supplemented whey permeate
Authors: Amrane Abdeltif , Couriol Catherine 
Published: September 2002

AbstractIn cultures of Lactobacillus helveticus with pH controlled at 5.9, growth and lactic acid production were under the control of nutritional limitations (carbon and nitrogen). In the absence of pH control, as was the case for seed cultures, an inhibitory effect on growth of both pH and the undissociated lactic acid concentration were evident before nutritional limitations. The variations of the specific growth rate with the undissociated lactic acid concentration followed exponential decay. Then, the inhibitory effect of pH was also taken into account through the Henderson–Hasselbach equation. The specific growth rate history has been previously found to follow sigmoidal variation. Integration of these relationships gave the theoretical biomass and lactic acid production kinetics. The model fitted experimental kinetic data well and allowed fine analysis of the various growth phases, since the growth‐associated, the deceleration and the stationary states can be characterized by means of the model parameters.© 2002 Society of Chemical Industry
Optimization of the production of β‐carotene from molasses by Blakeslea trispora: a statistical approach
Authors: Goksungur Y , Mantzouridou F , Roukas T 
Published: September 2002

AbstractThe effect of pretreatment of molasses, nitrogen sources, natural oils, fatty acids, antioxidant, precursors, and mixtures of the above substances on β‐carotene production by Blakeslea trispora in shake flask culture was investigated. Also, a central composite design was employed to determine the maximum β‐carotene concentration at optimum values for the process variables (linoleic acid, kerosene, antioxidant). The highest concentration of the carotenoid pigment was obtained in molasses solution treated with invertase. Corn steep liquor and yeast extract at concentrations of 5.0% and 0.5% (w/v), respectively, increased slightly the concentration of β‐carotene, while the natural oils, fatty acids, and precursors (except kerosene) did not improve the production of pigment when they were added separately to the medium. On the other hand, the mixture of linoleic acid, kerosene and antioxidant increased significantly the concentration of β‐carotene. The fit of the model was found to be good. Linoleic acid, kerosene and antioxidant had a strong linear effect on β‐carotene concentration. The concentration of β‐carotene was significantly affected by linoleic acid–antioxidant and kerosene–antioxidant interactions as well as by the negative quadratic effects of these variables. The interaction between linoleic acid–kerosene had no significant linear effect. Maximum β‐carotene concentration (790.0 mg dm−3) was obtained in culture grown in molasses solution supplemented with linoleic acid (30.74 g dm−3), kerosene (27.79 g dm−3) and antioxidant (10.22 g dm−3).© 2002 Society of Chemical Industry
Evaluation of a porcine model for pulmonary gene transfer using a novel synthetic vector
Authors: Cunningham Steven , Meng Qing‐Hai , Klein Nigel , McAnulty Robin J. , Hart Stephen L. 
Published: September 2002

AbstractBackgroundThe pig lung, given its gross anatomical, histological and physiological similarities to the human lung, may be useful as a large animal model, in addition to rodents, in which to assess the potential of vectors for pulmonary airway gene transfer. The aim of this study was to assess the utility of the pig lung as a model of gene transfer to the human lung with a synthetic vector system.MethodsThe LID vector system consists of a complex of lipofectin (L), integrin‐binding peptide (I) and plasmid DNA (D). LID complexes containing a β‐galactosidase reporter gene under a CMV promoter or a control plasmid at1 mg/3 ml PBS, or 3 ml buffer, was administered to the right lower lobe ofthe pig lung through a bronchoscope. Pigs were culled at 48 h and lung sections prepared for immunohistochemical and histological analysis. Bronchoalveolar lavage fluid was collected and analysed for TNF‐α by ELISA.ResultsImmunohistochemical staining for the β‐galactosidase reporter gene indicated high efficiency of gene transfer by the LID vector to pig bronchial epithelium with 46% of large bronchi staining positively. There was no evidence for vector‐specific inflammation assessed by leukocytosis and cytokine production.ConclusionsThis study demonstrates the use of the pig for studies of gene transfer in the lung and confirms in a second species the potential of the LID vector for gene therapy of pulmonary diseases such as cystic fibrosis. Copyright © 2002 John Wiley & Sons, Ltd.