摘要:

AbstractThis paper presents the new concept of ‘Targeting’ the properties of new membrane materials. Cost parameters are defined in terms of effective selectivity and cost permeability. These new parameters, obtained from the analysis of membrane plant suppliers' bids, are used in a procedure which determines the optimal degree of separation and recovery. The use of the targeting methods is illustrated here in the development of new membranes for the separation of CO from an H2/CO syngas for the large‐scale manufacture of acetic acid. The targeting approach can be extended to include other gas separation technologies and will aid the development of a generic methodology for the design of gas separation proc

ISSN:0268-2575    

DOI:10.1002/jctb.280620302

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY

摘要:

AbstractLinseed oil fatty acids were epoxidized by peracetic acid, then reacted with diethanolamine to give epoxidized hydroxy ethyl linseed oil fatty acid amide (I). This amide was rejected with toluene diisocyanate to produce epoxidized polyurethane‐amide (II). ComponentIwas also reacted with phthalic anhydride to give epoxidized polyesteramide (III). ResinsIIandIIIwere evaluated as coating materials. The results obtained were compared with commercial epoxy resin, and show that resinsIIandIIImay be suitable to use as petroleum pipeline coating

ISSN:0268-2575    

DOI:10.1002/jctb.280620303

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY

摘要:

AbstractTwo models were developed to predict the size of drops of aqueous sodium alginate solution formed at a two‐fluid nozzle. Experimental results revealed that actual drop sizes lay between the sizes predicted by the two models. Drop size was closely predicted by the volume mean of the two models. Several nozzles were tested and the influence of operating conditions on drop diameter was examined, with gas velocity and nozzle outer diameter having the largest effect. Only two nozzles would be needed to produce drops with diameters in the range 1–6 mm. The addition of yeast in amounts of up to 10% (w/w) had no effect on operation of the nozz

ISSN:0268-2575    

DOI:10.1002/jctb.280620304

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY

摘要:

AbstractTopological indices are determined for models of prospective pyridine extractants and the relationships structure–topological index and topological index–pyridine nitrogen basicity are described. The second order valence molecular connectivity index, the Balaban index and the Wiener number are appropriate structural descriptors of pyridine derivatives and, in several cases, permit the pyridine nitrogen basicity to be predicted. The relationships between pKavalues and the structural descriptors are given and descri

ISSN:0268-2575    

DOI:10.1002/jctb.280620305

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY

摘要:

AbstractBiological degradation of chloroguaiacols contained in sulphite pulp chlorine bleaching wastewater was studied in four parallel biological fluidised bed reactor systems—one single aerobic, one single anaerobic and two combined anaerobic–aerobic reactors. At low loading rates, trichloroguaiacols were removed nearly quantitatively. 4,5‐Dichloroguaiacol was only partly removed. At high loading rates the anaerobic–aerobic recycle reactor removed individual guaiacols more than the other reactors. Only 4,5,6‐trichloroguaiacol was removed best by the anaerobic–aerobic reactors in series. Even mixed culture biofilms adapted during several years of continuous operation did not satisfactorily remove these compounds. Synthetic wastewater, containing chlorinated guaiacols, treated with ozone produced formate and oxalate and quantitatively inorganic chloride. Combined ozonation–biotreatment in two reactors in series as well as in a recycle system allowed complete removal of all individual chlorinated guaiacols (<1 μmol m−3remained). The efficiency of non‐purgable organic carbon removal could be increased from ≤0.55 to about 4 mol carbon mol−1ozone by combination of ozonation with biotreatment. Simultaneously, the efficiency of removal of chlorinated guaiacols was increased by a factor of 10, which is essential for

ISSN:0268-2575    

DOI:10.1002/jctb.280620306

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY

摘要:

AbstractThe effects of ionic strength and pH on adsorption of lysozyme to three strong cation exchangers have been studied. Adsorption equilibrium data obtained using the batch techniques corresponded well to the Langmuir isotherm. Ionic strength had a considerable influence on the isotherms. In all cases, the maximum binding capacity of the three exchangers decreased while the apparent dissociation constant increased with increasing ionic strength. The maximum binding capacity also decreased while the apparent dissociation constant was not significantly affected by an increase in pH. It was found that the three exchangers exhibited different levels of binding capacity under identical solution conditions. This was shown to be caused by variation in the arrangement and distribution of charged groups. However, the ion‐exchange matrix had little effect on the apparent dissociation constan

ISSN:0268-2575    

DOI:10.1002/jctb.280620307

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY

摘要:

AbstractA suspended‐growth batch reactor was used to denitrify synthetic wastewater containing various proportions of nitrate and nitrite. A competitive phenomenon between nitrate‐ and nitrite‐reductase was studied utilizing various proportions of nitrate and nitrite in an anaerobic environment with a temperature of 30°C and methanol as carbon source.By using a non‐linear regression technique, biokinetic constants of the maximum specific reduction rates of nitrate and nitrite (k1,k2) and the Monod half‐saturation coefficients of nitrate and nitrite (Ks1,Ks2) for the proposed two‐step denitrifying kinetics were 1·29 day−1, 0·89 day−1and 14·3 mg NO 3−‐N dm−3, 10.9 mg NO 2−‐N dm−3, respectively. The result obtained from a series of chemostat studies indicated the Monod‐type kinetic model was more accurate when the distributed ratio of nitrate‐ and nitrite‐reductase in the proposed two‐step d

ISSN:0268-2575    

DOI:10.1002/jctb.280620308

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY

摘要:

AbstractThe transalkylation reaction of di‐isopropylbenzene with benzene and substituted benzenes over sulphate‐treated superacidic zironia catalyst was studied. The catalyst was found to show comparable activity to that of zeolite and acid‐treated clay (Filtrol‐24). However, it was found to deactivate because of the heavy compounds in the starting reaction mixture and coke fo

ISSN:0268-2575    

DOI:10.1002/jctb.280620309

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY

摘要:

AbstractThe use of ozone to degrade aldicarb in water was investigated under different conditions. The oxidation develops through the direct attack of ozone since the presence of hydroxyl radical inhibitors, such astert‐butanol, does not affect the degradation rate of aldicarb. The combination of ozone with hydrogen peroxide does not improve the oxidation rate which also confirms the absence of radical reactions to eliminate aldicarb. However, TOC removal increases 51% in the presence of hydrogen peroxide after 65 min of oxidation. The oxidation rate is strongly affected by the type of device for feeding ozone, which indicates that a fast gas‐liquid reaction is taking place. Therefore, mass transfer and chemical reaction steps are important factors in the establishment of the global rate of oxidation. Application of kinetic equations derived from gas absorption theories allows the determination of the rate constant of the direct ozone–aldicarb reaction, which was found to be:k= 3·18 × 1011exp(–6000/T) m

ISSN:0268-2575    

DOI:10.1002/jctb.280620310

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY

摘要:

AbstractParticles of two different sizes (0·105–0·295 mm and 0·84–1.00 mm diameter) of two marine algae,Sargassum fluitansandAscophyllum nodosum, were crosslinked with formaldehyde (FA), glutaraldehyde (GA) or embedded in polyethylene imine (PEI), followed by glutaraldehyde crosslinking. They were used for equilibrium sorption uptake studies with cadmium, copper, nickel, lead and zinc. The metal uptake by larger particles (0·84–1·00 mm) was higher than that by smaller particles (0·105–0·295 mm). The order of adsorption forS. fluitansbiomass particles was Pb>Cd>Cu>Ni>Zn, forA. nodosumcopper and cadmium change places. Uptakes of metals range fromqmax= 378 mg Pb g−1forS. fluitans(FA, big particles), toqmax= 89 mg Zn g−1forS. fluitans(FA, small particles) as the best sorption performance for each metal. Generally,S. fluitansis a better sorbent material for a given metal, size and modification, although there were several exceptions in which metal sorption byA. nodosumwas higher. The metal uptake for different chemical modifications showed the order GA>FA>PEI. A comparison of different sorption models revealed that the Langmuir sorption model fitted the expe

ISSN:0268-2575    

DOI:10.1002/jctb.280620311

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY