摘要:

AbstractThe continuous production of ultra pure water on an industrial scale uses ion exchange mixed beds as a major method of reducing ionic impurities to sub‐μg dm−3concentrations. Under such demanding operating conditions, particularly the high flow rate and high volume requirements of condensate purification in the power generation industry, it is the kinetics rather than the equilibria of the exchange processes that becomes the main controlling factor. The interactions between anion and cation exchange rates have been studied, particularly with respect to changes in the aqueous phase pH within a bed of exchange resins. The cause and effects of cation exchange resin fouling, both in laboratory tests and in practical applications, have been investigated. The most suitable choice of ion exchange system for ultra pure water production, whether mixed or separate beds, is discu

ISSN:0268-2575    

DOI:10.1002/jctb.280510402

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY

摘要:

AbstractA dispersed flow model previously developed to study substrate utilization in unsaturated media was experimentally verified and its practical application was considered. For this purpose, measurements were made using tap water and a synthetic feed solution. The importance of the change in fluid regime as regards to the simultaneous transport and reaction within biological filters were demonstrated. The effect of drop formation and the breakage of liquid jets inside the filters on substrate utilization was also shown.

ISSN:0268-2575    

DOI:10.1002/jctb.280510403

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY

摘要:

AbstractThe kinetics of the catalytic transformation of 3‐picoline to 3‐cyanopyridine by nitric oxide (NO) have been investigated over nickel oxide‐aluminium oxide catalyst (2NiO·Al2O3) in a differential flow reactor between 300 and 360°C. A maximum yield of 98% was achieved with a catalyst having a Ni: Al atomic ratio of 1:1 and preheated in the presence of air at 600°C for 24 h. The rate equation Rn= kpknPpPn/(kpPp+ knPn) deduced, assuming a steady state involving a two‐stage irreversible oxidation‐reduction process, represented the data most satisfactorily for conversion of 3‐picoline to nicotinonitrile. A tentative mechanism for the reacti

ISSN:0268-2575    

DOI:10.1002/jctb.280510404

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY

摘要:

AbstractA physical model is given in the present report for representing a three‐phase biological fluidized bed reaction system which consists of microorganism‐coated particles, waste water and air. The system is assumed to be well fluidized. The physical model can be represented by two differential equations describing, respectively, the substrate axial dispersion and diffusion/reaction. Numerical values of the physical parameters are selected from the literature or estimated from semi‐empirical equations. The governing system equations are solved by an iterative finite‐difference scheme. The theoretical predictions are compared with several experimental measurements and the agreement between them found to be very good, validating the physical model report

ISSN:0268-2575    

DOI:10.1002/jctb.280510405

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY

摘要:

Abstract3‐Aryloxymethyl‐4‐amino‐5‐mercapto‐s‐triazoles (1a–c) reacted with alkyl/aralkyl halides to give 5‐alkyl/aralkyl thio‐s‐triazole derivatives (2a–i) and with substituted phenacyl bromides afforded s‐triazolo‐thiadiazines (3a–l). Condensation of 1a–cwith aromatic/heterocyclic aldehydes furnished the corresponding schiff bases 4a–r. The latter compounds (4b,h,n) were further reacted according to Mannich reaction affording 5a–fand 6a–c. Moreover, interaction of 4b,h,nwith phenacyl bromides yielded the bicyclic compounds 7a–l. Some of these compounds were screened in vitro for their antimicrobial act

ISSN:0268-2575    

DOI:10.1002/jctb.280510406

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY

摘要:

AbstractThe removal of p‐toluene sulphonic acid (p‐TSA) from concentrated solution by granular activated carbon (GAC) was studied in batch experiments. The first order rate constant was found to be 5.5010 × 10−5s−1for a solution of 1000 mg dm−3. In order to establish the rate limiting step the pore and film diffusion coefficients were calculated from the half time equations. Film diffusion was found to be rate limiting. The average value of the external mass transport rate constant was 2.91 × 10−6cm s−1. The adsorption isotherm was adequately described by the Langmuir model and belongs to type ‘H’ of Gi

ISSN:0268-2575    

DOI:10.1002/jctb.280510407

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY

摘要:

AbstractVanadium(V) was determined spectrophotometrically by reaction with phenylfluorone (I) at pH 8.8 in the presence of cetylpyridinium bromide to form a 1:2 vanadium‐I chelate. The molar absorptivity of the sensitised chelate was 7.0 × 104dm3mol−1cm−1at 550 nm and the sensitivity index was 0.7 ng cm−2. Beer's law was followed up to 0.37 ppm of vanadium. The interference of other metal ions was eliminated by electrolytic separation using a mercury cathode. The developed method was successfully applied for the determination of vanadium i

ISSN:0268-2575    

DOI:10.1002/jctb.280510408

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY

摘要:

AbstractBagasse‐based paper mills in developing countries do not have sophisticated waste water treatment technology to combat water pollution released by these mills. This paper presents an overview of bagasse handling and sources of waste generation, the seriousness of pollution discharge, and treatment options available to tackle the waste water derived from bagasse‐based paper mills. Extensive laboratory treatability studies indicate that anaerobic digestion for biogas generation is a viable method for handling bagasse‐based paper mill wastes. The waste water was treated at an organic loading of 0.8 kg BOD m−3day−1and 1.6 kg COD m−3day−1and a detention time of 10 days, achieving 90% reduction in BOD and COD without supplementation of any nutrients. With a yield coefficient of 0.5, the average quantity of cells produced per day was calculated to be 1.683 kg day−1or 0.25 kg cells produced kg−1BOD removed. Intermittent checking on excess alkalinity in the anerobic system is necessary for achieving maximum tre

ISSN:0268-2575    

DOI:10.1002/jctb.280510409

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY

摘要:

AbstractThe fermentation reaction producing biosurfactant using Pseudomonas aeruginosa CFTR‐6 was studied. The progress of the bioreaction was monitored in terms of biomass production, product formation and substrate consumption in shake flask experiments using different initial sugar concentrations. A logistic model for biomass growth was found to be satisfactory. Average estimates of the specific growth rate, biomass yield coefficient and maintenance coefficients were obtaine

ISSN:0268-2575    

DOI:10.1002/jctb.280510410

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY

ISSN:0268-2575    

DOI:10.1002/jctb.280510411

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY