摘要:

AbstractThe properties of copper cyanoferrates and potassium cobalt ferrocyanide prepared at Imperial College and similar commercial products for caesium sorption have been investigated. Copper and cobalt based cyanoferrates have different chemical compositions and appear to be good adsorbers for the removal of caesium in aqueous solutions. Different caesium sorption mechanisms were observed for these cyanoferrates. A conventional ion exchange reaction, physical adsorption and a combination of the two processes were observed. The difference in caesium sorption mechanism also reflects the kinetics of the sorption process. Potassium copper ferrocyanide has the highest effective capacity but the caesium sorption rate is the slowest, whilst potassium cobalt ferrocyanide possesses faster kinetics but considerably lower effective capacity. Copper ferrocyanide tends to have better mechanical stability and moderate sorption kinetics and caesium uptake.

ISSN:0264-3413    

DOI:10.1002/jctb.504330702

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractKinetics of leaching of Raney Ni‐AI alloy (Ni: 50% w/w) with alkali has been studied in an agitated reactor by measuring the rate of H2evolved in the leaching process at constant alkali concentrations. The effects of various process parameters such as temperature, type and concentration of alkali, particle size of the alloy and stirring speed, on the leaching process have also been investigated. The kinetic data could be fitted to the empirical expression:q=α+βlog(t)Where,qis the amount of H2evolved in the leaching process;t, the reaction time; and a and β, the constants. The order of reaction with respect to alkali concentration and the activation energy for the leaching process were determined from the analysis of the initial rates. An appreciable fraction of the hydrogen, which is formed in the leaching process, has been found to be retained on the solid produc

ISSN:0264-3413    

DOI:10.1002/jctb.504330703

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractTwo methods of obtaining high purity HgI2by wet‐synthesis are described: one by direct synthesis from the elements and the other by a double exchange reaction. Further purification of the synthesised HgI2by recrystallisation, electrolysis and sublimation is described. The efficiency of the purification methods is tested by emission spectroscopy and by mass spectrometry analyse

ISSN:0264-3413    

DOI:10.1002/jctb.504330704

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractA method for optimising the conditions for the quantitative13C‐n.m.r. measurement is suggested and has been applied to the compositional studies of naphtha fractions (50–100°C and 100–150°C) of Darius crude oil. The novelty of the method is that we can pre‐estimate the pulse repetition time for unknown samples. It has been shown that the various compositional parameters thus obtained are in satisfactory agreement with those obtained from the elemental analysis, fluorescent indicator adsorption (FIA) and1H‐n.m.r. s

ISSN:0264-3413    

DOI:10.1002/jctb.504330705

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractTetrabutoxysilane and polybutoxysiloxanes were prepared by reacting SiCl4with I‐butanol and I‐butanol‐water mixtures in liquid phase. The effect of water content on some of the physical properties, such as viscosity, density, surface tension, refractive index, specific heat, thermal expansion and ultrasonic sound velocity, was determined. Also, the molecular weights and the percentages of silica and butoxy group were estimated. Using these experimentally determined physical properties, other properties such as Rao's number, molecular radius, Van der Waal's constant, isothermal and adiabatic compressibilities, the ratio of specific heats, thermal conductivity and the activation energies for vaporisation and viscosity were calculated theoretically. Based on the experimental values and theoretical calculations, the cyclic structure of some of the compounds was establ

ISSN:0264-3413    

DOI:10.1002/jctb.504330706

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractConditional stability constants and complexation capacities of extracellular polymers extracted from activated sludge with copper, nickel, cadmium and cobalt have been determined at high and low free metal concentrations using gel complexometry. The results compare favourably with those for other bacterial extracellular polymers, but less well with those for competing metal‐binding ligands present in sewage. The affinity of extracellular polymers for metals has been discussed in terms of their contribution to metal removal during the biological phase of wastewater treatmen

ISSN:0264-3413    

DOI:10.1002/jctb.504330707

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractThe fungicides, 3,5‐dimethyltetrahydro‐1,3,5‐thiadiazine‐2‐thione (DTTT) and 4‐tolyldiiodomethylsulphone (TDMS) have been prepared labelled with14C and incorporated into polyvinylacetate emulsion (PVA), styrene/acrylic emulsion (acrylic) or alkyd gloss (alkyd) paints. Test plates prepared from these paints have been exposed in both tropical and temperate conditions and losses of fungicides have been followed radiometrically. In outdoor conditions, DTTT is rapidly lost from all the paints. Indoors, DTTT is retained well (50% after 150 days) only by alkyd paint. TDMS is well retained in indoor conditions by all the paints. Outdoors however, retention in PVA and acrylic films is less than 50% after 150 days and is poorer in tropical conditions. About 90% of the TDMS is retained in alkyd films for an indefinite period in temperate conditions: in tropical conditions, 80% is retained after 150 days. Comparisons of losses from paint films of mercurial and non‐mercurial fungicides show that TDMS is a satisfactory substitute for the more commonly us

ISSN:0264-3413    

DOI:10.1002/jctb.504330708

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

ISSN:0264-3413    

DOI:10.1002/jctb.504330701

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY