In order to address ground and industrial water pollution, the University of Manchester has developed a novel and economic water treatment technology called the Arvia® process. This technology is being commercialized through a spin-out company, Arvia Technology Ltd. This process consists of adsorption and electrochemical regeneration in a single unit and can be carried out in batch or continuous modes where both operations can run simultaneously. This process has been successfully demonstrated for the removal and destruction of a number of organic contaminants using a graphite based adsorbent known as Nyex®1000. Nyex®1000 is an intercalation compound prepared from Chinese natural large fake graphite. This adsorbent has been found to be capable of fast adsorption and quick electrochemical regeneration in minutes due to its non-porous surface and high electrical conductivity. However, Nyex®1000 has a small adsorptive capacity for a number of organic pollutants and there is thus a need to develop new adsorbents with the aim of achieving high adsorptive capacity with maintaining good electrical conductivity. In this context, three routes for the development of adsorbents were selected, adsorbents developed through electrochemical intercalation, adsorbent developed through thermal and mechanical treatment of GIC-bisulphate and adsorbents developed through the formulation of composite materials. In order to strengthen the contributing effect of surface treatment, all raw graphite materials and developed adsorbents were characterized using Boehm titration, X-ray EDS, zeta potential, powder XRD, SEM, BET surface area, pore volume, particle size and bulk density techniques. These adsorbents were tested for the removal of a number of different target organic pollutants such as acid violet 17, mercaptans, phenol and humic acid using the Arvia® process. The performance of the developed materials was compared with the current adsorbent used in the Arvia® process i.e. Nyex®1000. A range of graphite types (synthetic graphite, Chinese natural large fake gra- phite, Madagascan medium fake graphite, natural vein graphite and recycled Abstract 27 vein graphite) were tested for the removal of acid violet 17 before and after electrochemical treatment in order to investigate the selection of the graphite types for the Arvia® process. The electrochemical surface treatment improved the adsorptive capacity by a factor of two for most of the graphite types tested and changed the surface of the graphite from hydrophobic to hydrophilic. Results obtained through surface characterization using Boehm titration, X-ray (EDS) elemental analysis and zeta potential measurements revealed a significant increase in oxygen containing surface functional groups on the surface of CNLFG in consequence of electrochemical surface treatment. The second type of adsorbent was developed through thermal and mechanical treatment of GIC bisulphate. It was tested for the removal of acid violet 17, mercaptans (ethane thiol & methyl propane thiol), phenol and humic acid using the Arvia® process. This material had twice the electrical conductivity of Nyex® 1000 and improved the adsorptive capacity by a factor of three for acid violet 17, approximately seven to eight for ethane thiol and methyl propane thiol, seven for phenol and two for humic acid. Starting and developed adsorbent materials were characterized using above mentioned techniques. The third type of adsorbent materials, three composite adsorbents were developed using high shear (wet) and compaction (dry) granulation methods. The composite adsorbent made through high shear wet granulation was found to have poor mechanical strength. The second and third composite adsorbents were developed through dry compaction granulation using carbon black, synthetic graphite and exfoliated graphite as raw materials. These adsorbents delivered improved adsorptive capacity for acid violet 17 by a factor of 100 and 9 respectively. Electrochemical regeneration efficiencies of around 100 % were obtained for these adsorbent materials. However, electrochemical parameters required to achieve 100 % regeneration, such as current density and regeneration time were found to vary depending on the adsorptive capacity of each adsorbent material for a particular polluting agent.

Corpora non agunt nisi fluida sive soluta" – substances do not react unless in a liquid or dissolved state. This ancient rule is no longer universally valid as attested "by the new phenomena "being found every day; column chromatography by solid powders may be one of the most noteworthy exceptions. In talking about column chromatography, immediately one thinks of Ion Exchange Resins. In fact, for the few past decades, analytical and inorganic chemists have concentrated their interest in the applications and theoretical interpretations of the behaviors of ion-exchange resins. Resins indeed deserve this, for so many fantastic achievements in chromatography have been made since the organic chemists had succeeded in their synthesis. But at the same time, the powders of celluloses have also been used widely and successfully for separations of biological and organic substances; this finally awakened inorganic and analytical chemists to realize that they might have ignored something which may be equally interesting and promising.

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Introduction: Part 1. Greenhouse studies were conducted to investigate the absorption of sodium, potassium, calcium and magnesium by lemon seedlings. The plants were grown in controlled nutrient solutions and analysis of the plant material was made to determine the relationship between the four cations in the different plant organs. Results of the experiment may be summarized as follows:- The occurrence of leaf burn appeared to be associated with a low calcium content, together with a high sodium, potassium or sodium + potassium content. The development of the seedlings was shown to be markedly influenced by the level of calcium supply and to a much lesser degree by the level of potassium supplied. The concentration of sodium, potassium, calcium and magnesium in the stem and leaf varied with position of the tissues on the main axis. The level of sodium was found to influence the distribution of sodium in the leaves, and the sodium content of the leaf, stem and root tissues gave a good reflection of the level of sodium supplied. The effect of the sodium treatment on the uptake of potassium appeared to be dependent on the calcium content of the tissues. Sodium treatment was found not to affect the leaf calcium content. In the stem and root tissues the calcium content was reduced when the calcium level in the nutrient medium was low, and increased the calcium content of these two tissues at the higher level of calcium supply. The sodium supply was shown to reduce the leaf magnesium only slightly, and its affect on the magnesium content of the stem and root tissues was shown to be dependent on the level of calcium supplied. The potassium content of the leaves, stems and roots increased when the supply of potassium was raised. Increasing the potassium level in the nutrient supply was found to cause a very slight reduction in the sodium content of the leaf, but did not affect the sodium content of the stem and root. Potassium did not affect the calcium content of the leaves and increased the stem calcium when sodium was not present in the nutrient media in high concentrations. In the roots potassium only increase the calcium content at the upper level of calcium supply. The magnesium content of the leaf and stem tissues was reduced as the potassium supply was increased. In the roots the general trend was for the magnesium content to increase when the level of potassium treatment was raised. The calcium content of all the plant parts increased with a rise in the calcium supply, the stem and root tissues having a greater percentage increase than the leaves. The sodium content of the plant tissue was reduced as the level of calcium supply was raised. The leaf potassium content decreased with a higher calcium level of supply. In the stem and roots the potassium content was increased by doubling the calcium supply. The calcium treatment had no influence on the magnesium content of the foliage, but in the stem and root tissues a decrease in magnesium content resulted from an increase in the calcium supply. Part II Potato tuber tissue and carrot root tissue were used as experimental material in the investigation of sodium9 potassium9 and calcium uptake by storage tissue. It was shown that when the tissue disks are transferred from distilled water to a solution of salts there is a rapid initial uptake of cation which is neither particularly selective, nor related to metabolism, but dependent on the external concentration. On the other hand, the prolonged active accumulation of cation exhibits selectivity. Potassium absorption by potato tuber tissue was shown to be stimulated by sodium9 whereas the potassium and calcium absorption by carrot root tissue was shown to be reduced by sodium. Similarly the sodium absorption by the carrot root tissue was reduced by potassium, thus suggesting that the cations compete with one another for the same absorption mechanism.

No description available.

In this work monolayers of alkyl amides adsorbed on a graphite surface have been successfully identified and investigated using a combination of synchrotron X-ray and neutron diffraction and Differential Scanning Calorimetry (DSC). Exceptionally stable solid layers have been observed at temperatures well above the bulk melting point, at both high multilayer coverages and, very unusually, at sub-monolayer coverages. The molecular structure of the two-dimensional crystals of these alkyl amides has been obtained from diffraction and interpreted in terms of the subtle intermolecular interactions, particularly the contribution of hydrogen bonding in monolayer assembly. Thermodynamic information provides insight on the mixing behaviour in adsorbed amide layers. A systematic study on the variation in monolayer crystal structures with alkyl chain length (between five and sixteen carbon atoms) of saturated alkyl amides using diffraction identifies that all the amide molecules investigated lie flat on the graphite surface. An odd-even variation isobserved in the monolayer crystal structures and this is supported by the melting enthalpies of the amides determined by DSC. The structure of the even members is found to support the qualitative monolayer arrangement proposed by an STM report of one member of the series, but with more quantitative insight here. Significantly, a new monolayer symmetry group for odd members of the homologous series has been identified. Characteristics of the hydrogen bond geometrybetween the molecules in the solid monolayers are reported exploiting the high level of detail available from the diffraction techniques. Secondly, the formation of solid monolayers of unsaturated alkyl amides has been reported and their crystal structures determined. This is believed to be the first report of these monolayer structures. The position and nature of the double bond have an important effect in the stability of the monolayer. Unusually, certain unsaturated amides that have a double bond conjugated with the amide group are found to form considerably more stable layers than their saturated homologues. The abnormally high melting points and enhanced stability of amide monolayers have been attributed to the existence of a network of hydrogen bonds in the layer. Phase diagrams obtained by DSC for binary mixtures of alkyl amides on graphite have been quantitatively analysed using a combination of thermodynamic models (ideal, eutectic and the regular solution models). The determined mixing behaviour is supported by conclusions based on the monolayer crystal structures of the individual components calculated using diffraction. Saturated amide mixtures that have the same plane group symmetry are found to mix non-ideally in the solid layer and phase separate if the symmetry is different, whereas the mixing behaviour of saturated/unsaturated amides considered here was found to depend on the nature of the double bond (cis/trans). Results from an initial investigation into the adsorption of alkyl amides at the polymer/air interface are also presented. This complements the study above and provides an alternative situation where amide monolayers have a central role. A reduction in the coefficient of friction is seen with increasing bulk concentration of the amide and with increasing time indicating migration of the amide to the surface. A powerful combination of surface reflection techniquesincluding neutron and X-ray reflection and ellipsometry have been used to gain uniquelyquantitative insight into this system. Initial estimates of the concentration of amides at the polystyrene surface are presented for the first time.

No description available.

. The kinetics of the absorption of carbon monoxide by basic solutions was studied at 80°C and carbon monoxide pressures up to 30 atmospheres. The reaction was followed by the rate of decrease of carbon monoxide pressure in a closed system. The observed kinetics in potassium hydroxide solutions yield a rate law of the form (formula omitted) No influence from Li⁺, Na⁺, K⁺ ions was detected and no catalytic effect from Ag(I),- Cu(II), T1(I), N0₃⁻, Mn0₄⁻ was observed. The kinetics are consistent with a mechanism which includes the insertion of a carbon monoxide molecule into the hydroxyl bond,viz. (formula omitted) The rate-controlling step above 90°C was found to be the mass transfer of carbon monoxide from the gas phase into the liquid phase under the conditions involved in this study. / Applied Science, Faculty of / Materials Engineering, Department of / Graduate

Two soil types, the Ladner silty clay loam and the Nicomekl loam, located in the Lower Fraser Valley, representing the modal profile characteristics were selected to study the permeability and the factors affecting it. Undisturbed core samples and fragmented samples were procured for laboratory characterization of the soils. Measurement of the soil permeability in the laboratory confirmed the field observations that the Nicomekl soil was more permeable than the Ladner soil. There was a good correlation in the soil permeability and the soil macroporosity as determined by tension table at 40 cm. water tension. The texture of the two soils, as determined by pipette method, was not sufficiently different to account for the permeability differences. The variations in the organic matter content, as determined by wet combustion method, seemed to have little effect on the permeability behaviour of these soils. The nature of exchangeable cations, as extracted by the ammonium acetate method and quantitatively determined by flame photometry and versenate titration, in the two soils, were found to be very different; the exchangeable cations, Na⁺, K⁺ and Mg⁺⁺, in the Ladner soil seemed responsible for the lower permeability in comparison with the Nicomekl soil which had very low percent base saturation and appeared to have mostly Al⁺⁺⁺ ions present in the exchange complex. The poorer physical conditions of the Ladner were also, perhaps, due to the differences in the exchangeable cations. The X-ray identification of clay minerals, using oriented "aggregate technique", monochromatic copper radiation and surface reflection method, revealed that the Ladner and Nicomekl soils were qualitatively similar in their clay content. Both soils contained montmorillonite, micaceous mineral, chlorite, feldspar and quartz; the presence of kaolinite and vertniculite could not be established. In an intricate mixture of clays as above, quantitative estimation of clay minerals was not performed; hence the effect of clay minerals on the permeability of the two soil types could not be evaluated. Permeability measurements on soil mixtures containing reference clay minerals, using air pressures in a water permeameter, revealed that Na-Bentonite even in small quantities rendered soil highly impermeable. The permeability of soil mixtures containing clays with exchangeable calcium improved with the application of Krilium while the clays with exchangeable sodium did not respond to similar treatment. The effect of Al⁺⁺⁺ ion and weak acids on the flocculation behaviour of Na-Bentonite suggested that the presence of both Al⁺⁺⁺ ions and weak acids promoted soil permeability. X-ray diffraction diagrams using unflitered cobalt radiation indicated that weak acids formed heat stable complexes with bentonite. The bentonite treated with aluminum chloride as well as phosphoric acid plus aluminum gave diffraction patterns indicating that increased c-spacing was due to the complexes formed with bentonite; the deposition of these complexes at the interlayer positions prevented the complete collapse of lattice at elevated temperatures. / Land and Food Systems, Faculty of / Graduate

Gas absorption with chemical reaction is an important unit operation in the chemical and petroleum industries for the selective removal of components from industrial gas streams. Apart from choosing absorption media, the most difficult problems facing the design engineer are the sizing and performance prediction of the absorption tower due to the scarcity of fundamental design data, especially when novel absorption media and/or packings are used. The solubility of carbon dioxide in 2 and 3 M solutions of 2-amino-2-methyl-1-propanol (AMP), which is a newly introduced absorbent, was determined at 20, 40, 60 and 80 °C and for CO₂ partial pressures ranging from approximately 1 to 100 kPa. The results were interpreted with a modified Kent-Eisenberg model which predicted the present and previous experimental results well. The absorption capacities of AMP and monoethanolamine (MEA) solutions were also compared. Detailed concentration and temperature measurements were reported for the absorption of carbon dioxide from air into NaOH, MEA and AMP solutions. A full-length absorber (0.1 m ID, packed with 12.7 mm Berl Saddles up to heights of 6.55 m) was used. It was operated in countercurrent mode and at 30 to 75 % flooding velocities which are typical for gas absorber operations. The following ranges of operating conditions were employed: superficial gas flow rate 11.1 to 14.8 mol/m² s; superficial liquid flow rate 9.5 to 13.5 m³/m² h; feed CO₂ concentration 11.5 to 19.8 %; total absorbent concentration 1.2 to 3.8 kmol/m³; liquid feed temperature 14 to 20 °C; total pressure 103 kPa. The measurements for the CO₂-NaOH and CO₂-MEA systems were compared with predictions from a previously developed mathematical model. Generally good agreement was obtained except at high CO₂ loadings of MEA solutions. Compared with MEA, AMP was found to have superior CO₂ absorption capacities and inferior mass transfer rates. A new procedure, called the Pilot Plant Technique (PPT), for designing gas absorbers with chemical reactions has been developed. The PPT is primarily intended for designing absorbers for which fundamental design information is lacking. It is based on the premise that full-length absorption columns can be sized by making a minimum number of tests using a small-scale pilot plant. Two special features of the PPT are (i) the details of hydrodynamic parameters (i.e. mass transfer coefficients, effective interfacial area and liquid hold-up) and the physico-chemical information of the system (e.g. reaction mechanism, reaction rate constants) need not be known and (ii) complex calculations are avoided. Using the PPT to size the height or to predict the performance of a given full-length absorber, the specific absorption rate, which is the essential information, can be measured directly using the pilot plant model (PPM) column if both columns have the same hydrodynamic conditions. This can be achieved by using the same type and size of packing in the PPM and the full-length columns and ensuring that the end and wall effects are negligible. The PPM column must also be operated at the same superficial fluid velocities as those of the full-length column. The specific absorption rate was then obtained from the gradient of the fluid composition profile along the PPM column. The validity of the PPT was demonstrated by determining the height and predicting the performance of the full-length column in which carbon dioxide was absorbed from air by aqueous solutions of NaOH and AMP at various operating conditions; good agreement was obtained. / Applied Science, Faculty of / Chemical and Biological Engineering, Department of / Graduate