The research provides data of pH and conductivity, some anions (e. g. fluoride, chloride, bromide, nitrate, phosphate and sulphate), monovalent cations (e. g sodium, ammonium and potassium), divalent cations (e. g calcium and magnesium) heavy metals (e. g. iron, copper, zinc, nickel, cobalt, cadmium and manganese) and organic compounds – from water samples of rivers of Brunei Darussalam, namely, Brunei River, Belait River, Tutong River and Temburong River. The higher values of certain parameters with respect to the acceptable standard limits for river water indicate the pollution in river water samples of the study area, make the waters unsuitable for various applications and do pose a human health hazard. The pH levels in Brunei Darussalam is quite reassuring and mostly safe. Although there are some stretches of rivers that show slightly lower levels of pH, there is no cause for any alarm as these waterways are not sources of drinking water. As for anions and cations, the only anion of significant levels detected in Brunei Rivers is chloride whereas only monovalent cation detected in significant levels, is sodium. The concentrations of chloride and sodium ions are below the standard concentrations. Brunei Rivers are still free from chloride and sodium pollution. For heavy metals, only iron is detected in Brunei Rivers. Brunei being a oil based country experiments were done to identify levels of a numbers of significant toxic organic compounds, including, toluene and benzene which have been detected in the waters of the oil mining district of Belait District but are within normal limits. The use of a photolytic cell system to achieve the photodegradation of benzene, toluene, ethylenediaminetetra-acetic acid (EDTA) and the surfactant – hexadecyltrimethyl-ammonium bromide (C19H42NBr) is reported. The system has been optimised by investigating the effects of the addition of hydrogen peroxide (H202) as an oxidant and the addition of titanium dioxide (TiO2) as a catalyst. The results show that the photolytic system can be used to achieve >99% degradation of organic contaminants. The research also includes a final chapter on management system which covers water protection, pollution control and solid waste management in Brunei. In addition to investigating various factors of the solid waste management in Brunei, the researcher has also exposed some of the weaknesses that need immediate addressing. Various measures have been suggested to make Brunei's water more efficient. Moreover, ways of preserving the high quality of Brunei's water figures in this chapter.

The work described in the two parts of this thesis is concerned with the development of two methods for the synthesis of substituted olefins. Both methods involve elimination reactions of (beta)-hydroxysilanes to form the double bond, therefore in the general introduction these reactions are discussed together with the methods available for the preparation of (beta)-hydroxysilanes ... [see pdf file for full abstract].

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Includes bibliographical references. / 1 v. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / The mechanism(s) by which calcium stabilises soil organic carbon against microbial attack was investigated in this study. / Thesis (M.A.)--University of Adelaide, Dept. of Soil Science, 1989

Bibliography: leaves 322-335. / xxxvii, 343 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Highlights the need for extensive testing of large particle coal devolatilization models with both volatile matter evolution and particle temperature data in order to ensure that the predictions generated by the model can be thoroughly trusted. By undertaking an in-depth investigation into the particle temperature measurements and associated model predictions, shows that accurate model predictions can be obtained for the evolution of volatile matter, and of individual volatile species. The model is also capable of predicting the behaviour of wet coal particles by assuming that drying is heat transfer controlled and that the enthalpy of drying observed by Chen is applicable. Ultimately, this model forms a sound basis for the on-going development of a model encompassing all of the reactions required to model the behaviour of a typical coal particle in a fluidished bed combustor or gasifier. / Thesis (Ph.D.)--University of Adelaide, Dept. of Chemical Engineering, 1999

Bibliography: leaves 322-335. / xxxvii, 343 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Highlights the need for extensive testing of large particle coal devolatilization models with both volatile matter evolution and particle temperature data in order to ensure that the predictions generated by the model can be thoroughly trusted. By undertaking an in-depth investigation into the particle temperature measurements and associated model predictions, shows that accurate model predictions can be obtained for the evolution of volatile matter, and of individual volatile species. The model is also capable of predicting the behaviour of wet coal particles by assuming that drying is heat transfer controlled and that the enthalpy of drying observed by Chen is applicable. Ultimately, this model forms a sound basis for the on-going development of a model encompassing all of the reactions required to model the behaviour of a typical coal particle in a fluidished bed combustor or gasifier. / Thesis (Ph.D.)--University of Adelaide, Dept. of Chemical Engineering, 1999

Persistent organic pollutants are a well-known threat to the environment. Substances such as polycyclic aromatic hydrocarbons and chlorinated organic compounds in contaminated soil and groundwater can have severe and long-lasting effects on health in animals and humans. There is an urgent need for the development of safe technologies for their effective removal. Originally developed for mineral processing, mechanical treatment by ball milling is an extremely versatile technique for the degradation of toxic compounds. Reactive milling can rapidly destroy organic compounds without producing hazardous wastes. Complete breakdown of the organic molecules is achieved after relatively short milling times. Successful tests were conducted on polychlorobiphenyls (PCBs), DDT, DDD, DDE, Dieldrin and hexachlorobenzene with a conversion yield in the of greater than 99% (Hall et al., 1996; Monagheddu et al., 2000; Zhang et al., 2001; Zhang et al., 2002; Tanaka and Zhang, 2003; Pizzigallo et al., 2004; Nomura et al., 2005; Bellingham, 2006).In this study reactive ball milling was used to investigate the destruction of two classes of persistent organic pollutants environmental contaminants. The compounds studied are either known environmental pollutants or simple analogues. These were chosen as being representative of pollutants to investigate the pathway using ball milling destruction and in most cases were relatively small molecules so that the intermediates could be more easily identified. The first class of compounds was polycyclic aromatic compounds. Some smaller members of this class such as naphthalene, anthracene were investigated. The second class of compounds were some analogues of environmentally hazardous hydroxylated and halogenated compounds such as chloronaphthalene, bromonaphthalene, 1- naphthol, 2-naphthol and pentachlorophenol under reactive milling using GCMS analysis of the degradation pathway. Destruction efficiencies greater than 99% have been achieved for a number of organic compounds. Several different intermediates have been identified during the milling degradation. There was also some evidence from this study that halogens could be transferred between compounds during milling. The final products of the milling destruction of these compounds are an amorphous carbon residue and inorganic chloride or bromides. It was proposed that large amounts of halogens could be found however the results showed that small amounts detected. At early stages of milling a number of intermediate breakdown products were detected which were destroyed on extended milling. The core objective of this research was to clarify the reaction mechanisms pathways used of more complex polycyclic aromatic hydrocarbons and aromatic organ halogen compounds. This study is a part of a long-term research project on the destruction of toxic organic compounds by reactive milling.

Thesis (M.S. - Hydrology and Water Resources)--University of Arizona. / Includes bibliographical references (leaves 270-273).