Effect of pH on the uptake of arsenate and vanadate and the stability of these anions in alkaline solutions – a Raman spectroscopic study

Hydrotalcites have been synthesised using three different pH solutions to assess the effect of pH on the uptake of arsenate and vanadate. The ability of these hydrotalcites to remove vanadate and arsenate from solution has been determined by ICP-OES. Raman spectroscopy is used to monitor changes in the anionic species for hydrotalcites synthesised at different pH values. The results show a reduction in the concentration of arsenate and vanadate anions that are removed in extremely alkaline solutions. Hydrotalcites containing arsenate and vanadate are stable in solutions up to pH 10. Exposure of these hydrotalcites to higher pH values results in the removal of large percentages of arsenate and vanadate from the hydrotalcite interlayer.

A Near-infrared and Raman spectroscopic study of the mineral richelsdorfite Ca2Cu5Sb[Cl|(OH)6|(AsO4)4]•6H2O

Raman spectroscopy has enabled insights into the molecular structure of the richelsdorfite Ca2Cu5Sb[Cl|(OH)6|(AsO4)4]·6H2O. This mineral is based upon the incorporation of arsenate or phosphate with chloride anion into the structure and as a consequence the spectra reflect the bands attributable to these anions, namely arsenate or phosphate and chloride. The richelsdorfite Raman spectrum reflects the spectrum of the arsenate anion and consists of ν1 at 849, ν2 at 344 cm−1, ν3 at 835 and ν4 at 546 and 498 cm−1. A band at 268 cm−1 is attributed to CuO stretching vibration. Low wavenumber bands at 185 and 144 cm−1 may be assigned to CuCl TO/LO optic vibrations.

A Raman and infrared spectroscopic study of the mineral delvauxite CaFe3+4(PO4,SO4)2(OH)8•4-6H2O- a ‘colloidal’ mineral

The mineral delvauxite CaFe3+4(PO4,SO4)2(OH)8•4-6H2O has been characterised by Raman spectroscopy and infrared spectroscopy. The mineral is associated with the minerals diadochite and destinezite. Delvauxite appears to vary in crystallinity from amorphous to semi-crystalline. The mineral is often X-ray non-diffracting. The minerals are found in soils and may be described as ‘colloidal’ minerals. Vibrational spectroscopy enables determination of the molecular structure of delvauxite. Bands are assigned to phosphate and sulphate stretching and bending modes. Two symmetric stretching modes for both the phosphate and sulphate symmetric stretching modes support the concept of non-equivalent phosphate and sulphate units in the mineral structure. Multiple water bending and stretching modes imply that non-equivalent water molecules in the structure exist with different hydrogen bond strengths.

Construction 2020 - A vision for Australia's Property and Construction Industry

Construction 2020 is a national initiative undertaken by CRC for Construction Innovation to focus its ongoing leadership of the Australian property and construction industry in applied research and best contribute to the industry's national and international growth and competitiveness. It is the first major report on the long-term outlook for the industry since the late 1990s. The report identifies nine key themes for the future of the property and construction industry. These visions describe the major concerns of the industry and the improved future working environment favoured by its stakeholders. The first and clearest vision, agreed across the industry, is that environmentally sustainable construction the creation of buildings and infrastructure that minimise their impact on the natural environment is an area of huge potential. Here technologies like Construction Innovation's LCADesign can make a big difference. This is a calculator that works out automatically from 3D computer-aided design the environmental costs of materials in a building all at the push of a button. By working with industry, we'd expect to have a comprehensive set of eco-design tools for all stages of the construction life cycle, to minimise energy use, greenhouse and other forms of waste or pollution. Other significant areas of focus in the report include the development of nationally uniform codes of practice, new tools to evaluate design and product performance, comparisons with overseas industries, and a worldwide research network to ensure that Australian technology is at the cutting edge.

Malaysia high-rise residential property management : 2004-2010 trends and scenario

Property management requires an understanding of infrastructure management, service life planning and quality management. Today, people are beginning to realize that effective property management in high-rise residential property can sustain the property value and maintaining high returns on their investment. The continuous growth of high-rise residential properties indicates that there is a need for an effective property management system to provide a sustainable high-rise residential property development. As intensive as these studies are, they do not attempt to investigate the correlation between property management systems with the trends of Malaysia high-rise residential property development. By examining the trends and scenario of Malaysia high-rise residential property development, this paper aims to gain an understanding of impacts from the effectiveness of property management in this scope area. Findings from this scoping paper will assist in providing a greater understanding and possible solutions for the current Malaysian property management systems for the expanding high-rise residential unit market. With current high rise units in excess of 1.3 million and increasing, the need for more cost effective management systems are of highly important to the Malaysian Property Industry.

Whole life cycle costing for Malaysia residential property development : the cultural environment

As knowledge of the residential development costing impact on resource and budgeting use increase, developers are moving towards more sustainable solution by implementing whole life cycle costing. Property management requires an understanding of infrastructure management, service life planning and quality management. Today, people are beginning to realize that effective property management in high-rise residential property can sustain the property value and maintain high returns on their investment. The continuous growth of high-rise residential properties indicates that there is a need for an effective property management system to provide a sustainable high-rise residential property development. For such reasons, this paper attempts to study the culture that have been applied due the residential property development in Malaysia as to improve to the best and sustainable practice in providing the best cost effectiveness management system in residential property development.

Molecular structure of Mg-Al, Mn-Al and Zn-Al halotrichites : an infrared spectroscopic study

Near infrared (NIR), X-ray diffraction (XRD) and infrared (IR) spectroscopy have been applied to halotrichites of the formula MgAl2(SO4)4∙22H2O, MnAl2(SO4)4∙22H2O and ZnAl2(SO4)4∙22H2O. Comparison of the halotrichites in different spectral regions has shown that the incorporation of a divalent transition metal into the halotrichite structure causes a shift in OH stretching band positions to lower wavenumbers. Therefore, an increase in hydrogen bonded water is observed for divalent cations with a larger molecular mass. XRD has confirmed the formation of halotrichite for all three samples and characteristic peaks of halotrichite have been identified at 18.5 and 24.5° 2θ, along with a group of six peaks between 5 and 15° 2θ. It has been observed that Mg-Al and Mn-Al halotrichite are very similar in structure, while Zn-Al showed several differences particularly in the NIR spectra. This work has shown that halotrichite structures can be synthesised and characterised by infrared and NIR spectroscopy.

Thermal analysis and infrared emission spectroscopic study of kaolinite-potassium acetate intercalate complex

The thermal behavior and decomposition of kaolinite-potassium acetate intercalation complex was investigated through a combination of thermogravimetric analysis and infrared emission spectroscopy. Three main changes were observed at 48, 280, 323 and 460 °C which were attributed to (a) the loss of adsorbed water (b) loss of the water coordinated to acetate ion in the layer of kaolinite (c) loss of potassium acetate in the complex and (d) water through dehydroxylation. It is proposed that the KAc intercalation complex is stability except heating at above 300 °C. The infrared emission spectra clearly show the decomposition and dehydroxylation of the kaolinite intercalation complex when the temperature is raised. The dehydration of the intercalation complex is followed by the loss of intensity of the stretching vibration bands at region 3600-3200 cm-1. Dehydroxylation is followed by the decrease in intensity in the bands between 3695 and 3620 cm-1. Dehydration is completed by 400 °C and partial dehydroxylation by 650 °C. The inner hydroxyl group remained until around 700 °C.

Infrared spectroscopic study of halloysite-potassium acetate intercalation complex

Mid-infrared (MIR) and near-infrared (NIR) spectroscopy have been used to study the molecular structure of halloysite and potassium acetate intercalated halloysite and to determine the structural changes of halloysite through intercalation. The MIR spectra show all fundamental vibrations including the hydroxyl units, basic aluminosilicate framework and water molecules in the structure of halloysite and its intercalation complex. Comparison between halloysite and halloysite-potassium acetate intercalation complex shows almost all bands observed for halloysite are also observed for halloysite-potassium acetate intercalation complex apart from bands observed in the 1700-1300 cm-1 region, but with differences in band intensity. However, NIR, based on MIR spectra, provide sufficient evidence to analyze the structural changes of halloysite through intercalation. There are obvious differences between halloysite and halloysite-potassium acetate intercalation complex in the all spectral ranges. Therefore, the reproducibility of measurement and richness of qualitative information should be simultaneously considered for proper selection of a spectroscopic method for molecular structural analysis.

The synthesis and spectroscopic characterisation of hydrotalcite formed from aluminate solutions

Raman spectroscopy has been used to characterise nine hydrotalcites prepared from aluminate and magnesium solutions (magnesium chloride and seawater). The aluminate hydrotalcites are proposed to have the following formula Mg6Al2(OH)16(CO32-).xH2O, Mg6Al2(OH)16(CO32-,SO42-).xH2O, and Mg6Al2(OH)16(SO42-).xH2O. The synthesis of these hydrotalcites using seawater results in the intercalation of sulfate anions into the hydrotalcite interlayer. The spectra have been used to assess the molecular assembly of the cations and anions in the hydrotalcite structures. The spectra have been conveniently subdivided into spectral features based upon the carbonate anion, the hydroxyl units and water units. This investigation has shown the ideal conditions to form hydrotalcite from aluminate solutions is at pH 14 using magnesium chloride. Changes in synthesis conditions resulted in the formation of impurity products aragonite, thenardite, and gypsum.

A Raman spectroscopic study of M2+M3+ sulfate minerals, römerite Fe2+Fe23+ (SO4)4· 14H2O and botryogen Mg2+Fe3+ (SO4)2(OH)·7H2O

The mixed valency (M2+M3+) sulphate minerals, römerite Fe2+Fe23+(SO4)4•14H2O and botryogen Mg2+Fe3+(SO4)2(OH).7H2O have been studied by Raman spectroscopy. The Raman spectra of the two types of crystals proved very similar but not identical. The observation of two symmetric stretching modes confirmed the presence of the two non-equivalent sulphate units in the römerite structure. The observation of multiple bands in the antisymmetric stretching region and in the bending regions proves the symmetry of the sulphate anion is significantly reduced in the römerite structure. The number of Raman bands related to the (SO4)2- symmetric and antisymmetric vibrations support the X-ray single crystal structure conclusion that two symmetrically distinct S6+ are present in the structure of botryogen. Römerite is a mineral of environmental significance as it is commonly found in tailings and dumps.

Raman spectroscopic study of the uranyl titanate mineral brannerite (U,Ca,Y,Ce)2(Ti,Fe)2O6 –Effect of Metamictization

Raman spectra of the uranyl titanate mineral brannerite were analysed and related to the mineral structure. A comparison is made with the Raman spectra of uranyl oxyhydroxide hydrates. Observed bands are attributed to the TiO and (UO2)2+ stretching and bending vibrations, U-OH bending vibrations, H2O and (OH)- stretching, bending and libration modes. U-O bond lengths in uranyls and O-H…O bond lengths are calculated from the wavenumbers assigned to the stretching vibrations. Raman bands of brannerite are in harmony with those of the uranyl oxyhydroxides. The mineral brannerite is metamict as is evidenced by the intensity of the UO stretching and bending modes being of lower intensity than expected and with bands that are significantly broader.

Regulating for Sustainability : Property Issues

All Australian governments recognize the need to ensure that land and natural resources are used sustainably. In this context, ‘resources’ includes natural resources found on land such as trees and other vegetation, fauna, soil and minerals, and cultural resources found on land such as archaeological sites and artefacts. Regulators use a wide range of techniques to promote sustainability. To achieve their objectives, they may, for example, create economic incentives through bounties, grants and subsidies, encourage the development of self-regulatory codes, or enter into agreements with landowners specifying how the land is to be managed. A common way of regulating is by making administrative orders, determinations or decisions under powers given to regulators by Acts of Parliament (statutes) or by regulations (delegated legislation). Generally the legislation provides for specified rights or duties, and authorises a regulator to make an order or decision to apply the legislative provisions to particular land or cases. For example, legislation might empower a regulator to make an order that requires the owner of a contaminated site to remediate it. When the regulator exercises the power by making an order in relation to particular land, the owner is placed under a statutory duty to remediate. When regulators exercise their statutory powers to manage the use of private land or natural or cultural resources on private land, property law issues can arise. The owner of land has a private property right that the law will enforce against anybody else who interferes with the enjoyment of the right, without legal authority to do so. The law dealing with the enforcement of private property rights forms part of private law. This report focuses on the relationship between the law of private property and the regulation of land and resources by legislation and by administrative decisions made under powers given by legislation (statutory powers).

A raman and infrared spectroscopic study of Ca2+ dominant members of the mixite group from the Czech Republic

Raman microscopy of two mixite minerals BiCu6(AsO4)3(OH)6.3H2O from Jáchymov and from Smrkovec (both Czech Republic) has been used to study their molecular structure, which is interpreted and the presence of (AsO4)3-, (AsO3OH)2-, (PO4)3- and (PO3OH)2- units, molecular water and hydroxyl ions were inferred. O-H…O hydrogen bond lengths were calculated from the Raman and infrared spectra using Libowitzky’s empirical relation. Small differences in the Raman spectra between both samples were observed and attributed to compositional and hydrogen bonding network differences.