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    Water and solutes in soil : hydraulic characterisation, sustainable production, and environmental protection : application for the degree of Doctor of Science from Massey University, Palmerston North, New Zealand
    (Massey University, 2002) Clothier, Brent E
    The soil of the rootzone, the fragile and fertile interface between the atmosphere and the subterranean realm, is characterised by massive transfers of water and solutes. Our understanding of the biophysical transport processes into, and through, soil has been enhanced by the research endeavours of the applicant, Brent Euan Clothier. Dr Clothier, a 1977 Ph.D. graduate of Massey University, has developed tools and techniques that increased the acuity of our vision of transport processes of water and solutes in soil, as well it has sharpened our ability to hydraulically characterise those mechanisms for the purpose of modelling and risk assessment. His research has also enhanced our understanding of how these biophysical processes affect sustainable agriculture, environmental protection, and the bioremediation of contamination. These endeavours are grouped, in this thesis, into four overlapping areas of research: • Processes and properties of water movement into and through soil • Processes and properties of solute movement through soil • Root uptake processes and sustainable irrigation • Plants, groundwater protection and bioremediation of contaminated soil. The key elements of these four themes, and their contribution to knowledge, form Chapters 2-5 of this thesis. Dr Clothier's awards, honours, and impact are discussed in Chapter 6.
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    Bioremediation of contaminated soil : a thesis presented in partial fulfilment of the requirements for the degree of Master of Technology in Environmental Engineering at Massey University
    (Massey University, 1997) Wotherspoon, Robert Jason
    The release of contaminants into the environment is inevitable. Contaminants are released through manufacture and use of products and as a result of treatment and disposal of wastes. Upon release to the environment, contaminants move and respond to a number of interrelated natural and man made factors. Penta-chloro-phenol (PCP) is one such contaminant that has been released into the environment and is known to have serious long term environmental effects. The objective of this study was to determine the effectiveness of biological processes to remediate soil contaminated with Penta-chloro-phenol (PCP). This thesis reviews mechanisms by which soil is contaminated, processes available to remediate soils, and in particular, process requirements for successful bioremediation. The abilities of bacteria to degrade PCP from soil contaminated with PCP was evaluated. Solid phase and slurry phase experiments were examined for their effect on PCP concentration over a four month period at the Department of Technology. Massey University. The objectives of this study were (1) To determine if aeration and inoculation of soil in-situ could produce significant removal of PCP. (2) Determine the effect of concentration on bioremediation rates. (3) Compare in-situ treatment with bio-slurry treatments. The experiments showed that it is possible to remove up to 95% of PCP from contaminated soil by inoculation with bacteria. Inoculum size and aeration were shown to be critical factors in affecting the rate of degradation. The larger the initial inoculum the greater the rate of degradation. Without aeration the inoculum was unable to significantly degrade PCP. The bio-slurry confirmed that PCP could be removed readily from soil to an aqueous state. In an aqueous state PCP is degraded at a faster rate than when it is incorporated into the soil matrix. The results of this work is to show that soil rehabilitation by way of biodegradation is a feasible and attractive process.
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    Biodegradation of pentachlorophenol : a thesis presented in partial fulfilment of the requirements for the degree of Master of Technology in Environmental Engineering at Massey University
    (Massey University, 1999) Flynn, Martha
    Three isolates previously isolated from pentachlorophenol (PCP) contaminated soil as a consortium were tested for their ability to remove PCP from a minimal mineral salts medium with and without vitamin supplementation. Only one of the isolates, designated Bradyrhizobium sp. strain ET01, could utilise PCP as a sole source of carbon and energy. The other two isolates designated Pseudomonas putida strain ET02 and formerly Pseudomonas aureofaciens strain ET03 could grow in the presence of PCP but could not utilise it as a sole source of carbon and energy. The effects of various initial PCP concentrations and vitamin supplementation on the kinetics of PCP removal and the cell numbers for ET01 and culture combinations was tested. An increasing initial PCP concentration affected the PCP removal rate, the lag period, the cell yield, cell numbers and specific growth rate. PCP removal by ET01 ceased at a concentration of 175mg/1. The PCP removal rate increased for ET01 in pure culture through the course of the experiments. The rate of removal at 150mg/1 initial PCP concentration improved from 1.48mg/1/hr to 1.85mg/1/hr. The rate of removal at 120mg/1 initial PCP concentration improved from 1.38mg/1/hr to a maximum of 2.10mg/1/hr. The shortest lag period was 4 hours for ET01 in pure culture on 20mg/1 initial PCP concentration. The lag period for ET01 in pure culture was 0.30 of the initial PCP concentration. The size of the inoculum of ET01 had an effect on the lag period and the rate of PCP removal. Cell yield was extremely low for ET01 and the culture combinations at all initial PCP concentrations tested. Measurable PCP removal was observed when the cell density of ET01 reached approximately 1x10 7 cells/m1. The final number of cells for ET01 for initial PCP concentrations over the range of 20mg/1 to 150mg/1 was approximately 5.5x107 cell per m1 (0.09mg/1). The highest specific growth rate for ET01, 0.06hr-1, occurred in media containing yeast extract and at an initial PCP concentration of 40mg/1. Continuous subculturing under the selective pressure of PCP as the sole carbon and energy source in media containing yeast extract led to an increased PCP removal rate and a decreased lag period for ET01. There was a slight increased rate effect of combining ET01 and ET02, but generally ET01 in pure culture removed PCP at a higher rate than any of the culture combinations.
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    Practical aspects of phytoextraction : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Earth Science, Massey University, Palmerston North, New Zealand
    (Massey University, 2000) Anderson, Christopher William Noel
    Phytoextraction for heavy metals is an emerging technology that has potential application for the remediation of many contaminated sites around the world. The technology has similar application to the mining of low-grade ore bodies. Several practical aspects of the technology are addressed in this thesis. Natural and induced-uptake phytoextraction trials have been conducted on two contaminated substrates: an area of industrial pollution in northern France, where base metals are present in an oxide and carbonate mineral phase, and an area of mine tailings in New Zealand, where base metals are present in a sulphide or sulphate mineral phase. The uptake response of several hyperaccumulator and non-accumulator plant species is described. Geochemical models are then presented that explain the observed metal uptake as a function of the predominant chemical form of metal present in the soil. Natural uptake is dependent upon the form of metal. It appears that the relative efficacy of various hyperaccumulator species to accumulate metals is also dependent upon site-specific geochemistry. The efficacy of chelating agents, in particular EDTA, to induce uptake is similarly dependent upon the chemical form of metals in the soil. A field trial for cadmium phytoextraction was conducted on an area of pastoral land contaminated with this metal due to the application of cadmium to soil through superphosphate fertilisation. Natural uptake at this site by the hyperaccumulator species Thlaspi caerulescens could remove the equivalent of 17 years of annual cadmium application in one harvest. The chelating agent EDTA (ethylenediaminetetraacetic acid) did not induce significant uptake by the non-accumulator Brassica species. Instead, the action of this chemical was to redistribute 14% of the cadmium initially present in the 0-5 cm soil depth to the 5-10 cm depth, and to leach approximately 4% of the cadmium initially present at the site to below 10 cm in the soil profile, as shown by mass balance calculations. Phytoextraction effected by T.caerulescens is proposed as a management tool for cadmium in the pastoral environment. Phytoextraction for nickel has been investigated at a field site in the central North Island of New Zealand. Hyperaccumulation was effected by two Alyssum species and by Berkheya coddii. However, the biomass of the harvested plant material was below that reported in the literature. The conclusion from this trial is that substrate modification of ultramafic soil may be necessary before phytoextraction for nickel could be implemented. A significant obstacle hindering the practical application of phytoextraction in some environments, is the paucity of hyperaccumulator species that are native to some parts of the world. Western Australia has many sites that may benefit from phytoextraction for nickel. However, only one hyperaccumulator species is native to this region, Hybanthus floribundus, a species that has in the past been difficult to germinate from seed. This thesis describes a successful approach to germination, involving the use of one-year-old seeds, treated with 'Regen 2000 smoke water' and germinated under dark conditions, that may overcome this practical aspect (a limitation) of phytoextraction technology. The most recent advance of induced phytoextraction technology has been the thioligand-induced uptake of gold by plants. The initial discovery and the geochemical rationale behind the induced uptake of gold is described. The maximum gold uptake presented is accumulation of 57 mg/kg dry weight gold by Brassica juncea and it is proposed that this level of uptake could make the phytomining of gold from tailings areas an economic proposition. The conclusion of this thesis is that potential for the implementation of phytoextraction is large. Globally, the technology could offer an environmentally and economically friendly alternative to the traditional decontamination of metals from some sites. There is also potential for the phytomining of metals from low-grade ores. The social implications of phytoextraction technology in third-world countries could also be large. Phytoextraction for gold, for example, from auriferous tailings in Africa and South America, has the potential to improve both the environment and the standard of living of the local communities who live off contaminated land.