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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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    Adsorption of pentachlorophenol onto activated carbon in a fixed bed : a thesis presented in partial fulfilment of the requirements for the degree of Master of Technology in Environmental Engineering at Massey University
    (Massey University, 1995) Slaney, Andrew James
    The adsorption of pentachlorophenol (PCP) from water onto granular activated carbon (GAC) was studied. Equilibrium and kinetic behaviour was studied, and the results used to predict fixed bed adsorber behaviour. Batch equilibrium tests showed that the adsorption capacity of activated carbon for PCP is best represented by the Freundlich isotherm, with constants of K = 95 and 1/n = 0.18. Batch adsorption kinetics experiments were conducted in a spinning basket reactor. Surface diffusion and external film transfer coefficients were determined by fitting the homogeneous surface diffusion model (HSDM) to the experimental batch adsorption data. A surface diffusion coefficient value of 2.26 x 10-9cm/s was calculated using this method, which was similar to surface diffusion coefficients for similar compounds found by other investigators. Using equilibrium and kinetic parameters, the HSDM was used to predict bench scale fixed bed adsorber breakthrough curves at varying flow rates. A correlation was used to calculate the film transfer coefficient. There was a good agreement between the experimental breakthrough curves and those predicted by the model. By varying parameters in the model it was found that the adsorption rate in the PCP-activated carbon system was primarily limited by surface diffusion. The homogeneous surface diffusion model was shown to be effective in predicting breakthrough of PCP and could conceivably be used to predict full scale adsorber performance or to aid pilot plant studies.
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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.