The microbial degradation of pyrene, a 4-ring polycyclic aromatic hydrocarbon (PAH), has been elucidated with the increasing number of pyrene-degrading bacteria that have been isolated in recent years. A pyrene degrading bacterium identified as Mycobacterium sp. strain S65, was isolated from a jet-fuel contaminated site in Sept-Iles, northern Quebec, Canada. S65 utilized pyrene, phenanthrene, and fluoranthene as sole carbon and energy sources, but did not degrade naphthalene, anthracene, and fluorene. Pyrene mineralization was enhanced by adding benz[a]anthracene, benzy[a]pyrene, or phenanthrene as cosubstrates. When added to PAH contaminated soil as a potential bioaugmentation agent, S65 did not appear to survive well, nor was it effective at degrading PAHs under these conditions. / Pyrene catabolic genes in S65 were partially characterized by Southern hybridization using a probe constructed from the naphthalene inducible pyrene dioxygenase gene, nidA, from the pyrene-degrading bacterium, Mycobacterium sp. strain PYR-1.

Numerous streams on the West Coast drain catchments impacted by active or abandoned coal mining areas. Acid mine drainage (AMD) from coal mining can have significant negative effects on stream communities. Changing environmental ethics and regulations mean that mining companies are now encouraged to treat acid mine drainage to enable streams communities to recover. However, remediation efforts have not always been ecologically successful, and mining companies are seeking methods to enhance macroinvertebrate community recovery. Initially, I conducted an extensive survey of 45 streams draining the Stockton Plateau, which is the site of the largest opencast coal mine in New Zealand. I assessed physical and chemical conditions at each site as well as sampling benthic communities. This spatial survey showed streams impacted by acid mine drainage were comprised of chironomids and AMD-tolerant caddisflies such as Psilochorema and stoneflies such as Spaniocercoides. Un-impacted streams typically had a pH of ~5 and were dominated by mayflies (Deleatidium or Zephlebia). Analysis revealed that stream location within the landscape also had a significant influence on macroinvertebrate community composition. Another aspect of stream recovery is the ability of species to recolonise a stream. Therefore, I investigated the flight direction of adult aquatic insects in order to determine longitudinal and lateral flight preferences. No significant differences in flight direction were observed. I also investigated the influence of riparian habitat on lateral dispersal and found that a number of patterns were evident. Scrub vegetation supported higher densities of adult aquatic insects dispersing further from the stream, in contrast to the rapid decline in open bedrock and forest. Furthermore, a comparison between downstream drift and aerial flight showed significantly more individuals where drifting downstream, and this method is liable to provide rapid recolonisation of macroinvertebrates within connected stream networks. At the local scale, organic matter (comprising leaves bags and timber) and artificial moss cover were added to six streams to determine if organic matter and habitat availability would improve macroinvertebrate communities in manipulated streams. A series of floods during the experiment reduced taxonomic richness and density in manipulated streams. Overall, this study has shown that after AMD has been treated, the geographic position of streams within the landscape and lateral dispersal barriers may prevent streams being rapidly re-colonised. Therefore, to promote rapid re-colonisation of macroinvertebrates, stream remediation projects should be targeted at streams that either have un-impacted headwaters or tributaries. This will allow macroinvertebrates to drift in and re-colonise faster. In my experiment I did not find that organic matter significantly enhanced the macroinvertebrate community, but moss additions did provide additional habitat for macroinvertebrates. These results highlight the importance that disturbance events can have on remediation projects.

Monitored natural attenuation is a cost-effective remediation strategy for the risk reduction of chemicals of concern (CoCs) in contaminated land and waters. This study considers three genuine sites in Germany, undergoing remediation. The objective was to measure a suite of physicochemical and biological parameters, and characterise the sites based on these data. The sites differed by their prevalent type of CoC, with one site impacted by polycyclic aromatic hydrocarbons (PAH), and two sites, situated in Hilden, impacted by BTEX. Sampling of microorganisms was performed using the industrial partner's newly developed matrix. This matrix was used for measurements of microbial respiration rate, ATP content, and 14C mineralisation rate, while groundwater samples were used for microbial luminescent biosensor assays (applying Escherichia coli HB101 pUCD607, Pseudomonas putida F1 Tn5, and Pseudomonas putida F1 TVA8), and for the chemical analysis of CoC, nitrate, iron, manganese, sulphate, and phosphate concentration. Microbial biosensors and respiration tests performed well in the identification of BTEX impacted wells at the Hilden sites, while the results for ATP content and 14C mineralisation were more ambiguous. Factor analysis showed a high impact of sulphate concentration. However, several strong correlations existed between measured parameters, so no single driving force, but a set of environmental influencing factors could be identified at the sites. The remediation progress could be demonstrated by the changes in cluster analyses between two time points. Sulphate and redox potential, the most influential parameters of the Hilden physico-chemical data set, were highlighted and confirmed by multiple linear regression, using a calculated attenuation rate as the dependent variable. Based on this outcome, a reduced sampling regime was proposed. This approach has the potential to reduce sampling costs and time at hydrocarbon contaminated sites, and has adequately demonstrated the use of statistical methods in assessing the remediation progress at a site.

This practicum investigates the reintroduction of a globally recognized at-risk plant community, Alvar, into an abandoned limestone quarry, located in the town of Inwood, in the Interlake Region of Manitoba. Alvar develops naturally over the course of thousands of years, and also naturally exists on exposed limestone bedrock, which is subsequently one of the greatest indicators of suitable areas for limestone quarrying. By utilizing recent techniques proven to be effective in Alvar regeneration, this practicum focuses on the landscape architect as a pivotal tool in creating a functional landscape, both in terms of environmental, social, and economic integrity. Using an ecotourism-based approach to engage the public with the site, while creating a platform for Alvar regeneration and future scientific research initiatives provides an economic, ecological, and social solution to some of the most negatively viewed aspects of the area. This practicum offers an alternative solution to traditional quarry rehabilitation strategies as well as the at-risk Alvar plant communities: strengthening it by reintroducing it in a post-industrial landscape, while raising awareness about its historic and ecological significance in an ecotourism-based outlet.

There is no abstract available for this thesis. / Department of Natural Resources and Environmental Management

No description available.

Petroleum hydrocarbon (PHC) contamination poses a serious threat to aquifer systems worldwide. Accidental releases of PHCs due to gasoline spills and leakage from underground storage tanks can often result in PHC subsurface contamination. The main compounds of concern associated with gasoline spills are benzene, toluene, ethylbenzene and xylenes (BTEX), trimethylbenzenes (TMBs) and naphthalene, due to their high mobility and potential human health risks. Sodium persulphate is one of the newest oxidants to gain widespread use for in situ chemical oxidation (ISCO), however its effectiveness in treating PHCs is not fully understood. In this study, the ability to use unactivated sodium persulphate as a remediation tool in treating dissolved and residual BTEX contamination was tested during a bench-scale laboratory study and within a pilot-scale field investigation. In both cases unactivated sodium persulphate was used at a concentration of 100 g/L. A laboratory-scale degradation potential batch test was conducted to assess the efficacy of unactivated sodium persulphate to oxidize petroleum hydrocarbon contaminated groundwater in conjunction with aquifer material from a field site. Data from the control reactions indicated that persulphate was stable for the entire 35-day experimental period and that the decrease in PHC concentrations for most of the samples followed a first-order degradation. The behaviour and ability for sodium persulphate to oxidize dissolved and residual BTEX contamination was further evaluated in a controlled pilot scale field study. 200 kg of sodium persulphate was dissolved in 2000 L of water and injected into the subsurface. Electrical conductivity (EC), pH, sodium, persulphate, sulphate and BTEX concentrations were all monitored throughout the 158-day study period. Field research showed that there was a strong correlation between EC and sodium concentrations. Hence, this relationship allowed for real-time EC measurements to be used to effectively predict the extent of the injectate. Based on the calculated aqueous density of sodium persulphate at a concentration of 100g/L, predicted simulation model results and observed tracer field results, density effects were present and played a very important role in the transport of the injectate. The heterogeneous geology of the site also greatly influenced the transport of the injectate. The majority of the injectate appeared to have flowed out of the layers with higher hydraulic conductivity that intersected the upper and lower portion of the injection well’s screen length. The extent of the injected slug in the layers with lower hydraulic conductivity located in the centre portion of the injection well’s screen length was less in comparison. In general, areas with elevated tracer, persulphate and sulphate concentrations, also showed a decrease in BTEX concentration. Four main responses were observed. Group 1 consists of sampling points where tracer levels were elevated along with a corresponding short-term decrease in dissolved BTEX. Group 2 consists of sampling points where elevated tracer levels was observed along with a long-term apparent decrease in dissolved BTEX. Group 3 consists of sampling points where the tracer was elevated however dissolved BTEX levels remained essentially at background levels. And finally, group 4 consists of sampling points where the tracer was not observed to be elevated hence no decrease in dissolved BTEX was observed. Laboratory studies showed that the oxidation of BTEX compounds by unactivated sodium persulphate could be very successful. However, field study results showed that complexities such as heterogeneity of the field site and injectate density effects play a key role in the success of the remediation system.

Thesis (M.S.)--University of Hawaii at Manoa, 2006. / Includes bibliographical references (leaves 138-163). / xii, 163 leaves, bound ill. 29 cm

The enhancement of bioremediation by bioaugmentation in soil contaminated with diesel fuel No. 2 and No. 6 (Bunker C) is uncertain. A clayey soil was contaminated with 6,000 mg of either diesel fuel per kg of soil and seeded (5 x 10-7 cells/g of soil) with a Hawaii soil bacterium (UH138) known to utilize several hydrocarbons. The soil was limed, fertilized, and incubated in jars at 30°C for several months. The concentrations of total petroleum hydrocarbons (TPH) and of polycyclic aromatic hydrocarbons (PAH) in soil were measured by gravimetry and immunoassay, respectively. Poisoned controls (0.6% HgCl2) were used to determine the extent of hydrocarbon degradation due to microbial activity. A rapid first order biodegradation of TPH (84% in 23 days) occurred in soil contaminated with diesel fuel No. 2, regardless of bacterial seeding. Biodegradation of PAH was linear and reached 84% by day 98 in both seeded and unseeded treatments. Bioaugmentation had no effect on bioremediation of diesel fuel No.2. The decrease in TPH and PAH was paralleled by an increase in populations of total bacteria, phenanthrene-degrading bacteria and microorganisms capable of utilizing hexadecane and diesel fuel No. 2 as well as by an enhancement in CO2 evolution by the soil. Indigenous Zygomycetes grew profusely in diesel fuel No. 2 contaminated soil. Cunninghamella echinulata var. echinulata was isolated from the soil and was shown to be able to utilize several hydrocarbons. Thus, Zygomycetes may have contributed to the rapid decrease in contaminant. In soil contaminated with diesel fuel No. 6, the measurements of TPH and PAH were more variable due to the uneven distribution of the product. No biodegradation of the contaminant occurred over a period of 138 days. The growth of Zygomycetes was scant. The counts of total bacteria remained unchanged after the addition of diesel fuel No. 6. However, counts of the indigenous phenanthrene-degrading bacteria increases dramatically ( 4 log units) during the first 54 days whereas the level of the seeded bacteria remained stable. The counts of mineral oil degraders decrease by 2 log units after day 2. Co2 evolution from the soil confirmed that diesel fuel No. 6 was not degraded by either the indigenous microflora or the seeded bacterium. Thus, diesel fuel No. 2 was highly degradable by the indigenous population, however, diesel fuel No. 6 was recalcitrant. / Thesis (M.S.)--University of Hawaii at Manoa, 1998. / Includes bibliographical references (leaves 106-117). / Available also on microfiche. / Department of the Interior; U.S Geological Survey via Water Resources Research Center

Thesis (M.S.)--California Polytechnic State University, 2009. / Mode of access: Internet. Title from PDF title page, viewed on March 30, 2009. Major professor: Yarrow Nelson, Ph.D. "Presented to the Electrical Engineering Department Faculty of California Polytechnic State University, San Luis Obispo." "In partial fulfillment of the requirements for the degree of Master of Science in Civil and Environmental Engineering." "March 2009." Includes bibliographical references (p. 133-140). Will also be available on microfiche.