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In this thesis, the measurements of carbon monoxide (CO) obtained from an nadir sounding Measurement Of Pollution In The troposphere (MOPITT) instrument are used. Atmospheric CO is one of the most abundant and widely distributed air pollutant and is a very important indirect greenhouse gas via its reaction with the OH radical which in turn controls the oxidising capacity of the troposphere. In this thesis, the MOPITT Level 2 Version 3 (L2V3) retrieved CO data is primarily used and compared with recently released (April 2009) Level 2 Version 4 (L2V4) retrieved CO data to examine the potential of the MOPITT instrument to differentiate emission features in the lowermost troposphere including mega-cities. This study develops a novel robust methodology using day-night difference profile simulations to examine the ability of the instrument to identify CO enhancements in the lowermost layer of the atmosphere using ‘typical’ averaging kernels. More realistic CO profiles from the TOMCAT model are then used to validate this methodology. The day-night difference simulations are performed for the Indian subcontinent. It is shown that for L2V3, the daytime and nighttime degrees of freedom for a signal (DOFS) exhibit a bi-modal distribution for all selected Indian regions. The L2V3 simulation study clearly demonstrates, for higher DOFS, that day700-night700 differences give a closer differentiation of lowermost CO than other measures for MOPITT data, the first time that this has been processed. For L2V4, similar DOFS distributions are observed for the Indian subcontinent. The L2V4 simulation study also demonstrates for the first time that day850-night700 CO differences give a closer differentiation of lowermost CO by taking account of L2V4 day and night a priori mixing ratios. Finally, the methodologies developed in chapter 3 and 4 are applied to identify spatially isolated signals of lowermost CO for one year of data i.e. 2007. Features associated with nearly 100 cities are identified, the use of thresholds for higher DOFS retrievals and the use of non-surface retrieval levels with less tie to a priori. The significant step forward being consistent day-night differences for two different analyses (L2V3, L2V4).

A factory in Colonie (NY, USA) emitted c. 4.8 ± 1 tonnes of depleted uranium (DU) particulates into a suburban environment during 1958 – 1984. These particulates were initially dispersed by prevailing winds. Quadrupole inductively coupled plasma mass spectrometry (ICP-MS), laser ablation multicollector (LA-MC-) ICP-MS, scanning electron microscopy (SEM) and microfocus extended X-ray absorption fine structure (μEXAFS) spectroscopy have been used to characterise soils, dusts, vegetation, and individual particles. The concentration range of natural uranium in Colonie soils is 0.7 — 2.1 μg g-1; with total uranium up to 500 ± 40 μg g-1 in DU contaminated soils. Bioturbation can account for dispersal of contaminant from the soil surface. Primary morphologies are described for uraniferous particles from soils and dusts. Polycrystalline, often hollow microscopic uranium oxide spheres are similar to particles produced by DU munitions impacting armoured targets. These survive as UO2+x and U3O8, the least bioaccessible oxides of uranium. Fruit and wood samples were contaminated by DU, demonstrating limited bioavailability. Deviation of 235U/238U from the natural isotope ratio allows detection of DU in soils to at least 5.6 km from site. The average DU ‘end-member’ composition aggregated in soil samples comprises (2.05 ± 0.06) x10-3 235U/238U, (3.2 ± 0.1) x10-5 236U/238U, and (7.1 ± 0.3) x10-6 234U/238U. Individual uranium oxide grains were analysed by LA-MC-ICP-MS, all of which were from DU, with variable isotopic compositions (236U/238U, 235U/238U & 234U/238U). There is no evidence of enriched uranium in Colonie soils and dusts. The isotopic compositions of the Colonie particles can be explained by the inhomogeneous mixing of at least seven batches of tails from the Paducah gaseous diffusion plant, which are identified as the origins of the DU feedstocks used by National Lead Industries at Colonie. LA-MC-ICP-MS is recommended for nuclear forensic applications. This case-study is an attractive analogue for battlefield contamination.

Benzyldimethyl Hexadecylammonium Chloride (BDHAC) is a quaternary ammonium compound (QAC) used in corrosion inhibitor formulations. It has both corrosion inhibition and biocidal properties. Studies have suggested that QACs in produced water are often discharged to the marine environment during oil exploration and production. The fate of these compounds on release to the marine environment, especially the ones with a benzyl ring, is not well understood. On reaching the marine environment, QAC adsorb onto sediment and may become bioavailable and toxic to the benthic communities. Therefore bioremediation of sediment could be useful to help preserve the marine environment. A biodegradation study was carried out using an enrichment culture technique with marine sediment, to identify which marine bacteria degraded BDHAC and subsequent degradation products. Following enrichment in the presence of BDHAC, different strains of bacteria, isolated from marine sediments, were shown to degrade BDHAC in a minimal salts medium. The bacteria identified by 16S rDNA sequencing, were shown to belong to several genera and were identified as Marine bacterium, Bacillus subtilis, Bacillus niabensis, Sporosarcina sp., Thalassospira sp, Rhodospirillaceae and Staphylococcus equorum. Investigations revealed that these bacteria were capable of degrading BDHAC when it was present at high concentrations, in the range 2 – 4 mg/ml. In media containing BDHAC, up to 90% of the substance was degraded within 43 days. Quantification of BDHAC after biodegradation experiments were performed by Colorimetric Dye Binding Assay (CDBA) and Electrospray Ionisation Tandem Mass spectrometry (ESI-MS/MS). Preliminary analysis of samples by ESI-MS/MS produced a peak with a parent-daughter ion transition of 136.0 91.0, corresponding to N, N-dimethylbenzylamine. The presence of this potential metabolite suggested the cleavage of the C alkyl-N bond as a step in BDHAC catabolism. This research will contribute to an understanding of the potential of the isolated strains of bacteria in bioremediating BDHAC contaminated sites. It will also assist operators and regulators in the oil and gas industry to understand the fate of BDHAC in the environment when the compound is used in corrosion inhibitor formulations. This understanding will assist environmental risk assessment of oil production facilities.

A risk assessment strategy considering the impact of chemicals on the whole ecosystem has been developed in order to create a sound and useful method for quantifying and comparing global risks posed by the main different hazardous chemicals found in the environment. This index, called the Environmental Risk Index for a Complete Assessment (ERICA), merges in a single number the environmental assessment, the human health risk assessment and the uncertainty caused by missing or unreliable data. ERICA uses a scoring system with parameters for the main characteristics of the pollutants. The main advantage is that it preserves a simple approach by condensing in this single value an analysis of the risk for the area under observation. The availability and reliability of the data is an important part of the work done to build the index. Experimental and predictive data were compared to evaluate the reliability. Data were derived both from literature sources (experimental models mainly) and predictive models. ERICA can be considered a diagnostic and prognostic tool for environmental contaminants in critical and potentially dangerous sites, such as incinerators, landfills and industrial areas or in broader geographical areas. The application of the proposed integrated index provides a preliminary quantitative analysis of possible environmental alerts due to the presence of one or more pollutants in the investigated site. This thesis presents the method and the equations behind the index and a first case study based on the Italian legislation and a pilot study on a location on the Italian seacoast.

Active pharmaceutical ingredients (APIs) and their metabolites are ubiquitous in the environment and their occurrence in the aquatic environment is of growing concern. However, despite the fact that these may cause harmful effects in organisms found within this niche, little is currently known about the effects of APIs in the aquatic environment. Chiral pharmaceuticals are of particular concern as the enantiomers may be metabolised differently, with the potential for the production of an array of harmful compounds. There are many racemic APIs for treating human and animal conditions, and even in these target organisms the pharmacodynamic effects of the enantiomers are not always known. Within recent years the importance of the interactions of these compounds within the aquatic environment has been realised and information regarding the fate and biodegradation of such environmental pollutants is of great importance. The advent of post-genomic technologies has proved advantageous in the study of the effects of these environmental pollutants. In this thesis, the effects of a range of chiral APIs, and other environmental pollutants, on environmentally relevant microorganisms were investigated at the metabolome level. The effects of chiral APIs were investigated in a number of prokaryotic and eukaryotic systems in order to provide a comprehensive study of the effects of the APIs in the aquatic environment. FT-IR spectroscopy was employed for metabolic fingerprinting of some environmentally relevant bacteria and GC-MS was subsequently employed for metabolite profiling of two pseudomonads that had shown differential chiral effects with Propranolol. In addition, FT-IR microspectroscopy was employed for the investigation of the phenotypic and localised effects of chiral APIs in a eukaryotic system. Furthermore, the effects of a range of environmental pollutants on a complex bacterial community were investigated with the use of FT-IR spectroscopy and multivariate analysis. Initial results indicated a large phenotypic response in relation to phenol, and this was further explored with a range of ageing experiments and metabolic fingerprinting. An FT-IR peak was found to be characteristic of the phenotypic changes in the actively degrading communities and this was likely to be a degradation product of phenol, and armed with this knowledge the activated sludge community was monitored during the active degradation of phenol with the use of GC-MS.The work presented in this thesis has shown for the first time that metabolomics allows subtle phenotypes in microorganisms to be revealed when they are exposed to chiral forms of APIs which are commonly found in the aquatic environment. Despite these APIs not being designed for any interaction with bacteria and aquatic life in general these are significant findings and may have implications as more and more APIs become detectable and concentrated in the environment due to continued use in man and indeed animals or aquaculture.

An urban street canyon represents an environment where pollutants such as particulate matter accumulate to high levels. Regulatory guidelines of particulate matter based on the mass metric have led to the development of clean engine technologies that emit smaller particles (ultrafine «IOOnm) and fine «1 urn) which are believed to have greater health implications upon exposure. The modelling of the transport and transformation of fine and ultrafine aerosols will grant insight into the nature of dispersion within urban canyons and inform future studies. This investigation was done using a Computational Fluid Dynamics platform coupled with the Modal Method. Considering an idealized 2-D framework, using the l" order eddy viscosity turbulence model and treating aerosol particles as an inert scalar, the model is able to account for the dispersion structure of aerosol particle number concentration. Consistent with previous measurement results, modelling studies show that the vertical concentration structure at the leeward side of the canyon is such that there is an increase in aerosol concentration up to approximately 2 m in height, followed by a decrease along the height of the canyon and an even sharper decrease within the turbulent shear layer. The gradient of the structure vary at different locations in the canyon and canyon geometries due to differing extents of advection and turbulent diffusion. It is found that the escape of aerosol particles from canyons (when driven by forced convection from the roof level wind) is dominated by turbulent flux, although natural convection could modify the relative importance of turbulent and advective flux, such that advective flux may be equally important. Assuming a constant exhaust emission within the canyon, a parameterization is developed to relate particulate matter flux (from canyons) with inflow wind speed and turbulent intensity. This parameterization is also able to predict aerosol flux within neighbourhood scales fairly well; suggesting that flux measured within the inertial sublayer is an aggregation of fluxes from individual street canyons in the vicinity. The inert scalar treatment of aerosol particles needs to be evaluated by relating lifetimes of aerosol processes in relation to the residence times of particles within the canyon. For the canyon scale considered, it is found that the inert scalar assumption may be used to describe aerosol number dispersion as effects of coagulation on aerosol properties is found to be insignificant. Condensation is found to be significant only at unrealistically high levels of in-volatile species in the vapour phase and in the abundance of soot. If the content of semivolatile compound within the aerosol population is high, then effects of partitioning on aerosol properties may be important, rendering the inert scalar assumption inadequate to characterize aerosol mass concentration dispersion. In addition, partitioning is found to be sensitive to accommodation coefficient and molecular mass of the in-volatile core within the aerosol particle, pointing towards the need for a more accurate characterisation of these parameters.

Endocrine disrupting chemicals (EDCs) are one of the many anthropogenic pollutants released into the environment. There is a substantial body of literature that has shown a detrimental impact on wildlife, particularly aquatic species, following exposure to these pollutants. In particular, exposure to EDCs can cause disruptions in sexual development and reproductive function. The majority of the effects observed are alterations in the physiology and behaviour of individuals and a key research question that has yet to be fully addressed is whether the effects seen in individuals exposed to EDCs manifest in measurable changes in population parameters. Whilst some work has been conducted previously investigating the population-level impacts of EDC exposure, this work has generally used mathematical models to examine whether measured short-term changes in individual fecundity and survival may lead to alterations in population viability and growth in the long-term. Such an approach ignores the potential impact of EDCs on more subtle factors (for example alterations in behaviour and genetics) that can potentially affect fish population dynamics. The work presented in this thesis used two model species, the zebrafish, Danio rerio and stickleback, Gasterosteus aculeatus, to examine whether exposure to EDCs had an effect on previously ignored factors that determine group dynamics, including behaviour, parentage and reproductive success. In groups of zebrafish (two males and two females) exposure to the model oestrogenic compound ethinylestradiol (EE2) at 10 ng/L caused a reduction in the paternity success of the most successful male, reducing the skew in paternity, relative to controls. This disruption in the reproductive hierarchy was associated with a suppression of 11-ketotestosterone (11-KT) concentrations in exposed males. Such alterations in reproductive hierarchies have implications for population genetic diversity as well as usual patterns of sexual behaviour and selection. In a second study, males were exposed to EE2 (females were not exposed) and then placed into colonies of varying size with either 1, 2 or 4 males competing to breed with one female. The reproductive success of the most reproductively successful male in colonies containing two males and one female was unaffected by previous exposure to EE2, relative to controls, but was significantly affected for the most reproductively successful male in tanks containing four males competing to breed with one female. This finding suggests that the impact of EDC exposure on reproductive hierarchies and success is dependent on the group structure and is not a straightforward monotonic effect. It is well known that there exist so-called ‘windows of sensitivity’ for the effects of EDCs on sexual development in fish. Exposure to EDCs during this period can cause dramatic alterations in development, including complete sex reversal if the magnitude and/or duration of exposure are sufficient. In the third study in this thesis, zebrafish were exposed during the key window of sexual development, from 20-60 days post fertilisation (dpf). The reproductive success of both mature males and females was then examined in competitive breeding scenarios. Whilst there were no obvious effects of the early life EE2 exposures on the gonadal phenotypes in either males or females at maturity, the reproductive success in males exposed to 2.76ng EE2/L was increased. In contrast, exposure of females to 9.86 ng EE2 /L during early life reduced their subsequent reproductive success. Given the importance of female reproductive capability in population demographics and dynamics, the effect of exposure to EE2 on female reproductive success may therefore have significant implications for exposed fish populations. Whilst conducting the EE2 exposure experiments, it became clear that the genetic diversity in the laboratory strains of zebrafish was much lower than that previously published for wild zebrafish. A study was therefore conducted in which several laboratory strains of zebrafish and a population of zebrafish obtained directly from the wild in Bangladesh were genotyped in order to elucidate the genetic diversity in the different strains. The results showed that the genetic diversity in commonly used laboratory strains (even those described as outbred or ‘wild type’) was significantly lower than that of wild zebrafish. Given the impact of reductions in genetic diversity and variation on fitness at both the individual and population level, this has implications for studies that extrapolate results from laboratory studies to wild populations, as exposure to EDCs may have a different impact on laboratory strains than their more genetically diverse wild counterparts. The final study conducted examined populations of wild sticklebacks (Gasterosteus aculeatus) from either clean sites or sites with a history of exposure to anthropogenic pollutants, particularly EDCs from sewage effluent. All the populations examined from sites with a history of pollutant exposure showed evidence of population bottlenecks, whereas populations from clean sites did not. Fish from the different populations were then placed into competitive breeding mesocosms. Each mesocosm contained an equal number of males from a clean, control reference site and from one of the polluted sites. The same number of females from a clean, control reference site was also added to the mesocosm. Males from all polluted sites were able to compete and breed successfully when placed in these competitive breeding scenarios and there was no evidence that they had reduced reproductive success. The implication of this finding is that even if exposure to anthropogenic EDCs has impacted on the genetics of a wild population, the reproductive potential of individuals may not necessarily be altered.

The loss of ecological integrity as a result of urban spread and construction threatens the overall biodiversity of urban areas and prompts us to consider means of better including ecological biodiversity within development projects. The UK’s best practice tool for ensuring the integration of ecology into such projects is the Building Research Establishments Environmental Assessment Method (BREEAM). This thesis seeks to identify the efficacy of the current approach to ecological integration within BREEAM, and enable development to foster biodiversity and ecology more positively in the urban environment. Qualitative and quantitative research techniques were used to develop a new approach to the integration of ecology within an existing and nationally recognised model. This began by exploring the efficacy of and the main flaws in the present system by a survey of ecologists with experience of the BREEAM process. This led to a new approach to establishing the ecological value of urban ecology utilising a new calculation methodology, adapting the current scheme to focus on land use change as a result of urban land use planning and development. This new approach utilises habitat changes at its core to measure positive and negative change and indicate potential design solutions in land use planning within a development. The innovative methodology was tested using an in depth case study to review and discuss its effective application. The outcome was a new way to address the important variables of habitat integration and linkages maintaining ecological integrity and provision of ecosystem services. It is considered that the outlined approach of the new Land Use and Ecology section of BREEAM is suitable for integration into the next iteration in 2010, which will enable development to positively foster biodiversity and ecology in the urban environment.

This thesis is comprised of a collection of work on urban, brownfield and heavy metal contaminated soils carried out within the North West of England from March 2007 to December 2009. Field and laboratory based experiments were used to determine the amount of carbon stored in urban soils and fluxes of dissolved organic carbon and soil respiration. The effects of added organic amendments on carbon storage and mobility as well as the onward implications to heavy metals and arsenic mobility and the impact of earthworms on these processes were also investigated. A city-wide topsoil survey of parkland and road verges in Liverpool showed that carbon storage ranged from < 3 to > 10 kg total organic carbon m-2 whilst physico-chemical characteristics and heavy metal and arsenic concentrations also varied considerably. The abundance oftechnogenic material restricted organic carbon storage and flux to the upper 30 cm of an inner city lawn soil studied in greater detail. Brownfield soil carbon storage and fluxes were enhanced by adding a small amount of green waste compost to these soils but large applications did not greatly increase carbon storage further. Enhanced losses of carbon by dissolved organic carbon leaching and increased soil respiration rates were consequences of greenwaste compost additions, although these effects were highly seasonal, occurring in greatest magnitude at the warmest periods of the year. Proportionately, the annual losses of carbon to soil respiration were far greater than those to dissolved organic carbon. An amendment consisting predominantly of woody material and a biochar amendment had a lower impact than composted greenwaste on dissolved organic carbon mobility, and the co-mobilisation of heavy metals and arsenic in a soil from a previously heavily industrialised centre of population. Earthworms reduced dissolved organic carbon when inoculated with compost and biochar amended soil, but increased this soluble fraction of carbon in woody amended soils, with attendant consequence to trace metal and arsenic mobility. Zinc and cadmium mobility were largely independent of changes in soluble carbon, but arsenic, copper and lead were heavily influenced by added carbon. Biochar amendment proved very effective in reducing concentrations of soluble cadmium and zinc in a heavy metal contaminated soil by adsorption, as well as having the added benefit of reducing total and bioavailable polycyclic aromatic hydrocarbon (PAH) concentrations. It is concluded that carbon storage in urban soils can potentially be increased by applying organic amendments, although longer-term carbon storage may only be substantially enhanced with repeated applications of amendments. However, in urban soils with significant residual pollution, it can be questioned whether this practice is environmentally sound, regarding mobilisation of potentially harmful trace elements. Biochar and larger woody fraction amendments to soils may be more efficacious.

The objectives of this project were to determine the bacterial diversity in a heavily contaminated metal region of Portugal. Both traditional and molecular based methods were used to identify tolerant strains and species. The most tolerant species were subsequently identified and utilized for examining the potential for using them to immobilize specific metals from contaminated waste streams by comparing different support materials. Heterotrophic bacterial populations were isolated and characterized from a contaminated industrial area in Northern Portugal. In a first sampling, 278 strains were isolated in different solid media. To assess the diversity of this ecological site and to select representative strains, the isolates were screened by using Random Amplified Polymorphic DNA (RAPD)-PCR profiles. Phenotypic characterization, phylogenetic analysis by sequencing the 16S rRNA genes and metal tolerance tests with zinc (Zn), cadmium (Cd) and arsenic (As) were performed with the selected strains. Recovered gram-positive isolates were related to class Actinobacteria and Bacilli. The majority of the isolates were related to genera Microbacterium and Bacillus. Strains from the genus Arthrobacter were also well represented. 16S rRNA gene sequence similarity of the gram-negative isolates showed that they were related to classes γ-Proteobacteria, ß-Proteobacteria, a-Proteobacteria and Flavobacteria. The most frequently isolated taxa were γ-Proteobacteria, related with the genus Pseudomonas, where a large number of isolates were clustered. These genera are common in metal contaminated environments. Many of the strains (approx. 17) had a high level of tolerance to the heavy metals tested. A total of 13 isolates were not able to grow when metals were present. In a second sampling the soil rhizosphere was screened for bacterial populations, using metal-based selective media for isolation. About 42 strains were recovered when metal supplemented media was used. The gram-positive population were predominantly Bacilli and Actinobacteria members. Bacillus, Microbacterium and Arthrobacter were the most common gram-positive genera. Gram-negative genera were from the same classes as in the first sampling however Sphingobacteria was present. γ-Proteobacteria and ß-Proteobacteria were the most common taxa. The isolates were shown to be very resistant to Zn and As, with about half of the isolates able to grow with Cd present. Interestingly, no strains could grow in the presence of metal mixtures. Despite the number of strains recovered in both samplings the majority of the isolates were clustered within a very small number of genera. During the sampling periods two strains showing low similarity to other bacteria were isolated. These strains were characterized and studied in detail justifying their classification as representing two novel species of the genus Chryseobacterium. The names proposed for these organisms are Chryseobacterium palustre sp. nov. (type strain 3A10[type strain]) and Chryseobacterium humi sp. nov. (type strain ECP37[type strain]). Three isolates 1C2, 1ZP4 and EC30 belonging to genera Cupriavidus, Sphingobacterium and Alcaligenes respectively, showing high tolerance to heavy metals, were selected for further study in immobilised systems for Zn and Cd removal. In most cases, matrices (alginate, pectate and a synthetic cross-linked polymer) with immobilised bacteria showed better metal removal. 1C2, a strain belonging to the Cupriavidus genera, was able to increased the removal of Zn; EC30, a bacteria related to Alcaligenes, was the most promising candidate for Cd removal, especially when combined with the synthetic polymer. Removal of metals as single or in binary mixtures was also assessed. Cd removal was most effective when single metal solutions were tested using immobilised bacteria and examining metal matrixes. Based on the strains used and the matrices tested, best results were obtained for removal of Zn from binary mixtures with Cd. Potential exists for further studies to exploit these bacterial strain to develop effective bioremediation approaches for the removal of heavy metals from waste water streams.

The carbon cycle modulates climate change, via the regulation of atmospheric CO2, and it represents one of the most important ecosystem services of value to humans. However, considerable uncertainties remain concerning potential feedbacks between the biota and the climate. I used an ecosystem-level manipulative experiment in freshwater mesocosms to test novel theoretical predictions derived from the metabolic theory of ecology (MTE), in an attempt to understand the consequences of warming for aquatic communities and ecosystems. The yearlong experiment simulated a warming scenario (A1B) expected by the end of the century. The experiment revealed that (1) Ecosystem respiration increased at a faster rate than primary production, reducing carbon sequestration by 13%. These results confirmed my theoretical predictions based on the different activation energies of these two processes. Furthermore, I provided a theoretical prediction that accurately quantified the precise magnitude of the reduction in carbon sequestration observed experimentally, based simply on the activation energies of these metabolic processes and the relative increase in temperature. (2) Methane efflux increased at a faster rate than ecosystem respiration and photosynthesis in response to temperature. This phenomenon was well described by the activation energies of these metabolic processes. Therefore, warming increased the fraction of primary production emitted as methane by 21%, and methane efflux represented a 9% greater fraction of ecosystem respiration. Moreover, because methane is 21 times more potent as a greenhouse gas, relative to CO2, this work suggests that warming may increase the greenhouse gas efflux potential of freshwater ecosystems, revealing a previously unknown positive feedback between warming and the carbon cycle. (3) Warming benefited smaller organisms and increased the steepness of the slope of the 3 community size spectrum. As a result the mean body size of phytoplankton in the warmed systems decreased by an order of magnitude. These results were down to a systematic shift in phytoplankton community composition in response to warming. Furthermore, warming reduced community biomass and total phytoplankton biomass, although zooplankton biomass was unaffected. This resulted in an increase in the zooplankton to phytoplankton biomass ratio in the warmed mesocosms, which could be explained by faster turnover within the phytoplankton assemblages. Warming therefore shifted the distribution of phytoplankton body size towards smaller individuals with rapid turnover and low standing biomass, resulting in a reorganisation of the biomass structure of the food webs. The results of this thesis suggest that as freshwater ecosystems warm they become increasingly carbon limited, resulting in a reduced capacity for carbon sequestration, elevated greenhouse gas efflux potential, and altered body size and biomass distribution.

A significant route for Endocrine disrupting chemicals (EDCs) such as natural and synthetic estrogens and nonylphenolics to enter the environment is via sewage treatment. Nanogram per litre levels of these compounds have been demonstrated to cause feminisation of aquatic organisms. The utilisation of treatments such as advanced oxidation and activated carbon could remove these compounds from effluent; however these technologies are expensive and energy intensive. Determining which operating parameters control the biodegradation of EDCs during activated sludge treatment, removal could be more sustainable. This study investigates which process parameters are responsible for controlling biodegradation of estrogens and nonylphenolics during activated sludge treatment. The role ammonia oxidising bacteria upon the breakdown of estrogens was also investigated. Field-based sampling campaigns were undertaken at three activated sludge plants and pilot-scale porous pot bioreactors were utilised to further examine the individual influences of loading, hydraulic retention time (HRT) and sludge retention time (SRT) upon EDC biodegradation.

Metabolomics is a technique that can be used to investigate the metabolic profiles of an organism by measuring a large number of the low molecular weight metabolites in the metabolic pool. 1H NMR spectroscopy is an analytical tool that is unbiased, and a non-destructive way of investigating metabolic perturbations in organisms exposed to environmental stress. In this study two model organisms, Mytilus edulis and Chironomus riparius were used to investigate the effects of several pesticides: lindane and atrazine in the mussels, and fenitrothion, methiocarb and permethrin in the midge larvae. The impact of hypoxia and starvation were also investigated alongside the exposure to atrazine in the mussel. The pesticides used in the mussel study have different modes of action, but produce similar changes to behaviour and can cause starvation and mild hypoxia. Acetonitrile/2H2O (60/40 % v/v) extracts of foot muscle of mussels subjected to hypoxia, or starvation, or to low or high doses of pesticide were analysed using 1H NMR spectroscopy to produce metabolic profiles associated with these treatments. Discriminant analysis showed significant differences between treated and control animals and gave a clear separation between all treatment groups. Atrazine profiles were clearly separated from the starved and hypoxic animals and the animals exposed to high and low doses were also separated. Lindane treatment was separated from control animals in a dose-dependent way. This was associated with an increase in alanine concentrations and a decrease in all other identified metabolites. The study of midge larvae used the same approach, but using extracts of pooled whole body homogenates (10 animals per sample) instead of tissue from individuals. The animals were subjected to low, environmentally relevant dose levels of three pesticides; fenitrothion, methiocarb and permethrin. The first two of these have a similar mode of action, inhibition of acetylcholine esterase, whilst the latter is an axonal poison acting on cation channels. The metabolic profiles associated with these treatments showed a clear separation between all treatment groups and between treated and control animals. Fenitrothion treatment was associated with an increase in alanine (on average of 93.3 M relative to controls) and lactate concentrations compared with controls and other treatments. Methiocarb caused a reduction in arginine, leucine and lysine concentrations to half of the control level. Permethrin produced a reduction in tyrosine and phenylalanine concentrations to half that of the control group. In both these experiments the use of 1H NMR metabolomics enabled the separation the effects of all of the treatments and stressors from each other and from the controls. It demonstrates the potential of the metabolomic approach to provide separation of the effects of poisoning from those of environmental stress, and to distinguish between toxicants with similar modes of action.

This thesis presents the results of a 6-year research project to investigate the radioecology of temperate coastal sand dunes. Samples (n = 617) of soil, water and biota were collected from the Drigg coastal sand dunes (West Cumbria, UK) between February 2005 and October 2007. Biota groups sampled included amphibians, birds, invertebrates, mammals, reptiles, plants (including lichens and mosses) and fungi. All samples were analysed for 40K, 137Cs and 241Am. A sub-set of samples (n = 26) was analysed for 90Sr, 99Tc, 238Pu and 239+240Pu. Additional soil analyses included soil moisture, bulk density, pH, organic matter content, carbonate content and cation concentrations (Ca2+, K+, Na+ & Mg2+). The application of three publicly-available environmental radiation protection models (ERICA, R&D128/Sp1a & RESRAD-BIOTA) to an assessment of ionising radiation impacts at the Drigg coastal sand dunes site was evaluated. Soil activity concentration data were used as input data and model results compared with measured activity concentrations in sand dune biota. Radionuclide concentration ratios (CRs) were identified as an important source of variation in model predictions. For sand dune small mammals, Am, Cs and Pu CRs were found to be 1 – 2 orders of magnitude lower than those for small mammals in other terrestrial ecosystems. For reptiles, the variability could be attributed to the paucity of data on transfer to this vertebrate group. Through literature review, mining of unpublished data sets and analysis of samples collected from the Drigg coastal sand dunes, CR databases were developed for reptiles (across a range of ecosystem types) and for sand dune biota. Analysis of sand dune soil data suggested that both sea-to-land transfer and the transport of sand grains in saltation influence the soil activity concentrations in coastal sand dunes. The low CRs for sand dune biota may be due to low bioavailability of particulate-bound radionuclides.

Manufacture, use, storage and improper disposal of the explosive 2,4,6-trinitrotoluene (TNT) have led to widespread, global contamination of soil and groundwater. TNT is highly toxic and recalcitrant to degradation resulting in environmental build-up with far reaching ecological and health implications. It is therefore a priority to remove contaminating TNT from the environment. Phytoremediation is a promising solution; suitable plants possess some natural ability to transform TNT, high biomass, deep root systems, requirement for minimal nutrient input and ability to reduce contamination spread by wind or water erosion; making them an attractive remediation system. Key genes involved in the detoxification of TNT by plants have been recently identified by expression studies and the encoded enzymes characterised. This has lead to the thorough investigation of the enzymes in the pathway of TNT detoxification; Phase I transformation includes oxophytodienoate reductases, with uridine diphosphate (UDP) glycosyltransferases (UGTs) playing a role in the Phase II conjugation step. The expression studies identified additional enzymes also likely to be involved in these phases including glutathione transferases (GSTs). GSTs are known to detoxify compounds by conjugation to glutathione (GSH), and like UGTs are Phase II detoxification enzymes. This thesis presents an investigation into whether plant GSTs play a role in the detoxification of TNT. In vitro analysis of recombinant GSTs was performed to elucidate the activity of GSTs towards TNT. Seven GSTs were cloned, expressed and purified from Escherichia coli. TNT assays performed with pure enzyme indicated that at least two of the GSTs were able to transform TNT. Analysis of the reaction product by mass spectrometry showed that TNT was conjugated to glutathione through substitution of a nitro-group, a highly desirable reaction as the removal of a nitro group from TNT is likely to increase the likelihood of subsequent mineralisation of the pollutant. This is the first identification of enzymes capable of this transformation. The two GSTs which exhibited activity towards TNT were overexpressed in Arabidopsis to clarify if the conjugating activity observed in vitro was able to confer increased tolerance to TNT to the transformed plants. Transgenic lines showed no enhanced growth compared to wild type plants on TNT amended media, root lengths appeared slightly shorter while TNT uptake and biomass were reduced. The role of GSTs in the detoxification of TNT remains unresolved however it is likely that GSTs do not play an integral role in TNT detoxification in plants. Nonetheless, the two GSTs characterised in the project are the first examples of plant enzymes which are able to catalyse the removal of nitro groups from TNT. Engineering these GSTs to improve their ability to transform TNT could offer an opportunity for effective environmental remediation.

This study aimed to investigate the RBT outcome as a function of the bacterial inoculum during adaptation to degrade the HAs dichloroacetic acid (DCA), trichloroacetic acid (TCA) and 2-monochloropropionic acid (2MCPA). The HAs investigated were ranked, in order of greatest recalcitrance; TCA > 2MCPA > DCA.  DCA degradation was associated with enrichment of a Ralstonia like phylotype and dehII expression.  TCA degradation in replicate RBTs was consistently associated with a Bradyrhizobium like phylotype and dehI gene expression, regardless of the inoculum concentration used, suggesting that TCA imposes a highly selective pressure on the community. TCA degradation was affected by the inoculum concentration, as the rate of degradation was slower at the lowest inoculum concentration used, implying that TCA degradation was accomplished by cometabolism. 2MCPA was associated with various Alpha-, Beta- and Gammaproteobacteria, and the presence and expression of both dehI and dehII genes. Biodegradation of 2MCPA was strongly influenced by inoculum concentration. At lower inoculum concentrations, 2MCPA was commonly associated with a biphasic dechlorination curve, which has not been reported previously.  Biphasic dechlorination curves were attributed to the enrichment of an initial degrading organism, always associated with dehII expression, which was succeeded following 50% dechlorination by a second organism, in association with dehI expression, which were supposed to act sequentially on the L- and D-2MCPA isomers, respectively. The delayed enrichment of a dehI containing organism was attributed to their low environmental abundance, relative to dehII containing organisms. This study highlights the utility of cultivation-independent methods to link more precisely community structure and function during adaptation to degrade xenobiotic compounds.

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.

The main objective of this research is to establish a user-friendly, tailor-made model by which legal and environmental policies on Groundwater Protection can be formulated. The intention is that this approach will be integrated within the National Water Policy as directed by European Union Directive on the protection of groundwater against pollution, with specific focus on the Island of Malta. The first chapter presents the research hypothesis and main objectives. It also outlines the evolution of groundwater exploitation and the importance of groundwater as a source of water production in Malta. In Chapter 2, an overview on the origins of and the reasons behind groundwater pollution in Malta is presented. Chapter 3 presents the various arguments which justify the need to effect a change in concept. In Chapter 4, analyses of the various Decision Support Systems currently being used in Groundwater Pollution Assessments is given. Chapter 5 presents the formulation of the proposed Aquifer Stress Approach (ASA) model. A thorough explanation of the methodology adopted to obtain the public attitudes towards groundwater protection issues is presented in Chapter 6 whilst in Chapter 7; the ASA model is applied to real life case studies. In the final Chapter, conclusions and recommendations are provided. The new approach involves parameters such as pollutant transport in the unsaturated zone defined by the Aquifer Vulnerability Index (AVI) as well as that in the saturated zone using the Residual Pollutant Index Module. Other parameters include development indices reflecting also people's awareness towards various man-made activities, obtained by a perception survey, and the quantitative effect of contamination generated by developments on groundwater storage. Conclusions, recommendations and ideas for future studies are included in the last chapter. The main conclusion of the research is that, notwithstanding the various socio-political, cultural and economic issues, an acceptable solution is possible and takes the form of a simple, rational methodology which integrates technical analysis with some established approaches. Integrating within a Legal Framework to cover all activities is seen as a better, more sustainable solution to redress present trends and reverse the general pollution levels in groundwater on Malta.

Endocrine disrupting compounds (EDCs) together with potentially toxic metals (PTMs), are present in large amounts in sewage sludge which was used as a tool to expose terrestrial molluscs to environmental concentrations of these pollutants. Pastures fertilised with sewage sludge had significantly fewer adult slugs collected per replicate (C: 58.4; T: 26.2; S.E.D. 0.14; p<.05) and eggs (C: 16.6; T: 9.1; S.E.D. 0.17; p<0.05).  No differences with treatment, in tissue concentrations of EDCs or PTMs or in hepatopancreas or gonad structure, were detected.  However, hepatopancreatic proteins (cyclophilin, paramyosin and trypsin) were significantly altered (p<0.01). In a laboratory study, exposure, via feed, to 0x (Control), 1x (T1), 10x (T2) or 110x (T3) the environmental dose of sludge extract resulted in a dose-related increase in mean mortality rates (relative to controls) in adult slugs (Deroceras reticulatum).  Exposure for 3 weeks induced no measurable differences in tissue pollutant concentrations or hepatopancreas or gonad histology. Fewer slug eggs exposed to sludge and/or dehydration (2x2; 10 eggs/replicate); hatched following sludge exposure (C hydrated 64.5%;T hydrated 24.5%; p<0.05; S.E.D. 2.169; C dehydrated 48.9%; T dehydrated 17.4%; p<0.05; S.E.D. 4.256) but not following dehydration.  There was no significant interaction between sludge exposure and dehydration but survival was lowest in animals exposed to both. Slug behaviour was affected by exposure to sludge, including increasing avoidance and huddling behaviours. The results indicate that terrestrial molluscs may be used as invertebrate sentinels to assess the effects of ECD and PTM exposure.

The focus of this thesis is the bioremediation of oil impacted sites. Chapter 3 considered “Oil Lakes” in Kuwait, a consequence of the First Gulf War, which pose a considerable human and environmental hazard.  The data revealed that across even a small “Oil Lake”, the hydrocarbon concentration varied significantly and that hydrocarbon concentration was the most important descriptor for determining the rate of remediation.  Effective and sustainable bioremediation strategy must be led by the focused use of underpinning empirical data and its application in a predictive capacity. Chapter 4 considered a similar integrated approach to assess the bioremediation potential of historically contaminated soils from Kuwait.  The analyses reveal that an optimised combination of chemical and biological characterisation were necessary to monitor processes involved in remediation of heavily weathered oil contaminated soils.  A predictive equation derived from empirical chemical and biological data could enhance certainty in the adoption of remedial strategies. Chapter 5 focussed on the toxicity of fractionated crude oils undergoing remediation. Chapter 6 compared a full scale trial of two remediation strategies done on the same site contaminated with bunker-fuel.  This trial reveals the benefit of developing risk and hazard-based approaches in defining endpoint bioremediation of heavy hydrocarbons when engineered biopile or window are proposed as treatment option. Bioremediation, to be effectively applied requires a considerably intense monitoring regime.  For freshly contaminated soils, there is sound justification for applying a predictive capacity but as the samples age, this becomes less certain.  New technologies are evolving which when properly applied and interpreted in the correct context may enhance our ability to sustainably manage hydrocarbon bioremediation.

This thesis aimed to provide improved understanding of the spatial and temporal variability of stream temperature, the influence of riparian woodlands on thermal regimes and examples of the ecological consequences of different thermal regimes.  First, the spatial and temporal variability of temperature within a large montane river basin at nested spatial scales was established.  It was from this analysis that (i) variation that can occur at all spatial scales was observed, (ii) different physical factors are controlling these variations at all scales, and (iii) greatest differences occur between different tributaries.  The extent of riparian forestry proved to be in important factor in determining river temperatures.  The results suggest that broadleaved tree species within the riparian zone are more able to reduced incoming solar radiation and consequently control stream temperature.  This highlights the potential of riparian plantings in mitigation efforts against high temperatures under future climate scenarios.  To complement these empirical assessments, the ecological significance of observed thermal variability was assessed in a laboratory study of the growth of juvenile Atlantic salmon.  The effects of the temperature regime on growth were in the range of about 3% reduction in final length in the variable regime compared to the constant one.  Relations between invertebrate growth, adult emergence patterns and thermal regime differences related to riparian cover were assessed in relation to the mayfly Baetis rhodani.  Statistically significant differences in mean size and size distribution of Baetis were found in the Girnock, between all sites separated by no more than 5 km.

Aromatic hydrocarbons are a prevalent constituent of crude oil. The refined products of crude oil such as petroleum and diesel can find their way into groundwater though oil-spillages and are also present in the oil and gas industry’s produced water. These aromatics are biorecalcitrant, however upon ingestion with water, may be metabolised to toxic intermediates that are carcinogenic or mutagenic in nature. Although some treatment technologies are available most of these are under development and are yet to be proven in the field. This illustrates the need for novel, economical and environmentally friendly technologies to be developed with a view to remediating aqueous systems that have been polluted with aromatics hydrocarbons. The supramolecular cyclodextrin molecule, with its hydrophobic interior and hydrophobic exterior seems to be an excellent molecule for the trapping of the pollutant molecules, however the inclusion complexes with this cyclic sugar are water-soluble therefore there is a need for the cyclodextrin to be rendered waterinsoluble. A study of the aqueous solubilities of some aromatic hydrocarbons that may be present in crude oil has been carried out and shows that the majority of these molecules have a degree of water solubility that may increase upon environmental weathering. The successful reaction between a solid-phase resin and the β-cyclodextrin molecule has been achieved, with the total dryness of the system being required including Soxhlet extraction of the resin with anhydrous acetone before the reaction. The reaction between β-cyclodextrin and a range of isocyanates proved unsuccessful, but a range of symmetrical aryl ureas were synthesised from their isocyanates with the influence that different activating or deactivating groups on the ring have on the propensity to form the ureas being shown. The successful alkylation between β-cyclodextrin and a series of haloalkanes has shown the effect of increasing chain length on the degree of alkylation. This reaction involved the deprotonation of the cyclodextrin by sodium hydride in anhydrous dimethyl sulphoxide followed by reaction with the alkyl iodide. Increasing the equivalents of hydride or iodide, or the reaction time did not have a noticeable effect on the degree of reaction indicating that steric constraints were limiting the degree of reaction. Testing several of these alkyl iodides gave an indication as to their tendency to uptake and remove several model pollutants that had been dissolved in water with the propylated β-cyclodextrin displaying potential for the remediation of aqueous systems that had been polluted. Several of these results were very promising leading to the conclusion that further derivatives of these alkylated sugars may be even more suitable for future research into the remediation of organically polluted aqueous systems.

Human activities are degrading marine ecosystems and undermining the ecological functions and processes which provide valued goods and services. European and UK marine policy developments aim to implement the Ecosystem Approach to support better management of activities and maintain the health of regional seas. Current public perceptions of the UK marine environment are overwhelmingly negative, creating a barrier to engaging society with marine environmental issues and policy. This thesis conducts a study of the attributes of a suite of 72 UK marine species to identify those which contribute most to marine ecological health. The findings show that structurally complex species are most important and are recommended as species to assess and monitor Good Environmental Status as defined by the EU Marine Strategy Framework Directive. Existing conservation policies are biased towards large vertebrate species, with ecologically important species being underprotected. A survey of public perceptions of the marine environment. revealed conflicting perceptions of charismatic megafauna. Charismatic species were the most interesting species but least important as measures of marine health. Ecologically important species were the least interesting, but ecological health concepts were considered important measures of marine health. Perceptions of the marine environment varied with socio-demographic and social value factors. By integrating these studies, barriers and opportunities to engaging society with the marine environment were identified. Communication strategies which address these are proposed, including a suite of Spokes Species, potential high profile species to champion the marine environment. These include puffin, cod, basking shark and seagrass. A series of themes are proposed which implement other key findings such as the importance of personal experience in building connections with marine species. Communication strategies are supported by ecologically defined assessments of marine environmental health, are relevant to current policy developments and will resonate with social values of the marine environment.

With the current expansion of offshore oil activities in Arctic regions, there is an urgent need to establish the potential effects of oil-related compounds on Arctic organisms. The scallop Chlamys islandica is distributed throughout the sub-Arctic and has been proposed as a sentinel species for this region. In addition, the temperate scallop Pecten maximus occurs in regions of oil activity and, with increasing sea temperatures, the limit of its distribution may extend further into sub-Arctic regions. P. maximus also accumulates contaminants to a greater extent than the current temperate sentinel Mytilus edulis. A hierarchical approach, similar to that adopted to assess vertebrate immune function, was used to determine immunocompetence in the Arctic scallop C. islandica and the temperate scallop P. maximus following exposure to oil and oil-related compounds. The Arctic scallop C. islandica demonstrated a reduced immunocompetence following both dispersed and acute oil exposure. Immunomodulation in the scallops exposed to low levels of dispersed oil appeared to be reversible following removal of the contaminant stress (Chapter 3). However, a simulated oil spill resulted in mortalities and it remains unclear if the organisms are able to recover from the substantial immune suppression observed (Chapter 4). A component of crude oil and the most abundant PAH in aquatic ecosystems, phenanthrene suppressed immune function in P. maximus. These results indicated a link between PAH-induced oxidative stress and the subsequent inhibition in haemocyte immune function (Chapter 5). However, the ability of scallop haemocytes to recognise and respond to a pathogen-associated molecular pattern was not affected by phenanthrene exposure (Chapter 6). The immune parameters used in this research were shown to be sensitive, reliable markers of immunocompetence that can be directly linked to host resistance (Chapter 7). These immune parameters were also used to assess the sublethal effects of drilling wastes associated with offshore oil production (Chapter 8), indicating their potential as ecotoxicological monitoring tools.

Very little information exists on the marine biogeochemistry of Rh, Pd and Pt, or the platinum group elements (PGE), an emerging group of contaminants whose principal emissions are associated with the abrasion of the catalytic converter in motor vehicles and chemotherapy drugs discharged in hospital wastes. In this study, Rh(III), Pd(II) and Pt(IV) were added individually and in combination to cultures of the marine microalga, Chlorella stigmatophora, maintained in coastal seawater at 15oC and under fluorescence lighting both in the presence and absence of trace nutrients (e.g. Fe, Co, Zn and EDTA). The accumulation of PGE was established under varying conditions (pH, algal biomass, PGE concentration, time) by ICP-MS analysis of seawater and nitric acid digests and EDTA washes of the alga, the latter giving a measure of PGE adsorption by C. stigmatophora. Under all conditions the extent of accumulation was in the order: Rh > Pd >> Pt. In short-term (24-h) exposures, accumulation isotherms were quasi-linear up to PGE concentrations of 30 ug L-1, although Pd displayed convexity, hence saturation of available binding sites, at greater concentrations. The pH, adjusted between about 5.5 and 9.5 by addition of acid or base, did not have a great impact on PGE accumulation, with Rh displaying a moderate increase in accumulation and Pd a moderate reduction with increasing pH. More important, all PGE displayed a significant reduction in accumulation on a weight-normalized basis with increasing concentration of algae, an effect not reported for metal-marine algal interactions previously in the literature. Longer-term experiments showed that the rates of both overall accumulation and internalization were greatest for Pd and least for Pt. Consistent with this observation, the toxicity to C. stigmatophora evaluated by both pigment content and growth rate, was significantly greater for Pd than for Pt. Differences in the biogeochemical behaviours among the PGE are attributed to differences in their aqueous speciation in seawater, different affinities for the algal surface, different tendencies to cross the cell membrane, and especially with regard to Pd and Pt, differences in the rates of these interactions. Thus, although the equilibrium chemistries of Pd and Pt are very similar, their differential biogeochemistries are the result of kinetic constraints on reactions involving the latter. Because the environmental concentrations of PGE are predicted to increase with increasing emissions from vehicles and hospitals, the results of this study make an important contribution to an improved understanding of the likely effects and fates of these emerging contaminants in the marine environment. The results are also more generally important to an improved understanding of the interactions of trace metals with microalgae in seawater.

Characterising the geochemistry and speciation of major contaminant radionuclides is crucial in order to understand their behaviour and migration in complex environmental systems. Organic complexing agents used in nuclear decontamination have been found to enhance migration of radionuclides at contaminated sites; however, the mechanisms of the interactions in complex environments are poorly understood. In this work, radionuclide speciation and sorption behaviour were investigated in order to identify interactions between four key radionuclides with different oxidation states (Cs(I) and Sr(II) as important fission products; Th(IV) and U(VI) as representative actinides), three anthropogenic organic complexing agents with different denticities (EDTA, NTA and picolinic acid as common co-contaminants), and natural sand (as simple environmental solid phase). A UV spectrophotometric and an IC method were developed to monitor the behaviour of EDTA, NTA and picolinic acid in the later experiments. The optimised methods were simple, applied widely-available instrumentation and achieved the necessary analytical figures of merit to allow a compound specific determination over variable background levels of DOC and in the presence of natural cations, anions and radionuclides. The effect of the ligands on the solubility of the radionuclides was studied using a natural sand matrix and pure silica for comparison of anions, cations and organic carbon. In the silica system, the presence of EDTA, NTA and, to a lesser extent, picolinic acid, showed a clear net effect of increasing Th and U solubility. Conversely, in the sand system, the sorption of Th and U was kinetically controlled and radionuclide complexation by the ligands enhanced the rate of sorption, by a mechanism identified as metal exchange with matrix metals. Experiments in which excess EDTA, NTA and picolinic acid (40 – 100 fold excess) were pre-equilibrated with Th and U prior to contact with the sand, to allow a greater degree of radionuclide complex formation, resulted in enhanced rates of sorption. This confirmed that the radionuclide complexes interacted with the sand surface more readily than uncomplexed Th or U. Overall this shows that Th and U mobility would be lowered in this natural sand by the presence of organic co-contaminants. In contrast, the complexation of Sr with the complexing agents was rapid and the effect of the ligands was observed as a net increase on Sr solubility (EDTA, picolinic acid) or sorption (NTA). As expected, Cs did not interact with the ligands, and showed rapid sorption kinetics. Finally, ESI-MS was used to study competitive interactions in the aqueous Th-Mn-ligand ternary system. Quantification presented a challenge, however, the careful approach taken to determine the signal correction allowed the competitive interactions between Mn and Th for EDTA to be studied semi-quantitatively. In an EDTA limited system, Th displaced Mn from the EDTA complex, even in the presence of a higher Mn concentration, which was consistent with the higher stability constant of the Th-EDTA complex.

Negative landscape change and impacts on biodiversity, as a consequence of development, must be mitigated for. In the UK mitigation is carried out through a variety of policy and planning instruments whose delivery measures are often piecemeal, thus restricting their ability to address the cumulative landscape impacts of multiple developments. One proposed response is the adoption of a type of mitigation banking - "habitat banking", where the creation, management or restoration of habitats is funded by the purchase of credits by the developer. This research proposes that spatial targeting of habitat bank locations is crucial to fully mitigate development impacts whilst maximising landscape function benefits. A landscape scale modelling approach was developed for a case study area in the South Midlands to investigate spatial targeting of habitat banks, with ecological networks and ecoprofiles employed to guide their location. Ecological effects of bank composition, size and location were examined, combined with a network analysis to determine people's access to natural greenspace in the same area, and subsequently compared against the current selection mechanism - Accessible Natural Greenspace Standards (ANGSt). Changes resulting from human population growth and habitat bank introduction were examined in association with impacts of climate change on potential bank locations over a 50 year period, whilst a chain of climate envelope, dispersal and colonisation models determined the ability of ecoprofiles to keep pace with climate changes. The ability of habitat banks to contribute to landscape functionality was determined both spatially and temporally. Habitat banks identified by the models increased the existing ecological network size by a factor of up to 2.72:1 and were able to deliver the majority of habitat creation targets set out in regional biodiversity action plans (BAPs). 100% of wetland, unimproved grassland and broadleaf and mixed woodland creation targets were met, whilst only 75% of the lowland heath target could be achieved. Multihabitat banks of over 3700 ha were identified with such areas determined to be of importance in achieving landscape improvements for a wide range of species. Although ANGSt targets were not met, habitat bank locations did increase overall greenspace accessibility for over 3000 people. The ability of ecoprofiles to track climate change was directly related to both the area and connectivity of habitat patches, with the broadleaf woodland ecoprofile being the most capable of adapting to predicted climate change. Habitat banks contributed to increased landscape functionality in the short-term but predicted climate change impacts become insurmountable in the medium to long-term, drawing into question the long-term viability of the landscape in its current state to withstand potential climate changes.

Organic contaminants from industrial and/or domestic effluents may be harmful to humans directly or indirectly by degrading the quality of the aquatic environment. Consequently these contaminants must be reduced to levels that are not harmful to humans and the environment before disposal. Chemical, physical and biological methods exist for the removal of these pollutants from effluents. Among the available chemical methods, heterogeneous photocatalytic oxidation has been found particularly effective in removing a large number of persistent organics in water. In this study, photocatalytic degradation was explored for the removal of reactive azo-dye (textile dye), triclocarban (disinfectant), clopyralid (herbicide) and three endocrine disrupting compounds (EDCs) (estrone, 17ß-estradiol and 17α-ethinylestradiol) from synthetic effluents. The major factors affecting the photocatalytic processes including the initial concentration of the target compounds, the amount of catalyst, the light intensity, the type of catalyst, the electron acceptor, the irradiation time and the pH were studied. Other oxidation techniques including (O3, H2O2, UV) were also studied. Generally UV light is used in combination with titanium dioxide, as photocatalyst, to generate photoinduced charge separation leading to the creation of electron-hole pairs. The holes act as electron acceptors hence the oxidation of organics occur at these sites. These holes can also lead to the formation of hydroxyl radicals which are also effective oxidants capable of degrading the organics. The results obtained in this study indicated that photolysis (i.e. UV only) was found to have no effect on the degradation of reactive azo-dye (RO16). However, complete photocatalytic degradation of 20 mg/L (3.24×10-2 mM) RO16 was achieved in 20 minutes in the presence of 1g/L TiO2 Degussa P25 at pH 5.5. Comparison between various types of catalysts (i.e. Degussa P25, VP Aeroperl, Hombifine N) gave varied results but Degussa P25 was the most effective photocatalyst hence it was selected for this study. For RO16 the optimum catalyst concentration was 0.5 g/L TiO2 with initial concentration of 20 mg/L RO16. It was found that the disappearance of RO16 satisfactorily followed the pseudo first-order kinetics according to Langmuir-Hinshelwood (L-H) model. The rate constant was k= 0.0928 mol/min. Photodegradation of TCC was studied in 70%v acetonitrile: 30%v water solutions. UV light degraded TCC effectively and the reaction rates increased with decreasing initial concentration of TCC. UV/TiO2 gave unsatisfactory degradation of triclocarban (TCC) since only 36% were removed in 60 minutes with initial concentration of TCC 20 mg/L. The degradation of clopyralid and the EDCs was studied using three oxidation systems UV/TiO2, UV/H2O2 and O3. Complete degradation of clopyralid (3,6-DCP) was achieved with UV/TiO2 in about 90 minutes at an optimum catalyst concentration of 1g/L. Zero-order kinetics was found to describe the first stage of the photocatalytic reaction in the concentration range 0.078-0.521 mM. At pH 5 the rate constant was 2.09×10⁻⁶ ± 4.32×10⁻⁷ M.s⁻¹. Complete degradation of all the three EDCs was achieved with UV/H₂O₂ in 60 minutes at catalyst concentration of (2.94×10⁻² M). On the other hand complete degradation of the EDCs was achieved in just 2 minutes with ozonation. For high concentration EDCs, TiO₂/UV gave low efficiency of degradation as compared with ozone and H2O2/UV. First-order kinetics was found to describe the photocatalytic reaction of the EDCs.

The impacts of environmental change on ecological communities are poorly understood relative to impacts on species. Impacts on inter-community (beta-) diversity are particularly neglected. As a result, our ability to forecast the impacts of environmental change on communities, and on individual species constrained by those communities, is seriously limited. However, as conservation efforts increasingly emphasise broad-scale approaches in terms of multi-species coverage and spatial scale, it is imperative that understanding ofbiodiversity change at these scales is enhanced so that conservation can be based on appropriate scientific evidence. Within this thesis I aimed to conduct multi-species analyses over multi-decada1 temporal scales at the spatial meso-sca1e to improve our understanding of such issues in both terrestrial and marine ecosystems. I discussed my findings in the theoretical context of G1easonian and C1ementsian views of species distributions (i.e. limitations to individualistic species responses) and their impact at the community scale. The temporal extent provided the opportunity to empirically test emerging concepts, including non-analogous communities, biotic homogenization, metacommunities and climate tracking responses at an appropriate meso-sca1e. Although no evidence for nonanalogous communities was found, biotic homogenization was supported and appeared to be caused by increased nitrogen and decreased light availability. An intertidal assemblage also converged but appeared to be driven by a reduced sea surface temperature gradient. Woodland plant metacommunity structure was demonstrated to be C1ementsian for woodland plants despite experiencing biodiversity loss. Hydrodynamic features were demonstrated to act as meso-sca1e dispersal barriers that limited intertidal invertebrates in tracking of climate (sea surface temperature) over the last 20 years. These barriers appear to alter when modelled under a scenario of sea level rise. Overall, results suggest that species are responding individualistically but that these responses are bounded by extrinsic constraints.

Land is a finite natural resource that is increasingly getting exhausted as a result of land contamination. Land is made up of soil and groundwater, both of which have many functions for which we depend on, including provision of food and water, supporting shelter, natural flood defence, carbon sequestration, etc. Contaminants in land also pose a number of threats to public health and the environment; other natural resources; and have detrimental effects on property such as buildings, crops and livestock. The most effective method of dealing with these contaminants is to cleanup and return the sites to beneficial use. The cleanup process involves making a choice from amongst competing remediation technologies, where the wrong choice may have disastrous economic, environmental and/or social impacts. Contaminated land management is therefore much broader than the selection and implementation of remedial solutions, and requires extensive data collection and analysis at huge costs and effort. The need for decision support in contaminated land management decision-making has long been widely recognised, and in recent years a large number of Decision Support Systems (DSS) have been developed. This thesis presents the development of a Web-based knowledge-based DSS as an integrated management framework for the risk assessment of human health from, and sustainable management of, contaminated land. The developed DSS is based on the current UK contaminated land regime, published guidelines and technical reports from the UK Environment Agency (EA) and Department for Environment, Food and Rural Affairs (DEFRA) and other Government agencies and departments. The decision-making process of the developed DSS comprises of key stages in the risk assessment and management of contaminated land: (i) preliminary qualitative risk assessment; (ii) generic quantitative risk assessment; and (iii) options appraisal of remediation technologies and remediation design. The developed DSS requires site specific details and measured contaminant concentrations from site samples as input and produces a site specific report as output. The DSS output is intended to be used as information to support with contaminated land management decision-making.

Uncontrolled landfills can cause the release of significant contamination. In South England and in other parts of the UK, historical landfills are spread along the coastal and estuarine marshes and mudflats, where waste was dumped without regard to the environment. Much of the pollution from these landfills may have been dispersed and diluted into coastal waters with little impact. However, fine-grained sediments within these environments may have trapped or sequestered metals. The aim of this study is to investigate the degree to which heavy metals from these historical sites may have contaminated the adjacent marshes and intertidal mudflats.

Manufactured nanoparticles are increasingly being used in the production of consumer products and appliances. A release in the environment, either intended through remediation or unintended through a spill at production sites, through wastewater or product degradation, is most likely to occur. Due to their small size, nanoparticles have a far greater surface area to unit mass ratio than conventional substances, rendering them potentially more reactive. This project aims to obtain key data on the ecotoxicology of nanoparticles in the aquatic environment. Initially, data from acute and chronic toxicity tests were gathered by exposing the invertebrate Daphnia magna to nanoparticles of carbon black, cerium dioxide, silver and titanium dioxide. The endpoints were mortality, moulting frequency, growth and number of offspring. The results indicate that a gradient of toxicity can be drawn, with cerium dioxide being the least toxic, to silver being the most toxic. Also a size dependent increase of toxicity was observed, with exposures to nano sized particles being more toxic than micro sized particles. Uptake and fate of nano sized materials were studied by exposing D. magna to fluorescent polystyrene beads of 20 nm and 1000 nm sizes and the results were compared. Both particle sizes were readily taken up in the gut and relocated in storage droplets within the body of D. magna. A quantification of the results showed that the mass of 1000 nm sized particles taken up was higher at equal exposure concentrations than the 20 nm sized particle but the excretion rate was higher as well for the 1000 nm particles. However, when assessing uptake as surface area or particle number dose, uptake of 20 nm particles exceeds uptake of 1000 nm particles. To assess the effect of nanoparticles on oxidative stress, the total antioxidant capacity was measured as well as the glutathione concentration of exposed D. magna. A decrease in total glutathione in D. magna was detected due to exposure to nano sized carbon black, while measuring the total oxidant capacity proved to be impossible due to interferences with the method used. The results show that, when negative effects are observed, these are more severe in exposures to nanoparticles than their micro sized counterparts and furthermore a clear route of uptake of nanoparticles in the body of D. magna can be observed.

A method to treat contaminated land is stabilisation/solidification (S/S), which physically encapsulates and chemically stabilises the contaminants. The current knowledge on the behaviour of S/S systems is based upon scarce and incomplete data, mostly obtained from laboratory simulations or small scale trials of the technology. The field performance of S/S soils is largely unknown. The aim of this research was to improve the understanding of the long-term performance of S/S soils, by examining samples retrieved from eight full-scale remedial operations. The sites were selected to encompass a broad range of contaminants, binder systems, environmental exposures, and ages since the remediation. Conceptual models for each site were developed, based upon historical information from the literature. The models were used to identify the environmental loads, acting at the sites, and to predict their likely impact on the S/S soils. These impacts were considered by examining the microstructure, mineralogy, leaching behaviours and mechanical properties of the aged soils. Risk indicators for the performance of S/S soils were identified and they included reactions involving sulfates, carbonation, microcracking and the presence of weathered minerals. There was no link between the age of the S/S soils and degradation. The performance of the S/S soils was site specific and was influenced by the design of the remediation formulation, the implementation of the treatment and not least the environment of exposure. The behaviour of S/S soils is commonly compared to that of concrete. However, whilst the results suggested that some degradation mechanisms occur, properties such as permeability and unconfined compressive strength differed. The S/S soils were two orders of magnitude weaker and five orders of magnitude more permeable than normal concretes. Microstructural investigations revealed that although expansive phases developed with time in the SIS soils, there was no damage associated with them. According to their mechanical properties seven out of eight soils performed to their design criteria, up to 16 years after remediation. However, three sites failed to meet the limits following pass/fail leaching tests. This was due in part to the choice of leaching test carried out for the evaluation and the use of inappropriate remedial leaching limits, such as Drinking Water Quality values. However, the pH dependent leaching test showed that the contaminants were well immobilised in the old SIS soils and their release, at the natural pH of these soils did not exceed 1 mg/1. The acid resistance of the aged SIS soil was low to moderate and was mainly assured by the carbonates present. This fact will impact on the durability of SIS soils; however, estimates from the literature indicate that the acid resistance of carbonated materials would be exhausted in thousands of years. Based upon these results, the integrity of the soils had endured, and no obvious signs of impending failure were observed.

For the past few years there has been increasing concern surrounding a group of chemicals known as phthalate esters. In mammals, phthalates are known antiandrogens, interfering with the production or activity of testosterone. Phthalates are ubiquitous in the aquatic environment. With recent findings suggesting that antiandrogens may be responsible for much of the endocrine disruption found in wild fish populations, the study of phthalate esters has become integral to determining whether or not these anti-androgenic chemicals are of concern. I investigated whether di-n-butyl phthalate (DBP) was able to cause antiandrogenic endocrine disruption in fish under controlled laboratory conditions. Three experiments were undertaken. In the first study, two generations of fathead minnows were exposed to nominal concentrations of 6 to 100 μg/L for 21 and 150 days, respectively. The second experiment examined the effects of early life-stage exposure to DBP (50, 100 and 200 μg DBP/L) on three-spined sticklebacks. The final experiment examined the effects of DBP on adult male three-spined sticklebacks in a 21-day nesting study (15 and 35 μg DBP/L). DBP had no effect on the fecundity, survival, growth, sex ratio, or gonadal histology of the exposed fish in any of the experiments. Further, it failed to alter the expression of two steroidogenic genes in adult male sticklebacks. In contrast, DBP was often found to significantly alter plasma androgen concentrations in both species, and spiggin concentrations in the three-spined stickleback, most notably causing significantly reduced spiggin concentrations in the adult males exposed to DBP. Ultimately, DBP-exposure did not disrupt the ability of the fish to reproduce successfully, and did not appear to alter reproductive behaviours or the expression of secondary sexual characteristics. In conclusion, while DBP did appear to have some capacity for endocrine disruption in fish, it was unable to interfere with the ability of the fish to develop normally and reproduce successfully. Thus, environmentallyrelevant concentrations of phthalate esters are likely not of particular concern to fish populations.