Section 1 deals with the effects of four low toxicity oiled drill cuttings samples and one diesel oiled cuttings sample on marine sediments. The sediments were contained in 18 onshore tank systems and, after equilibration for 3 months, cuttings were added at levels comparable to those found at about 500m from North Sea oil installations. Tanks containing uncontaminated sediments acted as controls. All contaminated tanks showed identical changes in redox profiles, becoming most reduced after 3 months and gradually recovering thereafter. The highest sulphide levels were recorded in tanks with the highest total oil and n-alkane levels and these reached a peak after 3 months before declining. Levels were still elevated after 15 months in all tanks. Total oil concentrations declined in all tanks over the period of the experiment, n-alkanes and naphthalenes being degraded first. A substantial decline in nematode abundance was observed in all treated tanks in the first month following cuttings application, after which the decline in diesel and the highest oil loaded low tox tanks continued more gradually. Nematode numbers in low tox tanks with lower oil loadings showed fluctuations with abundances greater than that of controls at some points. Interstitial copepods were eliminated in all tanks within the first three months and controls showed general declines over the experimental period. End/opibenthic copepods showed a more varied response with low tox treatments exhibiting enhanced populations, those with lowest oil levels showing the greatest abundances. Abundances in control and diesel treated tanks remained low and constant throughout the experiment. In the first few days after cuttings treatment the greatest evacuation rates for the burrowing bivalve Tellina were recorded from diesel treated sediments followed by the low tox treatments in order of oil loading. It is concluded that the long and short-term impact of diesel cuttings is greater than that of low tox cuttings containing equal oil concentrations. Section 2 deals with the effects of chemical inducing agents, drilling fluid base-oils, oiled drill cutting contaminated sediments and time of year on the hepatic cytochrome P-450 dependant monooxygenase system of the marine flatfish plaice (Pleuronectes platessa). Intraperitoneal injection of 3-methylcholanthrene, Aroclor 1254 and isosafrole greatly enhance several hepatic monooxygenase activities, with each inducing agent producing a slightly different profile of activity both in the presence and absence of a naphthoflavone in vitro. Intraperitoneal injection of oils from diesel and a low tox drilling fluid also induced several monooxygenase activities, and these oils also differed slightly in their induction profiles. These results suggest that more than one isozyme is responsive to chemical induction in the livers of these fish. Induction of monooxygenase was also demonstrated in fish exposed to cuttings contaminated sediments. Plaice exhibit a seasonal cycle for the basal levels of monooxygenase activity. These results are compared with similar work on rats and other fish species and the implications for environmental monitoring, carcinogenicity and reproduction are discussed.

Surface waters are increasingly polluted by the industries in Colombo, Sri Lanka. Among these the food and drink industries are prominent in urban Colombo. To understand the extent of pollution of the inland surface waters a project was undertaken in the San Sebastian canal, which runs through the heart of Colombo, and the connecting waterways. It entailed the chemical and physical monitoring of the surface waters and the waste water discharges of the industries. The results indicated that the San Sebastian canal was a highly polluted canal with a very low dissolved oxygen level. The oxygen sag was very marked at the industrial discharges. Most of the industries, by nature of the highly organic waste waters in addition to being untreated failed to meet the specified standards of discharges into inland surface waters. The rainfall-pollutant and the rainfall-lag analysis indicated the poor dilution of these strong waste waters, and the low assimilative capacity of the highly polluted canal system. Hence, the San Sebastian canal polluted the receiving river Kelani, into which it discharges in the east, and the Beira lake in the west, where the polluted waters are pumped from the canal to maintain the level of the lake.

There is growing concern about the fate and biological effects of chemical contaminants in the marine environment. In the United Kingdom, the present ability to detect the potential longterm effects of contaminants is limited by the lack of suitable laboratory methods for measuring chronic toxicity. The harpacticoid copepod Tisbe battagliai was selected as a candidate test organism and a suite of chronic toxicity test methods was developed for measuring the effect of chemical contaminants on individual copepods (postembryonic development, reproduction and life-table analysis) and populations of T battagliai. The development of chronic test methods proceeded alongside investigations of the influence of key environmental variables (temperature and food availability) on the biology of this species. These investigations provided a valuable insight into the potential importance of these environmental factors for influencing the development of populations of T battagliai in the field, and helped to define the optimum conditions for the culture and chronic toxicity testing of this species in the laboratory. The methods were further evaluated using pentachlorophenol (PCP) as a reference toxicant and the aim was to investigate the potential interaction between toxicant (PCP), environmental factors (temperature and food availability), and their effects on the population dynamics of T battagliai. In summary, results showed that temperature, and food quantity and quality, were important determinants of population dynamics. There were significant interactions between the chosen environmental variables (e. g. temperature), PCP, and subsequent biological effects on Tisbe battagliai, and results highlighted some important differences in toxicity testing approaches based on the measurement of individuals and populations of copepods. Established laboratory toxicity test procedures do not take account of the degree of complexity in the natural environment and this underlines the Miculty in extrapolating from laboratory. results to the field situation. In conclusion, the project was successful in its primary objective of developing a suite of techniques that can be used to measure the potential chronic toxicity of chemical contaminants in the marine environment. The methods using Tisbe battagliai are relatively simple to perform, are amenable to standardisation and provide relatively cost-effective measurements of chronic toxicity. The test methods can be used to provide chronic toxicity data but, more importantly, they can be used to address some of the current limitations associated with single species laboratory tests. For example, used in conjunction with key environmental variables, the methods provide a greater understanding of the potential interaction between contaminants and abiotic variables, thereby, improving the extrapolation of laboratory results to the field situation. The ability to carry out measurements on individual and populations of T. bauagliai provides a valuable insight into the predictive links between effects at different levels of biological organisation.

The use of suitable sewage sludge in agriculture is currently its cheapest disposal option, both in terms of monetary cost, resource utilisation and environmental impact Monitoring of die heavy metal content of the soil after sludge application is required by European Council Du-ective 86/278/EEC, and whilst the behaviour of metals from surface-applied sludge is well documented, the behaviour following other methods of application has received litde attention. The most important alternative land application method cturentiy in use is the subsurface injection of sludge. In this project, field- and laboratory-based experiments were set up to describe the postinjection disttibution of Cd, Cu, Ni, Pb and Zn and the effect on this of: tine design (using die straight tine, side-inclined tine and winged tine), rate of injection (225 m^ ha'-^ and 300 m3 ha"-^), and soil factors ^ H , cation exchange capacity, organic carbon, percentage clay,. Fe and Mn concentration, and redox potential). An assessment of the variability of die injection operation was also important, as account needs to be made of metal distribution and variability in order to delimit an appropriate sampling regime. The results of these experiments indicated that Cu, Pb and Zn are basically immobile, remaining widiin 120 mm of die centte of die original slot location. Tine design was seen to have a significant influence on the pattern of subsurface metal distribution, but neither this,' rate of injection nor soil factors adequately predicted die extent of diis distiibution. Instead, metal identity and concentration widiin the sludge were identified as the most influential factors, in that appreciable quantities of Cd and Ni are leached out of the profile to distances exceeding 300 mm from die sludge, and greater metal concentirations (of the remaining metals) in the injected sludge create distinct gradients in the soil and saturates exchange sites, thus promoting mobility via diffusion, over-riding normal metal chemistry. Of those measured variables that had a secondary effect on distribution, pH, Fe oxide concentration and percentage clay were identified as the most important soil factors.The winged tine was seen to promote soil disturbance and hence metal distribution, and the paraplow to restrict both. In practical terms, these conclusions indicate that the current sampling protocol is inadequate. An alternative regime is suggested.

The presence of sediment deposits within sewerage systems may lead to operational (premature surcharging and surface flooding) and potential environmental problems (sediments act as a store of pollutants which can be released during erosion events). The consequences of allowing these problems to persist have been recognised internationally. In the U.K., the water industry has promoted fundamental and applied research to develop the necessary operational and analytical tools to manage these problems. Under the Urban Pollution Management Research Programme the major aspects of sediments in sewers have been studied and their effects included in new methodologies and tools. Most studies in the U.K. and elsewhere have concentrated on the movement of non - cohesive sediments, whilst it has been recognised that combined sewer sediment deposits possess cohesive characteristics (although this cohesion primarily arises from agglutination and biological processes in the combined sewer rather than classical concepts of cohesion). New computer based models, e.g Mosqito (Moys 1987) and MOUSETRAP (WRc 1993) , are based on sediment transport capacity theories with the limited availability of sediment within the system recognised through storage layers which become available only when certain threshold levels of shear stress are exceeded. Studies in the U.K. to estimate the release of pollutants stored within sewer sediment beds also require a knowledge of the hydraulic shear stress conditions at which the sediment beds will erode and become entrained into the flow. The reported study examines the apparent cohesive nature of a sediment bed in a large diameter sewer concurrently with flow hydraulics, sediment bed deposit depth and suspended solids flux for a number of dry and wet weather periods. Instrumentation was developed and assessed for hydraulic measurements within the study sewer system and in particular, a novel system was devised to improve flow measurement accuracy in large diameter sewers. Development work was also undertaken on an ultrasonic device to monitor the temporal variation in sediment deposit depth at a point. The constituent materials of the sediment bed were examined and rheological techniques were employed to assess the structural strength of the sediment bed present in the study sewer. The results confirmed the apparent cohesive nature of the sediment bed, with the structural strength of the bed far exceeding the normal hydraulic shear stress ranges encountered in the sewerage system. A relationship between apparent yield strength and liquid content of the sediment bed was obtained from the rheological tests. The bed structural strength was then compared with temporal changes in the flow - induced shear forces. An empirical model was developed to predict the availability for erosion of the cohesive deposits in the combined sewer studied. This model was tested against further temporally varying data sets from the sewer and was found to predict the erosion of the sediment bed under varying levels of applied shear stress together with changes in the sediment transport flux. It was concluded that when Dry Weather Flows induce bed shear stresses in excess of 1-2 N/m erosion of the sediment bed structure can be caused, with storm flows which induce shear stresses in excess of 4-6 N/m eroding the bed to a greater depth. The sediment bed was observed to be rapidly re-established following an erosion event. The investigation and model developed contribute significantly to knowledge about the behaviour of sediments in sewers and provide for the first time a model to simulate erosion of a sediment bed with apparently cohesive properties and consequent increase in sediment and pollutant transport rates.

The rise in global energy demand has motivated the exploration and production of oil and gas in increasingly challenging marine environments and there is a continuous risk of accidental oil spills. One of the many fates of spilled oil is deposition on the seabed, which has been extensively studied following the Deepwater Horizon oil spill. However, post-depositional fates of oil in sediments are not well understood. Similarly, the effects of chemical dispersant on oil fate are currently under investigation as their overall contribution to mitigating oil spills environmental impacts remains debated. This project aimed to evaluate the potential for spilled oil to entrain marine sediments and the effects dispersant application had on the process under three transport regimes; (1) post-depositional transport via oil-sediment aggregate deposition in deep-sea sediments, (2) percolative transport in intertidal sands and (3) advective pore-water transport in intertidal and subtidal sands. Investigations into the sorption dynamics of two polyaromatic hydrocarbons in sediment-dispersantseawater systems were also undertaken to evaluate the influence of dispersant application on sorption of hydrocarbons to sediments. Finally, the effects of oil exposure at in situ conditions of pressure and temperature on sediment bacterial community composition were investigated. Oil transport experiments revealed that the tested regimes resulted in significant entrainment of hydrocarbons in marine sediments. Dispersant application resulted in enhanced oil entrainment into sands but not in silts and this effect depended on the water-solubility of hydrocarbons. Watersoluble components were less affected by dispersant than less water-soluble ones. Investigations into sediment bacterial responses to oil exposure at in situ conditions of pressure and temperature revealed a significant effect of both variables on diversity and community composition, highlighting the importance of conducting deep-sea microbial studies at conditions as close to in situ as possible.

Thesis (M.Eng.)--Memorial University of Newfoundland, 2005. / Restricted until October 2006. Bibliography: leaves 159-169.

Inductively coupled plasma-mass spectrometry (ICP-MS) offers exceptional sensitivity and multi-element capability for trace metal analysis but the formation of polyatomic ions (particularly below m/z = 80) can cause, serious interferences. Such species can be introduced via precursor atoms in atmospheric gases, the sample matrix or impurities in the argon support gas. This thesis describes the development of a portfolio of analytical methods coupled with ICP-MS detection for the determination of trace metals such as manganese, cobalt, copper, nickel, zinc, mercury and lead in complex matrices such as sea water. A literature review of coupled techniques is given in Chapter one. Chapter two discusses the effect of sea water on the analytical performance of ICP-MS. Initial studies were carried out using a single channel flow injection (FI) manifold and included an investigation of the addition of nitrogen to the nebulizer gas flow of the ICPMS for the reduction of the ArNa* polyatomic ion interference at m/z = 63 on the Cu signal. This was followed by a multivariate simplex optimisation for the suppression of the ArNa* polyatomic ion interference at m/z = 63 and non-spectroscopic interferences affecting other masses in sea water, for the determination of Cu, Cr, Mn, Ni, Co, Zn and Pb. In Chapter three an on-line FI-ICP-MS matrix elimination method for the determination of trace metals such as Mn, Co, Cu, Zn and Pb in sea water is discussed. The method involved chelation of the analytes onto Chelex-100 or MetPac CC-1 iminodiacetate (IDA) .resin, with the simultaneous removal of indirectly interfering matrix species, particularly Na and CI ions. Results showing how the effects of the interferences were overcome, together with validation of the method by the analysis of open ocean, coastal and estuarine certified reference materials are reported. s Chapter four compares FI approaches coupled with AFS, ICP-AES and ICP-MS detectors for the determination of total mercury. Initial studies compared figures of merit for FI (conventional pneumatic nebulization) and Fl-cold vapour generation (CVG) coupled with ICP-AES and ICP-MS. Detection limits for total Hg were improved by developing simple on- and off-line preconcentration procedures using a MetPac CC-1 micro-column incorporated in a FI manifold vAth conventional pneumatic nebulization. An AFS detector was then used in the development of a method for the determination of total mercury with an on-line bromide/bromate oxidation step. In chapter five an LC-ICP-MS method for the speciation of Hg in sea water samples is described. The method involved the separation of mercury(II) chloride, methylmercury chloride and ethylmercury chloride on a Cig ODS stationary phase with an ammonium acetate/acetonitriIe/2-mercaptoethanol mobile phase. In order to achieve the necessary detection limits required for the determination of mercury in real sea water samples (< 50 ng r^), an off-line preconcentration method using a dithiocarbamate resin was used.

The objective of this study was to develop novel techniques for on-line sample pre-treatment for use with atomic spectroscopy. Preconcentration of the analytes using either complexation of the analyte(s) on an analytical column or by in-situ (in atomiser) trapping on a pre-coated graphite tube has been used. The samples were manipulated using flow injection analysis and detection achieved in most cases by ETAAS. All aspects of the study are supported by reference to the literature. Using the above approach, a new method has been developed to determine mercury in environmental (sediment) and biological (tuna fish) samples. This approach successfully achieved a sample throughput of 20-30 sample per hour, with a method detection limit of 0.2 ng g*^ (3a) and a precision of less than 10% at the 0.1 ug g"^ level. An interference study was conducted and seven elements ( As\, Cd", Cu", Ni", Pb". Sb'' and Se"") shown to give less than a 5% interference when the interferent concentration was 2 orders of magnitude greater than the Hg. Silver showed a 9% interference when one order of magnitude greater than the Hg. The technique of "in atomiser trapping" was applied to the determination of As, Bi, Sb and Se, in lake water samples. The hydrides were sequestrated upon an Ir coated graphite tube and the instrumental and chemical parameters optimised for multi-element determinations. Iridium has been identified as the best trapping material (coating) for multi-element determinations. The final method gave detection limits of 0.82, 0.04, 0,26 and 0.29 ug 1'^ (500 ul sample loop) for As, Bi, Sb and Se respectively. A characteristic mass of 177 pg for As, 91 pg for Bi, 107 pg for Sb and 90 pg for Se was achieved. Good agreement was obtained with certified and standard reference materials and the method was successfully applied to the determination of As, Bi, Sb and Se in lake water samples. Six elements (Cd, Cu, Fe, Mn, Ni and Pb) were selected for determination in seawater samples by multi-element on-line column preconcentration. The sample stream was mixed on-line with a buffered solution of diethylammonium dithiocarbamate (DDDC). and the metal-DDC complex retained upon a Cie RP silica column. Ethanol was then used to elute the metals from the column directly into the graphite tube. Disappointing results, were obtained due to interference problems, and although more work is required before this approach may be routinely used, it is shown to have potential for the future. Overall, this study has shown that novel methods employing flow injection methodologies for separation and preconcentration are a viable way to prepare environmental sample for analysis by ETAAS. Further it has demonstrated that multi-element analysis is possible for low levels of analyte despite the presence of troublesome matrices, although further work is required to achieve the ultimate goal of a universal method suitable for all analytes irrespective of the sample type.

No description available.