Chapter two investigates the adsorption of chlorpropham on six different absorbents including three soil types; the adsorption-desorption of chlorpropham from soil including the development of an analytical method suitable for the analysis of chlorpropham residues in drinking water. The analytical method involved preconcentration of chlorpropham residues on a solid sorbent (C18) followed by elution with a suitable solvent to achieve an environmentally safe and sensitive method for the detection and quantification of chlorpropham. Octaedecyl silylbonded silica cartridges (C18) proved to be very efficient for the determination of chlorpropham residues with a high recovery and reproducibility of 97%. The adsorption study of chlorpropham was carried out on six different adsorbents including three soil types in an effort to find out their efficacy for the purification of chlorpropham polluted water. The studies were carried out using three types of soils - Downholland (peat), Midelney (clay), and Dreghorn (sand) - and charcoal, bark, wheat straw, at three different temperatures and concentrations. The results showed generally, that charcoal had the greater adsorption efficacy followed by tree bark, wheat straw, Downholland (peat), Midelney (clay), and Dreghorn (sand) soil under all investigated temperatures and concentrations. The desorption study was carried out to determine the extent of reversibility of the adsorption process for all the adsorbents under the same conditions of temperatures and concentrations. The results of the assessment indicated that desorption, in general, was more at higher temperature for all the studied adsorbents. However, for charcoal, adsorption was irreversible except at zero time at higher concentrations. For Downholland (peat), Midelney (clay) and tree bark, there was zero desorption at lower concentration levels.

Cooking fume have been found to be a significant component of ambient particulate matter and also to contribute to high concentrations of aerosol indoors. A linkage of individual exposure to cooking emissions with adverse health effects has been found and thus has led to the need for further understand the composition of this source of particulate matter. This study was concerned with gaining further insights into the chemical composition of aerosol generated from typical styles of cooking and the understanding of trends of the formation of particles among different culinary methods. Cooking source profile for African, Chinese, Western and Indian styles was obtained in a specially designed laboratory based kitchen. These profiles were used as input in a Chemical Mass Balance model where ambient data collected in Birmingham, UK were analysed in order to apportion the quantity of organic matter from cooking sources in the location sampled. It was found that cooking generated a significant mass of aerosol with the particle sizes largely within the respirable size range. The Chinese style of cooking was found to generate the highest concentration of particles with PM mass of 21.61µg/m3. The source profile from cooking obtained from the study were found to correlate well with each other with Indian and Western profiles exhibiting the highest correlation. When used for the CMB model runs, these two profiles provided the best output with the model runs apportioning 16% of the Organic Carbon to be from cooking, with traffic, wood smoke and soil debris contributing 44%, 18% and 24% respectively.

The primary aim of this project is to investigate potential new materials for application in ion exchange processes to remove \(^9\)\(^0\)Sr from nuclear waste streams. This work can be broadly split in to two sections, work on attempts to synthesise new materials and work to investigate ion exchange properties of two recently prepared materials AV-7, a synthetic analogue of tin-kostylvite and AV-3, a synthetic analogue of petarasite. Synthesis on new materials was focused on metal silicate materials, in particular titanium, zirconium and tin silicates containing exchangeable group I and II cations. These synthesis attempts initially were focus on targeted mineral phases such as noonkanbahite, BaKNaTi\(_2\)(Si\(_4\)O\(_1\)\(_2\))O\(_2\), followed by a series of brief surveys examining the effects of various changes to precursor gels such as concentration of bases such as NaOH, metal to silicon ratios and the presence of mineralizing agents such as sodium fluoride. The synthesis of two synthetic mineral phases potentially interesting for ion exchange is also reported here, titanite and fresnoite. Ion exchange studies focused mainly on AV-7 and AV-3 but also included well known ion exchange materials for comparison such as clinoptilolite and Nb-doped crystalline silicotitanate and brief investigations in to the ion exchange of fresnoite and titanite. Ion exchange was followed using X-Ray fluorescence, ion chromatography and radioactive \(^8\)\(^5\)Sr exchanges measured using scintillation counters.

Polycyclic aromatic hydrocarbons (PAHs) play an important role in urban air quality due to the toxic and carcinogenic hazard they present. A class of pollutants receiving increasing interest from researchers are oxygenated (OPAH) and nitrated (NPAH) derivative compounds. There is a need for an improved understanding of the sources, concentrations, behaviour and fate of these pollutants as they can pose a similar public health risk as PAHs and can enter the environment both from primary combustion emissions and secondary formation from atmospheric reactions. This study investigates the airborne concentrations of PAH, OPAH and NPAH compounds in U.K. atmosphere at heavily trafficked and urban background sites. Sampling campaigns were conducted to assess the spatial and temporal trends, primary and/or secondary sources, gas-particle phase partitioning and atmospheric degradation of PAHs, NPAHs and OPAHs. Differences in atmospheric concentrations between trafficked sites and the urban background site indicate a variable influence of road traffic emissions between different PAH, OPAH and NPAH compounds. Seasonal, diurnal and temporal patterns as well as positive matrix factorisation (PMF) source apportionment provide evidence of the key influencing factors governing the concentrations of PAHs, OPAHs and NPAHs in the urban atmosphere, in addition to the strength of road traffic emissions.

The fate and transport of citrate and PVP silver nanoparticles (AgNPs) was determined using large scale mesocosm studies with synthetic water and seasonal variations of natural lake water. We were able to produce a simple diffusion-sedimentation mathematical model which modifies sedimentation and diffusion equations for particles moving through a column. We introduced AgNP parameters including size and starting concentration to predict concentration and infer transport mechanisms in a 1 meter tall column over time. Ionic strength had a direct impact upon the behaviour and transformations observed by the two different surface coated AgNPs. Water collected in summer contained high TOC concentrations with low ionic strength. We observed increased stability to the citrate AgNPs and PVP AgNPs remained as nanoparticles for the duration of the study in the surface water. Winter water had the lowest TOC concentrations with high ionic strength. Citrate AgNPs showed increased aggregation and dissolution, whereas the PVP AgNPs remained stable. At different times of the year the transformations of the NPs change and during the warmer months AgNPs persist in particulate forms for longer periods of time in the surface waters.

There is growing public awareness regarding the risk associated with poor indoor air quality (Ward, Underberg et al. 2009) and indoors like in the home and workplace (Bernstein, Alexis et al. 2008). The aim of the study is to measure the magnitude of concentration in indoor environments, and personal levels of some air pollutants such as volatile organic compounds, PM2 s, polycyclic aromatic hydrocarbons, oxy-PAHs and Black carbon. Estimate the mass of BC that might be in the breathing zone and the lung dose. To conduct the personal exposure and home and workplace measurements, 45 healthy, non-smoking adult volunteer subjects were recruited. Concentration of the compounds might vary across volunteer's activities, therefore the importance of having personal exposure data which might be more representative. To accurately assess the human exposure and the human risk associates with the air pollution. New or recently remodeled building were found to have high concentration of VOC, therefore, a decay time should be considered before to move into a new buildings. BC particle size concentrations need to be investigate deeply as few information is available. Moreover not information about BC deposited dose was found.

This is the first study undertaken in a controlled environment to understand the kinetics of the release of soluble reactive phosphorus and copper from sediments of natural systems with an associated biofilm, and to identify which of the size compartments affected those fluxes most. It was found that of the sediment size fractions in the system, the stones that had a substantial biofilm growth attached had the greatest influence. Differences in the responses were observed between the sediment size fractions and the two sites, where contaminant concentrations varied. The equilibrium phosphate concentration and a phosphorus transfer index were used to establish if there was a net uptake or release of phosphorus by the sediment size at the time of sampling. The sediment having a biofilm and associated particulate material resulted in a greater flux than fine sediment, which does not support a filamentous biomass. The kinetic results imply a different mechanism than diffusion being involved. It was demonstrated that both gravel and stone substrates can have an important control over the release of soluble reactive phosphorus due to their role as firm substrate for a biofilm growth. Changes in the steady-state concentration of dissolved copper suggest that the bed sediment is responding to reduced river water concentration and setting a new steady-state. The kinetics of the reaction of the sediment to copper were of a similar order, and rate constants increased through the season, but were of a similar magnitude for both sites. The differences in the n and rate constant values indicate a difference in the mechanisms (i.e. the order of the kinetics) of uptake of copper through the seasons. The kinetics are described by a rate law which yields a method of estimating the flux to the sediment for recovery time after a pollution incident and how far downstream the copper concentration would remain elevated after a pollution incident or sediment.

During the late Miocene, exchange between the Mediterranean Sea and Atlantic Ocean changed dramatically, culminating in the Messinian Salinity Crisis (MSC). Understanding Mediterranean-Atlantic exchange at that time could answer the enigmatic question of how so much salt built up within the Mediterranean, while furthering the development of a framework for future studies attempting to understand how changes may have impacted global thermohaline circulation. Due to their association with specific water masses at different scales, radiogenic Sr, Pb, and Nd isotope records were generated from various archives contained within marine deposits to endeavour to understand better late Miocene Mediterranean-Atlantic exchange. The archives used include foraminiferal calcite (Sr), fish teeth and bone (Nd), dispersed authigenic ferromanganese oxyhydroxides (Nd, Pb), and a ferromanganese crust (Pb). The primary focus is on sediments preserved at one end of the Betic corridor, a gateway that once connected the Mediterranean to the Atlantic through southern Spain, although other locations are investigated. The Betic gateway terminated within several marginal sub-basins before entering the Western Mediterranean; one of these is the Sorbas Basin, a well-studied location whose sediments have been astronomically tuned at high temporal resolution, providing the necessary age control for sub-precessional resolution records. Since the climatic history of the Mediterranean is strongly controlled by precessional changes in regional climate, the aim was to produce records at high (sub-precessional) temporal resolution, to be able to observe clearly any precessional cyclicity driven by regional climate which could be superimposed over longer trends. This goal was achieved for all records except the ferromanganese crust record. The 87Sr/86Sr isotope record (Ch. 3) shows precessional frequency excursions away from the global seawater curve. As precessional frequency oscillations are unexpected for this setting, a numerical box model was used to determine the mechanisms causing the excursions. To enable parameterisation of model variables, regional Sr characteristics, data from general circulation model HadCM3L, and new benthic foraminiferal assemblage data are employed. The model results imply that the Sorbas Basin likely had a positive hydrologic budget in the late Miocene, very different to that of today. Moreover, the model indicates that the mechanism controlling the Sr isotope ratio of Sorbas Basin seawater was not restriction, but a lack of density-driven exchange with the Mediterranean. Beyond improving our understanding of how marginal Mediterranean sub-basins may evolve different isotope signatures, these results have implications for astronomical tuning and stratigraphy in the region, findings which are crucial considering the geological and climatic history of the late Miocene Mediterranean is based entirely on marginal deposits. An improved estimate for the Nd isotope signature of late Miocene Mediterranean Outflow (MO) was determined by comparing Nd isotope signatures preserved in the deeper Alborán Sea at ODP Site 978 with literature data as well as the signature preserved in the Sorbas Basin (Ch. 4; -9.34 to -9.92 ± 0.37 εNd(t)). It was also inferred that it is unlikely that Nd isotopes can be used reliably to track changes in circulation within the shallow settings characteristic of the Mediterranean-Atlantic connections; this is significant in light of a recent publication documenting corridor closure using Nd isotopes. Both conclusions will prove useful for future studies attempting to understand changes in Mediterranean-Atlantic exchange. Excursions to high values, with precessional frequency, are also observed in the radiogenic Pb isotope record for the Sorbas Basin (Ch. 5). Widening the scope to include locations further away from the gateways, records were produced for late Miocene sections on Sicily and Northern Italy, and similar precessional frequency cyclicity was observed in the Pb isotope records for these sites as well. Comparing these records to proxies for Saharan dust and available whole rock data indicates that, while further analysis is necessary to draw strong conclusions, enhanced dust production during insolation minima may be driving the observed signal. These records also have implications for astronomical tuning; peaks in Pb isotope records driven by Saharan dust may be easier to connect directly to the insolation cycle, providing improved astronomical tuning points. Finally, a Pb isotope record derived using in-situ laser ablation performed on ferromanganese crust 3514-6 from the Lion Seamount, located west of Gibraltar within the MO plume, has provided evidence that plume depth shifted during the Pliocene. The record also suggests that Pb isotopes may not be a suitable proxy for changes in late Miocene Mediterranean-Atlantic exchange, since the Pb isotope signatures of regional water masses are too similar. To develop this record, the first published instance of laser ablation derived 230Thexcess measurements are combined with 10Be dating.

Tributyltin (TBT) is a pollutant, mainly introduced to the environment as a marine anti-fouling agent. The aim of this work was to assess and develop sustainable and cost-effective remediation technologies for TBT-contaminated dredged materials. For this purpose, analytical methods were developed for sediments and sediment leachates. For the sediments, a triple extraction followed by derivatisation and measurement by gas chromatography with pulsed flame photometric detection was employed, avoiding the lengthy concentration step of the organic layer. The TBT detection limit of ca 0.04 mg Sn/kg in sediment was below the suggested limit of 0.1 mg/kg for sea disposal of TBT-contaminated dredgings (OSPAR Commission). For the leachates, derivatisation and extraction into hexane was used. Also, a new procedure, with the potential for automation, was developed for the simultaneous analysis of multiple water samples, based on in situ extraction and derivatisation on C18 solid phase extraction cartridges. No legislative limits existed for TBT in leachates, therefore the detection limits of ca 6-10 ng Sn/L achieved were regarded satisfactory, as they were below or similar to the EQS for coastal and estuarine waters or freshwaters (2-20 ng/L TBT). A pilot investigation was carried out on a dockyard to evaluate the use of X-Ray fluorescence as a screening method for the presence of TBT in sediments. Due to tin contamination such a technique was not suitable for the site examined. Incineration was found to remove TBT but it would incur very high costs. Ultrasonic destruction was not effective enough, even on TBT-spiked water solutions. Carbon products, pure clays, organically modified clays, zero valent iron, fly ash and cements were screened for their abilities to prevent TBT leaching, using a leaching test. The best performer was a powdered activated carbon product which, even mixed with cement that increases the leaching of TBT, delivered a TBT-free (< 5 ng Sn/L) leaching test result 33 days after the mixing. The result showed that this technique could provide a solution for the immobilisation of TBT in contaminated dredgings by mixing this relatively low-cost, multi-purpose and inert additive, with or without cement according to the site specific requirements.

No description available.