Contamination of aquatic environments via anthropogenic release of metals is an increasing global environmental concern. The greatest concerns exist within estuarine and harbour environments, where point and non-point metal sources are prevalent. Historically, monitoring programs were initially (and largely) based on chemical analyses; however, the identification of a number of shortcomings in this approach resulted in a shift towards the complementary use of biological monitoring (biomonitoring). The aim of this study is to investigate and compare the suitability of selected aquatic invertebrate taxa biomarker responses (by production of metallothionein- MT) for assessment of aquatic environmental conditions in three coastal estuaries in Southern England: Poole Harbour, the Fal estuary and the Solent. This was delivered through a critical review of the current status of metal contamination in biota, water and sediment within these estuaries; by investigation of the suitability of selected species’ metallothioneins to act as biomarkers by assessing their correlation with metal pollution; by assessment of the effectiveness of these organisms as bioindicators in biomonitoring studies; and though investigation of the potential use of MT concentrations in these species as biomarkers of metal exposure in monitoring programmes. Legislation has been established to facilitate the protection, and enhance the quality, of all water bodies, including coastal waters and estuaries to prevent their deterioration and to ensure they achieve ‘good’ ecological health; but examination of water and sediment samples showed that historical metal pollution has not been dispersed and still affects environmental quality. In Poole Harbour, metal contamination was detected in all environmental compartments. The enclosed nature of the harbour and its secondary embayments make it vulnerable to the effects of these metal sources which disperse extremely slowly due to restricted tidal exchange; and a significant part of the pollution load remains in coastal areas close to land based contamination sources. In Poole Harbour, water was polluted with As (ranged from 29.6 to 212.8 μg/l) and Hg (ranged from 0.368 μg/l to 11.06 μg/l) which are above the Environmental Quality Standard (EQS) set by the European Union dangerous substances directive (EUDSD). Sediment metals were mostly within “the possible effect range” at which adverse effects occasionally occur, according to the Canadian Sediment Quality Guidelines (CSQG). Although cockles (Cerastoderma edule) had higher tissue concentrations of Ni, Ag and Hg in areas close to pollution sources, and sponges (Haliclona oculata) had accumulated Cu and Zn with a very high magnitude, the absence of EQS for metals in living organisms’ tissues makes it difficult to specify whether the metal concentrations reached a dangerous level or not in these organisms. The results confirmed the presence of a marked metal pollution gradient in the Fal Estuary between the ‘clean’ sites in the north and east of the estuary and the ‘polluted’ sites in the west of the estuary which were historically polluted by water from mines. Moreover, the concentrations of metals in almost all of the contaminated sites in the Fal and Solent estuaries have not changed significantly over the past few decades. This study investigated the potential of MT as biomarker of metal pollution in the following wild species: two well-studied bioindicators- common cockles (C. edule) from Poole Harbour, and mussels (Mytilus edulis) from the Fal estuary and the Solent; and tested the following novel bioindicators: sponges (H. oculata) from Poole Harbour, ragworms (Hediste diversicolor) From the Fal estuary, and limpets (Patella vulgata) from the Solent. The spectrophotometric method was used to measure MT in these species as it has been reported to be a sensitive, time saving, and low-cost technique able to detect MT content in the tissues of aquatic organisms. The results showed that MT concentration in these estuarine wild invertebrates vary between sites; however, these variations were not exclusively associated with metal concentrations and that other environmental factors may explain some of the MTs variability. The many uncertainties surrounding MT in wild organisms indicate that it may have limited potential as a biomarker in estuarine environments. It is also apparent that the importance of biotic and abiotic factors at polluted sites may limit its application. In this study, transplanted mussels (M. edulis) and Manila clams (Tapes philippinarum) were used as active biomonitoring tools in Poole Harbour. It was found that under extreme conditions of metal pollution, the relationship between metal concentrations and MT deviates from linearity: a threshold appears to be reached beyond which the physiological capacity of organisms introduced to polluted areas is exceeded. In the above transplanted animals, MT induction increased to peak levels with increased metal concentration, and then declined with further increases in the concentration.

The disposal of biosolids poses a major environmental and economic problem. Agricultural use is generally regarded as the best means of disposal. Although the impact on soil ecosystems remains uncertain. Biosolids can improve soil properties by supplying nutrients and increasing organic matter content but there is also a potentially negative impact arising from the introduction of heavy metal contaminants into soils. It is widely acknowledged that the bioavailable fraction, rather than total metal content, is indicative of plant metal uptake and toxicity. The bioavailable metal fraction in turn is dependent on soil properties. Therefore, the overall aim of this work was to determine the bio-geochemical factors that control the dynamics of trace element bioavailability in soils that have been subject to the disposal of sewage sludge for over 100 years. Three main investigations were undertaken. In order to determine the current metal composition of the site and identifying the geochemical factors that control the dynamics of metals bioavailability, thirty -eight fields, from a dedicated sewage sludge disposal site for over 100 years, were sampled for both soil (bulk and rhizosphere) and plant. Special attention was devoted to determining soil properties that govern metal partitioning between different metal pools (i.e. total, isotopically exchangeable, Ca(NO3)2-extractable and free ion activity). In order to identify the best estimate of plant uptake and toxic response, a pot experiment was carried out to compare the effects of Zn on plant growth in soils recently spiked with Zn and soils historically amended with biosolids to identify soil properties that best predict metal uptake and subsequent phytotoxicity. The effect of biosolids on soil microorganisms was assessed. Terminal restriction fragment length polymorphism, a fingerprint molecular technique, in combination with multivariate data analysis were used to relate soil microbial diversity and community structure to metal accumulation and bioavailability. High levels of contamination, exceeding the current limits for the use of biosolids in agriculture, were observed in the studied soils reflecting extensive long-term biosolid application. Enrichment factors in relation to background levels in the area were greater than 5 and followed the trend Cd>Cu>Zn>Pb>Ni. Copper and Cd exhibited extremely high enrichment levels, up to 106 and 151 respectively. Except for Pb, the isotopically exchangeable pool of the studied metals (E-value) was mainly controlled by the total metal content in soil, accounting for more than 90% of the variation in E-values. Lead lability was primarily controlled by the total P, LOI and Fe oxides. Metal labilities expressed as % of total metal content were < 40% for the five studied elements following decreasing order of Cu > Cd > Zn ≈ Ni > Pb. Apart from Pb, all the bioavailability estimates (total, E-values, Ca(NO3)2-extractable and free ion activity) correlated strongly with metal concentration in plant, accounting for more than 70% of the variation in plant concentrations. Ca(NO3)2-extractable provided the best estimate out of the four measures of bioavailability, accounting for 87, 77, 87 and 83% of the variation in plant concentration of Ni, Cu, Zn and Cd respectively. The results of the pot trial showed that 67-90% of the added Zn remained isotopically exchangeable after 3 months of Zn addition, suggesting that rapid adsorption processes take place, followed by a slow aging process that cannot be detected over the period of the experiment (3 months). The speciation of soil solution showed that Zn was present mainly (80% on average) as free ion indicating the low affinity of this metal to complexation by dissolved organic matter. An antagonistic relationship was observed between Zn and Cd suggesting that greater Zn availability suppressed Cd uptake by plant. Although Zn addition increased Cd concentration in the soil solution, Cd transfer factor was simultaneously inversely correlated with Zn concentration in soil solution. The free ion activity model (FIAM), based on the biotic ligand model (BLM), accounted for 94% of the variation Zn concentration in plant. Cadmium appeared to play an important role in competing with Zn for uptake. A simple regression model utilising soil total Zn, soil organic matter and soil pH accounted for 88% of the variation in plant uptake. This indicates the possibility of using soil properties that are measured routinely as input for prediction of plant uptake. The results of the Zn phytotoxicity test indicated that the intensity of the exposure (i.e. free ion activity) was the key quantity in the context of predicting plant toxic response, describing 80% of the variation in the response of barley growth to Zn toxicity. Only labile Zn from the quantity based extraction was able to describe the toxic response explaining only 46% of the variation. The study of the effect of biosolids on soil microorganisms showed that soil total Zn concentration could be adopted as a good indicator of the overall (historical) biosolids loading. A biosolids loading, equivalent to 700 – 1000 mg kg-1 Zn appeared to be optimal for maximum bacterial and fungal diversity. This markedly exceeds the maximum soil Zn concentration of 300 mg kg-1permitted under the current UK Sludge (use in agriculture) Regulations. Redundancy analysis (RDA) suggested that the soil microbial communities had been altered in response to the accumulation of trace metals, especially Zn, Cd, and Cu. Based on the findings of this thesis, it can be concluded that (i) the estimation of metal speciation, both in the solution and solid phase is a key factor in determining the bioavailability and thus, has greater chemical and biological significance than soil total metal content; (ii) the maximum beneficial effect of biosolids on soil microbial diversity occurred at a metal (Zn) concentration well in excess of current regulations governing application of biosolids to agricultural land. This indicates that soil microbial diversity is unlikely to be determining factor for regulatory limits for biosolids disposal to agricultural lands.

Natural reedbed habitat in the UK has suffered severe declines in the last few centuries. With only 5,000 ha remaining and much of what remains is highly fragmented and degraded. The loss and fragmentation of reedbed habitat in the UK has had a profound effect on the species associated with it. Constructed reedbeds are artificial wetlands dominated by Phragmites australis designed to treat wastewater. They have been widespread in the UK because they are perceived to be a green solution, but their conservation value has never been assessed. This project aims to determine how they contribute to biodiversity. This study surveyed 24 sites, 12 constructed sites paired to 12 natural sites, for small mammals, moths and stem-dwelling invertebrates. Results show that there is no difference between constructed and natural sites. The indication is that constructed reedbeds, despite their small size, young age and contamination, are just as diverse as natural reedbeds. The implications of this for reedbed and wetland conservation are potentially substantial. There are over 1,000 constructed reedbeds in the UK that are just as diverse as their natural equivalents, which could provide connectivity across unsuitable agricultural and urban landscapes.

This thesis describes an investigation into the phenomenon of air entrainment in vertical dropshafts conveying water from a high level to a lower level. The study initially commenced with hydraulic tests on scale models of a vortex-entry dropshaft arrangement. This subsequently expanded into a more detailed analysis of the mechanisms involved in the air entrainment, rejection and transport processes evident in the early stages of the work. An attempt has been made to define the criteria controlling these three modes of operation in air/ water systems. The physical process of initial entrapment by the plunging water film was researched extensively. The inability to accurately reproduce the bubble sizes in scale models conclusively shows that this aspect is fundamental to the understanding of the problem. A dimensional analysis of the parameters controlling the rate of entrainment in the system was undertaken in the investigations. A number of dimensionless groups were obtained to describe the relationships between the parameters involved in the process. This enables the rate of air entrainment to be predicted in any.system of dropshafts under certain flow and geometrical conditions. The downward passage of air bubbles in water (just one mode of operation in two-phase flow systems) was investigated to establish the air transport capabilities of various flows and hence the air rejection process. An empirical relationship was derived which describes the air void ratio at various discharges and hence enables many aspects of the transport of air bubbles to be studied. A series of values defining the limits of operation of the phases invovled in air entrainment were also identified, e.g. onset of air entrapment and air transport.

There is a growing concern that current levels of economic activity have outgrown the physical limits of the planet. In the face of global constraints, humanity continues to deplete nature, through resource harvesting and waste generation, faster than nature can regenerate itself. The UN World Commission on Environment and Development (WCED) introduced the idea of sustainable development in 1987, with the release of Our Common Future. Sustainable development has since become a powerful and controversial theme, creating seemingly impossible goals for policy makers. Sustainable indicators can be a key mechanism for encouraging progress in the right direction by providing a measuring tool that gives a clearer understanding as to whether sustainability is being achieved. The ecological footprint has emerged as an innovative technique to measure the ecological dimension of sustainability. The research tests the ecological footprint as a tool for guiding humanity towards sustainability. The research establishes whether or not the ecological footprint provides an effective accounting framework for the biophysical services that a given society requires from nature. With Guernsey as the case study, the research investigates whether or not the ecological footprint is a comprehensive tool for local policy decision-making. Considering the methodology of the ecological footprint, its use for time series analysis and the development of scenarios does this. The ecological footprint is also tested for its ability to act as a tool to communicate the ideas of sustainability. In conclusion, while containing some limitations, the ecological footprint is a tool that can facilitate the comparison of policy choices society inevitably must face. At the local level, the ecological footprint is a valuable part of the sustainable indicator tool kit. The use of the ecological footprint as a communication tool for sustainable development is invaluable. It is an indicator that can be understood by the general public and one that links individual lifestyle choices to global environmental problems. The ecological footprint is only an empirical tool and in itself cannot change anything. It is a first step in a process of change and the political will and desire to change must be the driving force. Its great advantage over other sustainability indicators is that it is holistic and makes connections between different activities and impacts. However, the ecological footprint is based on assumptions as the ratios/equations calculated by others. In conclusion, the ecological footprint demonstrates that intelligent rationalisation of means and prudent moderation of ends is the only solution. By providing common ground, the ecological footprint builds bridges between different worldviews and amplifies the resonance between all disciplines working on sustainability.

The inherent nature of surfactants to aggregate at surfaces makes measurement of log P (octanoll water partition coefficient) for these substances extremely difficult. It is possible, however, to calculate a log P descriptor based on the method described by Hansch and Leo (1979). Work presented in this thesis describes the study of the acute toxicity of sulphonated esters (FAES) of general formula R-CH(S03"Na +)-C02-R' to Daphnia magna. Due to structural similarities of this class of anionic surfactant to linear alkylbenzene sulphonate (LAS), it was considered that the log P based QSAR originally developed to describe the toxicity of LAS to D. magna (Roberts, 1989) also would be a good predictor of the acute toxicity for FAES substances. Results of the toxicity studies showed that FAES substances were less toxic than predicted. However, when plotted against log P' Calculated using the conventional fragment approach of Hansch and Leo with the addition of a position dependent branching factor (PDBF) to account for water sharing between hydrocarbon chains, the regression slope was para"el to but distinct from that of LAS. This indicated that either FAES substances were not acting as by the same mode of action as LAS or that modification of the log P calculation was required. Further studies of the toxicity of binary mixtures of FAES with known polar and non-polar narcotics, established that FAES exhibited concentration addition with LAS and phenol. This indicated that they behaved with a similar mode of action and it would be expected that LAS and FAES would share the same QSAR. The difference of the regression slopes of FAES and LAS observed? earlier, therefore, suggested the requirement of a modification to the original log P calculation. The modified proximity factor developed in this thesis considers the effects of relative size of proximal polar fragments on log P.? Spherical hydration sheaths surrounding each fragment were assumed and 'overlapping volumes calculated for fragments at different carbon separation. When incorporated into the log P calculation, the new log P values now allow toxicity values for LAS and F AES substances to be incorporated into the same QSAR.

The design demands on water and sanitation engineers are rapidly changing. The global population is set to rise from 7 billion to 10 billion by 2083. Urbanisation in developing regions is increasing at such a rate that a predicted 56% of the global population will live in an urban setting by 2025. Compounding these problems, the global water and energy crises are impacting the Global North and South alike. High-rate anaerobic digestion offers a low-cost, low-energy treatment alternative to the energy intensive aerobic technologies used today. Widespread implementation however is hindered by the lack of capacity to engineer high-rate anaerobic digestion for the treatment of complex wastes such as sewage. This thesis utilises the Expanded Granular Sludge Bed bioreactor (EGSB) as a model system in which to study the ecology, physiology and performance of high-rate anaerobic digestion of complex wastes. The impacts of a range of engineered parameters including reactor geometry, wastewater type, operating temperature and organic loading rate are systematically investigated using lab-scale EGSB bioreactors. Next generation sequencing of 16S amplicons is utilised as a means of monitoring microbial ecology. Microbial community physiology is monitored by means of specific methanogenic activity testing and a range of physical and chemical methods are applied to assess reactor performance. Finally, the limit state approach is trialled as a method for testing the EGSB and is proposed as a standard method for biotechnology testing enabling improved process control at full-scale. The arising data is assessed both qualitatively and quantitatively. Lab-scale reactor design is demonstrated to significantly influence the spatial distribution of the underlying ecology and community physiology in lab-scale reactors, a vital finding for both researchers and full-scale plant operators responsible for monitoring EGSB reactors. Recurrent trends in the data indicate that hydrogenotrophic methanogenesis dominates in high-rate anaerobic digestion at both full- and lab-scale when subject to engineered or operational stresses including low-temperature and variable feeding regimes. This is of relevance for those seeking to define new directions in fundamental understanding of syntrophic and competitive relations in methanogenic communities and also to design engineers in determining operating parameters for full-scale digesters. The adoption of the limit state approach enabled identification of biological indicators providing early warning of failure under high-solids loading, a vital insight for those currently working empirically towards the development of new biotechnologies at lab-scale.

The project aim was to investigate the potential of a large scale, inexpensive, solar thermal façade in the UK climate. Profiled steel cladding was utilised as a solar absorber, with the channels used to form a series of parallel ducts when covered by a glass surface. Air was considered to flow through the ducts in two modes; forced or buoyant convection. The factors affecting air flow were investigated in a laboratory experiment. The factors affecting solar heat transfer to the air were investigated using prototypes in field conditions. Three models for forced convection and two for buoyant were found in the literature. These were developed and compared against the experimental results to establish appropriate design models. The design models were used to optimise the duct geometry for three desirable outputs; mass flow, temperature output or power output. Optimal duct geometry was found to depend on the flow mode assumed. In addition, the optimal geometry also depended on the required output. Thus it was determined that an optimal hybrid system which could switch modes as required, could not be configured; the function and utility of the system must be decided at the design stage and not reconfigured afterwards. The annual performance of a building-scale south facing façade fitted with such a system (optimised for power output) was modelled for forced and buoyant convection modes. It was found that both flow modes had the potential to generate significant amounts of heat energy which could be used, for instance, to preheat ventilation air. The buoyant system also showed the potential for the generation of significant natural ventilation. However the forced convection system would have the advantage of being more controllable, have a better seasonal distribution of performance and have a greater potential for higher air exit temperatures to be achieved in winter.

Building construction industry has significant impact on sustainability. The construction, operation and maintenance of buildings account for approximately 50% of global energy usage and anthropogenic greenhouse gas (GHG) emissions. In recent years, the embodied energy and carbon are identified increasingly important in terms of sustainability throughout building life cycle. Incorporation of sustainable development in building structural design becomes undoubtedly crucial. The effective building design requires smart and holistic tools that can process multi-objective and inter-connected domain knowledge to provide genuine sustainable buildings. With the advancement of information and communication technologies, various methods and techniques have been applied to accomplish the multiple objectives of sustainable development in building design. One of the most successful approaches is building information modelling (BIM), which requires further enhancement of interoperability. The emergence of Semantic Web technology provides more opportunity to improve the information modelling, knowledge management and system integration. The research presented in this thesis investigates how ontology and Semantic Web rules can be used in a knowledge-based holistic system, in order to integrate information about structural design and sustainability, and facilitate decision-making in design process by recommending appropriate solutions for different use cases. A research prototype namely OntoSCS incorporating OWL ontology and SWRL rules has been developed and tested in typical structural design cases. The holistic approach considers five inter-connected dimensions of sustainability, including structural feasibility, embodied energy and carbon, cost, durability and safety. In addition, the selection of structural material supplier and criteria in sustainability assessment are taken into account as well. This research concludes that the Semantic Web technology can be applied to structural design at early stage to provide multi-criteria optimised solution. The methodology and framework employed in this study can be further adapted as a generic multi-criteria and holistic decision support system for other domains in construction sector.

The concerns of global warming are guiding most industries and commercial properties towards addressing their energy usage. In large buildings where air conditioning is required, there is often a need for “chillers” to control the temperature of the building. This process is not environmentally friendly and expensive in terms of energy used and maintenance issues. The alternative is to cool buildings using natural resources such as induced wind drafts and water extraction from rivers and canal. The latter has not been used with optimum effectiveness because the prediction procedures are not sufficiently developed to satisfy environmental legislation. The mathematical approaches are unrealistic and extremely conservative in their analysis and this causes many valid proposals to be rejected. This research is aimed at addressing that situation. It will provide a valid interactive 3-dimensional analysis procedure that will better evaluate the potential of using any British Waterways canal or similar water source for cooling purposes. After water has been used for cooling it is returned to the canal in a heated state as a thermal plume. It is the boundaries of the plume that must be predicted with reasonable accuracy so that environmental legislation is not infringed and livestock is not jeopardised. It is equally important to ensure the analysis is not over sensitive so as to result in rejection of valid proposals. Earlier work studied heat distribution but did not consider the thermal discharge into still and shallow water, as in a British Waterways canal. The studies below investigate several canal sites to evaluate a variety of situations where the discharge plume differs. Criteria including discharge direction, volume of water, temperature differences, speed of discharge and depth of discharge pipe all play a part in the formation of the plume. As such it is possible to develop an understanding of how the thermal plume merges into the still water and how the heat is diffused into the general body of water. In conjunction with site measurements a laboratory experimental scale model tank was built to replicate the real canal site. This allowed data to be varied and measured more readily. Two different types of discharge have been the subject of this research - the first being when the discharge pipe is located at the surface of the receiving water, the second being when it is submerged deeply below the surface. In all cases the temperature and velocity are measured at various points and at a variety of depths to provide a three dimensional plot across the mixing zone. In addition to the mathematical analysis, thermal imaging was used to predict the heat diffusion profiles on the surface of the receiving water in both the canal site and the model tank. CFD software is also used to evaluate the distribution of temperature and velocity within the mixing zone. The mathematical analysis produced an equation to predict the heat diffusion profile in surface discharge. And a number of equations were produced to model the plume path line in submerged discharge- relating to temperature and velocity dilution along and across the path lines. The relative effects of the bed and free surface proximity appeared significantly in the equations. A 3-dimensional model of the size of the plume is presented to demonstrate the results. The procedure followed in this study will enable the Environment Agency personnel to assess the waste heat utilization with greater thoroughness and within a shorter period.