Endocrine disrupters and trace organic contaminants are recently recognized contaminants in wastewaters. Current concept is the multibarier approach where the contaminants are removed from the water cycle both by water and wastewater treatment facilities, as well as natural die-away. In this thesis work LC/MS/MS determination of selected EDC compounds, namely, diltiazem, progesterone, estrone, carbamazepine, benzyl butyl phthalate and acetaminophen, at ultra trace levels, have been carried out by optimizing analytical parameters. In addition, new methods were developed for their analysis in sludge samples at sub ppb levels. Following optimization and method development, occurrence of these contaminants in wastewaters and their removal in two full-scale and two pilot-scale membrane biological reactors (MBRs) was studied. Progesterone, estrone and acetaminophen were completely removed from wastewater by biodegradation. CBZ and diltiazem were not removed at all during the study. There was little effect of flux and sludge retention times on the removal of selected EDCs in these membrane plants. In SBR combined with membrane filtration, 13 different micropollutants, including Fluoxetine (FLX), Ibuprofen (IBP), Naproxen (NPX), Diclofenac (DCF), Carbamazepine (CBZ), Trimethoprim (TMP), Roxithromycin (ROX), Erythromycin (ERY), Sulfamethoxazole (SMX), Diazepam (DZP), Galaxolide (GLX), Tonalide (TON), Celestolide (CEL). CEL, GLX, TON and FLX were removed by adsorption onto the sludge while ROX, ERY, SMX, IBP and NPX were removed by biological degradation. The CBZ, DZP, TMP and DCF were not removed by biodegradation or adsorption. Whereas, following the addition of powdered activated carbon, all these compounds were removed entirely from the wastewater stream by accumulating in sludge.

This thesis is a case study investigation of the sustainability of private sector participation in water supply and sanitation in developing countries, with a particular emphasis on South Africa. It is essentially an empirical contribution, which adds to the body of literature pertaining to the privatisation of water supply and sanitation services in developing countries. South Africa, like many developing countries, faces a significant challenge in providing a sustainable water supply and sanitation service to its citizens. It has a vast water supply and sanitation infrastructure backlog, because of the previous apartheid) government's minimal attention to the basic service needs of the African, Indian and Coloured people. This lack of basic services has had a negative effect on people's health and their basic living conditions. The traditional delivery vehicles for water supply and sanitation delivery in South Africa have been its municipalities. After the demise of the apartheid government, the democratic national government restructured these municipalities under various. processes. They merged neighbouring towns and villages, which incorporated former rural areas to achieve economies-of-scale. The intention was to ensure service delivery to the previously disadvantaged, through a mechanism of cross-subsidisation from the affluent to the indigent. However, these newly-demarcated non-metropolitan municipalities, still do not have the finances to extend the water supply and sanitation infrastructure network to rural areas within their jurisdiction. They also lack the good credit ratings to borrow funds from banks to finance new water supply and sanitation infrastructure. The rural population also has low abilities-to-pay for water supply and sanitation services. With total basic infrastructure backlogs estimated to exceed R270 billion in South Africa, the challenge to all tiers of government is considerable. Just rural water supply and sanitation over the next ten years requires R13.5 billion for the financing of new and rehabilitation of old, infrastructure. Faced with this dilemma, national government has attempted to resolve it by following the route taken by other developing nations, that is, by seeking the assistance of the private sector, National,provincial, or access to it. and some local governments argue that it is only the private sector that has the financial resources to fund this infrastructure backlog. To facilitate this change in service delivery vehicles. national government developed legislation to create an enabling environment for the entry of the private sector in the arena of water supply and sanitation provision. This transition has occurred with significant controversy and opposition. Many opponents to any form of privatisation base their argument on privatisation's fundamental drivers not being aligned with the goals of a development state. In the South African situation, these opponents include some organised labour trade unions, researchers, and labour-based research organisations. With firm pressure from this antiprivatisation coalition, private sector participation in water supply and sanitation services has been significantly staggered or impeded. Whilst this study provides evidence that this case of privatisation is not sustainable in the long-term, which is in agreement with this anti-privatisation coalition, the reasons underpinning the conclusion of this study, differ significantly from those of this coalition. The arguments that underpin differences in the opposition's views and this thesis are analysed throughout the rubric of this study. Three elemental constructs underpin the theoretical framework of this study. These constructs are compartmentalised into the nature of public goods and their natural monopoly status, the efficiencies of privatisation and its relation to ethics. and globalisation issues specifically dealing with the roles oftransnational companies. The study will show that the transfer of water supply and sanitation service delivery to the private sector in South Africa has not been sustainable due to various factors. These factors are investigated through the medium of empirical and case study analyses at a national and global comparative scale. Factors investigated include the reasons behind the privatisation, its transition period and procurement of public and other stakeholder buy-in to the change in service delivery, the role that the state has played in providing the enabling environment for privatisation, and the effectiveness of the opposition in delaying or impeding the pace of privatisation. The study also reveals that pilot projects have a special status and access to greater institutional support, which might facilitate its success. This extra attention might not be realisable in successive projects. Factors underpinning a successful privatisation include issues of efficiency, regulation and financial issues. These are also investigated within the rubric of the empirical and case study analyses. The impact of globalisation and the role of transnational companies with apparently "new technologies" and foreign direct investment, which pervade water supply and sanitation privatisation in developing countries, are also discussed. The case study examinations also provide evidence that in the South African situation, these apparent foreign technological innovations have yet to be confirmed. For South Africa and the other developing nations, the foreign direct investment has also been minimal in comparison to the profits that leave these host countries from the water supply and sanitation sector. The primary case study that underpins this research is the pilot project test case for the South African national government, the Dolphin Coast concession in its Kwazulu-Natal province . A comprehensive investigation of this concession provides evidence of the project's commercial failure. However, the concession remains in the hands of a private sector operator, due to the municipality controversially renegotiating the terms of the contract to facilitate the concession's continuity. This "municipal intervention" trend is noticeable in some international case studies. The English privatisation case is also investigated to provide a contrast between privatisation in a developed nation and a developing one. It also provides an insight into the facilitative environment of the English privatisation case, as compared to that of developing nations. The English privatisation, although not without controversy, was a decision taken by the government on efficiency grounds, whilst developing nations have taken the privatisation step based on reasons of infrastructure deficiency and a lack of finance. Essentially, the former is a push factor, whilst the latter has been a pull factor. This thesis includes a case study investigation conducted at the World Bank in New Delhi, India, which provides evidence of the opposition from state bureaucrats to privatisation in India. This serves as a contrast to the organised worker opposition in South Africa, and highlights some of the differing impediments that face privatisation attempts in each respective country. It shows that the reasons underpinning the opposition to privatisation in developing nations facing similar crises are, in fact, dissimilar. The study also investigates the success that can be achieved through the economies-of scale of a public sector utility in South Africa, shown by the Umgeni Water case study. This is essentially a public agency that has corporatised5 along business principles and employed economies-of-scale to become a successful example of public sector water supply and sanitation provision in a developing country. Cumulatively, this study provides evidence that, in South Africa, the transfer of water supply and sanitation services to the private sector is not sustainable without some degree of state intervention. This is especially evident in cases where there are no economies-of-scale to be exploited, and a lack of affluent people to ensure a critical degree of payment of tariffs or cross-subsidisation to the indigent. In effect, by transferring these services to private hands, this would serve only to postpone the eventual lack of sustainability that these services are currently experiencing in public sector hands. The evidence reveals that the privatisation of water supply and sanitation services in South Africa is not a commercially viable option in the long-term, under the normal mechanisms of supply and demand of the market. Concomitantly, the South African national government and its municipalities are faced with a new dilemma. The private sector can provide immediate sources of financing for urgent water supply and sanitation infrastructure development that cannot be similarly procured from limited state funds or other sources. Considering the urgency to provide water supply and sanitation infrastructure, because of the health-related effects that no access creates, privatisation, with strong regulation, may be a more amicable alternative to the current financial restrictions on municipalities, until a more comprehensive and sustainable solution is found. / Thesis (Ph.D.)-University of Natal, Durban, 2003.

Lightweight engineering plastics have been increasingly used in automotive applications(3), this tends toward more fuel efficient vehicles(1). Glass reinforced plastics commonly include thermosetting polymers. These cannot be re-moulded, unlike thermoplastics, thus thermoset scrap is currently disposed of in landfill. This is increasingly targeted by legislation(14) and is becoming more expensive. This thesis describes work to maximise resource recovery from scrap thermoset composites. A review of relevant literature identified thermal processes for treating scrap thermoset composites. Combustion is particularly suitable for the mixed and contaminated materials arising from end of life vehicles. The literature showed that heating glass fibres reduced their properties, which is a concern for any thermal recycling process. The methodology of this work is to recover energy from the composite polymer and reuse the incombustible residues. Two experimental processes are reported: Fluidised Bed Co-combustion of Thermoset Composites with Coal. The common composite filler of calcium carbonate captures the sulphur emissions from the coal combustion. Results show that scrap composites can successfully be burned in a commercial scale fluidised bed. Retention of the sulphur from the coal by the composite filler was up to 75 % of the input. Although a technical success, economic analysis shows this disposal to be unviable compared with similar desulphurisation via crushed limestone. Fluidised Bed Thermal Processing Rig for Recovering Glass Fibres. The incombustible constituents of a crushed Sheet Moulding Compound were released from processing above 400 ° C in the fluidised bed test rig. The reinforcing glass fibres were elutriated as monofilaments, suitable for use in a veil product, and recovered from the flue gases. Scanning Electron Microscopy showed that the fibres were intact. The tensile strength of fibres from 450°C processing was reduced by approximately 50% and by 90% from 650°C(73). Strength was also found to reduce with increasing time at a temperature(76) . Flue gas analysis showed that carbon monoxide and hydrocarbons were present. This indicated that full combustion did not take place and the associated heat energy lost. Measured nitrogen oxides and sulphur dioxide concentrations were low. After initial testing, the test rig was refined by the incorporation of a Rotating Screen Collector to separate the fillers and fibres. The fibre contamination was reduced by 50% via this novel equipment. Fibre recovery rates of up to 57% were achieved. Resin Decomposition Model. Results indicate that the resin endothermic energy of decomposition maintained the temperature of the Sheet Moulding Compound significantly below the bed temperature.

Cementitious building components, although widely used in low-income countries, are too expensive for many applications related to low-income housing. This thesis explores three options for reducing component cost: 1. Use of local fine aggregates, often with clay contamination, instead of low-fines sands transported from a distance. 2. Improved designs, to achieve better material economy. 3. Change of production environment, from on-site to component prefabrication followed by transport to site. Water storage tanks for rainwater harvesting were used as the example for component design, and as a case-study for considering the effect of changing the production environment. The work showed that: In some cases, use of local aggregates will give a cost saving of around 10%. Improved design can give significant reduction in materials usage, of up to 40%. Off-site prefabrication of components, followed by on-site assembly to produce the desired product, does not seem preferable to the prevelant practice of entirely on-site production from raw materials. However, factory-based manufacture of complete products, followed by transport to site, has a number of attractions over entirely on-site production. Out of the three options examined, improved component design offers the greatest benefits for the case study considered.

The rise velocity of injected air phase from the injection point toward the vadose zone is a critical factor in in-situ air sparging operations. It has been reported in the literature that air injected into saturated gravel rises as discrete air bubbles in bubbly flow of air phase. The objective of this study is to develop a quantitative technique to estimate the rise velocity of an air bubble in coarse porous media. The model is based on the macroscopic balance equation for forces acting on a bubble rising in a porous medium. The governing equation incorporates inertial force, added mass force, buoyant force, surface tension and drag force that results from the momentum transfer between the phases. The momentum transfer terms take into account the viscous as well as the kinetic energy losses at high velocities. Analytical solutions are obtained for steady, quasi-steady, and accelerated bubble rise velocities. Results show that air bubbles moving up through a porous medium equilibrate after a short travel time and very iv short distances of rise. It is determined that the terminal rise velocity of a single air bubble in an otherwise water saturated porous medium cannot exceed 18.5 cm/sec. The theoretical model results compared favorably with the experimental data reported in the literature. A dimensional analysis conducted to study the effect of individual forces indicates that the buoyant force is largely balanced by the drag force for bubbles with an equivalent radius of 0.2-0.5 cm. With increasing bubble radius, the dimensionless number representing the effect of the surface tension force decreases rapidly. Since the total inertial force is quite small, the accelerated bubble rise velocity can be approximated by the terminal velocity.

Current activated sludge models are deterministic in character and are constructed by basing on the fundamental biokinetics. However, calibrating these models are extremely time consuming and laborious. An easy-to-calibrate and user friendly computer model, one of the artificial intelligence techniques, Artificial Neural Networks (ANNs) were used in this study. These models can be used not only directly as a substitute for deterministic models but also can be plugged into the system as error predictors. Three systems were modeled by using ANN models. Initially, a hypothetical wastewater treatment plant constructed in Simulation of Single-Sludge Processes for Carbon Oxidation, Nitrification &amp / Denitrification (SSSP) program, which is an implementation of Activated Sludge Model No 1 (ASM1), was used as the source of input and output data. The other systems were actual treatment plants, Ankara Central Wastewater Treatment Plant, ACWTP and iskenderun Wastewater Treatment Plant (IskWTP). A sensitivity analysis was applied for the hypothetical plant for both of the model simulation results obtained by the SSSP program and the developed ANN model. Sensitivity tests carried out by comparing the responses of the two models indicated parallel sensitivities. In hypothetical WWTP modeling, the highest correlation coefficient obtained with ANN model versus SSSP was about 0.980. By using actual data from IskWTP the best fit obtained by the ANN model yielded R value of 0.795 can be considered very high with such a noisy data. Similarly, ACWTP the R value obtained was 0.688, where accuracy of fit is debatable.

This study was carried out to investigate performance of a Vacuum Rotating Membrane (VRM) type membrane bioreactor (MBR). During the study, the VRM plant was erected from scratch and operated in METU campus. The plant was composed of two tanks. First one was about 100 m3 and it was used for biological treatment / the second tank, about 30 m3, was used as filter chamber. The permeate flow rate was adjusted between 6 and 8.5 m3/h giving a hydraulic retention time (HRT) of 18 hours during the study. In the aeration tank, dissolved oxygen (DO) was adjusted to between 4 and 0.1 mg/L to see the effect of the dissolved oxygen concentration on the process. In the filter chamber, total of 540 m2 flat sheet membrane surface were used for the separation of the treated wastewater from the activated sludge. During the 140 days of operation, MLSS concentration increased from 2.5 g/L to 20 g/L. A 99.99% BOD removal and above 95% COD removal were achieved most of the time during the study. At the time when organic loading rate was between 0.35 and 0.1 kg COD/ kgVSS-day, sludge production was very low. Therefore, sludge retention time (SRT) was taken as infinite. The turbidity in the effluent was less than 1 NTU at all the time, and was below that of the tap water. In the aeration tank, 100% Total-N removal was observed when DO was 2 mg/L and MLSS was 8.36 mg/L on 80th day of operation. This indicates that simultaneous nitrification and denitrification was taking place at these conditions. Later, N-removal decreased when DO was deliberately decreased to 0.1 mg/L in the aeration tank to prevent nitrification / for treated wastewaters were intended to be used for irrigation. Since the pores of the membrane were 0.038 &amp / #956 / m, treated wastewaters were sterile with respect to bacteria

Radioisotopes of caesium (Cs) and strontium (Sr) have been distributed in the environment due to weapons testing, nuclear power production and accidents at nuclear facilities. Radiocaesium and radiostrontium are of major concern in the medium to long term following accidental releases as they have high energies, long half lives (137Cs≈30 years; 90Sr≈29 years) and their easy assimilation into biological systems due to their similarity to the biologically important elements potassium (K) and calcium (Ca), respectively. Radio-caesium and -strontium are transferred to humans primarily via plant root uptake, and therefore minimising this uptake has been the focus of a number of remediation strategies, such as ploughing and fertiliser application. Species or cultivar substitution, where a species/cultivar that has higher uptake is replaced by a species/cultivar that has lower uptake, has been proposed as an effective and socially acceptable remediation strategy for contaminated agricultural land, but not enough is known about its efficacy for it to be recommended internationally. The aim of this thesis is to evaluate the potential of species or cultivar substitution as a remediation strategy for contaminated agricultural areas. Chapter 2 consists of meta-analysis of the available data (115 experiments) on the inter-cultivar variation in Cs and Sr accumulation by 27 plant species. Chapter 3 includes experiments conducted in the laboratory (UK) and two experiments in the field (Ukraine) investigating inter-cultivar variation in radiocaesium and radiostrontium accumulation in Brassica oleracea, and whether consistently lower-accumulating cultivars could be identified. Chapter 4 details analysis of samples from grass breeding experiments in Aberystwyth and Edinburgh (UK) from four forage grass species; hybrid ryegrass (Lolium perenne L. x Lolium multiflorum Lam.), L. perenne, L.multiflorum and Festuca arundinacea Shreb., and investigates inter-species and inter-cultivar variation in uptake of stable Cs and Sr. Hybrid ryegrass cultivars that were lower-accumulating in Cs and/or Sr were also identified. Chapter 5 compares the stable Cs and Sr uptake in six L. perenne and two F. arundinacea cultivars grown in Aberystwyth and Narodychi (Ukraine). Chapter 6 compares the performance in terms of yield and forage quality (elemental concentrations, digestibility and water soluble carbohydrate content) of six hybrid ryegrass cultivars and ten F. arundinacea cultivars identified as consistently lower-accumulating in Cs and/or Sr against the performance of two commercial hybrid ryegrass cultivars. The mean inter-cultivar variation in Cs and Sr was 1.8-fold and 2.0-fold,respectively when 27 plant species were studied. Thirty-five-fold variation in radiocaesium and 23-fold variation in radiostrontium was found between c.70 Brassica oleracea cultivars. In two field experiments in Ukraine, five cultivars had consistently lower radiocaesium concentration ratios and two cultivars consistently lower radiostrontium concentration ratios. One cultivar had lower radiocaesium and radiostrontium concentration ratios. Festuca arundinacea cultivars had lower Cs and Sr concentration ratios than cultivars of hybrid ryegrass, L. perenne and L. multiflorum. Three out of 17 hybrid ryegrass cultivars had consistently lower Cs concentration ratios, two cultivars consistently lower Sr and one consistently lower Cs and Sr. Despite differences in soil properties and environmental conditions, F. arundinacea cultivars grown in Aberystwyth and Narodychi accumulated less stable and radioactive Cs and Sr than L. perenne cultivars. One L. perenne cultivar also accumulated less Cs and Sr at both sites. F. arundinacea cultivars accumulated less Cs and Sr than commercial hybrid ryegrass cultivars, but alsohad up to 59% lower yield and a reduction of up to 19% in K accumulation, up to 46% in Ca accumulation, up to 7% in dry matter digestibility and up to 17% in water soluble carbohydrate content. Selecting lower accumulating cultivars was found to reduce Cs and Sr accumulation less, but with a smaller yield penalty and a smaller reduction in digestibility and water soluble carbohydrate content. It is concluded that species and cultivar substitution could be an effective remediation strategy in contaminated agricultural land provided implications for yield and quality are considered.

The conversion of ocean wave energy has the potential to supply utility magnitudes of electrical generating capacity. It has been predicted that the UK has an annual, practical wave energy resource of 50 TWh which represents 12.5 % of the total electricity consumption. The lack of convergence in the design of wave energy converters, demonstrates that there is not yet a clearly superior concept and so the development of novel technologies is continuing. OWEL’s novel wave energy converter was intended to overcome some limitations of floating OWCs whilst retaining many of the beneficial synergies. The simplicity of the collector, no submerged moving parts and a uni-directional air turbine PTO are all advantages of the technology. A review of the previous development work concluded that little was known about the operating principle of the device and that its hydraulic design was not understood. Through the extensive small scale, physical modelling of three different device geometries, the conversion process was investigated to increase knowledge and inform the hydrodynamic design. Initial studies considered a simplified duct geometry and found that the suggestions from the previous development phases of the technology were inaccurate and so were discounted. The methodologies developed were used in subsequent testing and provided initial learning on which the future experiments were based. A multi-duct model was tested in a wave basin in order to investigate whether such a configuration would be suitable as a future commercial device. Energy conversion efficiencies exceeding 40 %, proved the potential of the configuration but the testing highlighted the many complexities of the platform that should be addressed before being further developed. A single duct was studied to evaluate and improve the design of a proposed marine demonstrator being developed consecutively with this research in a commercial project. Testing the sensitivity of performance to changes in the geometric design and naval architecture resulted in a configuration that maximised the conversion efficiency. Various numerical modelling options were considered to create a performance model. CFD was deemed to be the most suitable method to capture all of the relevant flow physics in the conversion process and to provide a useful design tool. A preliminary model was developed to demonstrate the applicability of the method and provide the foundation for further work. Annual, large scale energy productivity analysis for the optimised device predicted that a 42 m long, single duct would be able to generate 154 MWh/yr at Wave Hub. This was equivalent to a 124 % increase over the original baseline design. Predicted electricity generation for the EMEC site was comparable to the predictions for a competing technology. Although both predictions were relatively low, it was anticipated that these would increase as the designs mature.

A laboratory scale prototype mesh bioreactor (MeBR) for the two-stage anaerobic digestion (AD) of biodegradable municipal waste (BMW) was successfully designed and tested. The development involved a number of preliminary stages; creation and characterization of a synthetic BMW (SBMW), exploration of its single-stage AD characteristics under both methanogenic and hydrolytic conditions, and AD trials of a two-stage reactor system where SBMW was fed to a 1st stage hydraulic flush (HF)reactor and centrifuging was used as a method to produce liquid effluent which was fed to a 2nd stage anaerobic filter (AF) reactor. The single stage digestion of SBMW suffered from process instability at very low organic loading rates (OLR) of 2-2.5 gVSl-1d-1 whilst the two-stage HF/AF system was robust up to a maximum OLR of 7.5gVS/ld. The HF reactors became methanogenic due to the effect of effluent recycling. After this, two different prototypes designs of MeBR were built and tested in continuous two-stage AD trials (AF 2nd stage). The aim was to replace the centrifuging of the HF reactors with continuous mesh filtration whilst maintaining the stable and robust digestion process. The first design confirmed the ability to filter SBMW digestate through nylon meshes of pore size 30-140 >m at an OLR of 3.75 gVSl-1d-1. The mesh system operated similarly to the HF/AF system and efficient two-stage AD of the SBMW was shown. Problems with stirring thick digestate limited the OLR on both the mesh and HF systems. To address this limitation on OLR, a 2nd MeBR was designed which employed a rotating drum for low effort mixing and 100 >m nylon mesh sections on the drum surface for filtration. This reactor system operated stably at an OLR of up to 15 gVSl-1d-1 albeit with reduced specific methane production. Application of this type of system will be dependant on requirements for high plant throughput, system robustness and a compact process to make up for slightly lower methane production and waste stabilisation compared to single stage digestion.