China has been building at least 50GW of new coal‐fired power plants every year since 2004. Previous carbon capture and storage (CCS) research has mainly focussed on technology improvements or stakeholder opinion surveys, without picturing the overall concerns and barriers for deploying such technology in China. This thesis therefore explores the engineering and policy requirements to implement CCS and CO2 Capture Ready (CCR) in Chinese coal‐fired power plants, key enablers for future deployment. A preliminary study of the Chinese gasification industry shows there are early opportunities to capture carbon dioxide from gasification plants. However, as power from conventional pulverised coal (PC) accounts for the majority of electricity generated in China, the most promising emission reduction method for China could be through implementation of CCS technology in large PC plants. An investigation of the current PC plant layouts and operating parameters has been carried out during the course of the study. The results show that, in the absence of CCR designs, a large fraction of such new coal power plants built within the next decade could face ‘carbon lock-in’. A site specific system model using ASPEN Plus to demonstrate the possible changes that could be applied to an existing power plant and a retrofit plant is included in the study. A capture ready power plant site selection method has also been developed, to identify possible sites and to aid understanding of the criteria that should be considered when planning a capture ready plant. A case study of a capture ready power plant in Guangdong province, China shows the benefit of regional planning. Finally, the result of the first stakeholder perception survey on making new coal‐fired plants CCR, conducted in early 2010, are presented and analysed. Evidence for a supportive attitude towards CCR could indicate that this may be a route to early commercial demonstration of CCS in China.

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Freshwater is a finite resource. Faced with this challenge in the 21st century, there is an urgent need to augment existing sources of freshwater with sustainable alternatives. By adopting innovative demand management, water efficiency and conservation strategies, smart economics and advanced water technologies, water sustainability can be achieved as well as water security. The thesis posits that a decentralised system, like rooftop RWH, is feasible as an additional freshwater source running parallel to supplement and/ or complement the existing centralised mains water supply system for non-potable use even in high technology countries. Singapore, an urban city with abundant rainfall in a developed country context, is selected as a case study. As more than 80% of Singapore population lives in high-rise public housing, the HDB flats, rooftop RWH would augment the freshwater supply for urban storm runoffs that are discharged to the sea and are not collected in the stormwater collection ponds or reservoirs. Considerable potable water and cost savings would result as at least 25% of the potable mains water presently used for toilet-flushing, irrigation and floor-washing purposes could be substituted by rainwater. The centralised mains water supply system, as the main freshwater supply in socio-economic terms, is questioned as roofwater, with comparative good water quality, can be for non-potable use and thus supplement to meet the increasing water demand. RWH being a decentralised system, with numerous scattered water points throughout a city, has greater flexibility and autonomy and is less vulnerable to disruption in a distribution system, biological warfare and terrorism. For RWH to be successful, it must be carefully planned and designed to meet specific needs and conditions. In addition to enhancing technical guidelines, a combination of legislation, together with incentives, taxes and penalties helps to promote RWH and to maximize the benefits of implementing these systems. RWH is an under-used technology and strategy that can provide multiple benefits. When successfully implemented, RWH in the Singapore model can help close the gap in the total water cycle. It shows that even in a highly developed technological country like Singapore, there is room for a low but environmentally sound technology like RWH to play an important and relevant role. It is hoped that the lessons learned in Singapore can be replicated in other similar situations on a global scale.

The use of biomass as fuels, feedstock and materials has gained recognition in recent years. Developing sustainable solvents for biomass processing and recovery remains a challenge of the chemical industry. Room temperature ionic liquids have been designed for application in biomass waste recovery. Their polarities have been determined and it was found that protic alkylammonium ionic liquids have high α and β values. A comparison of the Kamlet Taft properties with that of alkylimidazolium ionic liquids shows that polarities can be expanded by changing the functionalities on the anion and cation. The stabilities of ammonium ionic liquids as shown by thermogravimetric analysis are lower than their imidazolium counterparts. All ionic liquids have been found to heat up appreciably under microwave irradiation. Their effectiveness as solvents for carbohydrates and biomass has been examined. It was found that the solubility of carbohydrates by ionic liquids is dependent on the polarity of the ionic liquids and other factors such as temperature and the presence of water. High α HBD ability and high β HBA ability were found to promote solubility of glucose and sucrose in ionic liquids, while high β and low α were found to promote cellulose solubility. A novel extraction protocol for the delignification of lignocellulosic biomass wastes under microwave irradiation has been designed that can reduce the amount of waste effluents produced from the process.

The aim of this thesis was to assess the potential of a Submerged Anaerobic Membrane Bioreactor (SAMBR) for the treatment of saline organic wastewater. Firstly, it was found that anaerobic biomass can be acclimatised to salinities up to 20 g NaCl/L over a period of about 35 days during three batch feedings. Experiments were also carried out to evaluate the performance of anaerobic biomass during a sudden reduction and re-exposure to salinity; anaerobic biomass showed high performance during fluctuations in salinity. Then, SAMBRs were used for saline sewage treatment and it was found that 99% Dissolve Organic Carbon (DOC) removal could be obtained at 8 hours hydraulic retention time (HRT). Different start-up strategies and inoculation of halotolerant species into a SAMBR were investigated. In addition, the reduction of biogas sparging time caused an increase in TMP by 0.025 bar, but also an increase in effluent DOC removal and inside the SAMBR by 10% and 20%, respectively. Powdered Activated Carbon (PAC) addition resulted in a TMP decrease of 0.070 bar, and a 30% and 5% increase in DOC removal inside the SAMBR and effluent, respectively.The mechanisms of anaerobic biomass under high salinity were studied by investigating the role of compatible solutes, extracellular polysaccharides (EPS), and Archaeal microbial evolution. Glycine betaine was found to have the most positive effect on anaerobic biomass when added to medium with high salinity. This was found not only in batch experiments, but also in continuous ones using a SAMBR. The effluent composition from the SAMBR treating saline wastewater was analysed, and post treatment strategies using mainly PAC were analysed. The treatment of this effluent with 1.7 g PAC/L can lead to greater than 80% DOC removal. The treatment of wastewater with high salinity and Cr (III) in a system consisting of a SAMBR, an aerobic Memebrane Bioreactor (MBR) and a PAC column was examined. The system obtained 95% and 70% removal of Cr (III) and Chemical Oxygen Demand (COD), respectively. Using molecular techniques inside the SAMBR, species were identified that were capable of surviving in high salinity and Cr (III). In a short-period experiment, relaxation, liquid backwash and gas backwash techniques were compared and showed the superiority of gas backwashing to reduce fouling of the membrane. The specific resistances of a membrane operated for 100 days in the SAMBR showed that more than 90% of the total resistance was attributed to the biofilm cake layer, about 5-7% to the compounds attached on the membrane surface and about 3% to the membrane resistance and to the compounds in the inner pores of the membrane.

In this dissertation the waste incineration process has been described, an overview of the state of the art control methodologies given and a new approach, based on input/output linearization and extremum seeking has been presented. This approach has been tested on a model appositely designed. The results have shown that it is possible to control the waste bed temperature to certain reference values, with robustness against changes in the waste composition. It is furthermore possible to identify reference values for the waste bed temperature such as the steam ow rate is maximized, while at the same time fulfilling operational constraints.

The WRATE LCA model was used to compare the environmental impacts of incineration and MBT to landfilling residual household waste, using The London Borough of Barnet as a case study. Incineration performed best, followed by MBT processes that produced fuel. MBT that produced stabilised material for landfill showed little advantage over landfilling directly. The applicability of the internationally obtained WRATE dataset to the UK was assessed by analysing samples of UK MBT outputs for biological content. These results were used in GasSim to produce long-term gas emission profiles from a landfill. Total gas emissions were reduced, but the timescale of emissions was similar to untreated waste presenting a challenge to landfill management. The WRATE model assumes products resulting from MBT will be used for their intended purpose, however, an assessment of the potential UK market was lacking. Interviews with representatives from relevant industries and a literature review were conducted to fill this data gap. It was found that approximately half of the biodegradable household waste produced annually could be used as SRF, depending on reliability, and competition with other renewable fuels. The use of MBT outputs as a soil conditioner is less likely in the current regulatory framework, however, ongoing trials may prove that it's safe to use, significantly increasing the potential market. GHG emissions from application to land, which has been overlooked in previous research, was addressed using UK samples. A common flux chamber technique was successfully adapted for this new purpose. The dependence of the perceived environmental benefit of incineration and SRF use on the fuels used to generate electricity was modelled and found to be significant, especially for incineration, which in one case had a similar impact to landfilling. Limitations to using LCA for waste management decision-making are discussed and alternative approaches considered. Opportunities for prevention of biodegradable wastes are considered significant.

Perceived drinking water quality is a factor known to cause the failure of drinking water schemes in developing countries. This leads to the loss of health benefits which are the main aims of such schemes. This thesis examines the relationship between perceived and actual drinking water quality and the factors which feed into perceived drinking water quality in a developing countries context. A mixed methodology approach was used which included the use of the following methods: a questionnaire (n=96), participant observations, interviews, a media study, analysis of other texts, sanitary surveys, and analysis of source (2006 n=32, 2007 n=70) and household (2006 n=58, 2007 n=91) water samples for thermotolerant coliforms, chlorine, pH, turbidity and colour. The drinking water situation was found to be more complex than originally thought and drinking water practices were found to be supply driven. The quality of water at the source had little influence on the quality of water drunk in the household, as water was becoming contaminated during collection and in the home. Household water managers prioritised the importance of the different water sanitation and hygiene interventions as the water situation changed, but the rating of drinking water quality remained consistent and was rated as the most important intervention in both periods. The factors that were associated with perceived drinking water quality significantly changed from 2006 to 2007, but the importance of perceived drinking water quality remained consistent. Therefore the factors that influenced the perception of drinking water quality were not fixed and were responsive to changes in the water situation in the community. A surprising relationship was found between perceived and actual drinking water quality, which can be attributed to chlorine being associated with ‘good’ drinking water.

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