Amine functionalised silica adsorbents are promising materials for post combustion carbon capture. They exhibit high CO2 equilibrium adsorption capacities and selectively adsorb CO2 in the presence of water. A practical method of regenerating these materials in fossil fuel power stations is to utilise steam regeneration. There is a lack of understanding of the long term stability of amine functionalised silica in the presence of steam. This thesis explored the deactivation mechanism of impregnated and covalently tethered amine adsorbents under steam regeneration and humid adsorption conditions. The adsorbents were characterised using organic analysis and nitrogen sorption before and after aging. The effect of steam regeneration aging led to a significant decrease in the CO2 adsorption uptakes of the adsorbents. Impregnated amine adsorbents were deactivated by leaching of the impregnated amine component from the largest pores of the support. Steam aging also led to diminished amine accessibility caused by amine polymer agglomerating within pores below 8 nm. To address this issue of instability in the presence of steam amine impregnated silica adsorbents were post functionalised with organosilanes. Under certain conditions this silane functionalisation was shown to selectivity occur at the exterior and pore mouths of the adsorbent. The presence of silane coatings preserved the CO2 adsorption capacities of the adsorbents after aging. A compromise exists between adsorbent stability and CO2 uptake behaviour as silane functionalisation led to a reduction in the CO2 uptake capacity. Post functionalisation of amine impregnated silica with hydrophobic silanes limits the intrusion of water within the pores of the adsorbent. This reduction in water intrusion limits the rate of solubilisation of the amine polymer, thus preventing leaching. The impregnation of amine polymers onto porous silica supports typically leads to agglomerations and significant pore blocking. This limits the rate of adsorption and uptake capacity of the adsorbents. The introduction of aminesurfactant mixtures into the adsorbent was found to increase accessibility of the adsorption sites leading to enhanced rates of adsorption and CO2 equilibrium uptakes. The addition of surfactants also yielded a reduction in the regeneration requirements of the adsorbents, by the formation of favourable thin films of amine within the pores of the adsorbent.

Thesis (B.S.)--Massachusetts Institute of Technology, Dept. of Civil Engineering, 1906 (first author), and Thesis (B.S.)--Massachusetts Institute of Technology, Dept. of Civil and Sanitary Engineering, 1906 (second author). / by Norman P. Gerhard and Charles F. Breitzke. / B.S.

Thesis (Ph. D.)--University of Washington, 1997. / Vita. Includes bibliographical references (leaves [212]-293).

Today the water industry faces a huge challenge in supplying a sustainable, energy efficient and safe supply of drinking water to an increasing world population. Slow sand filters (SSFs) have been used for hundreds of years to provide a safe and reliable source of potable drinking water, with minimal energy requirements. However, a lack of knowledge pertaining to the treatment mechanisms, particularly the biological processes, underpinning SSF operation, has meant SSFs are still operated as “black boxes”. This lack of knowledge pertaining to the underlying ecology and ecophysiology limits the design and optimisation of SSFs. This thesis represents the most comprehensive microbial community survey of full-scale SSFs to-date. Using traditional microbiological methods alongside up-to-date molecular techniques and extensive water quality analyses, specific taxa and community metrics are linked to changes in water quality production. Furthermore, it has been verified that laboratory scale SSFs can mimic the microbial community and water quality production of full-scale filters. This allowed rigorous experiments pertaining to operational differences, pathogen and novel contaminant removal to be performed. This has revealed, for the first time, that multiple trophic interactions within SSFs are integral to optimal performance. This thesis has shown that SSFs are phylogenetically and metabolically diverse systems capable of producing high quality water, with the ability to adapt to remove novel contaminants. Using the information gathered, improvements to filter maintenance and operation can be achieved. Future work will apply the microbial and macrobial community dynamics and impact of novel contaminants on filter performance discovered in this thesis into predictive models for water quality.

With a rising demand for nanomaterials and their continual increase in production, the release of nanoparticles (NPs) into the environment is inevitable (Petosa et al., 2010). Problematically, NPs can have a wide range of toxic effects, which are exacerbated by their size (at least one dimension smaller than 100 nm)(Engineering., 2004). Detrimental effects include brain, intestinal and respiratory injury, delayed embryonic development, DNA damage which ultimately lead to increased mortality (Trouiller et al., 2009), (Handy et al., 2008). Natural and manufactured NPs also have the ability to bind and transport chemical pollutants, thus enhancing their toxicity (Moore, 2006). While an array of techniques are available for in situ remediation of numerous groundwater contaminants, there are currently none for in situ remediation of nanoparticles. This fundamental technology gap means we are poorly prepared to deal with nanoparticle pollution events. The aim of this PhD was to develop mechanisms to immobilise and remove nanoparticles from water and waste water in order to prevent the transport of nanoparticles to sites where they have the potential to cause harm. Experiments conducted demonstrate the potential of microbially mediated mineral formation to immobilise nanoparticles from water. The ureolytic bacteria Sporosarcina pasteurii was used to induce calcium carbonate precipitation in batch and column experiments. Nanoparticle immobilisation was tested as a function of nanoparticle size and surface charge. The results demonstrate the successful immobilisation of negatively charged nanoparticles (both large and small, 150 and 35 nm respectively), while failing to remove positively charged nanoparticles from solution. In order to capture positively charged nanoparticles a second mineral, struvite, was tested. The precipitation of struvite successfully immobilised positively charged nanoparticles. However, in comparison to the calcite precipitation experiments the removal of positively charged nanoparticles was found to be pH and ionic strength dependant. Finally, the ability of Bacillus subtilis, a common groundwater bacterium and wastewater treatment biofilm to adsorb and remove nanoparticles from solution was examined. Here both biosorbent materials were highly efficient at removing positively charged nanoparticles from solution whilst negatively charged nanoparticles remained in suspension. The research presented here demonstrates that microbially induced mineral precipitation may be used as a tool to immobilise nanoparticles from contaminated groundwater. In addition, bacteria and wastewater treatment biofilm were found to be highly efficient biosorbents of positively charged nanoparticles. These findings hold implications for the fate and transport of nanoparticles through environmental systems and wastewater treatment plants.

A new Spatial Decision Support System (SDSS) has been designed and developed to address a wide spectrum of semi-structured spatial decision problems. These problems are related to site selection, site ranking and impact assessment. The proposed SDSS is conceptualised as a holistic, informed and impact-based multicriteria decision framework. The system has been developed using the .NET C# programming language and open source geoinformatics technologies such as DotSpatial and SpatiaLite. A combination of existing Multi Criteria Decision Analysis (MCDA) and Artificial Intelligence (AI) techniques, with a few novel variations have been developed and incorporated into the SDSS. The site selection module utilises a theme-based Analytical Hierarchy Process (AHP) and Weighted Linear Combination (WLC). Two site ranking techniques have been introduced in this research. The first technique is based on the systematic neighbourhood comparison of sites with respect to key indicators. The second technique utilises multivariate ordering capability of the one-dimensional Self-Organizing Maps (SOM) to rank the sites. The site impact assessment module utilises a theme-based Rapid Impact Assessment Matrix (RIAM). A spatial variant of the General Regression Neural Networks (GRNN) with a genetic algorithm for optimisation has been developed for the prediction and regression analysis. A number of other spatial knowledge discovery and geovisual-analytics tools have been provided in the system to facilitate spatial decision making process. An application of the SDSS has been presented to investigate the potential of Coalbed Methane (CBM) development in Wales, UK. Most potential sites have been identified by utilising the site selection and site ranking tools of the developed SDSS. An impact assessment has been carried out on the best sites by using Rapid Impact Assessment Matrix. Further analysis has uncovered the spatial variability expected in the potential impacts of the sites, considering key indicators. The application has demonstrated that the developed system can help the decision makers in providing a balanced regime of social, environmental, public health and economic aspects into the decision making process for engineering interventions. The generic nature of the developed system has extended the concept of Spatial Decision Support System to address a range of spatial decision problems, thereby enhancing the effectiveness of the decision making process. The developed system can be considered as a useful modern governance tool, incorporating the key factors into decision making and providing optimal solutions for the critical questions related to energy security and economic future of the region.

The local climate of Malaysia with high air temperature and relative humidity and inconsistent air movement throughout the day provides challenges for architects and designers to design a building including a mosque that can provide better indoor thermal condition. Thermally uncomfortable indoor environment in a typical Malaysian mosque can be sensed due to the poor attendance of believers during communal prayers conducted five times a day at the mosque. A study was carried out in four typical mosques in Malaysia to investigate the thermal comfort level together with what and how the thermal comfort factors affecting the condition. They study also looks at the influence of roof design of the mosque in affecting thermal condition inside the prayer hall since the roof design is a significant feature of the building not only as a filter to the outdoor climate but also as the identity of the building and the society. From the investigation, it has been revealed that air temperature is the primary factor in affecting thermal comfort. When the air temperature is at neutral or comfort temperature, the presence of other factors can be ignored. However, when the primary factor is no longer at its neutral condition, the secondary factors which are air movement and humidity will play their roles in influencing thermal comfort in naturally ventilated mosques in Malaysia. In many cases, air movement is always desirable and able to improve the thermal comfort level. Therefore, the need for the availability of air movement should be particularly considered in designing a mosque to ensure that the mosque is thermally comfortable. The research has also discovered that the pitched and doomed roofs have different abilities to control the distribution of air, for examples, the pitch roof mosque has the ability to circulate the air inside the prayer hall to achieve the equilibrium state whereas the domed roof mosque has the ability to stratify the air according to the temperature where the coolest air located at the lowest level of the space. With the pitch roof, a mosque is able to create air movement inside the space whereas the dome roof mosque will provide stagnant but cooler air at the active level due to the stratification process. Due to these findings, the pitched roof mosque is considered a better option for this climate for its ability to provide natural air circulation inside the space which is desirable by the users. With the understanding on the ability of the roof designs namely, domed and pitched roof in controlling air movement of the interior and the interdependencies of the main factors affecting thermal comfort, strategies for improvement on the design of the mosque can be made to achieve better indoor thermal condition of the prayer hall.

Oil pipelines play a significant role in crude oil transportation and bring danger close to communities along their paths. Pipeline accidents happen every now and then due to factors ranging from operational cause to third party damage. In the Niger Delta pipeline system, interdiction is common; therefore, every length and breadth of land covered by a pipeline is vulnerable to oil pollution, which can pose a threat to land use. Weak enforcement of rights of way led to encroachment by farmers and human dwellings, thereby bringing people in close proximity to pipelines. Considering the impact exposure can have on human health, a method was developed for identifying vulnerable communities within a designated potential pipeline impact radius, and generic assessment criteria developed for assessing land use exposure. The GIS based model combines four weighted criteria layers, i.e. land cover, population, river and pipeline buffers in a multi-criteria decision making with analytical hierarchy process to develop an automated mapping tool designed to perform three distinct operations: firstly, to delineate pipeline hazard areas; secondly, establish potential pipeline impact radius; and thirdly, identify vulnerable communities in high consequence areas. The model was tested for sensitivity and found to be sensitive to river criterion; transferability on the other hand is limited to similar criteria variables. To understand spatial distribution of oil spills, 443 oil spill incidents were examined and found to tend towards cluster distribution. Meanwhile, the main causes of spills include production error (34.8%) and interdiction (31.6%); interdiction alone discharged about 61.4% of crude oil. This brings to light the significance of oil pipeline spills and the tendency to increase the risk of exposure. The generic assessment criteria were developed for three land uses using CLEA v 1.06 for aromatic (EC5-EC44) and aliphatic (EC5-EC44) fractions. The use of the model and screening criteria are embedded in a framework designed to stimulate public participation in pipeline management and pipeline hazard mitigation, which policy makers and regulators in the oil industry can find useful in pipeline hazard management and exposure mitigation.

In Britain, projected population rise and climate change threaten future water availability. UK water companies run education programmes to encourage more efficient usage, but these tend to focus on primary schools and adults, missing the opportunity to engage secondary school pupils as the next generation of homeowners and bill payers. Educational interventions also traditionally follow the theory of rational choice, envisaging learners as able to change their attitudes and behaviours in accordance with newly acquired information. Sociological research on social practices and ordinary consumption, however, sees water as playing an inconspicuous role in daily domestic activities. Technological infrastructure and prevalent social norms mould behaviour and limit the ability of water users to alter their consumption. This interdisciplinary thesis attempts to break the impasse between works from educational and sociological perspectives, using the theoretical lens of water citizenship. A review of current water education provision in the East Midlands region was undertaken, and a school-based study involving questionnaires, focus groups and exploratory lessons around water. The young people involved in the study tended to show ambivalence towards water conservation, despite general pro-environmental motivations. While some teenagers perceived they were ‘doing their bit’ for the environment, this tended to be limited to accepting and invoking ‘water saving tips’, and many teenagers eschewed water conservation altogether. These findings indicate that innovative educational programmes are needed to raise the standard of water literacy in the UK. This thesis argues firstly for making water use more ‘visible’ in daily activities, by deconstructing the routines and habits that use water, and by recognising the influences that social norms exert on water use. Secondly, it argues that educational initiatives for water literacy could develop young people’s sense of citizenship and responsibility towards water resources by connecting personal actions to impacts at local, national and global scales.

The demand for better indoor environment has led to a wide use of heating, ventilating and air conditioning (HVAC) systems. Employing advanced HVAC control strategies is one of the strategies to maintain high quality indoor thermal comfort and indoor air quality (IAQ). This thesis aims to analyse and discuss the potential of using advanced control methods to improve the indoor occupants’ comfort. It focuses on the development of controllers of the major factors of indoor environment quality in buildings including indoor air temperature, indoor humidity and indoor air quality. Studies of the development of control technologies for HVAC systems are reviewed firstly. The problems in existing and future perspectives on HVAC control systems for occupants’ comfort are investigated. As both the current conventional and intelligent controllers have drawbacks that limit their applications, it is necessary to design novel control strategies for the urgent issue of indoor climate improvement. Hence, a concept of designing the controllers for indoor occupants’ comfort is proposed in this thesis. The proposed controllers in this research are designed by combining the conventional and intelligent control technologies. The purpose is to optimize the advantages of both conventional and intelligent control methods and to avoid poor control performance due to their drawbacks. The main control technologies involved in this research are fuzzy logic control (FLC), proportional-integral-derivative (PID) control and neural network (NN). Three controllers are designed by combining these technologies. Firstly, the fuzzy-PID controller is developed for improvement of indoor environment quality including temperature, humidity and indoor air quality. The control algorithm is introduced in detail in Section 3.2. The computer simulation is carried out to verify its control performance and potential of indoor comfort improvement in Section 4.1. Step signal is used as the input reference in simulation and the controller shows fast response speed since the time constant is 0.033s and settling time is 0.092s with sampling interval of 0.001s. The simulating result also proves that the fuzzy-PID controller has good control accuracy and stability since the overshot and steady state error is zero. In addition, the experimental investigation was also carried out to indicate the fuzzy-PID control performance of indoor temperature, humidity and CO2 control as introduced in Chapter 5. The experiments are taken place in an environmental chamber used to simulated the indoor space during a wide period from late fall to early spring. The results of temperature control show that the temperature is controlled to be varying around the set-point and control accuracy is 4.4%. The humidity control shows similar results that the control accuracy is 3.2%. For the IAQ control the maximum indoor concentration is kept lower than 1100ppm which is acceptable and health CO2 level although it is slightly higher than the set-point of 1000ppm. The experimental results show that the proposed fuzzy-PID controller is able to improve indoor environment quality. A radial basis function neural network (RBFNN) PID controller is designed for humidity control and a back propagation neural network (BPNN) PID controller is designed for indoor air quality control. Then, in order to further analyze the potential of using advanced control technologies to improve indoor environment quality, two more controllers are developed in this research. A radial basis function neural network (RBFNN) PID controller is designed for humidity control and a back propagation neural network (BPNN) PID controller is designed for indoor air quality control. Their control algorithms are developed and introduced in Section 3.3 and Section 3.4. Simulating tests were carried out in order to verify their control performances using Matlab in Section 4.2 and Section 4.3. The step signal is used as the input and the sampling interval is 0.001s. For RBFNN-PID controller, the time constant is 0.002s, and there is no overshot and steady state error. For BPNN-PID controller, the time constant is 0.003s, the overshot percentage is 4.2% and the steady state error is zero based on the simulating results. Simulating results show that the RBFNN-PID controller and BPNN-PID controller have fast control speed, good control accuracy and stability. The experimental investigations of the RBFNN-PID controller and BPNN-PID control are not included in this research and will carried out in future work. Based on the simulating and experimental results shown in this thesis, the indoor environment quality improvement can be guaranteed by the proposed controllers.