Water shortage is a global problem, which requires a global solution. Desalination technologies, whether thermal or membrane processes, are having practical limitations, which result in high operating and capital costs. The thermal desalination process, namely Multi-Stage Flash (M.S.F.) distillation, is still the most commonly used distillation method, especially in the Middle East. However, the MSF units are generally large-scale and very sophisticated, which require expertise to perform regular technical control and servicing. The aim of the present study is the development of a cost-effective with easy operation distillation system, to satisfy the basic water needs in remote areas in developing countries. A novel small scale three-stage compact distillation system has been designed, constructed, installed and commissioned in a pilot plant study at the University of Surrey. The study involved both theoretical experimental investigations as well as economical analysis. An extensive experimental programme were carried to study the effect of a number of parameters including increasing the heat input, heater temperature and the number of chambers (stages) on the distillate rate as well as the water product cost. The results have shown that: Increasing the number of chambers, heat input and heater temperature have lead to improvement in both the distillate and the production rate; Increasing the number of chambers has increased both the capital and running costs but reduced the specific energy consumption, as well as the unit cost of the produced water; The water production cost decreased by about 13.0% and 28.0 % when the numbers of chambers were increased to two and three chambers respectively, The integration of the system with solar energy source is expected to provide a lower energy cost, which would reduce the final product cost. While the water production cost is estimated to be increased when the system integrated with the fossil fuel as energy source due to increase the oil price during the year of this study.

Two novel processes based on ionic liquid methodology, including steps to recover the ionic liquids for reuse and recycle, are developed for the recovery of key value components from food wastes: namely glycosaminoglycans (GAGs) from seafood waste (scallop gut) and chitin-glucan complexes from cider yeast wastes. Both these components are high-added value materials in nutraceuticals and the chitin- glucan complexes are of particular interest because they are recovered from a vegetarian source. GAG recovery from scallop gut involves treatment of the wet waste with the ionic liquid, HBetNTf2, in a low temperature (30oC) process to separate the insoluble GAG mixture from other components of the waste, which are soluble. The important aspects of this process from the point of view of economic viability are: (i) it is a low-temperature process, (ii) the extraction of the unwanted components occurs quickly, (iii) the product GAGs are obtained in good yield, and (iv) all solvents used can be recovered. The recovery of chitin-glucan involves enzymatic pre-treatment of the cider yeast waste to give a digested pellet from which the complex can be recovered by treatment with the IL, BMIMCl. Two low temperature ionic liquid processes (TESA/TESAC and P6,6,6,14 Cl) for re-refining waste lubricant oils to recover base oils, of sufficient quality to be reused in lubricant applications, are also developed. The TESA/TESAC process is based on a reversible reaction from a solvent, TESA, in which the base oil is soluble to an ionic liquid, TESAC in which the base oil is insoluble. The conversion occurs when carbon dioxide is passed through the solvent and reversed by heating above 50oC. In the P6,6,6,14 Cl process the base oils are recovered from a direct solution of the hydrocarbon content of the waste in the ionic liquid. In both processes all solvents used can be recovered for reuse.

This work has investigated the use of charcoal in the remediation of land contaminated with mixtures of metals and hydrocarbons using two strategies. Firstly, the removal of metal toxicity using highly metal adsorbent charcoals to stimulate the degradation of hydrocarbons and secondly, the use of charcoal as a microbial carrier to provide a population of specific contaminant degraders to enhance their degradation. In a soil contaminated with a mixture of heavy metals, arsenic and phenanthrene, addition of highly metal adsorbing charcoal (nettle charcoal) and iron filings, alone and in combination, were effective at reducing copper leaching, restoring microbial function and enhancing phenanthrene degradation. In addition, iron filings were effective at reducing leachable arsenic levels, but had a negative effect on the soil structure. Wood charcoals were evaluated as microbial carriers for use in bioaugmentation. Survival of P. fluorescens colonising wood charcoals was found at copper concentrations thirty times higher than that toxic to free cells. This effect could be attributed to the formation of a biofilm within the porous charcoal structure. Microcosm trials using charcoals inoculated with populations of hydrocarbon degraders were carried out to determine the necessity of bioaugmentation in the bioremediation of soils contaminated with both metals and hydrocarbons. The efficacy of microbial communities enriched on different hydrocarbon substrates to enhance the degradation of polyaromatic hydrocarbons and diesel range organics was assessed. In the soil examined, the use of specifically selected degrading populations were found to be unnecessary for enhancing the biodegradation of diesel range organics and phenanthrene once metal toxicity was removed by the addition of nettle charcoal. Removal of pyrene was low, despite the provision of pyrene degraders on inoculated charcoal, probably due to its low bioavailability to microorganisms. Removal of metal toxicity by charcoal amendment is highly effective at enhancing the degradation of organic compounds but low bioavailability remains a key limiting factor in bioremediation.

Water is the most common substance on earth, covering more than 70% of the planet's surface. The supply of fresh water has been shrinking; up until now water has been treated as an unlimited resource that has been provided as cheaply as possible and in any quantity desired. Yet by the year 2020 there will only be half as much water per capita as there was in 1970s. Therefore, the world has to consider efficient water management, introduce recycling, prevent pollution and promote water conservation. Although Khartoum City (the Sudanese capital) is located in the central part of Sudan at the confluence of two rivers (the White Nile and the Blue Nile); the problems of urban water shortage are chronic; the water service does not cover all the towns in Khartoum State, and the supplied water is not 100% pure water due to the pollution of shallow underground water sources and this can cause disease. The continuous breakdown in the supply of urban water in the Khartoum districts leads users to use bottled water for drinking and for other purposes. Additionally, the consumers utilize tanks to store water for use during the breakdown periods. It has been found that problems with the water system directly affect the traffic and environmental health in Khartoum. The main aim of this research is to investigate the current situation of the urban water and sanitary system in Khartoum and to identify the impact of these social, economical and environmental factors on the city. The research also aims to draw up a list of recommendations that will lead to improving the implementation and management of the quality and quantity of the water supply in Khartoum City. To achieve this aim, the methodologies used included a literature reVIew, survey questionnaires and interviews with different levels of managers within the Water Authority, Khartoum State. The research discussed and analyzed the results from previous books, research papers, conference proceedings and magazines in the same field as to how to manage urban water in other cities and states. This information and data was analyzed. The results of analysis were tested by second interviews with the same managers within the Khartoum Water Corporation. Their answers and comments were incorporated and a list of recommendations to improve the urban water system in Khartoum is presented at the end of this research.

This research presents a viability assessment of using urea as an energy vector. Urea is attractive in comparison to the chemicals previously considered for supplying hydrogen since it is non-toxic, non-flammable and stable at room temperature and atmospheric pressure. Urea is cheap to produce and has an existing manufacturing infrastructure, but it also has a huge untapped natural resource, of which this study found that the knowledge to extract was technically attainable. Modelling predicted that when urea is heated with steam, a simple hydrogen-rich synthesis gas is formed, with product concentrations of ca. 60 % H2, 20 % CO2 and 20 % N2. Relatively mild temperatures of 500 °C ≤ T ≤ 700 °C were predicted for optimum steam conversion and H2 yield. Experimental steam reforming in this temperature range using a fixed bed catalytic flow reactor was developed specifically for aqueous urea fuel using a novel drop-feed and passively cooled inlet system. Steady state operation created a hydrogen rich syngas with a composition closely matching that predicted at equilibrium. A nickel catalyst was found to be effective and robust for the process, permitting repeated cycling without observed degradation. Characterisation of the catalyst revealed urea steam reforming to be clean, with no evidence of carbon formation apparent. The experimental study used urea solutions in the steam to urea (S:C) range of 3:1 to 7:1. Preliminary analyses of these mixtures confirmed that the fuel would be unaffected by isomerisation and decomposition prior to reactor input. Further preliminary experimentation of kinetic mechanisms confirmed that thermal urea conversion alone would be at worst 99.9 % within 0.5 seconds at T ≥ 500 °C. Simultaneous thermal analyses explored a greater than previously reported range of evolved species produced by thermolysis of urea and urea solution in the presence of nickel catalyst.

Reliable operation of large scale electric power networks requires a balance of generation and end-user. The electricity markets mainly depend on the real-time balance of supply and demand because no sufficient power storage is available at present. As the difference between the peak and off-peak loads is significant, it is very expensive for the power companies to deal with the demand-supply mismatch. The situation is getting more challenging with the increasing use of renewable energy sources particularly wind and solar, which are intermittent and do not match the actual energy demand. This makes the large scale energy storage and power management increasingly important. This thesis studies a Cryogen based Energy Storage (CES) technology which uses cryogen (or more specifically liquid air/nitrogen) as an energy carrier for large scale applications in Supply Side Management (SSM). The aim of this research is to seek the best routes and optimal operation conditions for the use of the CES technology. A systematic optimisation strategy is established by extending the concept of ‘superstructure’ and combining with Pinch Technology and Genetic Algorithm. Based on this strategy a program named Thermal System Optimal Designer (TSOD) is developed to evaluate or optimise both the thermodynamic and economic performances of thermal systems. Three types of CES systems are proposed and optimised for the applications of load levelling, peak-shaving and cryogenic energy extraction. In the load levelling system it is found that the integration of air liquefaction and energy releasing process gives a remarkable improvement of the round trip efficiency. If the expander cycle is used to supply cold energy and the waste heat with a temperature higher than 600K is available, the round trip efficiency attains to 80 - 90% under rather reasonable conditions. Economic analyses reveal that such a CES system is very competitive with the current energy storage technologies if the operation period of the energy releasing unit is longer than 4 hours a day. In the peak-shaving system CES is integrated with Natural Gas Combined Cycle (NGCC) to form oxy-fuel combustion for CO2 capture. The optimisation of such systems gives an exergy efficiency of 70% and electricity storage efficiency of 67% while using helium or oxygen as the blending gas. Economic analyses show that both the capital and peak electricity costs of the peak-shaving systems are comparable with the NGCC which are much lower than the oxy-NGCC if the operation period is relatively short. And the use of helium as the blending gas gives the lowest costs due to the lowest combustion pressure and mass flowrate. A new solar-cryogen hybrid power system is proposed to extract cryogenic energy and to make use of solar radiation for power generation. The system is compared with a solar thermal power system and a cryogen fuelled power system. Thermodynamic analyses and optimisation show that the hybrid system provides over 30% more power than the summation of the power outputs of the other two systems. The results also suggest that the optimal hot end temperature of the heat carrier heated by the solar collectors be about 600K for the hybrid system. Although interesting and promising results are obtained in this study, practical applications of CES technology meet a number of challenges including the dynamic operation and economic optimisation of the system in the simulation aspect and related experimental demonstration for both the key components and the integrated systems.

The feasibility of faecal sludge treatment by an upflow anaerobic sludge blanket (UASB) reactor was studied using first, untreated primary sludge from a sewage treatment works treating only domestic sewage, and then actual faecal sludge. The primary sludge was diluted in the ratio 1:20 - 1:10 while the faecal sludge was diluted in to the ratio 1:6. The UASB reactor treating the primary sludge had a volume of 15 litres and was operated at a mean hydraulic retention time (HRT) of 9.8 h, at a temperature of 37 °C, and at an organic loading rate (OLR) in the range of 5.6 - 15.0 kg COD/m\d. The UASB reactor treating the faecal sludges had a volume of 50 litres and was operated at a mean HRT of 12.1 h, at ambient temperatures in the range of 23.0 - 31.2 °C, and at OLR in the range of 1 2 .5 -2 1 .5 kg COD/nr\d. The first experiment involving the untreated primary sludge was run for 114 days while the second was run for 119 days. The results from both experiments indicate that it is feasible to treat faecal sludges using the UASB reactor. The average removal efficiencies obtained for the first experiment were: 78% for COD, 62% for total solids (TS), 75% for total volatile solids (TVS) and 91% for total suspended solids (TSS). The pH was in the range of 6.9 - 7.4. With regards to faecal sludges, the average removal efficiencies were: 71% for COD, 61% for TS, 74% for TVS and 73% for TSS. The removal efficiencies are comparable to those obtained for a UASB reactor treating for domestic sewage. High removal efficiencies were obtained in a much shorter time compared to UASB reactors treating domestic sewage. The COD concentration in the effluents is too high for direct discharge and hence a form of post-treatment would be necessary. The calculated volume of methane in the biogas collected ranged from 4 - 8 1/kg COD, not accounting for practical losses.

Water pollution control is presently one of the major areas of scientific activity. While coloured organic compounds generally impart only a minor fraction of the organic load to wastewater, their colour renders them aesthetically unacceptable. Effluent discharges from the textile industries to neighbouring water bodies and wastewater treatment systems have been given of much concern especially in recent years. Colour removal, in particular, has recently become of major scientific interest, as indicated by the large number of related research reports. The bacterium, Shewanella strain J 18 143, has been reported to be capable of directly inducing the reduction of azo bonds in reactive azo dyes and, indirectly being involved in the reduction of azo/ketohydrazone chromophores in pigment molecules. Two approaches have been used to extend the applications of Shewanella strain J 18 143 in the treatment of textile wastewaters. The first approach concerned the use of this bacterium, in an immobilised form, in removing the colour from reactive azo dye solutions. The second approach was the use of this bacterium, in a free form, in reducing colour from selected metal-complex azo dye solutions. A grafted cellulose copolymer was chosen as the immobilisation substrate. The cotton fabric was firstly pre-treated and then underwent copolymerisation with the use of acrylic acid as the monomer and potassium persulphate as an initiator. Soxhlet extraction as used for after-treatment of the modified cellulose. The grafting yield of the graft copolymer was controlled at 5.5%. The bacterial cells were immobilised by three methods. The first method, "growing-in", was carried out by growing the bacterial starter culture with the presence of graft cellulosic copolymer. The cells were therefore bound to the substrate. The immobilisation method of adsorption was carried out by allowing the pre-grown, resting cells to physically adsorb onto the copolymeric substrate. The third method, chemical coupling, was carried out by coupling the bacterial cells onto the substrate using a coupling agent, carbodi-imide (CMC). Protein assay of immobilised cells was studied. The method derived from the use of the BCA kit was applied for a qualitative confidence of the presence of the immobilised cells. Decoloration of Remazol Black B solution was carried out using the immobilised cells. In all of the three methods the immobilised cells were able to decolorise the dye. The immobilisation methods of "growing-in" and chemical coupling were found more effective in decoloration. Complete decoloration of the dye solutions was observed. The potential use of the graft copolymer substrate was confirmed. Four Irgalan series metal-complex azo dyes, Irgalan Grey GLN, Irgalan Black RBLN, Irgalan Blue 3GL and Irgalan Yellow 3RL KWL, were decolorised using planktonic cells of Shewanella strain J 18 143. The bacterial cells completely decolorised the solution of Irgalan Grey GLN, apart from that some coloured by-products were observed in the system. Irgalan Grey GLN is a mixture of Irgalan Black RBLN and Irgalan Blue 3GL. Colour reductions of these two metal-complex azo dyes were achieved using planktonic bacterial cells. The results obtained were similar to that of the Irgalan Grey GLN. The colour of the solutions was reduced. Some coloured materials were produced at the bottom and at the top of the aqueous treating system. Colour reduction of Irgalan Yellow 3RL KWL was carried out using the planktonic biological cells Shewanella strain J18 143. Not too much colour reduction can be found from the visual results and from the UV-visible spectra. However, some changes were made by the biological cells. Some precipitation was observed at the bottom the evaluating system which contained Irgalan Yellow 3RL KWL and the cells. This observation was further proved by the particle sizing analysis. The particle cells analysis has shown the standard dye solution has 35% of particles with a size no more than 1.1 nm. The biological treated the aqueous system contained particles, up to 20%, with a size range of 500 nm to 7000nm. The effect of the dye concentration, the incubation temperature and the pH on the colour reduction of the selected metal-complex azo dyes was studied. The evaluations were carried out by evaluating the colour reduction rate against the varied factors. For the colour reduction of Irgalan Grey GLN. the colour reduction rate was increased as the dye concentration increased, the optimum temperature of for the colour reduction was around 50°C, and the reduction rate has shown to be higher at pH range 6 to 9. Same results have shown to the colour reduction of the Irgalan Black RBLN and Irgalan Blue 3GL, except that the optimum operating temperature for the Irgalan Blue 3GL was at 40°C. Although the colour reduction of the Irgalan Yellow 3RL KWL was not significant, the effects of these factors were investigated. The maximum colour reduction was achieved at a dye concentration of 0.11 g dm-3, at a temperature of 40°C and pH range from 6 to 8.

In this study, a simulated Organic Fraction of Municipal Solid Waste (OFMSW) was treated inan anaerobic two-stage membrane process. The OFMSW feedstock was fed to a ten litre hydrolyticreactor (HR) where solid and liquid fractions were separated by a coarse mesh, whilethe leachate was fed to a three litre submerged anaerobic membrane bioreactor (SAMBR) within-situ membrane cleaning by biogas sparging beneath a flat sheet Kubota membrane. Theaim was to develop and optimize this two-stage process where the use of a membrane in bothreactors to uncouple the Solid and Liquid Retention Times (SRT and HRT) would allow us toimprove the current performances obtained with single stage designs. The Denaturing GradientGel Electrophoresis (DGGE) technique was used to monitor the microbial population in the reactorsand have a better understanding of the archaeal and bacterial distribution in a two-stageprocess. It was found that meshes with pore sizes of 10 microns and 150 microns were inappropriateto uncouple the SRT and HRT in the HR. In the former case, the mesh became clogged, whilein the latter case, the large pore size resulted in high levels of suspended solids in the leachatethat built up in the SAMBR. The most important parameter for Volatile Solids (VS) removal in theHR was the SRT. Maximum VS removals of 70-75% could be achieved when the SRT was equalto or greater than 50-60 days. This was achieved at a HRT of 9-12 days and an Organic LoadingRate (OLR) of 4-5 g VS.l-1.day-1.Increasing the SRT to beyond 100 days did not significantlyincrease the VS removal in the HR. However, at an OLR of 10 g VS.l-1.day-1 in the HR the SRThad to be reduced due to a build up of TS in the HR that impeded the stirring. Below 20 daysSRT, the VS removal reduced to between 30 and 40%. With kitchen waste as its main substrate,however, an OLR of 10 g VS.l-1.day-1 was achieved with 81% VS removal at 23 days SRT and1.8 days HRT.The SAMBR was found to remain stable at an OLR up to 19.8 g COD.l-1.day-1 at a HRT of0.4 day and at a SRT greater than 300 days, while the COD removal was 95%. However, theperformance at such low HRTs was not sustainable due to membrane flux limitations whenthe Mixed Liquor Total Suspended Solids (MLTSS) went beyond 20 g.l-1 due to an increase inviscosity and inorganics concentration. At 35 ?C the SAMBR was found to be stable (SCODremoval 95%) at SRTs down to 45 days and at a minimum HRT of 3.9 days. The SAMBRcould achieve 90% COD removal at 22 ?C at an OLR of 13.4 g COD.l-1.day-1 and 1.1 days HRT(SRT = 300 days).The DGGE technique was used to monitor the archaeal and bacterial diversity and evolutionin the HR and SAMBR with varying SRTs, HRTs, OLRs and temperatures in the biofilm andin suspension. Overall, it was found that stable operation and high COD removal correlatedwith a high bacterial diversity, while at the same time very few species (2-4) were dominant. Only a few dominant archaeal species were sufficient to keep low VFA concentrations in theSAMBR at 35 ?C, but not at ambient temperatures. It was found that some of the dominantspecies in the HR were hydrogenotrophic Archaea such as Methanobacterium formicicum andMethanobrevibacter while the other dominant species were from the genus Methanosarcinaor Methanosaeta. The presence of hydrogenotrophic species in the HR could be fostered byreinoculating the HR with excess sludge from the SAMBR when the SRT of the SAMBR wasgreater than 45 days. Among the bacterial species Ruminococcus flavefaciens, Spirochaeta,Sphingobacteriales, Hydrogenophaga, Ralstonia, Prevotella and Smithella were associated withgood reactor performances.

Public awareness on the impacts that micropollutants and emerging contaminants have on aquatic resources has increased in recent decades and has become a significant driver for reducing levels of contaminants in the environment. The most recent and comprehensive initiative of the European Union in the area of water protection is the Water Framework Directive (WFD), which entails the application of new technical standards for surface water quality. It has been reported that sewage treatment works (STWs) are a major source of micropollutants for receiving aquatic environments. As a result of this, STWs are increasingly becoming a target for regulatory and public pressure with regard to their discharges to the environment. The micropollutants and emerging contaminants considered in this thesis have been identified under the European Union as substances that are toxic, persistent, and likely to bioaccumulate. This thesis aimed to develop a model to estimate concentrations and loads of micropollutants and emerging contaminants at site specific STWs to aid the implementation of the WFD by 2015. The thesis also focused on a case study to evaluate the need for tertiary treatment to remove micropollutants and emerging contaminants using a detailed laboratory analysis to assess the removal ability of a selected tertiary treatment. The results of the model designed in this research were used as part of a risk assessment which focused on understanding the risk that site specific STWs posed to the environment, and on their removal efficiencies. The risk assessment enables the most at risk STWs to be prioritised for investment and will facilitate management options in seeking to satisfy the WFD. The thesis, through extensive research, also aimed to detail knowledge gaps present in the UK water industry regarding sources, pathways, fate, and behaviour of micropollutants and emerging contaminants. Finally, recommendations were outlined regarding future steps to help meet the requirements of the WFD.