The thesis reports on Submerged Aerated Filter (SAF) as a tertiary treatment for carbonaceous removal and nitrification. SAFs are relatively new in wastewater treatment and used where available space is limited and any odour must be avoided. They are common as additional or an add on treatment step to meet new standards. Further development of SAF is needed. Most literature is commercial and further academic studies are necessary. This research investigates the possibility of using natural wool fleece as a SAF biosupport media. Most existing plants use sand or plastic. It was hypothesized that wool fleece would have some potentially desirable effluent treatment properties. These were their hydrophobic characteristics, natural and sustainable origin and a fibrous expanded format. Wool is also a cheap, easily available material. This project is an experimental study to determine whether a filter packed with wool could have a better performance than a standard plastic media to treat municipal pollutants.

The high concentration of organics, their toxic nature and possibly low pH levels restrict the application of biological treatments or traditional physicochemical treatments to cork boiling water. Highly efficient wastewater treatment intended for the reduction of contaminants levels is therefore required if the liquor is to be reused in the boiling stage or to be purified to meet the public waste limits before disposal.

Wastewater reuse for irrigated practice is un alternative solution in which food production can be improved especially in the arid-region where freshwater resources are often limited However; the potential public health risk associated with wastewater reuse remain a major concern. as well as public perceptions towards wasteater. This research was conducted in two main agricultural cities within the Saudi Arabia

Scale formation is one of the major flow assurance problems in the water treatment and in the oil and gas sectors. Calcium carbonate (CaCO3) is the most common scale encountered in industry. Barium sulphate (BaSO4) scale is the most difficult to deal with as it is highly insoluble and requires chemical and/or physical treatments. Scale build up results in reduced water flow through pipes and could lead to an entire shutdown of installations leading to important financial losses. Nowadays, the main ways to treat and prevent scale formation are periodic squeeze treatments and/or the continuous injection of scale inhibitors. The use of nitrogen and phosphorous compounds, such as polyphosphino carboxylic acid (PPCA), has already been shown to significantly decrease calcium carbonate scale formation. However, the discharge of such inorganic chemicals into the environment represents a real threat and green inhibitors (such as Polymaleic acid (PMA), Poly-Aspartate (PA) and Carboxymethyl-inulin (CMI) are an altemative. A simultaneous comparison of their inhibition effects on scale precipitation and deposition has been carried out in this study. Several different scale preCipitation prediction models have been developed. However, these models are based on thermodynamics and give, at most, a scale tendency to form. Scale Deposition rate equations or prediction of scale deposition have been largely ignored. Moreover, no attempts have been made to associate precipitation data in the bulk solution with deposition data on a solid surface. If a comparison is made with corrosion prediction where a time-based rate is given (in millimetres per year), then it can be seen that a scale kinetic deposition model would be more useful for the flow assurance and the integrity management. This study present a first attempt for a calcium carbonate and barium sulphate scale deposition kinetic model giving an amount of scale (quantity as a mass or thickness) on a stainless steel surface in function of the saturation index, the temperature, the pressure and flow regime

Understanding the interaction between surfaces at the intermolecular level in ambient conditions is not only a fundamental science, but is of increasing value to water treatment systems. Here the uses of the atomic force microscopy (AFM) modified with particles of interest are assessed, and compared to bench-scale experimental techniques. In the first part of this study, the results from force measurements performed with calcite-modified probes in synthetic hard water (SHW) on selected substrates showed there was no correlation with macroscale scaling rate experiments. However, unmodified tips showed some correlation with non-metal substrates, where carbon coatings (Dymon-iC and Graphit-iC) were least adhesive. Although unmodified tips were unlikely to represent one of the surfaces of interest in water treatment systems, the findings suggest they can be used to screen materials with Ra < 50 nm. Contact angle measurements complemented force data, indicating the origin of repulsive forces on carbon coatings was due to hydrophilic repulsion because carbon and calcite were highly basic. Enhanced adhesion was caused by hydrophobic attraction and the presence of acidic surface groups. In the 2nd part of this study, force measurements were performed on natural organic matter (NOM) polyanions such as humic acid fraction (HAF), fulvic acid fraction (FAF) and hydrophilic acid (HPIA) using modified and unmodified tips. The results showed in symmetric NOM-NOM interactions with modified tips, HPIA-HPIA dominated both adhesion and detachment lengths, while FAF-FAF and HAF-HAF gave similar adhesion profiles. It is thought these intermolecular interactions can be transferred to floc size data, where HPIA flocs were bigger than FAF flocs. In non-symmetric systems adhesion between FAF-NOM was indiscriminate, compared to HAF and HPIA polyanions, indicating FAF polyanions were most likely to control coagulation performance during NOM removal.

No description available.

The growing need for suitable water resources has attracted attention to new water and wastewater treatment processes, such as membrane filtration. Due to the excellent properties of poly(vinylidene fluoride) (PVDF) polymer and membranes, such as excellent chemical and thermal resistance along with great mechanical strength, the PVDF membrane is a suitable candidate for the water and wastewater industry. As a result, there have been many attempts to improve the performance of PVDF membranes, particularly in terms of water flux and fouling resistance, in order to increase the membrane’s lifespan and reduce operating costs. This thesis explores such PVDF membrane performance improvements through hydrophilic modification of the bulk membrane. In this study, the recently developed process of atom transfer radical polymerisation (ATRP) was used to graft hydrophilic chains of poly(ethylene glycol) methyl ether methacrylate (POEM) onto the backbone of the PVDF polymer to synthesise an amphiphilic copolymer (PVDF-g-POEM). A new, environmentally-friendly and cost-effective method was introduced to purify the synthesised amphiphilic copolymer by using water instead of volatile solvents. The amphiphilic copolymer was used as a blend in the spinning dope and the effect of blending this amphiphilic copolymer on the prepared hollow fibres was studied in detail. A wide range of hydrophilic PVDF based hollow fibres was achieved by changing the spinning parameters and dope compositions. Moreover, nano-sized γ-Al2O3 particles were used as an additive to improve PVDF flat sheet membranes. By using alumina particles, the filtration performance, surface hydrophilicity and fouling resistance of membranes improved significantly. In addition, by using triethyl phosphate (TEP) as the solvent, PVDF hollow fibre membranes with interconnected pore structures were produced via a single step immersion precipitation technique. The resultant PVDF hollow fibre membranes displayed excellent mechanical properties because of their macro-void free structures. Polyethylene glycol (PEG) was used as an additive to improve the water flux of the produced membranes and PVDF hollow-fibre membranes suitable for water and wastewater treatments in the range of ultrafiltration were obtained.

There is an increasing demand for the provision of cleaner safer water. In the last 5 years, the global water supply industry has spent > £57 billion on purification treatments. With an increasing population and energy costs, investment is predicted to increase over the next 10 years. Moreover, the industry is attempting to move towards more efficient and sustainable processes for the treatment of a wide range of contaminants. This project focuses on two novel sustainable technologies for remediation of common waste water contaminants: photoelectrocatalysis (pathogens and 2,4-DCP) and biosorption (heavy metals - HMs). The application of semiconductor photocatalysis in waste water treatment has been intensively investigated over the past decade. These studies mainly involve nano dimensional titanium dioxide as a photocatalyst using ultra-violet light as an energy source. However, practical applications are still limited by its poor visible light activity. In this study a photoelectrocatalytic batch cell (PECB) and photoelectrocatalytic fuel cell with a flow through configuration (PECFC) containing a visible light active tungsten trioxide (W03) photocatalyst have been optimised and assessed for contaminant remediation. The potential for the PECB to disinfect a surrogate human pathogen, the lux-marked E. coli HE 101 pUCD607, is investigated in Chapter 3. Disinfection experiments indicated that a > 99 % decrease in CFU/rnl occurred within 15 min. Although, this experiment showed that bacterial disinfection can be achieved by light alone (photolysis), the results indicated that disinfection rates were enhanced considerably by using the immobilised thin film W03 photoelectrocatalyst. This alternative catalyst was further assessed in a flow through PECFC system. The combination of the visible light enhanced W03 and the proton exchange membrane fuel cell (PEMFC) technology to remediation of 2,4-DCP in waste waters is investigated in Chapter 4. Degradation of 2,4-DCP was monitored over a period of 24 hrs. A total decrease of 74 % in 2,4-DCP concentration was observed, from which ea. 54 % were accountable to photoelectrocatalytic degradation processes and 20 % due to losses by adsorption or volatilisation. This decreased further to > 98 % removal over 6 days. A combination of chemical (HPLC) and bacterial biosensor (lux-marked Escherichia coli HB101 pUCD607) toxicity responses confirmed degradation of the parent compound with a concomitant increase in toxicity due to formation of intermediates, respectively. The reduction in 2,4-DCP concentration was observed to follow first order kinetics assuming a perfect flow model for the PECFC. However, more work is required to improve sustain ability of this technique as reduced efficiency of the PECFC occurred with prolonged use of the MEA (potentially due to occlusion of the catalytic sites), leading to loss of membrane conductivity. A major constraint with PECFC is the presence of eo-contaminants such as HMs that limit the efficiency of the MEA. Therefore, Chapter 5 assesses the efficacy and mechanisms for a sustainable biosorbent (distillery spent grain - DSG) to remove HMs from contaminated waters. A batch system was employed to determine the sorption of five different HMs from aqueous solution to DSG. Adsorption occurred up to a saturation point of 11.8, 14.1, 11.2, 38.1 and 14.6 mg of Co, Cu, Ni, Pb and Zn / g DSG, respectively. Adsorption for all HMs conformed to the Freundlich isotherm model, indicating heterogeneity of the DSG surface. The sorption of HM followed the pseudo- second-order kinetic model, indicating that the rate-controlling step in the process was chemical interaction between the HM ions and the functional groups on the DSG surface. An increased sorption efficiency of the DSG occurred with increased storage time as decomposition of the organic matrix resulted in increased number of active sorption sites. However, deterioration in the aesthetic quality of the DSG meant that a balance was required between optimum performance and ease of handling in the application of this material; an optimum storage period of 3 months has been proposed. The batch equilibrium sorption experiments estimated sorption under optimal conditions where there was no limiting rate of interaction between HM and DSG active sites. A leaching set up more reminiscent of a 'real life' in-stream remediation scenario is assessed in Chapter 6. Successful sorption of all five HMs was observed but this was significantly reduced compared to batch equlibia. Moreover, an assessment of the effect of competing ions (NaCl) on HM sorption efficiency of the DSG indicated that increasing the ionic strength of the HM solution generally resulted in a decrease in HM sorption capacity of DSG at lower initial HM concentrations but the opposite effect was observed at the highest initial HM concentration. Sequential extractions, carried out on the BM-laden DSG after leaching experiments indicated that all five HMs studied were strongly bound within the organic matrix of the DSG as < 10 % of the sorbed HMs were loosely bound on labile or exchangeable sites. A preliminary investigation of DSG as a potential sorbent for 2,4-DCP is described in Chapter 7. For two concentrations (16.3 and 40.75 mg/l) , 66.0-68.9- % and 39.6-44.3 % of the 2,4-DCP was removed in batch and leaching experimental set-ups, respectively. The W03 photoelectrocatalytic fuel cells (batch PECB and continuous flow PECFC) and waste-derived biosorbent investigated during the course of this study are both promising emerging technologies for sustainable waste water treatment technologies. Moreover, there is potential for both technologies to act as complementary systems in a treatment train with the DSG deployed upstream of the PECFC (Chapter 8). This DSG- PECFC arrangement could potentially improve the efficiency of the PECFC to degrade organic contaminants, as the DSG will sorb both HM and organic pollutants, thereby reducing the contaminant concentration load stream entering the PECFC. This proposed set-up could in principle be adapted for application in-line of existing waste water treatment systems.

Ce travail de thèse est consacré au concept des réseaux d’assainissement intelligents. Il a été mené dans le cadre du projet international SunRise Smart City, qui consiste en la construction d’un démonstrateur de la ville intelligente et durable sur le campus de la Cité Scientifique de l’Université de Lille 1. Nos travaux de recherche menés sur ce campus équivalent à une ville de 25 000 usagers sont organisés en 4 parties. La première partie comporte une synthèse bibliographique des travaux réalisés sur les réseaux d’assainissement et leur gestion. Elle montre tout l’intérêt d’une gestion dynamique des réseaux d’assainissement dans le cadre du concept de la ville intelligente. La seconde partie présente le site du campus de la Cité Scientifique qui sert de site pilote de démonstration pour ce travail de thèse. Cette partie est consacrée pour la collecte des données du réseau d’assainissement et les données d’inspection et pour l’intégration de toutes ces données dans un système d’information géographique (SIG). La 3ème partie présente une synthèse des analyses de contrôle de la qualité d’eau dans le réseau d’assainissement. Elle décrit dans le détail la présence de divers éléments qualitatifs dans les effluents et en en donne une explication. La dernière partie décrit l’instrumentation mise en place sur le site pilote et les premiers résultats obtenus. Elle décrit notamment l’analyse de fonctionnement du réseau des eaux usées du campus de la Cité Scientifique à partir des données collectées et d’une modélisation numérique. Des améliorations du fonctionnement du réseau d’eau usée sont proposées suite à ces analyses. / This thesis concerns the implementation of the concept of smart sewage network. It was conducted within the SunRise Smart City project, which aims at the construction of a demonstrator of the Smart and Sustainable City on the Scientific City Campus of the University of Lille 1. Our research work carried out on the campus which equivalent to a town of 25 000 users is organized into 4 parts. The first part includes a literature survey of researches conducted on sewage networks as well as their management. It shows all the advantages of the dynamic management of sewage networks within the Smart City concept. The second part presents the site of the Scientific City Campus, which is used as a pilot site for the demonstrator in this thesis. It describes the collection of data concerning both the sewerage infrastructure and inspection and the integration of these data in a geographic information system (GIS). The 3rd part summarizes the results of the water quality control in the sewerage network. It describes in detail the presence of various quality components in the effluent and gives an explanation. The last part describes the instrumentation set up as part of this work and the first results. It provides analysis of the sewage network using the collected data as well as a numerical modeling. It results in recommendations for the improvement of the management of the sewage network.

Azolla filiculoides has been evaluated for the adsorption of trace toxic metals from aqueous solution. The adsorption performance of the material was compared with commercial resins and fitted using the Langmuir and Freundlich models. The Freundlich model described the adsorption of copper and cadmium. Whilst the Langmuir isotherm had the better fit of the mercury data. The assumptions of the Freundlich model include multi-layer adsorption and different functional group binding. Conversely the Langmuir model suggests mono-layer adsorption and can infer single group reactivity. The pH effect on the uptake of the metals was investigated and an increase in removal was observed at higher pH with all the metals studied. The material has been thoroughly characterised using physical methods, such as, scanning electron microscopy X-ray photoelectron spectroscopy and electrophoretic mobility measurements. This enabled conclusions to be made regarding the surface functionality of the solid. Chemical characterisation included direct titrations, revealing a gradual dissociation of acidic groups as the pH increased within the experimental range. Kjeldahl nitrogen and amino acid analysis of several biological materials that have been used in metal sorption experiments showed A. filiculoides as having a large proportion of these cell constituents. The kinetics of metal ion uptake by the biosorbent was investigated and compared with commercially available resins. The kinetics are slower than conventional ion exchange resins and carbon adsorbents but entirely adequate for utilisation in a column process. The mechanism hypothesized for metal ion removal by the biosorbent is primarily attributed to ionogenic groups exchanging ions for copper and cadmium removal. Mercury on the other hand is said to be predominantly involved in a reduction-precipitation reaction on the surface of the adsorbent. Regeneration was successfully accomplished for copper and cadmium after minicolumn trials, with greater than 95 % elution of the metals using 0.1M HCI. The mini column trials showed a sharp breakthrough for these metals singularly and a dynamic equilibrium was observed during multi-metal processing. Mercury removal was much slower and more difficult with the same eluant, achieving a maximum of 50% removal. A method for a semi-continuous biosorbent process has been evaluated and proven to be successful in processing metal laden solution.