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Halifax, United Kingdom

Fabrizi L.,Cranfield University | Jefferson B.,Cranfield University | Parsons S.A.,Cranfield University | Wetherill A.,Yorkshire Water | Jarvis P.,Cranfield University
Environmental Science and Technology | Year: 2010

Dosing polymer to improve floc characteristics is a widely practiced method in water treatment to improve floc strength, and there is strong operational evidence showing the benefit of polymer dosing. However, there is a paucity of information on how polymer operates in terms of quantifying the resulting floc size and strength over different size scales. A dual particle sizing approach was used to monitor large floc that contain most of the sludge volume and small floc that can cause downstream treatability problems for systems with and without polymer dosing. The polymer investigated was a slightly anionic polyacrylamide dosed in water collected post dissolved air flotation at concentrations of 0 - 0.03 mg L-1. With increasing polymer dose, median floc size increased from 228 to 325 μm. Floc responses to increased shear rate showed that polymer dosing increased resistance to floc break-up. While all of the f Iocs showed high potential to regrow, regrowth was greatest in polymer-dosed systems, where flocs exceeded the size that they had reached previously. Increasing the dose of polymer showed increased removal of small particles (<8 μm) showing that polymer was able to effectively remove particles that are liable to cause downstream problems. © 2010 American Chemical Society. Source

Agency: GTR | Branch: EPSRC | Program: | Phase: Research Grant | Award Amount: 199.11K | Year: 2008

The water industry is the fourth most energy intensive secotr in the UK and uses approximately 2 -3 % of net UK electricity releasing approximately four million tonnes of green house gas emissions (carbon dioxide equivalent) every year. The industry is making progress to produce more renewable energy from its waste biomass sources. However, only 493 GWh was generated by water utilities in the UK in 2005/06 about 6.4 % of its actual requirements. The government has called for research into potentially more efficient energy generation technologies from biomass which would contribute significantly to the UKs policy objectives of 10% of electricity supply from renewable energy by 2010 and for the reduction of greenhouse gas emissions. Innovative research into low carbon treatment and production and storage and use of biogas in the water sector has the potential to offer step-change benefits to the UKs energy system. This project seeks to secure a paradigm shift in wastewater treatment and biogas application. A pilot scale feasibility study is proposed to examine: (1) the fundamental operation of an anaerobic bioreactor using fortified influent wastewater; and (2) increasing the energy-production capacity of the generated renewable biogas. This approach significantly alters the wastewater treatment flow-sheet by reducing dependence on the energy intensive activated sludge process. The project has the potential for UK energy savings of 0.12 kWh per cubic metre of wastewater treated. Over 1 million cubic metres of wastewater are treated every day which potentially corresponds to savings of 438GWh per year and 188,469 tonnes of carbon dioxide per year. This is approximately equivalent to off setting 122,000 people flying London to New York return. Potentially fortified anaerobic treatment will also yield >10 % more biogas than is currently available from anaerobic digesters. Therefore, it is important to increase its energy production capacity in line with government developments for local energy and increased energy security. Currently biogas is used in combined heat and power in the UK water sector but biogas use in fuel cells, as a transport gas and for gas supply could provide greater flexibility and efficiency with more storage opportunities. However, these applications require biogas to be upgraded. This project seeks to examine in-situ methane enrichment to provide a better economy of scale for upgrading biogas and thereby maximising the overall energy production capacity of wastewater carbon. This project will therefore help to provide the scientific advance and industrial innovation to utilise biomass to meet the increasing demands for sustainable products from renewable sources called for by the government.

Booth J.N.,Yorkshire Water | Deuchar J.L.,Yorkshire Water
Dams: Engineering in a Social and Environmental Context - Proceedings of the 17th Conference of the British Dam Society | Year: 2012

This paper will illustrate by example a number of cases where the problem of insufficient spillway capacity has been dealt with in ways other than just increasing the size of spillway channels. It will also illustrate the benefits of physical modelling and a number of problems associated with the environment and planning restrictions. Source

Tanner A.,Cranfield University | McIntosh B.S.,Cranfield University | Seth A.,Yorkshire Water | Widdowson D.,Yorkshire Water
Modelling for Environment's Sake: Proceedings of the 5th Biennial Conference of the International Environmental Modelling and Software Society, iEMSs 2010 | Year: 2010

Computer-based decision and information support tools (DISTs) have potentially important roles to play in the embedding of sustainability appraisal processes into the planning and operation of water utilities. This paper reports on preliminary outcomes from research employing a particular model of sustainability, the Five Capitals model, to identify and facilitate the exploitation of opportunities for improved incorporation of sustainability appraisal into business process and practice within a major UK water and sewerage company (WaSC). In particular, the aims of this paper are to characterise and critically assess WaSC decision and information support needs by interpreting the findings of having applied the Five Capitals model. Five Capitals sustainability principles were applied as a questioning framework in a series of focus groups within the asset delivery business unit of the WaSC. The approach enabled the researcher to create a shared comprehension of sustainability, whilst mapping the perspectives of the business unit as to the form and efficacy of current sustainability appraisal activities. From the results of the focus group the researcher was able to identify key information support needs and to develop a set of sustainability key performance indicators with WaSC staff to service these needs. The results of the focus groups demonstrated that there was no need for computerised decision support, and that the primary role for information support was twofold - (i) to capture data to provide a basis, in the medium-long term, for improved organisational learning about the sustainability performance of different treatment and distribution assets, and; (ii) to capture data to provide a basis, over the short-medium term, for influencing the decisions made by companies contracted to design and build new treatment and distribution assets for the WaSC. These needs contrast against the standard view of the role of decision support as automating certain aspects of human decision-making. Source

Jolly M.,Black and Veatch Ltd | Green S.,Yorkshire Water | Wallis-Lage C.,Black and Veatch Corporation | Buchanan A.,Black and Veatch Ltd
Water and Environment Journal | Year: 2010

Many activated sludge plants (ASP) use fine bubble diffused air as their source of oxygen. Blowers are attached to air pipework, which distributes air to a network of diffusers installed on the floor of the ASP tank. Modern diffusers are made from a rubber membrane which flexes to allow fine bubbles of air to pass through holes in the diffusers which then pass into the mixed liquors in the tank. The diffusers come as circular discs, tubes and more recently mats or panels. Yorkshire Water is in the process of building new ASP at some of their biggest sewage treatment works to meet new final effluent consent standards associated with the freshwater fisheries directive (FFD). These new works will treat sewage from a combined population of over two million people in the Yorkshire area. Black & Veatch is involved in some of the first works to have a new type of fine bubble diffuser installed in the ASP basins. These diffusers resemble a mat or panel and are fixed to the floor of the tank as opposed to circular and tubular diffusers which as fixed above the floor. Oxygen transfer testing has been carried out to show the efficiency of these aeration systems, which may offer significant savings in operating costs to water operators. This paper examines the results from the tests and compares them with other tests carried out in the United States and tests that have been carried out on other types of diffusers. The paper will discuss the results of the oxygen transfer tests and present capital and net present costs (NPC) for various diffuser installations. © 2009 The Authors. Journal compilation © 2009 CIWEM. Source

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