Browsing by Author "Avery, L. M."

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    Bacteriophages - potential for application in wastewater treatment processes.
    (Elsevier Science B.V., Amsterdam., 2005-03-01T00:00:00Z) Withey, S.; Cartmell, Elise; Avery, L. M.; Stephenson, Tom
    Bacteriophages are viruses that infect and lyse bacteria. Interest in the ability of phages to control bacterial populations has extended from medical applications into the fields of agriculture, aquaculture and the food industry. Here, the potential application of phage techniques in wastewater treatment systems to improve effluent and sludge emissions into the environment is discussed. Phage-mediated bacterial mortality has the potential to influence treatment performance by controlling the abundance of key functional groups. Phage treatments have the potential to control environmental wastewater process problems such as: foaming in activated sludge plants; sludge dewaterability and digestibility; pathogenic bacteria; and to reduce competition between nuisance bacteria and functionally important microbial populations. Successful application of phage therapy to wastewater treatment does though require a fuller understanding of wastewater microbial community dynamics and interactions. Strategies to counter host specificity and host cell resistance must also be developed, as should safety considerations regarding pathogen emergence through transduction.
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    Impacts of residence time during storage on potential of water saving for grey water recycling system
    (Elsevier Science B.V., Amsterdam., 2010-01-01T00:00:00Z) Liu, S.; Butler, D.; Memon, Fayyaz Ali; Makropoulos, C.; Avery, L. M.; Jefferson, Bruce
    Grey water recycling has been generally accepted and is about to move into practice in terms of sustainable development. Previous research has revealed the bacteria re-growth in grey water and reclaimed municipal water during storage. However, in most present grey water recycling practices, impacts of water quality changes during storage on the system's performance and design regulation have not been addressed. In this paper, performance of a constructed wetland based grey water recycling system was analysed by taking the constraint of residence time during storage into account using an object based household water cycle model. Two indicators, water saving efficiency (WSE) and residence time index (RTI), are employed to reflect the system's performance and residence time during storage respectively. Results show that WSE and RTI change with storage tank volumes oppositely. As both high WSE and RTI cannot be achieved simultaneously, it is concluded that in order to achieve the most cost-effective and safe solution, systems with both small grey and green tanks are needed, whilst accepting that only relatively modest water saving efficiency targets can be achieved. Higher efficiencies will only be practicable if water quality deterioration in the green water tank can be prevented by some means (e.g. disinfection).
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    Media surface properties and the development of nitrifying biofilms in mixed cultures for wastewater treatment.
    (Institute of Chemical Engineers, 2013-07-01T00:00:00Z) Stephenson, Tom; Reid, E.; Avery, L. M.; Jefferson, Bruce
    Plastic was tested to select biofilm support media that would enhance nitrification in the presence of heterotrophs. Eight different types (acrylonitrile butadiene styrene, nylon, polycarbonate, polyethylene, polypropylene, polytetraflouroethylene (PTFE), polyvinyl chloride and tufnol) were immersed in an aerobic fed-batch reactor receiving domestic settled wastewater. Nitrification rates did not correlate with biomass concentrations, nor surface roughness of the plastics as measured by atomic force microscopy (AFM). The maximum nitrification rate of 1.5 g/m2d1 was obtained from biofilms growing on PTFE which had the lowest surface adhesion force (8nN). Nitrification rates for the biofilms were inversely correlated with the attraction forces as measured by the AFM.