Browsing by Author "Cunningham, R."

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    Assessing the potential of enhanced primary clarification to manage fats, oils and grease (FOG) at wastewater treatment works,
    (Elsevier, 2020-04-20) Collin, T.D.; Cunningham, R.; Asghar, M.O.; MacAdam, J.; Jefferson, B.; Villa, R.
    Daily, sewage treatment works (STWs) receive large volumes of fats, oils and greases (FOG), by-products of food preparation. To increase FOG removal at STW, conventional primary sedimentation tanks (PSTs) can be enhanced using chemical coagulant or through dissolved air flotation (DAF) techniques. This work aimed to assess the potential benefits of enhanced primary treatment for FOG removal through an energy and costs analysis. To achieve this, a five-year sampling programme was conducted monthly at 15 STWs measuring FOG concentrations in crude and settled sewage (i.e. after primary treatment). In addition, two DAF pilot systems were trialled for four months and their performance, in terms of FOG removal, was assessed and compared to that of a control primary clarifier. Across the 15 STWs, influent FOG concentrations were found at 57 ± 11 mg.L−1. Chemical coagulants dosed prior to PSTs increased FOG removal rates on average to 71% whilst traditional sedimentation only achieved 50% removal. Effluent FOG concentrations were found between 12–22 mg.L−1 and 19–36 mg.L−1 respectively. By contrast, DAF achieved FOG effluent concentrations on average at 10 ± 4 mg.L−1 corresponding to 74% removal from a relatively low influent concentration of 40 ± 30 mg.L−1. Thus, enhanced primary treatments have the potential to reduce organic load to secondary treatment and increase energy generation through anaerobic digestion. The overall net energy balance was estimated at 2269 MWh.year−1 for the DAF compared to 3445 MWh.year−1 for the chemically-enhanced PST making it a less financially attractive alternative. Yet, in the case where the works require upgrading to accommodate flow or load increases, DAF appeared as a sensible option over sedimentation offering significantly lower capital costs and footprint. In relation to FOG management, upgrading all STWs is not realistic and will require understanding where the benefits would be the highest.
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    Characterisation and energy assessment of fats, oils and greases (FOG) waste at catchment level
    (Elsevier, 2020-01-13) Villa, R.; Collin, C.; Cunningham, R.; Jefferson, C.
    Several of the waste materials that have a negative impact on the sewer system are produced by fats, oils and greases (FOG) discharged from commercial and domestic kitchens. These materials accumulate at different points in the sewer catchment, from kitchens to pumping stations, sewers and sewage treatment works (STWs), and comprise oily wastewater, floating agglomerates and hard deposits. Despite their detrimental effects, these waste materials have a high calorific content and are an ideal feedstock for energy recovery processes. So far, the overall volume of each type of waste and their physical-chemical properties in relation to their collection point are unknown. However, from a management point of view, knowledge on each feedstock quality and volumes is necessary to develop an economic viable solution for their collection and for energy recovery purposes. In this study, FOG wastes collected from households, food service establishments (FSEs), sewage pumping stations, sewers and STWs, were compared to sewage sludge in terms of organic contents and energy potentials. As expected, FOG recovered at source (households and FSEs) were ‘cleaner’ and had a higher energy content. Once mixed with wastewater the materials changed in composition and lost some of their energy per unit mass. Our results showed that around 94,730 tonnes.year-1 of these materials could be recovered from the Thames Water Utilities’ catchment, one of the most populated in the UK. These materials could produce up to 222 GWh.year-1 as biogas, close to double of what is produced with sewage sludge digestion and around 19% of the company energy needs. Finally, even with over six million households in the catchment, the results showed that most of the FOG waste was produced by FSEs (over 48,000 premises) with an estimated average of 79,810 tonnes.year-1 compared to 14,920 tonnes·year-1 from private households. This is an important outcome as recovery from FSEs will be cheaper and easier if the company decides to implement a collection system for energy recovery.
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    Using conversation analysis to investigate the efficacy of the Hanen Parent Programme for parents of preschool children with learning disabilities/language disorder.
    (2007-03) Hickin, J.; Cunningham, R.; Flanagan, J.; Brown, Adam
    The Hanen Training Programme, (Manolson, 1975)1 was devised to empower parents and caregivers to help children to communicate to the best of their abilities. In line with moves within the speech and language therapy profession towards an enabling model, the programme has been used widely by speech and language therapists with parents of children who have delayed language development. Conversation analysis is a qualitative methodology which allows evaluation of interactional aspects of language from naturally-occurring data and which thus has strong ecological validity. Whilst it has been used in speech and language therapy research to analyse interaction and motivate therapy with adults with aphasia, there is limited data published to date using conversation analysis with children. However studies are now emerging which demonstrate the utility of this methodology in relation to this client group (e.g. Volden, 2004)2. This study investigated the interactions between children and parents before, during and after participation in a Hanen programme, using video tapes which were subjected to conversation analysis. Five children aged between 2½ and 4 years with severe/moderate learning difficulties and their parents who were selected for Hanen intervention by their speech and language therapist in a child development centre participated. Videos were transcribed (including nonverbal behaviour) following standard conventions. The three principles advocated by Hanen (allowing, adapting and adding) were investigated by using conversation analysis focussing on: initiation within the parent-child interaction, facilitation used to enable the child to participate, the balance between parent and child turns, and patterns of repair. The researchers analysing the videos were blind to the order of recording. The results of the study will be discussed in terms of their implications for evaluating the effectiveness of the widely used Hanen training techniques, and will provide direction for further research.