Ra Fenner

Embedding sustainable development at Cambridge University Engineering Department

Purpose – The paper seeks to examine the latest stage in a process of change aimed at introducing concepts of sustainable development into the activities of the Department of Engineering at Cambridge University, UK.Design/methodology/approach – The rationale behind defining the skills which future engineers require is discussed and vehicles for change at both undergraduate and postgraduate level are described. Reflections on the paradigms and pedagogy of teaching sustainable development issues to engineers are offered, as well as notes on barriers to progress which have been encountered.Findings – The paper observes that the ability to effectively initiate a change process is a vital skill which must be formally developed in those engineers wishing to seek sustainable solutions from within the organisations for which they will work. Lessons are drawn about managing a change process within a large academic department, so that concepts of sustainable development can be effectively introduced across all area...

Monitoring wastewater BOD using a non-specific sensor array

An electronic nose incorporating a non-specific sensor array of 12 conducting polymers was evaluated for its ability to monitor wastewater samples. Sewage samples collected from the inlet works, settlement tank and final effluent outlet over 5 months (January-May) were used to correlate the sensor responses of these samples with their corresponding 5-day biochemical oxygen demand (BOD) values. Canonical correlation analysis (a linear reduction technique) showed that the relationship between the sensor responses and BOD over the 5 months was non-linear. However, the separate analyses of subsets of these samples for shorter time periods showed that a linear relationship is apparent for time periods of 4 weeks or less, suggesting a correlation window occurs between the sensor responses and BOD. Preliminary neural network analysis supported these observations and using a three-layer back-propagation network showed that it is possible to predict BOD values from electronic nose analysis of a wastewater sample. The findings suggest that electronic nose technology could be used for the non-invasive monitoring and/or control of a wastewater treatment process.

An integrated representation of the services provided by global water resources.

Water is essential not only to maintain the livelihoods of human beings but also to sustain ecosystems. Over the last few decades several global assessments have reviewed current and future uses of water, and have offered potential solutions to a possible water crisis. However, these have tended to focus on water supply rather than on the range of demands for all water services (including those of ecosystems). In this paper, a holistic global view of water resources and the services they provide is presented, using Sankey diagrams as a visualisation tool. These diagrams provide a valuable addition to the spatial maps of other global assessments, as they track the sources, uses, services and sinks of water resources. They facilitate comparison of different water services, and highlight trade-offs amongst them. For example, they reveal how increasing the supply of water resources to one service (crop production) can generate a reduction in provision of other water services (e.g., to ecosystem maintenance). The potential impacts of efficiency improvements in the use of water are also highlighted; for example, reduction in soil evaporation from crop production through better farming practices, or the results of improved treatment and re-use of return flows leading to reduction of delivery to final sinks. This paper also outlines the measures needed to ensure sustainable water resource use and supply for multiple competing services in the future, and emphasises that integrated management of land and water resources is essential to achieve this goal.

Exploring key sustainable development themes through learning activities

Purpose – The purpose of the paper is to examine how a number of key themes are introduced in the Masters programme in Engineering for Sustainable Development, at Cambridge University, through student‐centred activities. These themes include dealing with complexity, uncertainty, change, other disciplines, people, environmental limits, whole life costs, and trade‐offs.Design/methodology/approach – The range of exercises and assignments designed to encourage students to test their own assumptions and abilities to develop competencies in these areas are analysed by mapping the key themes onto the formal activities which all students undertake throughout the core MPhil programme. The paper reviews the range of these activities that are designed to help support the formal delivery of the taught programme. These include residential field courses, role plays, change challenges, games, systems thinking, multi criteria decision making, awareness of literature from other disciplines and consultancy projects. An ax...

System interactions of stormwater management using sustainable urban drainage systems and green infrastructure

This study explores system interactions of stormwater management solutions using Sustainable Urban Drainage System (SuDS) and Green Infrastructure (GI) within the wider urban landscape. A series of interdependencies between urban components relating to stormwater management are identified. These include physical interdependency, geographical interdependency, cyber interdependency and logical interdependency, as defined by Peerenboom (2001). Stormwater management using SuDS/GI are viewed according to their Hydrological, Ecological and the Built Environment functions during events up to the design rain (non-flood condition) and during controlled exceedance and uncontrolled inundation (flood condition). The inclusion of SuDS/GI into the urban fabric is shown to modify urban functional and relational interdependencies under both these conditions. Within the context of the UK, there are fragmented responsibilities across planning scales created by SuDS/GI solutions which have not addressed the relational complexities that exist between agencies and competent authorities. The paper identifies the key barriers towards effective adoption of SuDS/GI within the context of the UK as physical barriers, perception/information barriers and organisational barriers.

Visualising a Stochastic Model of Californian Water Resources Using Sankey Diagrams

This paper describes a novel approach to the analysis of supply and demand of water in California. A stochastic model is developed to assess the future supply of and demand for water resources in California. The results are presented in the form of a Sankey diagram where present and stochastically-varying future fluxes of water in California and its sub-regions are traced from source to services by mapping the various transformations of water from when it is first made available for use, through its treatment, recycling and reuse, to its eventual loss in a variety of sinks. This helps to highlight the connections of water with energy and land resources, including the amount of energy used to pump and treat water, the amount of water used for energy production, and the land resources that create a water demand to produce crops for food. By mapping water in this way, policy-makers can more easily understand the competing uses of water, through the identification of the services it delivers (e.g. sanitation, food production, landscaping), the potential opportunities for improving the management of the resource and the connections with other resources which are often overlooked in a traditional sector-based management strategy. This paper focuses on a Sankey diagram for water, but the ultimate aim is the visualisation of linked resource futures through inter-connected Sankey diagrams for energy, land and water, tracking changes from the basic resources for all three, their transformations, and the final services they provide.

A decision support model for the rehablitation of “non-critical” sewers

Abstract 20% of the UK drainage network is made up of “critical sewers” (those with the highest economic consequences of failure) and in the last 15 years these have been systematically rehabilitated. The remaining 80% of non-critical sewers are dealt with by reactive maintenance only. The paper describes how a flexible and rational decision support model for rehabilitating non-critical sewers has been developed by analysing existing sewer performance data and asset information. The method represents information contained in asset and event databases in a GIS to rank variable sized grid squares into priority zones for action. A second stage uses a Bayesian statistical analysis of each pipe length within those grid squares most at risk from sewer failure. The model has been validated on data from several water company regions and whilst it does not enable an absolute prediction of sewer condition, the procedures help to distinguish those parts of the system in greatest need of attention.

Evaluation of Alternative Media for Pebble Matrix Filtration Using Clay Balls and Recycled Crushed Glass

Protecting slow sand filters (SSFs) from high-turbidity waters by pretreatment using pebble matrix filtration (PMF) has previously been studied in the laboratory at University College London, followed by pilot field trials in Papua New Guinea and Serbia. The first full-scale PMF plant was completed at a water-treatment plant in Sri Lanka in 2008, and during its construction, problems were encountered in sourcing the required size of pebbles and sand as filter media. Because sourcing of uniform-sized pebbles may be problematic in many countries, the performance of alternative media has been investigated for the sustainability of the PMF system. Hand-formed clay balls made at a 100-yearold brick factory in the United Kingdom appear to have satisfied the role of pebbles, and a laboratory filter column was operated by using these clay balls together with recycled crushed glass as an alternative to sand media in the PMF. Results showed that in countries where uniform-sized pebbles are difficult to obtain, clay balls are an effective and feasible alternative to natural pebbles. Also, recycled crushed glass performed as well as or better than silica sand as an alternative fine media in the clarification process, although cleaning by drainage was more effective with sand media. In the tested filtration velocity range of ð0:72–1:33Þ m=h and inlet turbidity range of (78–589) NTU, both sand and glass produced above 95% removal efficiencies. The head loss development during clogging was about 30% higher in sand than in glass media.

Selecting sanitation systems for sustainability in developing countries.

This paper presents a methodology for systematically incorporating multi-dimensional sustainability considerations into the selection of wastewater options for developing countries and the evaluation and comparison of these options. Appropriate technologies for developing countries were screened based on their function and their use of operational sustainability features; this list of technologies can then be used to elaborate design options. Sustainability indicators are used to enable a parallel comparison of the options from environmental, economic, and socio-cultural perspectives. For illustration, the indicator approach is applied to a case study of the sanitation options for peri-urban/rural areas of the eThekwini Municipality in South Africa.

Project Neptune: improved operation of water distribution networks

Water service providers (WSPs) in the UK have statutory obligations to supply drinking water to all customers that complies with increasingly stringent water quality regulations and minimum flow and pressure criteria. At the same time, the industry is required by regulators and investors to demonstrate increasing operational efficiency and to meet a wide range of performance criteria that are expected to improve year-on-year. Most WSPs have an ideal for improving the operation of their water supply systems based on increased knowledge and understanding of their assets and a shift to proactive management followed by steadily increasing degrees of system monitoring, automation and optimisation. The fundamental mission is, however, to ensure security of supply, with no interruptions and water quality of the highest standard at the tap. Unfortunately, advanced technologies required to fully understand, manage and automate water supply system operation either do not yet exist, are only partially evolved, or have not yet been reliably proven for live water distribution systems. It is this deficiency that the project NEPTUNE seeks to address by carrying out research into 3 main areas; these are: data and knowledge management; pressure management (including energy management); and the associated complex decision support systems on which to base interventions. The 3-year project started in April of 2007 and has already resulted in a number of research findings under the three main research priority areas (RPA). The paper summarises in greater detail the overall project objectives, the RPA activities and the areas of research innovation that are being undertaken in this major, UK collaborative study.