Residents’ perceptions of sustainable drainage systems as highly functional blue green infrastructure

Blue-green infrastructure for storm water management in the UK is considered to be part of Sustainable Drainage Systems (SuDS). Design guidance recommends that source control and treatment trains are embedded within developments. This means that residents live next to SuDS performing functions such as infiltration, conveyance and storage. In addition to hydraulic attenuation, SuDS can provide benefits such as water quality improvement, wildlife habitat and amenity. However, economic pressure to maximise development opportunity means that designs do not always maximise these benefits. Therefore, residents’ perceptions of the benefits and problems of living with SuDS are important as these may affect residential property values and willingness to pay management fees, which could justify high quality designs that deliver multiple benefits. This study aimed to investigate these issues through a survey of residents living with SuDS across six housing developments in England, 406/2916 responses were collected. The developments had good quality SuDS, with an established residential population and active housing market. The residents had varied levels of awareness of the presence and function of SuDS. Generally, residents liked the wildlife and green space but this was tempered with concerns over pests (rats and mosquitoes) and litter. Maintenance of SuDS was also an issue and at three sites residents were charged management fees which were not well understood and caused concern. The majority of residents were unwilling to contribute more to maintenance. Most residents and local estate agents did not perceive that SuDS increased property values. Raising awareness of the benefits of SuDS may lead to greater acceptance by residents and encourage developers to include them in developments, which could contribute to overcoming one of the barriers to wider implementation

Urban resilience:two diverging interpretations

This paper uses two diverging interpretations of resilience to review and assess current UK policies for urban resilience. Both developed in scientific studies, the first interpretation is based on a mechanistic model of systems that can recover their original state after shocks, and the second is based on an evolutionary model enabling adaptation to disturbances. The literature review demonstrates that at present urban resilience is predominantly associated with the former. By contrast, only few policies and studies are inspired by the latter, although this is better suited to analyse dynamics of urban adaptation and manage cities accordingly. The contribution of this paper to an understanding of urban resilience is therefore twofold. First, an identification of the long-term consequences on the built environment associated with each model is provided, with the mechanical model ultimately hindering adaptation. Second, some approaches to generate effective responses to environmental and societal change are identified. Ultimately, this paper emphasises that the idea of a resilient city is fit for this age characterised by uncertainty, albeit it requires the recognition within planning practice that urban adaptation cannot be attained with current methodologies, and that much can be learned from theories on the resilience of ecosystems.

Nanostructured fusiform hydroxyapatite particles precipitated from aquaculture wastewater

The present work represents a new approach for the isolation of uniform nano particulate hydroxyapatite (HAp). The chemical characterization of a calcium phosphate product obtained from industrial trout farm aquaculture wastewater by two different routes, washing either with a basic aqueous medium (washNaOH) or followed by a further washing with ethanol (washEtOH), is explored. Characterization of the isolated materials includes morphology studies (SEM and TEM), structural (XRD, electron diffraction), compositional (EDX) and thermogravimetric analysis (TGA). The obtained products are a mixture of different compounds, with hydroxyapatite the predominant phase. The morphology is unusually nanometric size with fusiform shaped particles, such characteristics are ordinarily only obtained by synthetic routes. This process of phosphate precipitation represents a unique self-sufficient process to be compared to conventional chemical or biological practices for precipitating phosphate