Water and sanitation provision in a low carbon society: The need for a systems approach

In the face of climate change threatening to cause major alterations to hydrological cycles and taking into account the relationship between water, energy use, and food production, water management challenges today prove more complex than ever to address. This paper, recognising the progress made through science and engineering in the last century, reflects on the need to manage water resources more sustainably. It proposes that a change in mindsets is required in order to reconsider our approach in applying established solutions and utilising current technologies and tools to deliver them, with a renewed focus on re-assessing what the real problems are from a systems perspective. Focusing on the water-energy-food nexus, water reuse using desalination processes as a management option is revisited. Findings demonstrate that interdisciplinary, integrated and holistic solutions have the potential to deliver benefits across different sectors, disciplines, and systems, with a real potential for taking us a bit closer to sustainability

Optimal design of water treatment processes

Predicted water shortages assign water treatment a leading role in improving water resources management. One of the main challenges associated with the processes remains early stage design of techno-economically optimised purification. This work addresses the current gap by undertaking a whole-system approach of flowsheet synthesis for the production of water at desired purity at minimum overall cost. The optimisation problem was formulated as a mixed-integer non-linear programming model. Two case studies were presented which incorporated the most common commercial technologies and the major pollution indicators, such as chemical oxygen demand, dissolved organic carbon, total suspended solids and total dissolved solids. The results were analysed and compared to existing guidelines in order to examine the applicability of the proposed approach

Desalination and the commons: tragedy or triumph?

A policy is more likely to be economically efficient when its costs and benefits fall on the same group, but politicians can allocate costs and benefits to different groups within their jurisdictional commons. This article examines the distribution of costs and benefits from desalination projects using examples from San Diego, Almeria and Riyadh. The examples illustrate how mismatches between costs and benefits can persist or change as politicians adjust the policy portfolio to balance inefficiency and political risk.Global Challenges (FGGA

Detection of low concentration of assimilable organic carbon in seawater prior to reverse osmosis membrane using microbial electrolysis cell biosensor

Purpose: Difficulty swallowing, oropharyngeal dysphagia, is widespread among many patient populations (such as stroke and cancer groups) and aged community-dwelling individuals. It is commonly managed with bolus modification: altering food (usually cutting, mashing or puréeing) or fluids (typically thickening) to make them easier or safer to swallow. Although this treatment is ubiquitous, anecdotal evidence suggests patients dislike this management, and this may affect compliance and well-being. This review aimed to examine the impact of bolus modification on health-related quality of life. Methods: A systematic review of the literature was conducted by speech pathologists with experience in oropharyngeal dysphagia. The literature search was completed with electronic databases, PubMed and Embase, and all available exclusion dates up to September 2012 were used. The search was limited to English-language publications which were full text and appeared in peer-reviewed journals.Results: Eight studies met the inclusion criteria. Generally, bolus modification was typically associated with worse quality of life. Modifications to foods appeared to be more detrimental than modifications to fluids, but this may be due to the increased severity of dysfunction that is implied by the necessity for significant alterations to foods. The number of studies retrieved was quite small. The diverse nature of methodologies, terminologies and assessment procedures found in the studies makes the results difficult to generalise. Conclusion: Overall, even though the severity of dysphagia may have been a confounding factor, the impact of bolus modification on health-related quality of life in patients with oropharyngeal dysphagia appears to be negative, with increased modification of food and fluids often correlating to a decreased quality of life. Further, associated disease factors, such as decreased life expectancy, may also have affected health-related quality of life. More research is needed

Biological and corrosion aspects of a multi-stage flash seawater desalination plant after deaerator modification

Deaeration units of a commercial multi-stage flash (MSF) cogeneration facility underwent venting modifications to increase system distillate productivity without increasing energy consumption or elevating top brine temperatures. Three MSF units were investigated after oxygen levels of deaerators spiked above design limits (20 ppb). The investigation found a significant biotic presence in the deaerator unit’s MSF heat rejection sections that included algae, bacteria, bivalves, and bivalve larvae. The bivalve taxa consists of Barbatia parva, Diodora funiculata, Pinctada margaritifera, Amiantis umbonella, and Acrostergma assimile. Galvanic corrosion exacerbated by biofilm was also observed in heat rejection sections. While attesting to the tenacity and adaptability of marine life, the presence of biological communities is symptomatic of the abnormally high oxygen levels in deaerator units. Elevated oxygen levels contribute to systems performance declines resulting from biological fouling of deaerator packing materials, partially responsible for inefficiencies in reducing the gas solubilities of MSF process feed waters and elevated concertation ratios [1,2]. Several thermal desalination units presented similar process issues, but one was selected for detailed inspection and evaluation