Desalination augmented by energy storage

Paper presented to the 10th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Florida, 14-16 July 2014.Desalination has become imperative as a drinking water source for many parts of the world. Due to the large quantities of thermal energy and high quality electricity requirements for water purification, the desalination industry depends on waste heat and renewable energy sources such as solar collectors, photovoltaic arrays, geothermal and wind and tidal energy sources. Due to the mismatch between the source supply and the demand and intermittent nature of these natural energy sources, energy storage is a must for reliable and continuous operation of these facilities. Thermal energy storage requires a suitable medium for storage and circulation while the photovoltaic/wind generated electricity needs to be stored in batteries for later use. Desalination technologies that utilize thermal energy and thus require storage for uninterrupted process operation are multi-effect evaporation (MED), low temperature desalination (LTD) and humidification-dehumidification (HD) and membrane distillation (MD). Energy accumulation, storage and supply are the key elements of thermal energy storage concept which result in better economics, resource management and lower environmental emissions of a variable energy source powered desalination system, for instance, solar energy. Similarly, the battery storage is essential to store electrical energy for electrodialysis (ED), reverse osmosis (RO) and mechanical vapor compression (MVC) technologies. This research-review paper discusses current energy storage options for different desalination technologies using various renewable energy and waste heat sources with focus on thermal energy storage and battery energy storage systems. Principles of energy storage are discussed for the first time with details on design and sizing and desalination process applications.dc201

Treatment of gram-positive deep sternal wound infections in cardiac surgery -experiences with daptomycin-

The reported incidence of deep sternal wound infection (DSWI) after cardiac surgery is 0.4-5% with Staphylococcus aureus being the most common pathogen isolated from infected wound sternotomies and bacteraemic blood cultures. This infection is associated with a higher morbidity and mortality than other known aetiologies. Little is reported about the optimal antibiotic management. The aim of the study is to quantify the application of daptomycin treatment of DSWI due to gram-positive organisms post cardiac surgery

Energy Audits and Energy Efficiency in Small Wastewater Treatment Plants: A Case Study

Energy plays an important role in the water sector. In fact, energy consumption by this sector accounts for nearly 44% of municipalities’ energy costs in developed countries. To minimize adverse environmental and human health impacts wastewater can undergo three treatment levels before discharge or reuse. Since it is an energy intensive process, wastewater treatment represents the largest share of water-related electricity consumption in developed countries. According to the literature, there is a potential for improvement and energy savings in wastewater treatment facilities. Indeed, International Energy Agency states that, the energy consumption in the water sector can be reduced by 15% if this potential is harnessed. Consequently, energy audits can provide valuable information about those facilities, allowing to assess their energy performance and to identify energy-saving opportunities. In this paper the results of internal energy audits conducted in two “small” wastewater treatment plants, located in the North of Portugal, are presented and analyzed. The results, 13% and 22% savings, show that simple energy audits, which can be implemented by company members, should not be considered as a cost, but rather as a step to a more efficient energy use, reducing energy costs and environmental impacts