27 research outputs found

    The current situation for the water sources in the Maltese Islands

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    This commentary addresses issues related to the scarcity of water in the Maltese Islands and its main causes. Some basic metrics related to the abstraction of freshwater, contamination of groundwater by nitrate and the limitations and challenges of the water sources in the Maltese Islands are highlighted. Hereafter, the relation between water scarcity, rainfall and population density, as well as the resultant effects on the sustainability of the freshwater sources of the Maltese Islands are presented. The current focus is on the production of good quality water based on a number of Reverse Osmosis (RO) plants that are found around the Maltese Islands. The significant energy requirements of this technology are compared with those for groundwater and wastewater treatment production. Current practices in the Maltese Islands regarding the treatment and use of sewage effluent by Sewage Treatment Plants (STPs) are described. The use of treated sewage effluent as an alternative source of water to RO water and of groundwater for second class uses is discussed. This paper concludes that the technology needed to employ treated effluents for unrestricted agricultural use and also for aquifer recharge is now in existence.peer-reviewe

    The role of temperature and carbon dioxide climatic stress factors on the growth kinetics of Escherichia coli

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    The global level of carbon dioxide and temperature in the atmosphere is expected to increase, which may affect the survival of the stress-adapted bacteria. In this study, the effect of temperature and dissolved carbon dioxide on the growth rate of Escherichia coli was studied, thus assessing its response to induced environmental stress factors. Methods and results A kinetic assay has been performed using a microplate reader with a spectrofluorometer to determine the specific growth rates. Polynomial models were developed to correlate the environmental conditions of temperature and carbon dioxide with E. coli BL21 (DE3) growth in culture media and dairy by-products. At a temperature of 42 °C, as the dissolved CO2 increased, a decrease of the ÎŒmax by 0.76 h−1 was observed. In contrast, at 27 °C, this increase led to a rise of the ÎŒmax by 0.99 h−1. Moreover, a correction factor was added when applying the model to dairy whey samples. Conclusions The application of this developed model can be considered a useful tool for predicting the growth of E. coli using climate projections.peer-reviewe

    Aqueous and gaseous plasma applications for the treatment of mung bean seeds

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    Sprouts are particularly prone to microbial contamination due to their high nutrient content and the warm temperatures and humid conditions needed for their production. Therefore, disinfection is a crucial step in food processing as a means of preventing the transmission of bacterial, parasitic and viral pathogens. In this study, a dielectric coplanar surface barrier discharge (DCSBD) system was used for the application of cold atmospheric plasma (CAP), plasma activated water (PAW) and their combination on mung bean seeds. Germination assessments were performed in a test tube set-up flled with glass beads and the produced irrigation water. Overall, it was found that the combined seed treatment with direct air CAP (350W) and air PAW had no negative impact on mung bean seed germination and growth, nor the concentration of secondary metabolites within the sprouts. These treatments also reduced the total microbial population in sprouts by 2.5 log CFU/g. This research reports for frst time that aside from the stimulatory efect of plasma discharge on seed surface disinfection, sustained plasma treatment through irrigation of treated seeds with PAW can signifcantly enhance seedling growth. The positive outcome and further applications of diferent forms, of plasma i.e., gaseous and aqueous, in the agro-food industry is further supported by this research.peer-reviewe

    Plasma applications for the treatment of bean sprouts : safety, quality and nutritional assessments under aqueous and gaseous set-ups

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    Sprouts are particularly prone to microbial contamination due to their high nutrient content and the warm temperatures and humid conditions needed for their production. Therefore, disinfection is a crucial step in food processing as a means of preventing the transmission of bacterial, parasitic and viral pathogens. In this study, a dielectric coplanar surface barrier discharge (DCSBD) system was used for the application of cold atmospheric plasma (CAP), plasma activated water (PAW) and their combination on mung bean seeds. Overall, it was found that the combined seed treatment with direct air CAP (350 W) and air PAW had no negative impact on mung bean seed germination and growth, nor the concentration of secondary metabolites within the sprouts. These treatments also reduced the total microbial population in sprouts by 2.5 log CFU/g. This research reports for first time that aside from the stimulatory effect of plasma discharge on seed surface disinfection, sustained plasma treatment through irrigation of treated seeds with PAW can significantly enhance seedling growth. The positive outcome and further applications of different forms, of plasma i.e., gaseous and aqueous, in the agro-food industry is further supported by this research.peer-reviewe

    Plasma applications for the treatment of bean sprouts : safety, quality and nutritional assessments under aqueous and gaseous set-ups

    Get PDF
    Sprouts are particularly prone to microbial contamination due to their high nutrient content and the warm temperatures and humid conditions needed for their production. Therefore, disinfection is a crucial step in food processing as a means of preventing the transmission of bacterial, parasitic and viral pathogens. In this study, a dielectric coplanar surface barrier discharge (DCSBD) system was used for the application of cold atmospheric plasma (CAP), plasma activated water (PAW) and their combination on mung bean seeds. Overall, it was found that the combined seed treatment with direct air CAP (350 W) and air PAW had no negative impact on mung bean seed germination and growth, nor the concentration of secondary metabolites within the sprouts. These treatments also reduced the total microbial population in sprouts by 2.5 log CFU/g. This research reports for first time that aside from the stimulatory effect of plasma discharge on seed surface disinfection, sustained plasma treatment through irrigation of treated seeds with PAW can significantly enhance seedling growth. The positive outcome and further applications of different forms, of plasma i.e., gaseous and aqueous, in the agro-food industry is further supported by this research.peer-reviewe

    FeMn and FeMnAg biodegradable alloys : an in vitro and in vivo investigation

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    Iron-based biodegradable metal bone graft substitutes are in their infancy but promise to fill bone defects that arise after incidents such as trauma and revision arthroplasty surgery. Before clinical use however, a better understanding of their in vivo biodegradability, potential cytotoxicity and biocompatibility is required. In addition, these implants must ideally be able to resist infection, a complication of any implant surgery. In this study there was significant in vitro cytotoxicity caused by pure Fe, FeMn, FeMn1Ag and FeMn5Ag on both human foetal osteoblast (hFOB) and mouse pre-osteoblast (MC3T3-E1) cell lines. In vivo experiments on the other hand showed no signs of ill-effect on GAERS rats with the implanted FeMn, FeMn1Ag and FeMn5Ag pins being removed largely uncorroded. All Fe-alloys showed anti-bacterial performance but most markedly so in the Ag-containing alloys, there is significant bacterial resistance in vitro.peer-reviewe
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