Sustainability Indicators for the Use of Resources—The Exergy Approach

Global carbon dioxide (CO2) emissions reached an all-time high in 2010, rising 45% in the past 20 years. The rise of peoples’ concerns regarding environmental problems such as global warming and waste management problem has led to a movement to convert the current mass-production, mass-consumption, and mass-disposal type economic society into a sustainable society. The Rio Conference on Environment and Development in 1992, and other similar environmental milestone activities and happenings, documented the need for better and more detailed knowledge and information about environmental conditions, trends, and impacts. New thinking and research with regard to indicator frameworks, methodologies, and actual indicators are also needed. The value of the overall indicators depends on the production procedure of each material, and indicates their environmental impact. The use of “exergy indicators” based on the exergy content of materials and the use of the second law of thermodynamics in this work presents the relationship between exergy content and environmental impact

Optimisation of reverse osmosis based wastewater treatment system for the removal of chlorophenol using genetic algorithms

YesReverse osmosis (RO) has found extensive applications in industry as an efficient separation process in comparison with thermal process. In this study, a one-dimensional distributed model based on a wastewater treatment spiral-wound RO system is developed to simulate the transport phenomena of solute and water through the membrane and describe the variation of operating parameters along the x-axis of membrane. The distributed model is tested against experimental data available in the literature derived from a chlorophenol rejection system implemented on a pilot-scale cross-flow RO filtration system with an individual spiral-wound membrane at different operating conditions. The proposed model is then used to carry out an optimisation study using a genetic algorithm (GA). The GA is developed to solve a formulated optimisation problem involving two objective functions of RO wastewater system performance. The model code is written in MATLAB, and the optimisation problem is solved using an optimisation platform written in C++. The objective function is to maximize the solute rejection at different cases of feed concentration and minimize the operating pressure to improve economic aspects. The operating feed flow rate, pressure and temperature are considered as decision variables. The optimisation problem is subjected to a number of upper and lower limits of decision variables, as recommended by the module’s manufacturer, and the constraint of the pressure loss along the membrane length to be within the allowable value. The algorithm developed has yielded a low optimisation execution time and resulted in improved unit performance based on a set of optimal operating conditions

Kinetics of progenitor hemopoetic stem cells in sepsis: Correlation with patients survival?

BACKGROUND: Current theories underline the crucial role of pro-inflammatory mediators produced by monocytes for the pathogenesis of sepsis. Since monocytes derive from progenitor hemopoetic cells, the kinetics of stem cells was studied in peripheral blood of patients with sepsis. METHODS: Blood was sampled from 44 patients with septic syndrome due to ventilator-associated pneumonia on days 1, 3, 5 and 7 upon initiation of symptoms. Concentrations of tumour necrosis factor-alpha (TNFα), interleukin (IL)-6, IL-8 and G-CSF were estimated by ELISA. CD34/CD45 cells were determined after incubation with anti-CD45 FITC and anti-CD34 PE monocloncal antibodies and flow cytometric analysis. Samples from eight healthy volunteers served as controls. RESULTS: Median of CD34/CD45 absolute count of controls was 1.0/μl. Respective values of the total study population were 123.4, 112.4, 121.5 and 120.9/μl on days 1, 3, 5 and 7 (p < 0.0001 compared to controls). Positive correlations were found between the absolute CD34/CD45 count and the absolute monocyte count on days 1, 5 and 7. Survival was prolonged among patients with less than 310/μl CD34/CD45 cells on day 1 compared to those with more than 310/μl of CD34/CD45 cells (p: 0.022). Hazard ratio for death due to sepsis was 5.47 (p: 0.039) for CD34/CD45 cells more than 310/μl. Median IL-6 on day 1 was 56.78 and 233.85 pg/ml respectively for patients with less than 310/μl and more than 310/μl CD34/CD45 cells (p: 0.021). CONCLUSION: Stem cells are increased in peripheral blood over all days of follow-up compared to healthy volunteers. Patients with counts on day 1 less than 310/μl are accompanied by increased survival compared to patients with more than 310/μl

Renewable energy systems: the environmental impact approach

High energy consumption and the world population increase will lead to shrinking reserves of fossil fuels. Concern about carbon dioxide emissions may discourage widespread dependence on fossil fuels and encourage the development and use of renewable energy systems employing a variety of technologies Renewable energy systems have themselves an environmental impact. Land use and material employed are two areas that may have an adverse impact on the positive environmental picture of the renewable energy systems. The objective of this paper is to analyse these impacts with the use of a very powerful tool, the Life Cycle Assessment (LCA).carbon dioxide emissions; renewable energy systems; global warming; environmental impact; life cycle assessment; LCA; land use; materials; energy efficiency; solar energy; solar power; wind power; wind energy; geothermal energy; geothermal power.

Sustainability Indicators for the Use of Resources—The Exergy Approach

Global carbon dioxide (CO2) emissions reached an all-time high in 2010, rising 45% in the past 20 years. The rise of peoples’ concerns regarding environmental problems such as global warming and waste management problem has led to a movement to convert the current mass-production, mass-consumption, and mass-disposal type economic society into a sustainable society. The Rio Conference on Environment and Development in 1992, and other similar environmental milestone activities and happenings, documented the need for better and more detailed knowledge and information about environmental conditions, trends, and impacts. New thinking and research with regard to indicator frameworks, methodologies, and actual indicators are also needed. The value of the overall indicators depends on the production procedure of each material, and indicates their environmental impact. The use of “exergy indicators” based on the exergy content of materials and the use of the second law of thermodynamics in this work presents the relationship between exergy content and environmental impact

Sustainable Peach Compote Production: A Life Cycle Thinking Approach

Peach production as well as the fruit canning industry is one of the most important agricultural supply chain sectors in Greece. In 2016 Greek canned peach production reached 300,000 tones. In this study we perform an environmental analysis of a peach compote production system in Greece, using Life Cycle Assessment. The system studied includes the stages of cultivation, transportation of peaches to the peach compote plant, the canning and finally packaging. The data used were collected directly from an orchard located in Larissa, in central Greece, and covers the production year of 2016. The functional unit adopted is the production of one paper box containing 24 cans of peach compotes. The Life Cycle Analysis results indicate that 48.41%, 25% and 20.98% of the environmental burdens are attributed to the acidification potential, global warming potential and particular matter formation impact categories, respectively; whereas eutrophication impact potential and photochemical oxidation formation impact accounted for 5.38% and 0.23%, respectively. The results of this study provide an understanding of the key environmental impact issues related to peach compote production in Greece