Life cycle assessment for biodiesel production under Greek climate conditions

The aim of this paper is to understand and to model the environmental performance of biodiesel produced by various Greek raw materials under current conditions. Three energy crops (rapeseed, sunflower and soybean) have been studied, with regard to their levels of biodiesel productivity. Throughout the entire process, current Greek climatic conditions and cultivation parameters have been taken into account. At the stage of assessment, we conclude that the environmental impacts per crop area indicate that soybean has the lowest environmental impacts. However, by assessing the results per quantity of produced biodiesel, the crop with the minimum environmental impacts is sunflower. This paper shows that environmental benefits from biodiesel have better results, compared to conventional diesel, thus leading to the conclusion that it is feasible to succeed improved environmental performance

Environmental Impacts of Conventional versus Organic Eggplant Cultivation Systems: Influence of Electricity Mix, Yield, Over-Fertilization, and Transportation

We report a comparative environmental study of organic and conventional open-field eggplant cultivation systems under Mediterranean (northern Greece) climatic conditions. Actual life cycle inventory (LCI) data were collected from local farm systems. Using life cycle assessment (LCA), organic eggplant cultivation exhibited better environmental performance per unit area (24.15% lower total environmental footprint compared to conventional cultivation), but conventional cultivation performed better per unit of mass (28.10% lower total environmental footprint compared to organic cultivation). The conventional system attained higher scores in eutrophication (up to 37.12%) and ecotoxicity (up to 83.00%) midpoint impact categories, due to the use of chemical fertilizer and pesticide. This highlights the need for spatially explicit LCA that accounts for local environmental impacts at the local scale. For both cultivation systems, the main environmental hotspot was groundwater abstraction for irrigation owing to its infrastructure (drip irrigation pipes and pump) and electricity consumption from the fossil fuel-dependent energy mix in Greece. Excessive addition of soil fertilizer greatly affected the environmental sustainability of both systems, especially conventional cultivation, indicating an urgent need for fertilizer guidelines that enhance environmentally sustainable agricultural practice worldwide. Results were sensitive to lower marketable fruit yield, with the organic system performing better in terms of environmental relevance with respect to maximum yield. When renewable energy sources (RES) were used to drive irrigation, both systems exhibited reductions in total environmental footprint, suggesting that RES could help decarbonise the agricultural sector. Finally, eggplant transportation greatly affected the environmental sustainability of both cultivation systems, confirming that local production and consumption are important perquisites for environmental sustainability of agricultural products.</jats:p

The environmental footprint of a membrane bioreactor treatment process through Life Cycle Analysis

This study includes an environmental analysis of a membrane bioreactor (MBR), the objective being to quantitatively define the inventory of the resources consumed and estimate the emissions produced during its construction, operation and end-of-life deconstruction. The environmental analysis was done by the life cycle assessment (LCA) methodology, in order to establish with a broad perspective and in a rigorous and objective way the environmental footprint and the main environmental hotspots of the examined technology. Raw materials, equipment, transportation, energy use, as well as air- and waterborne emissions were quantified using as a functional unit, 1 m3 of urban wastewater. SimaPro 8.0.3.14 was used as the LCA analysis tool, and two impact assessment methods, i.e. IPCC 2013 version 1.00 and ReCiPe version 1.10, were employed. The main environmental hotspots of the MBR pilot unit were identified to be the following: (i) the energy demand, which is by far the most crucial parameter that affects the sustainability of the whole process, and (ii) the material of the membrane units. Overall, the MBR technology was found to be a sustainable solution for urban wastewater treatment, with the construction phase having a minimal environmental impact, compared to the operational phase. Moreover, several alternative scenarios and areas of potential improvement, such as the diversification of the electricity mix and the material of the membrane units, were examined, in order to minimize as much as possible the overall environmental footprint of this MBR system. It was shown that the energy mix can significantly affect the overall sustainability of the MBR pilot unit (i.e. up to 95% reduction of the total greenhouse gas emissions was achieved with the use of an environmentally friendly energy mix), and the contribution of the construction and operational phase to the overall environmental footprint of the system.This work was funded by Nireas, International Water Research Center of the University of Cyprus (ΝΕΑ ΥΠΟΔΟΜΗ/ΣΤΡΑΤΗ/0308/09), which was co-funded by the European Regional Development Fund and the Republic of Cyprus through the Research Promotion Foundation. The authors are grateful to the manufacturer company of the MBR pilot unit, S.K. Euromarket Ltd., as well as to Ms. Popi Karaolia of Nireas-IWRC of the University of Cyprus, for providing technical information to the study

Environmental sustainability of light-driven processes for wastewater treatment applications

A comparative analysis is presented of light-driven advanced oxidation processes in terms of environmental sustainability. Photochemical oxidation has proven a viable option for treating emerging and priority pollutants at laboratory scale. Nevertheless, as a nascent technology, photocatalysis is yet to be widely applied at large-scale water treatment plants. This paper presents a powerful tool that should enable stakeholders to develop sustainable, large-scale, photocatalytic treatment plants by providing knowledge of environmental sustainability and hotspots (where technological flaws have high environmental impact) and understanding as to how process sustainability can be improved through scenario analyses. The following processes were examined: natural and simulated solar photolysis, solar photo-Fenton without hydrogen peroxide addition (solar/Fe), solar photo-Fenton (solar/Fe/H2O2), photolysis under UV-A irradiation (UV-A), titania-mediated photocatalysis (UV-A/TiO2), photolysis under UV-C irradiation (UV-C), and UV-C treatment with hydrogen peroxide addition (UV-C/H2O2). Actual life cycle inventory data were collected at bench scale, and the environmental performances estimated by means of life cycle assessment. Effective removal of 1 μg of 17α-ethynylestradiol per liter of wastewater, a commonly occurring micropollutant and endocrine disrupting chemical, was used as the functional unit. Solar photolysis exhibited an environmental footprint about 23 times higher than solar/Fe. Solar/Fe/H2O2 minimized the environmental footprint. Being energy intensive, simulated solar irradiation had a much higher (∼5-fold) environmental footprint than natural solar light. UV photolysis exhibited low environmental impact, with UV-C found to be about 3 times more environmentally friendly than UV-A photolysis. Addition of TiO2 to UV-A and H2O2 to UV-C caused their total environmental impacts to decrease by about 97% and 88%, implying that UV-A/TiO2 was better than UV-C/H2O2. In terms of total environmental footprint, the advanced oxidation processes descend in the following order: solar photolysis > UV-A > UV-C > solar/Fe > UV-A/TiO2 > UV-C/H2O2 > solar/Fe/H2O2. The environmental sustainability of all processes was directly proportional to treatment efficiency but inversely proportional to treatment time (due to the large energy input per unit time). Although reagent use (i.e. titania, iron, and hydrogen peroxide) was not associated with high environmental impact, its addition greatly improved process efficiency as well as environmental sustainability. For all examined light-driven processes, the main environmental hotspot was electricity consumption. Introduction of renewable energy sources could reduce the environmental footprint of oxidation processes by up to 87.5%