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The acidification potential is given in sulphur dioxide equivalents (SO2-Eq.). The acidification potential is described as the ability of certain substances to build and release H + - ions. Certain emissions can also be considered to have an acidification potential, if the given S-, N- and halogen atoms are set in proportion to the molecular mass of the emission. The reference substance is sulphur dioxide. Appendix A Appendix A 5 Eutrophication Potential (EP) Figure A 2: Acidification Potential (ISO 14044:2006) Eutrophication is the enrichment of nutrients in a certain place. Eutrophication can be aquatic or terrestrial. Air pollutants, waste water and fertilization in agriculture all contribute to eutrophication. The result in water is an accelerated algae growth, which in turn, prevents sunlight from reaching the lower depths. This leads to a decrease in photosynthesis and less oxygen production. In addition, oxygen is needed for the decomposition of dead algae. Both effects cause a decreased oxygen concentration in the water, which can eventually lead to fish dying and to anaerobic decomposition (decomposition without the presence of oxygen). Hydrogen sulphide and methane are thereby produced. This can lead, among others, to the destruction of the eco-system. On eutrophicated soils, an increased susceptibility of plants to diseases and pests is often observed, as is a degradation of plant stability. If the nutrification level exceeds the amounts of nitrogen necessary for a maximum harvest, it can lead to an enrichment of nitrate. This can cause, by means of leaching, increased nitrate content in groundwater. Nitrate also ends up in drinking water. Nitrate at low levels is harmless from a toxicological point of view. However, nitrite, a reaction product of nitrate, is toxic to humans. The causes of eutrophication are displayed in Figure A 3. The eutrophication potential is calculated in phosphate equivalents (PO4-Eq). As with acidification potential, it‟s important to remember that the effects of eutrophication potential differ regionally. NOX NOX Figure A 3: Eutrophication Potential (ISO 14044:2006) 62 H 2SO 44 Air pollution N2O HNO 3 NH3 NH3 Waste water -3 PO4 PO4 SO 2 NO X Fertilisation NO3 - NO3 - + NH4 NH4
Appendix A Appendix A 6 Photochemical Ozone Creation Potential (POCP) Despite playing a protective role in the stratosphere, at ground-level ozone is classified as a damaging trace gas. Photochemical ozone production in the troposphere, also known as summer smog, is suspected to damage vegetation and material. High concentrations of ozone are toxic to humans. Radiation from the sun and the presence of nitrogen oxides and hydrocarbons incur complex chemical reactions, producing aggressive reaction products, one of which is ozone. Nitrogen oxides alone do not cause high ozone concentration levels. Hydrocarbon emissions occur from incomplete combustion, in conjunction with petrol (storage, turnover, refuelling etc.) or from solvents. High concentrations of ozone arise when the temperature is high, humidity is low, when air is relatively static and when there are high concentrations of hydrocarbons. Today it is assumed that the existence of NO and CO reduces the accumulated ozone to NO2, CO2 and O2. This means, that high concentrations of ozone do not often occur near hydrocarbon emission sources. Higher ozone concentrations more commonly arise in areas of clean air, such as forests, where there is less NO and CO (Figure A 4). In Life Cycle Assessments, photochemical ozone creation potential (POCP) is referred to in ethyleneequivalents (C2H4-Äq.). When analyzing, it‟s important to remember that the actual ozone concentration is strongly influenced by the weather and by the characteristics of the local conditions. Hydrocarbons Nitrogen oxides Appendix A 7 Ozone Depletion Potential (ODP) Figure A 4: Photochemical Ozone Creation Potential (ISO 14044:2006) Ozone is created in the stratosphere by the disassociation of oxygen atoms that are exposed to short-wave UV-light. This leads to the formation of the so-called ozone layer in the stratosphere (15 - 50 km high). About 10 % of this ozone reaches the troposphere through mixing processes. In spite of its minimal concentration, the ozone layer is essential for life on earth. Ozone absorbs the short-wave UV-radiation and releases it in longer wavelengths. As a result, only a small part of the UV-radiation reaches the earth. Anthropogenic emissions deplete ozone. This is well-known from reports on the hole in the ozone layer. The hole is currently confined to the region above Antarctica, however another ozone depletion can be identified, albeit not to the same extent, over the midlatitudes (e.g. Europe). The substances which have a depleting effect on the ozone can essentially be divided into two groups; the fluorine-chlorine-hydrocarbons (CFCs) and the nitrogen oxides (NOX). Figure A 5 depicts the procedure of ozone depletion. One effect of ozone depletion is the warming of the earth's surface. The sensitivity of humans, animals and plants to UV-B and UV-A radiation is of particular importance. Possible 63 Ozone Dry and warm climate Hydrocarbons Nitrogen oxides
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GaBi Education Handbook for Life Cy
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Table of Contents 1 Introduction to
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Table of Figures Figure 1: Overview
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Purpose of this Handbook The purpos
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The following is just a brief list
Page 11 and 12: 2.1.2 Scope The intended applicatio
Page 13 and 14: Figure 3: Process Flow Diagram A sy
Page 15 and 16: Figure 5: Allocation Example Figure
Page 17 and 18: Figure 6: Data Collection and Calcu
Page 19 and 20: Conducting Life Cycle Assessments o
Page 21 and 22: 2.3.2 Selection of Impact Categorie
Page 23 and 24: Conducting Life Cycle Assessments o
Page 25 and 26: Conducting Life Cycle Assessments p
Page 27 and 28: 3 Procedure Procedure This chapter
Page 29 and 30: 3.2 Activating a database Procedure
Page 31 and 32: Procedure In most cases there are s
Page 33 and 34: Procedure GaBi now searches for all
Page 35 and 36: Procedure Well, because this proces
Page 37 and 38: Procedure You will notice the searc
Page 39 and 40: Procedure The reference quantity of
Page 41 and 42: Procedure Waste flows are, not surp
Page 43 and 44: 3.19 Adding processes Procedure You
Page 45 and 46: 3.23 Linking processes Procedure Le
Page 47 and 48: Procedure Let´s assume that the us
Page 49 and 50: Procedure Since each plan requires
Page 51 and 52: Procedure 91. Click on the „Balan
Page 53 and 54: 96. Select the „separate IO table
Page 55 and 56: 3.32 View option: Quantity view Pro
Page 57 and 58: Procedure By right clicking on a co
Page 59 and 60: 4 Literature Literature GABI 2003 G
Page 61: Appendix A Appendix A 3 Global Warm
Page 65 and 66: The surface of the model is divided
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