Cement, Energy and Environment

interna onally standardized method (ISO-14040) and is commonly used for environmental assessments of products and services. According to the ISO standard, LCA is composed of four phases as illustrated in Figure 1: Goal and scope defini on, inventory analysis, impact assessment, and interpreta on. LCA was chosen as the method for environmental assessment because it is a comprehensive tool covering a wide range of environmental impacts. It takes a life cycle perspec ve which enables the es ma on of direct and indirect environmental impacts related to the remedia on ac vi es being inves gated. A remedia on system is composed of several direct remedia on ac vi es on- or off- site that falls into the different phases of the remedia on project: installa on, opera on, monitoring and dismantling phase. Each of these phases requires inputs from upstream ac vi es in terms of materials and energy and generates waste for downstream treatment. The waste treatment may produce energy or raw material that links back to the upstream produc on processes or to other life cycles that u lize these commodi es. Figure 1 – ISO 14040: 2006 Life Cycle Assessment (LCA) framework - four phases The gas emissions from landfill have been calculated using the US EPA model LandGEM (Landfill Gas Emissions Model, Version 3.02). LCA is performed using the so ware SIMAPRO and accessing the relevant datasets from the Ecoinvent database and real data extracted from Muller (2013) and SINTEF's baseline report (2017). The ra o between biogenic carbon (carbon contained in biomass) and fossil carbon in the sludge is assumed to be 50/50; the input data to the different management scenarios are considered accordingly. The environmental impacts were calculated using the CML2 method and Eco Indicator 99. Refer to the glossary sec on for defini ons on impact categories of CML2 impact assessment method such as abio c deple on, acidifica on, eutrophica on, global warming, human toxicity, freshwater aqua c ecotoxicity, marine aqua c ecotoxicity, terrestrial ecotoxicity and photochemical oxida on. Eco Indicator 99 is developed with the aim to simplify the interpreta on. One of the intended applica ons is the calcula on of single-point eco- indicator scores that can be used by designers in day to day decision making. An eco-indicator is a value that expresses the environmental impact of a product or a process or service in a single figure. The environmental effects of each of the impact categories are normalised rela ve to a reference. The reference used to obtain the normalisa on factors for each of the impact categories is related to the environmental impacts in each of 56