Life Cycle Assessment in Municipal Solid Waste Management

Integrated Municipal Solid Waste (MSW) management is a tedious task requiring the simultaneous fulfilment of technical, economical and social constraints. It combines a range of collection and treatment methods to handle all materials in the waste stream in an environmentally effective, economically affordable and socially acceptable way (McDougall, 2001). Due to the complexity of the issues required for effective integrated MSW management, various computer-aided approaches that help the decision makers reach their final decision have been engaged since the early days of integrated MSW management. Any computer-based system supporting decision making is defined as a DSS (Finlay, 1989). DSS incorporate computer-based models of real life biophysical and economic systems. There are two main categories of DSS applied to solid waste management: the first one, based on applied mathematics, emphasises application of statistical, optimisation or simulation modelling. The second category of DSS provides specific problem-solving expertise stored as facts, rules and procedures. In addition, there are also hybrid approaches. Recently, there has been a major shift towards Life Cycle Assessment (LCA) computer-aided tools. LCA is a holistic approach that is increasingly utilised for solid waste management especially in the decision-making process and in strategy-planning. LCA can be categorised as a hybrid approach since it utilises equations for inventory analysis and recycling loops on the one hand, while on the other it requires expertise input for impact assessment and characterisation. Life Cycle Assessment (LCA) is a holistic approach that quantifies all environmental burdens and therefore all environmental impacts throughout the life cycle of products or processes (Rebitzer et al. 2004). LCA is not an exact scientific tool, but a science-based assessment methodology for the impacts of a product or system on the environment (Winkler & Bilitewski 2007). It is increasingly utilised for solid waste management systems especially in the decision-making process and in strategy-planning. LCA has been utilised for sustainable MSW management since 1995 (Güereca et al. 2006). LCA is an ideal tool for application in MSW management because geographic locations, characteristics of waste, energy sources, availability of some disposal options and size of markets for products derived from waste management differ widely (White et al., 1997; Mendes et al., 2004). LCA can help reduce local pressures and waste management costs, while considering the broader effects and trade-offs felt elsewhere across society (Koneczny and Pennington, 2007). The LCA procedure has been standardized in 1998 and revised in 2006 (ISO 14040, 2006). Based on this standard, LCA consists of the following four sections: