Environmental and economic analysis of aluminium recycling through life cycle assessment

Aluminium is the most-used metal in the world after steel, with a wide range of applications in the industrial field owing to its physical and mechanical properties. The aim of this study was environmental and economic analysis of secondary aluminium. In particular, this study demonstrated that aluminium recycling offers many advantages to both consumers and industry:

• Increased energy savings compared to primary aluminium production;

• Recovery and reuse of raw materials for future production avoids consumption of non-renewable resources;

• Reduction in landfill waste and consequent environmental damage;

• Reduction in bauxite mining which, in turn, will reduce the socio-economic impact on populations of those countries, mainly underdeveloped, that contain mines;

• Economic advantages for Italy, the first European producer of secondary aluminium, which lacks bauxite mines and has high energy costs.

This study used the Life Cycle Assessment (LCA) method, the modified Eco-indicator 99 method for damage calculation, and the SimaPro calculation code. The study examined secondary aluminium production by ICMET, based in Reggio Emilia, Italy. The economic and environmental evaluation utilised environmental information supplied by the company.     

Comparing indoor wastewater-fed aquaculture with two conventional wastewater treatment plants using adopted sustainable process indices

Highly aggregating 'Sustainable Process Indices' (SPI) were calculated for an indoor wastewater-fed aquaculture and two conventional wastewater treatment plants to make a direct comparison between the three facilities possible. The goal was to find out which technology would be better suited for use in a sustainable economy. The SPI provides a type of 'ecological footprint' for the three facilities on the basis that, in a sustainable economy, solar energy would be our main energy source and that surface area would become the limiting factor for economic development, because the transformation of solar energy into other forms of energy, products or services requires area. SPI calculations consider the area necessary for the sustainable dissipation of byproducts and wastes of a process into the environment. The SPI thus uses area as its basic unit for comparisons between different technologies, products or services.

Energy consumption, as well as treatment performance (both the quality and quantity of treated effluent), and multi-functionality of facilities were key variables in determining how much area a wastwater treatment plant would need to be embedded sustainably into the environment. The calculated SPIs reveal that the wastewater-fed aquaculture requires the least area to be embedded sustainably into the environment, therefore, it would be better suited for use in a sustainable economy compared to the two conventional wastewater treatment plants.