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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:
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Increased energy savings compared to primary aluminium production;
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Recovery and reuse of raw materials for future production avoids consumption of non-renewable resources;
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Reduction in landfill waste and consequent environmental damage;
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Reduction in bauxite mining which, in turn, will reduce the socio-economic impact on populations of those countries, mainly underdeveloped, that contain mines;
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Economic advantages for Italy, the first European producer of secondary aluminium, which lacks bauxite mines and has high energy costs.
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With rapid urban development, municipal solid waste (MSW) has become a pressing issue. Estimation of carbon discharge through municipal solid waste provides a way to assess environmental load of solid waste from the viewpoint of the carbon cycle. With few studies on carbon research and provides insights into human impacts on the carbon cycle. Based on a comprehensive fieldwork investigation of a typical Chinese tourist city – Haikou City, Hainan Island – the characteristics of MSW carbon discharge and human activities that influenced it were analysed. The results indicated that, in 2001, the total carbon discharge from 261.9 Gg of MSW was 105.1 GgC per year, and 174.6 kgC per capita per annum. Carbon is discharged in the form of food scraps (24%), plastics (20%), wood (17%), fabrics (14%), paper (13%), and dust and stone (12%). If landfill received all the waste, 4.7% of MSW carbon would be transformed into methane, with a value of 4.9 GgC. Between 1991 and 1999, Haikou's per capita MSW carbon discharge increased by 59.9%, and total MSW carbon discharge increased by 124.9%. MSW carbon discharge in Haikou is significantly affected by the growth of residential expenditure and urbanisation. Local characteristics of tourism also influence Haikou's MSW carbon discharge, not only in terms of its yearly variation, but also its monthly variation. Integrating data on carbon discharge with carbon consumption will provide a systematic view of the carbon metabolism in urban ecosystems, and further insights into the generation of urban environmental pollution. 相似文献
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