A fundamental principle of sustainable materials management is to maximize the utility of materials to the greatest extent possible with disposal only as the last resort. Yet society has not yet fully embraced this fundamental principle.
Between 1980 and 2002, collectively there was a 36% increase in global resource extraction; extraction of metals increased by 56% (Behrens et al., 2007). The US has consumed more resources in the past 50 years than in all previous history; it consumes 57% more materials than in 1975 and the vast majority of materials currently consumed are non-renewable (US EPA, 2009).
A consequence of this increased consumption is the simultaneous increase in the total and per capita generation and subsequent disposal of municipal solid waste (MSW). Estimates of the annual global generation of MSW vary, but are significant: Lacoste and Chalmin (2007) estimated that the annual global generation rate of MSW is 1.2 billion Mt, Hoornweg and Bhada-Tata (2012) estimated 1.3 billion Mt, and UNEP (2010) estimated between 1.7 and 1.9 billion Mt. By 2025, the estimated global annual generation of MSW will be 2.2 billion Mt (Hoornweg and Bhada-Tata, 2012).
The member countries of the Organization of Economic Co-operation and Development (OECD) continue to generate the highest portion of the global amount of MSW (Hoornweg and Bhada-Tata, 2012). The US, an OECD member, generated 227.6 million Mt of MSW in 2012 (US EPA, 2014).1 Between 1960 and 2012, the total amount of MSW generated in the US increased by 164.3% and the per capita MSW generation rate increased by 64.2% to 1.98 kg per day (US EPA, 2014). The current annual per capita generation rate of MSW in the US is approximately 723 kg, which is the highest in the world.
In spite of the adoption of the waste management hierarchy of reduce, reuse, and recycle for MSW, worldwide, landfilling continues to be the most common management of MSW (Lacoste and Chalmin, 2007). An accurate count on the number of legal landfills and illegal or unregulated dumps worldwide is infeasible. According to Hoornweg and Bhada-Tata (2012), 60% of the MSW generated by OECD countries is landfilled and nearly all of Africa’s MSW is landfilled or dumped.
In spite of the adoption of the waste management hierarchy of reduce, reuse, and recycle for MSW, worldwide, landfilling continues to be the most common management of MSW (Lacoste and Chalmin, 2007). An accurate count on the number of legal landfills and illegal or unregulated dumps worldwide is infeasible. According to Hoornweg and Bhada-Tata (2012), 60% of the MSW generated by OECD countries is landfilled and nearly all of Africa’s MSW is landfilled or dumped.
In the EU alone there are an estimated 150,000–500,000 closed and active landfills with an average size of 8000 m2 (Krook et al., 2012). Ratcliffe et al. (2012) estimated that the more than 150,000 landfills in Europe contain 30–50 billion m3 of waste. In 2012, there were 1908 operating MSW landfills in the US (US EPA, 2014).
The total amount of MSW generated is increasing worldwide, valuable materials continue to be a significant portion of MSW, the per capita generation rate of MSW remains high, and the majority of waste generated continues to be landfilled—we continue to discard significant amounts of underutilized materials, including metals, in landfills. Given the current and expected global demand for materials, especially metals, and the negative environmental, social, and geopolitical aspects of excessive reliance on mining ores, there is recognition that significant amounts of comparatively concentrated, valuable materials reside in relatively shallow surface deposits in landfills that are relatively close to industrial centers with access to transportation. This is especially true for post-1960 landfills which are more likely to have greater percentages of recyclables and contain larger volumes of waste (Hermann et al., 2014).
The total amount of MSW generated is increasing worldwide, valuable materials continue to be a significant portion of MSW, the per capita generation rate of MSW remains high, and the majority of waste generated continues to be landfilled—we continue to discard significant amounts of underutilized materials, including metals, in landfills. Given the current and expected global demand for materials, especially metals, and the negative environmental, social, and geopolitical aspects of excessive reliance on mining ores, there is recognition that significant amounts of comparatively concentrated, valuable materials reside in relatively shallow surface deposits in landfills that are relatively close to industrial centers with access to transportation. This is especially true for post-1960 landfills which are more likely to have greater percentages of recyclables and contain larger volumes of waste (Hermann et al., 2014).
Although the discarding of high-value metals while simultaneously mining for these same materials is a highly unsustainable practice, the potential to recover these previously disposed metals represents an important resource that can offset the mining of virgin ores. Given this situation, there is increased attention worldwide to the potential to mine landfills to recover metals (Krook et al., 2012). More of the case study (Science Direct) - link - picture (envirotech) - link - more like this (landfill mining) - link - more like this (landfill diversion) - link - more like this (waste management) - link
No comments:
Post a Comment