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  3. There’s Gold in Them there Landfills[A] In the movie WALL ‘E,

There’s Gold in Them there Landfills[A] In the movie WALL ‘E,

游客2023-08-15  19
问题                   There’s Gold in Them there Landfills
[A] In the movie WALL ‘E, humankind has left Earth in a bit of a mess. The planet is choked with garbage and all the people have shipped out, leaving robot WALL‘E to clean the place up and make it habitable again. Things may not be quite that bad yet, but there’s no doubt that we produce a huge amount of waste. Even with increased recycling, landfill sites are filling up by the day and—in the absence of a brave robot—the waste experts of planet Earth are working on the next best thing: landfill mining.
[B] The idea is simple. Instead of disappearing under mountains of our own waste, while paying through the nose for diminishing commodities, why not dig up and recycle what we have already thrown away?
[C] Next week, industry experts will gather in London for the first global landfill mining conference. Bringing together environmental scientists, economists and landfill operators, the one-day meeting promises to show delegates how to turn waste into "garbage gold".
[D] Landfill mining has been tried before. The first scheme began in 1953 at Hiriya garbage dump outside Tel Aviv, Israel, and aimed to reclaim fine-particle waste rich in minerals to improve soil quality at local fruit farms. The landfill closed in 1998, but the recycling plant that remains on the site still produces soil improver from green waste. Then during the 1960s and 1970s, a handful of sites in the US began separating waste to recycle the steel and to compost food scraps. In the late 1980s, a pilot programme was set up to extract recyclables from a small, community landfill in the town of Edinburg, New York, and burn the solid leavings to generate energy. This pilot proved uneconomical but during the oil price rising of the 1990s interest in the economic value of waste soared. Investors claimed to snap up scrap metal companies, only for the price of commodities to drop through the floor in the mid-1990s.
[E] Yet now that commodities prices are rising once more, environmental issues are high on everyone’s list of priorities and land prices are increasing, every square kilometre is worth too much to use for landfill. Raiding the dump seems like a good idea again. This time the prospects are more promising. Thanks to a decade of innovation by the recycling industry, the technology to process landfill waste is more readily available.
[F] So what’s in a landfill worth recycling? For a start, the average landfill is filled with valuable—and sometimes even precious—metals. Aluminium, from drinks cans, is just one example. According to Patrick Atkins, environmental consultant for private equity fund Pegasus Capital Advisors, and until recently director of energy innovation at US aluminium producer Alcoa, Americans throw away 317 aluminium cans every second of every day. Around half of these, totalling 680,000 tonnes of aluminium each year, dodge the recycling basket and end up in landfill. Given that the cost of aluminium peaked at $2,700 per tonne in July this means America is burying up to $1.83 billion worth of metal per year. Atkins estimates that there is now more aluminium in US landfills than can be produced from ores globally in one year. And it’s not only aluminium that is hiding down there with the used diapers (尿布) and grocery bags. One tonne of scrap from discarded PCs contains more gold than can be produced from 16 tonnes of ore, he says. And the world throws away 18 million tonnes of electronic waste each year.
[G] Nowadays it is relatively easy to separate the metal you want from the junk you don’t using recycling technologies. Eddy current (漩涡流) magnets, for example, can avert aluminium and other metals from a flowing stream of waste. Plastic, too, is becoming easier to pick out. Rather than the more expensive process of doing it by hand, some plastic sorting plants are now using some scanners, which sort different types based on the spectrum of light they absorb. And since rising prices are making oil seem like an expensive raw material to produce plastics, recycling existing plastic from landfill seems sensible.
[H] Metals and plastics are only part of it, says William Hogland, an environmental engineer at the University of Kalmar in Sweden. All that smelly food and other organic waste rots down sooner or later. And as the TelAviv project discovered back in the 1950s, even this can be worth digging up.
[I] "The earth fraction of landfill can be one of the most profitable as coverage material, compost (堆肥) and for lawn improvement," Hogland says. There’s also plenty of flammable material in landfills. One kilogram of the coarse earth fraction—containing particles greater than 50 millimetres across—yields between 6 and 10 megajoules (兆焦) of energy, Hogland says, and the average Swedish landfill has 40 million tonnes of the stuff. Burning that waste is a controversial idea because of toxins (霉素) that may be released in the process. But, Hogland says, thanks to new technology for cleaning flue gases, Sweden is building new incinerators (焚烧炉) to provide heat and light for local communities.
[J] So if landfill sites are, sometimes literally, gold mines, why aren’t companies tearing into them already? For its part, Alcoa has invested heavily in stopping as many cans as it can from reaching a landfill, but has stopped short of digging them up again. "It’s not something we are doing at this point," said Alcoa spokesman Kevin Lowery. "If we thought it was the most efficient thing, we’d do it."
[K] Part of the reason for this is that while aluminium can be recycled at a fraction of the cost of producing it from ore, and using 94 per cent less energy, that’s only the case once you have collected the cans. Getting them out of landfill is more expensive than buying aluminium directly from a recycling plant. Plus no two landfill sites are the same. Each has a different blend of useful materials, mixed with all kinds of less useful or dangerous materials. And when you consider that companies would likely want to mine more than one site, covered perhaps by different state or national regulations, it starts to look like too much trouble.
[L] Reid Lifset, an industrial ecologist at Yale University who has investigated the prospect of extracting copper from landfills, has come to a similar conclusion. "With current technology and prices, landfill mining is generally not economically feasible," he says. "The benefits such as revenue from sale of recovered metals, and reduction in regulatory costs, generally did not outweigh the costs." In other words, there may be a lot of copper buried in landfills, but if copper is your thing, a huge mine with gigantic equipment makes more sense than picking your way through several different landfill sites.
[M] Advocates of landfill mining argue that with more imagination and a sober assessment of the true cost of burying rubbish, there is a reasonable economic case for landfill mining. He and his colleagues have calculated that reclaiming sites in the Baltic region alone could generate billions of euros from various revenue streams. Rather than approaching landfill mining with one outcome in mind, Hogland says, you have to look at the overall advantages, including environmental services like protecting water quality. [br] Digging metals up from the dump is not the most efficient thing.
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答案 J
解析 根据the most efficient thing定位到J段最后一句。该段第2句but后面的内容表明Alcoa没有把铝罐从垃圾场中挖出来；Kevin Lowrey说如果这个方法有效的话，他们会这样做的，言外之意是这个方法并非最有效的。
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