美國人的垃圾分類 - 生態環境討論

因為看到上一篇，想起我前陣子在另一個地方po的文章，

關於美國的垃圾分類回收問題--

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問：八卦版有人說
雖然多數美國一般大眾不做垃圾分類
但收垃圾的單位的確有在做垃圾分類
真的嗎？聽起來像是貴得離譜的人工……


答：先看一下這篇文章

http://www.economist.com/displaystory.cfm?story_id=9249262

The truth about recycling
Jun 7th 2007
(From The Economist print edition)

[僅節錄一些相關的重點]

Originally kerbside programmes asked people to put paper, glass and cans
into separate bins. But now the trend is toward co-mingled or
“single stream” collection.

About 700 of America's 10,000 kerbside programmes now use this approach.

...the switch towards single-stream collection is being driven by new
technologies that can identify and sort the various materials with little
or no human intervention.

The process begins when a truck arrives and dumps its load of recyclables
at one end of the building. The materials are then piled on to large
conveyer belts that transport them to a manual sorting station.

Next, a magnet pulls out any ferrous metals, typically tin-plated or steel
cans, while the non-ferrous metals, mostly aluminium cans, are ejected by
eddy current.

Finally, the glass is separated by hand into clear, brown, amber and green
glass.

For each load, the entire sorting process from start to finish takes about
an hour.

Although all recycling facilities still employ people, investment is
increasing in optical sorting technologies that can separate different
types of paper and plastic.

Paper and plastic items are spread out on a conveyor belt in a single
layer. When illuminated by a halogen lamp, each type of material reflects
a unique combination of wavelengths in the infra-red spectrum that can be
identified. Numerous types of paper, plastic or combinations thereof can
thus be sorted with up to 98% accuracy.


結論：還是要盡量把「可回收」跟「不可回收」的垃圾分開，
但是科技已經進步到可以將許多種可回收資源垃圾分開，
只有在最初步以及玻璃的部份需要用人工處理，
所以選擇把所有的可回收垃圾混合收集，
減少民眾所花的時間，可提高回收意願與回收率。


美國各地的回收制度與流程都很不一樣，
有的公司或機關可能會花錢，請廢棄物處理公司承包所有垃圾處理，
不管能不能回收垃圾就統統混著丟，
讓垃圾公司去負責分類，
垃圾公司自己會評估是否投資設備人力，去整理出資源垃圾來賣錢。

但我猜想各個城市最主要的還是curbside recycle，
至少居民要幫忙做第一步，
把資源垃圾分出來，按時放到家門口。

這篇文章有個圖，比較美國與其他國家各種資源的回收率，
EPA也有提供類似的數據，
http://www.epa.gov/epaoswer/non-hw/muncpl/faq.htm#8

2006年美國資源回收的狀況如下：

* Newspapers: 87.9%
* Corrugated Cardboard Boxes: 72.0%
* Steel Cans: 62.9%
* Yard Trimmings: 62.0%
* Aluminum Beer and Soft Drink Cans: 45.1%
* Magazines: 40.5%
* Tires: 34.9%
* Plastic HDPE Milk and Water Bottles: 31.0%
* Plastic Soft Drink Bottles: 30.9%
* Glass Containers: 25.3%

其實以報紙、紙箱、鐵罐的回收率來看還算不錯的，
塑膠跟玻璃為什麼會這麼低我就不明白了，
難道是大家懶得清洗飲料罐、啤酒瓶？

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