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"As much as we love them, our pets leave a lot of
manure behind them in yards and on the street and that can be a
major source of contamination of groundwater."
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San Francisco, a leader in urban recycling, is preparing to enlist its
canine population for a first
in the United States: converting dog poop into energy.
Norcal Waste Systems Inc., the city's largest garbage company, plans to
test collection carts and biodegradable bags in a city-center park popular
with dog walkers.
A city study found that almost 4 percent of all the garbage picked up
at San Francisco homes was from animal waste destined for the city's
landfill, Norcal Waste spokesman Robert Reid said. San Francisco has an
estimated 120,000 dogs.
"The city asked us to start thinking about a pilot program to
recycle the dog poop in order to cut back adding more waste in landfills,"
Reid said.
Dog feces could be scooped
into a methane digester, a device that uses bugs and microorganisms to
gobble up the material and emit methane, which would be trapped and burned
to power a turbine to make electricity or to heat homes.
Dogs and cats in the United States produce about 10 million tonnes of
waste a year, Will Brinton, an environmental scientist and owner-director
of Woods End Laboratories in Maine, said.
"As much as we love them, our pets leave a lot of manure behind them in
yards and on the street and that can be a major source of contamination of groundwater," Brinton said.
European cities such as Zurich, Frankfurt, Munich and Vienna are
operating biomass programs to turn waste into gas, he said.
San Francisco runs an aggressive program to recycle bottles, cans,
paper and other trash and now diverts two-thirds of its garbage away from
landfills.
The city's goal is a 75 percent diversion by 2010 and zero new waste in
landfills by 2020.
(Agencies) |
舊金山在城市垃圾的回收利用方面一直走在世界前列，最近又打算在其市內的"狗公民"身上大做環保文章。這是美國國內第一次嘗試將狗糞轉化為能源。
舊金山最大的垃圾處理公司，諾考爾廢物系統有限公司計劃在市中心一個遛狗人經常光顧的公園里試點使用垃圾車和可降解塑料袋。
該公司的發言人羅伯特·里德說，據一份舊金山的城市調查顯示，在抽樣的所有家庭中，幾乎4%的垃圾都來自動物排泄物。而這些動物排泄物會被送往該市的垃圾掩埋場處理掉。在整個舊金山，大約有12萬只狗。
羅伯特說："為了不再給垃圾掩埋場增添更多的負擔，市里要求我們開始考慮這個試點項目，即，回收利用狗的排泄物。"
狗糞將被倒入一個沼氣消化池的裝置，然后被蟲子和微生物分解并釋放出沼氣。而這些沼氣被收集起來，燃燒之后可以帶動渦輪發電或者給室內供暖。
緬因州伍茲恩德實驗室的所有者及主管、環境科學家威爾·布林頓說，在美國，貓和狗每年產生的排泄物可達約1000萬噸。
布林頓說道："我們有多愛我們的寵物，它們就在院子和大街上留下多少'肥料'。然而這些肥料將成為地下水的主要污染源。"
他還提到，像蘇黎士、法蘭克福、慕尼黑和維也納這些歐洲城市也都正在開展將排泄物轉化為天然氣這樣的生物項目。
舊金山對廢舊瓶子、罐子、紙張和其它垃圾的回收再利用實行了大膽的計劃。如今，該市三分之二的垃圾都不用再送到垃圾掩埋場處理了。
舊金山的目標是，到2010年，該城市的垃圾轉化率達到75％，而到2010年，沒有垃圾會再被送到垃圾掩埋場。
(中國日報網站編譯) |
Updated: 2006-02-28 08:37
