可生物降解标签不能确保无害降解
文章来源:未知 文章作者:enread 发布时间:2020-04-14 05:18 字体: [ ]  进入论坛
(单词翻译:双击或拖选)
假如你买了一些塑料制品,上面标明“可生物降解”。那你就可以放心了,因为你知道将它扔掉后它会无害降解。嗯,不要太快下结论。
“当我们从适合垃圾填埋场的特性这一角度考虑生物降解能力时,会发现它并不是理想的材料属性。原因是,我们在设计生物降解能力时,通常会追求快速的生物降解,然而垃圾填埋场尚未开始收集两年内产生的气体,生物降解产生的如此多的甲烷气体,会在安装气体收集系统之前就被释放到环境中。”莫顿·巴拉兹说到。他是北卡罗莱纳州立大学土木、建筑和环境工程系主任。
 
So you buy something made of plastic and it's labeled biodegradable. You can rest easy knowing that after you throw it out it will harmlessly break down. Well, not so fast.
"When we look at biodegradability as it pertains1 to landfills, biodegradability is not a desirable attribute for a material. And the reason for this is that when we design for biodegradability, we're typically designing for rapid biodegradability, and yet landfills do not begin to collect the gas that's produced typically for two years...so much of the gas, the methane2, from biodegradability is released to the environment before gas collection systems are installed."
Morton Barlaz. He heads the Department of Civil, Construction and Environmental Engineering at North Carolina State University. And he spoke3 June 6th on Capitol Hill at the third "Science on the Hill" event, co-hosted by Scientific American and California Congressman4 Jerry McNerney. The theme of this session: "Solving the Plastic Waste Problem."
"Now I just answered the question from a landfill perspective. If I were to switch hats and say, well, is it desirable from a litter perspective, sure. If it actually biodegrades and is converted to gas, then the litter would disappear, and that's desirable. But let's make sure it's really biodegrading and not just degrading into small pieces that nobody can see. That's degradability, it's not biodegradability."
 
Also on the panel, Kara Lavender Law, Research Professor at the Sea Education Association in Woods Hole. She studies plastic debris5 in the ocean. What about biodegradability there?
KL: "I do not think that it is possible to design a material that will do that in the open environment and certainly not in the ocean...my understanding is that a lot of the standards around classifying a material as biodegradable are done under temperatures of 30 C, and for reference the average temperature of the surface ocean spans 0 C to 25 C. With an average temperature of 4 C. So even if you had a magical material that satisfied all the other environmental criteria6, it's likely that that kind of breakdown7 would occur on such slow timescales that waste would build up and probably cause environmental harm. So...we shouldn't think of the ocean or the environment as a magical disposal of our waste."
 
 
 


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1 pertains 9d46f6a676147b5a066ced3cf626e0cc     
关于( pertain的第三人称单数 ); 有关; 存在; 适用
参考例句:
  • When one manages upward, none of these clear and unambiguous symbols pertains. 当一个人由下而上地管理时,这些明确无误的信号就全都不复存在了。
  • Her conduct hardly pertains to a lady. 她的行为与女士身份不太相符。
2 methane t1Eyx     
n.甲烷,沼气
参考例句:
  • The blast was caused by pockets of methane gas that ignited.爆炸是由数袋甲烷气体着火引起的。
  • Methane may have extraterrestrial significance.甲烷具有星际意义。
3 spoke XryyC     
n.(车轮的)辐条;轮辐;破坏某人的计划;阻挠某人的行动 v.讲,谈(speak的过去式);说;演说;从某种观点来说
参考例句:
  • They sourced the spoke nuts from our company.他们的轮辐螺帽是从我们公司获得的。
  • The spokes of a wheel are the bars that connect the outer ring to the centre.辐条是轮子上连接外圈与中心的条棒。
4 Congressman TvMzt7     
n.(美)国会议员
参考例句:
  • He related several anecdotes about his first years as a congressman.他讲述自己初任议员那几年的几则轶事。
  • The congressman is meditating a reply to his critics.这位国会议员正在考虑给他的批评者一个答复。
5 debris debris     
n.瓦砾堆,废墟,碎片
参考例句:
  • After the bombing there was a lot of debris everywhere.轰炸之后到处瓦砾成堆。
  • Bacteria sticks to food debris in the teeth,causing decay.细菌附着在牙缝中的食物残渣上,导致蛀牙。
6 criteria vafyC     
n.标准
参考例句:
  • The main criterion is value for money.主要的标准是钱要用得划算。
  • There are strict criteria for inclusion in the competition.参赛的标准很严格。
7 breakdown cS0yx     
n.垮,衰竭;损坏,故障,倒塌
参考例句:
  • She suffered a nervous breakdown.她患神经衰弱。
  • The plane had a breakdown in the air,but it was fortunately removed by the ace pilot.飞机在空中发生了故障,但幸运的是被王牌驾驶员排除了。
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