Growing algae for use in has a greater environmental impact than sources such as corn, switch grass and canola, researchers found in the first life-cycle assessment of algae growth.
在研究人员对藻类生命循环的首次评估中，他们发现为了生产生物燃料而种植的藻类将比玉米，杂草和油菜籽对环境的危害更大。
ALGAE FOOTPRINT: Researchers find that algae is a bigger energy hog than other biofuel sources.
/DAVESHAFER
Interest in algae-based biofuels has blossomed in the past year, sparking major investments from and , and it has gained steam on Capitol Hill, as well. But the nascent industry has major environmental hurdles to overcome before ramping up production, according to research published this week in Environmental Science and Technology.
去年人们对藻类制油兴趣大增，而且吸引了埃克森美孚和陶氏化学的大笔投资，国会山也大力支持这种制法。不过根据本期《环境科学与技术》杂志文章的说法，在大规模生产之前它还需要越过环境危害这道门槛。
“我的发现令人吃惊，”弗吉尼亚大学市政和环境学工程师Andres Clarens教授在其署名文章中说到。“开始的时候我们和其他人一样乐观。”
Algae production consumes more energy, has higher greenhouse gas emissions and uses more than other biofuel sources, like , switch grass and canola, Clarens and his colleagues found by using a statistical model to compare growth data of algae with conventional crops.
藻类生长，相比其他生物燃料来源如玉米，杂草和油菜来说，消耗更多能源，释放更多温室气体，也消耗更多的水。这是Clarens的团队通过统计学模型对比藻类和几种作物的生长数据之后得出的结论。
Clarens说“从生物循环的角度来说，藻类wq不是人们所认为的那样，这很令人吃惊。”
The culprit, the researchers say, is fertilizer. in open ponds is akin to producing them in a shallow swimming pool, Clarens said, so all of the nutrients needed to keep them alive and boost their production come from outside sources.
And that fertilizer has an environmental impact because its often made from petroleum feedstocks, Clarens said.
Clarens指出，罪魁祸首是肥料。在开放池塘中养殖藻类就如同在浅水池中养殖他们一样，刺激生长所需要的营养元素都需要外部供给。
而这些肥料因为来源于原料油而通常具有环境危害性。
Carbon dioxide also contributes to algaes economical to pull it out of coal-fired power plant smokestacks or other industrial sources, it comes from -based sources, as well.
Algae production has some other negative environmental impacts, Clarens said. For one, to convert algae into fuel, producers centrifuge the algae-laden water to separate the two, and that takes Clarens said.
“你种植玉米的时候，可以轮种大豆来固定氮，你仍然需要施很多非，但是种植再累时，所有的氮都来自于肥料，所以所需的肥料要多得多。”
二氧化碳也是藻类的一大环境危害。藻类利用阳光和水将二氧化碳转化为能轻易变成燃料的物质。但是二氧化碳必须有来源，而在火电厂及其他来源的二氧化碳变得具有经济价值之前，我们只能依靠石油来提供二氧化碳。
此外藻类还有一些其他的环境影响。其一就是，要把藻类转化为燃料，你必须先用离心机将水和藻类分离，这需要很大的能量。
But Clarens and his colleagues arent writing off algae as a potential future energy source.
Clarens said.
The algae industry has called for life-cycle assessments and is working on its own complete analysis, Mary Rosenthal, executive director of the , said in an e-mailed statement. She said her organization had not had time to fully review the paper and could not comment on it specifically.
但是Clarens小组并未否认藻类具有称为燃料来源的潜力。
“我们是想指出藻类生产的弊端，这样如果要利用藻类生产燃料，我们就知道改如何改进。”
而在藻类生物质组织的主管Mary Rosenthal的一封邮件中指出，藻类工业自己也在进行独立的生物循环评估和分析，而她的组织还没有来得及充分研究上述报告，所以无法进行评论。
她还说，“不过，总体上，藻类生物质组织严肃的认为，生物循环评估是非常必要的，必须jq的评估量化藻类生产给环境造成的影响。我们的成员单位支持生物循环评估，但他们认为这需要成员们的共同支持，包括藻类制油技术公司，非政府组织和其他科学家。