It may seem ridiculous, but in the hunt for sources of alternative energy researchers have come up with fuel cells which are pow

admin2015-01-31  44

问题     It may seem ridiculous, but in the hunt for sources of alternative energy researchers have come up with fuel cells which are powered by cheese—or at least whey, a by-product in cheese making. Whey is rich in lactose, a sugar which Georgia Antonopoulou, a biochemical engineer at the University of Patras, Greece, says can be consumed by cultures of bacteria contained within a fuel cell to generate an electric current. Microbial fuel cells, as such devices are known, are not a new idea but they are attracting more attention.
    The organic contents of whey pose an environmental hazard and many governments now impose strict regulations requiring factories to pay for its treatment before disposal. Whey constitutes about 70% of the volume of the milk were used to make cheese. So, just one small feta facility will need to dispose of as such as 4,000 tonnes of whey in a single year, says Dr Antonopoulou. Microbial fuel cells could help, and not just in the cheese-making industry. Breweries, pig farms, food-processing plants and even sewage works could gain from the technology.
    Traditional fuel cells work by using a catalytic material to oxidize a fuel, such as hydrogen, and make an electric current flow between two electrodes. Microbial fuel cells function in much the same way except that the catalytic reactions are carried out by bacteria contained within the fuel-cell chamber. Under anaerobic conditions(where oxygen is absent), metabolising the fuel by feeding off it and in doing so produce natural chemical reactions that produce a current.
    In theory microbial fuel cells can run on almost any kind of organic matters, says Chris Melhuish, head of the Bristol Robotics Laboratory, England. "All you have to do is match the microbial culture with the type of stuff you want to use as fuel," he says. Dr Melhuish has been trying to power robots on domestic waste-water, but it is tricky. Ideally you would want to use cheap raw-waste products, he says. But traditionally the fuel cells work best with a refined fuel in the form of solutions containing synthetic sugars, such as glucose.
    However, Dr Antonopoulou has now shown that, using a culture of bacteria obtained from her local waste-water plant, it is possible to get almost as much power from raw whey as from refined fuel, provided the whey is diluted. The trouble is the power output still only amounts to milliwatts, barely enough to trickle-charge a cellphone. And working with raw waste water also presents challenges.
    Initially Dr Antonopoulou and her colleagues found that the coulombic efficiency of their cells-a measure of how many electrons produced actually flow into a circuit-was particularly low, at around just 2%. This turned out to be because a second set of microbes, within the whey itself, was absorbing them. So, by sterilizing the whey first to kill these other bugs they have now boosted the coulombic efficiency to around 25%.
The best title of the passage may be______.

选项 A、Whey Can Pose Environmental Harzard
B、The Whey to Greener Electricity
C、Why the Whey Can Generate Electricity
D、A Seemingly Ridiculous Research

答案B

解析 主旨题。本文主要讲述了奶酪中的乳清可以用于加工微生物电池,这样不仅可以提供新的能源,而且可以清除乳清所含的有机物对环境造成的危害,可谓变废为宝,乳清变身成了绿色能源。B项最符合文意,故选择B。
转载请注明原文地址:https://kaotiyun.com/show/kth7777K
0

最新回复(0)