Air-water fluxes of N₂O and CH₄ during microalgae (Staurosira sp.) cultivation in an open raceway pond.
Air-water fluxes of N₂O and CH₄ during microalgae (Staurosira sp.) cultivation in an open raceway pond.
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DOI：
10.1021/es302396j
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发表时间：
2012-09
影响因子：
11.4
通讯作者：
S. Ferrón;D. T. Ho;Z. Johnson;M. Huntley
中科院分区：
文献类型：
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作者：
S. Ferrón;D. T. Ho;Z. Johnson;M. Huntley
在过去的几十年里，从培养的微藻中工业规模生产生物燃料已经引起了相当大的兴趣。虽然微藻养殖因捕获大气中的CO（2）而产生的气候效益是已知的，但其他温室气体的潜在排放的抵消作用尚未得到很好的量化。在这里，我们报告的研究结果进行了工业试验设施在夏威夷，以确定空气-水通量的N（2）O和CH（4）从开放的跑道池塘用于增长的海洋硅藻Staurosira sp.作为生物燃料的原料。在24小时的循环中测量溶解的O（2）、CH（4）和N（2）O浓度。在此期间，进行了四次SF（6）示踪剂释放实验，以量化池塘中的气体传输速度，然后将其用于计算气水通量。结果表明，池塘沃茨中CH（4）的饱和度高达725%，平均释放量为19.9 ± 5.6 μmol CH（4）m（-2）d（-1）。当NO（3）（-）耗竭时，池塘从N2 O的源转变为汇，在实验期间总的净吸收量为3.4 ± 3.5 μ molN 2 O m（-2）d（-1）。以CO2当量表示的N2 O和CH 4的气水通量比微藻吸收CO2的总量小2个数量级。
The industrial-scale production of biofuels from cultivated microalgae has gained considerable interest in the last several decades. While the climate benefits of microalgae cultivation that result from the capture of atmospheric CO(2) are known, the counteracting effect from the potential emission of other greenhouse gases has not been well quantified. Here, we report the results of a study conducted at an industrial pilot facility in Hawaii to determine the air-water fluxes of N(2)O and CH(4) from open raceway ponds used to grow the marine diatom Staurosira sp. as a feedstock for biofuel. Dissolved O(2), CH(4), and N(2)O concentrations were measured over a 24 h cycle. During this time, four SF(6) tracer release experiments were conducted to quantify gas transfer velocities in the ponds, and these were then used to calculate air-water fluxes. Our results show that pond waters were consistently supersaturated with CH(4) (up to 725%) resulting in an average emission of 19.9 ± 5.6 μmol CH(4) m(-2) d(-1). Upon NO(3)(-) depletion, the pond shifted from being a source to being a sink of N(2)O, with an overall net uptake during the experimental period of 3.4 ± 3.5 μmol N(2)O m(-2) d(-1). The air-water fluxes of N(2)O and CH(4) expressed as CO(2) equivalents of global warming potential were 2 orders of magnitude smaller than the overall CO(2) uptake by the microalgae.