Hydrogen peroxide measurements in subtropical aquatic systems and their implications for cyanobacterial blooms
Hydrogen peroxide measurements in subtropical aquatic systems and their implications for cyanobacterial blooms
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DOI：
10.1016/j.ecoleng.2019.07.011
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发表时间：
2019-11
影响因子：
3.8
通讯作者：
Luka K. Ndungu;J. H. Steele;Taylor L. Hancock;Richard D. Bartleson;E. Milbrandt;M. Parsons;H. Urakawa-H.
中科院分区：
文献类型：
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作者：
Luka K. Ndungu;J. H. Steele;Taylor L. Hancock;Richard D. Bartleson;E. Milbrandt;M. Parsons;H. Urakawa-H.
过氧化氢被广泛认为是天然沃茨中生物和非生物途径产生的活性氧中最稳定的一种。它在介导氧化还原转化中的高反应性可能直接或间接地影响水生生态系统功能，包括初级生产力。然而，光合自养生物，特别是蓝藻，和过氧化氢之间的环境相互作用知之甚少。为了更好地了解过氧化氢和蓝藻的相互作用，我们确定了过氧化氢浓度的存在和不存在的蓝藻水华在西南佛罗里达。使用快速响应安培过氧化氢微电极测定过氧化氢浓度。我们在淡水水体（池塘、湖泊和Caloosahatchee河）中的测量值范围为0至5.3 µM，在雨水中的测量值范围为0至92.9 µM。在一般情况下，过氧化氢水平与蓝藻水华的条件，表明蓝藻在过氧化氢生产在淡水中的潜在作用。为了确定在黑暗条件下样品运输过程中过氧化氢的潜在生物降解性，水样在取样后立即通过0.2 µm孔径过滤器，并与实验室中未过滤的水样进行比较。我们发现，过滤后的水样比未过滤的样品保留了更高浓度的过氧化氢，平均生物降解速率为44 ± 10.6 nmol/h。在总共26个样品中，只有一个未过滤的样品显示出比过滤的样品更高的过氧化氢浓度。总的来说，我们的研究发现微电极技术可以准确地测量各种淡水水体样品中的过氧化氢浓度。该测量方法揭示了过氧化氢浓度随蓝藻水华的时空动态而变化。
Hydrogen peroxide is widely recognized as the most stable of the reactive oxygen species (ROS) produced by both biotic and abiotic pathways in natural waters. Its high reactivity in mediating redox transformations may, directly or indirectly, affect aquatic ecosystem functions, including primary productivity. However, environmental interactions between photoautotrophs, particularly cyanobacteria, and hydrogen peroxide are poorly understood. To gain a better understanding of hydrogen peroxide and cyanobacterial interactions, we determined the hydrogen peroxide concentrations in the presence and absence of cyanobacterial blooms in southwest Florida. Hydrogen peroxide concentrations were determined using a fast response amperometric hydrogen peroxide microelectrode. Our measurements ranged from 0 to 5.3 µM in freshwater bodies (ponds, lakes and the Caloosahatchee River) and 0 to 92.9 µM in rainwater. In general, hydrogen peroxide levels were highly associated with cyanobacterial bloom conditions, indicating the potential role of cyanobacteria in hydrogen peroxide production in freshwater. To determine the potential biodegradation of hydrogen peroxide during sample transportation in the dark condition, water samples were passed through 0.2 µm pore size filters immediately after sampling and compared with unfiltered water samples in the laboratory. We found that filtered water samples retained higher concentrations of hydrogen peroxide than unfiltered samples with a mean biodegradation rate of 44 ± 10.6 nmol/h. Out of a total of 26 samples, only one unfiltered sample showed a higher hydrogen peroxide concentration than the filtered samples. Overall, our study found the microelectrode technique could accurately measure hydrogen peroxide concentrations in the samples from various freshwater bodies. This measurement method revealed that hydrogen peroxide concentrations vary with temporal and spatial dynamics of cyanobacterial blooms.