Controls on the photochemical production of hydrogen peroxide in Lake Erie
Controls on the photochemical production of hydrogen peroxide in Lake Erie
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伊利湖光化学过氧化氢生产的控制
DOI：
10.1039/d2em00327a
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发表时间：
2022
期刊：
影响因子：
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通讯作者：
Cory, Rose M.
中科院分区：
文献类型：
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作者：
Pandey, Dhurba Raj;Polik, Catherine;Cory, Rose M.
在伊利湖，产生毒素的有害藻华（HABs）发生在高浓度过氧化氢（H2O2）之后。H2O2浓度与赤潮的相关性揭示了伊利湖H2O2生成控制的知识空白。产生H2O2的一种方式是溶解有机物（CDOM）的显色部分吸收阳光。这种光化学生成H2O2的速率可能与CDOM中H2O2的表观量子产率（ΦH2O2,λ）成比例地增加。然而，CDOM产生H2O2的ΦH2O2 λ仍然非常有限，无法预测光化学产生H2O2的大小和范围，特别是在伊利湖这样的淡水中。为了解决这一知识差距，从2019年6月至9月，在伊利湖西部盆地大约每两周测量ΦH2O2 λ，并进行支持分析（例如CDOM浓度和组成）。伊利湖的平均值ΦH2O2，λ在先前报道的范围内。然而，ΦH2O2 λ在空间和时间上变化了5倍。在伊利湖的一条支流莫米河中观测到最高的ΦH2O2 λ。在伊利湖近岸水域，从6月到9月，ΦH2O2 λ下降了大约五倍。综合伊利湖H2O2光化学生成的控制因素表明，光化学H2O2生成速率的变化主要是由于ΦH2O2，λ。在近海海域，CDOM浓度也强烈影响光化学生成H2O2。总之，这些结果证实了之前的研究结果，即光化学产生的H2O2有助于但可能不能解释伊利湖与赤潮有关的所有H2O2。
In Lake Erie, toxin-forming harmful algal blooms (HABs) occur following high concentrations of hydrogen peroxide (H2O2). Correlation between H2O2 concentrations and HABs revealed knowledge gaps on the controls of H2O2 production in Lake Erie. One way H2O2 is produced is upon absorption of sunlight by the chromophoric fraction of dissolved organic matter (CDOM). Rates of this photochemical production of H2O2 may increase in proportion to the apparent quantum yield of H2O2 (ΦH2O2,λ) from CDOM. However, the ΦH2O2,λ for H2O2 production from CDOM remains too poorly constrained to predict the magnitude and range of photochemically produced H2O2, particularly in freshwaters like Lake Erie. To address this knowledge gap, the ΦH2O2,λ was measured approximately biweekly from June–September 2019 in the western basin of Lake Erie along with supporting analyses (e.g., CDOM concentration and composition). The average ΦH2O2,λ in Lake Erie was within previously reported ranges. However, the ΦH2O2,λ varied 5-fold in space and time. The highest ΦH2O2,λ was observed in the Maumee River, a tributary of Lake Erie. In nearshore waters of Lake Erie, the ΦH2O2,λ decreased about five-fold from June through September. Integration of the controls of photochemical production of H2O2 in Lake Erie show that the variability in rates of photochemical H2O2 production was predominantly due to the ΦH2O2,λ. In offshore waters, CDOM concentration also strongly influenced photochemical H2O2 production. Together, the results confirm prior work suggesting that photochemical production of H2O2 contributes but likely cannot account for all the H2O2 associated with HABs in Lake Erie.