Photochemical production of hydrogen peroxide in size-fractionated Southern California coastal waters
Photochemical production of hydrogen peroxide in size-fractionated Southern California coastal waters
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DOI：
10.1016/j.chemosphere.2009.01.076
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发表时间：
2009-06-01
期刊：
影响因子：
8.8
通讯作者：
Jones, Joshua G.
中科院分区：
文献类型：
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作者：
Clark, Catherine D.;De Bruyn, Warren J.;Jones, Joshua G.
过氧化氢(H_2O_2)光化学产生量是在散装和分级的冲浪区和水源水(美国加利福尼亚州奥兰治县)测量的。照射后(60min：300W无臭氧氙灯)，H_2O_2的最大浓度接近10000 nm(源)和1500 nm(SURF区)。平均初始过氧化氢产生速率在散体源水(11+/-7.0nM S(-1))高于海浪带(2.5nM/-1 nM S(-1))。非净化溶解有机碳与吸光度系数m(-1)(300 Nm)呈良好的线性关系。对于散装和分级水源水，HPPR随着吸光度系数的增加而增加，这与CDOM的光化学生产一致。然而，吸光度系数相同的海浪带样品的HPPR变化很大(5倍)，尽管光学性质表明来自盐沼源水的CDOM占海浪带的主导地位。为了比较不同CDOM水平的样品，计算了过氧化氢光化学产生的表观量子产率(Phi)。水源水的PHI在散装、大型(1000 Da(1 KDa))和小型(1000 KDa)之间没有显著差异(
Hydrogen peroxide (H2O2) photochemical production was measured in bulk and size-fractionated surf zone and source waters (Orange County, California, USA). Post-irradiation (60 min: 300 W ozone-free xenon lamp), maximum H2O2 concentrations were similar to 10000 nM (source) and similar to 1500 nM (surf zone). Average initial hydrogen peroxide production rates (HPPR) were higher in bulk source waters (11 +/- 7.0 nM s(-1)) than the surf zone (2.5 +/- 1 nM s(-1)). A linear relationship was observed between non-purgeable dissolved organic carbon and absorbance coefficient (m(-1) (300 nm)). HPPR increased with increasing absorbance coefficient for bulk and size-fractionated source waters, consistent with photochemical production from CDOM. However, HPPR varied significantly (5x) for surf zone samples with the same absorbance coefficients, even though optical properties suggested CDOM from salt marsh source waters dominates the surf zone. To compare samples with varying CDOM levels, apparent quantum yields (Phi) for H2O2 photochemical production were calculated. Source waters showed no significant difference in Phi between bulk, large (>1000 Da (>1 kDa)) and small (