Effects of nitrate on phosphorus release from lake sediments
Effects of nitrate on phosphorus release from lake sediments
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DOI：
10.1016/j.watres.2021.116894
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发表时间：
2021-02-13
期刊：
影响因子：
12.8
通讯作者：
Jeppesen, Erik
中科院分区：
文献类型：
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作者：
Ma, Shuo-Nan;Wang, Hai-Jun;Jeppesen, Erik
沉积物中磷的释放是影响富营养化缓解效果的关键过程。我们推测，高硝酸盐（NO3-）输入对沉积物P释放可能具有双重作用：通过改善沉积物氧化来减少沉积物P释放，或通过刺激浮游植物生长来促进P释放，增加沉积物水界面的分解速率和耗氧量。测试不同NO3 +的效果；浓度，我们在15个水泥罐中（1 m(3)）进行了为期3个月的实验，有5种NO3-的目标浓度：对照、2 mg L-1、5 mg L-1、10 mg L-1和15 mg L-1。结果表明：i) NO3-1时；维持在高水平：NO3-(1)；>= 5 +/- 7 mg L &负；1（中位数范围），NO3-1对沉积物的净P释放没有影响，可能是因为NO3和负的正作用；（增加氧化）被浮游植物生长的促进所抵消。ii) NO3-1添加终止后NO3-1；低氮处理的P释放量较小，高氮处理的P释放量较大，这可能反映了NO3-1的抑制作用；对磷释放的促进作用减弱，而高浓度NO3-的促进作用仍在继续。因此，研究结果支持了我们关于沉积物P释放的双重效应的假设，并表明NO3-具有剂量依赖性；在高NO3和高负离子条件下，沉积物中P的释放是明显的；超过5- 7mg L-1(C) 2021年Elsevier Ltd.出版
Phosphorus (P) release from sediment is a key process affecting the effectiveness of eutrophication mit-igation. We hypothesized that high nitrate (NO3-) input may have dual effect on sediment P release: reduce the sediment P release by improving the oxidation of sediment or promote P release by stim-ulating the growth of phytoplankton and increase the decomposition rates and oxygen consumption at the sediment water interface. To test the effect of different NO3 & minus; concentrations, we conducted a three-month experiment in 15 cement tanks (1 m(3) ), with five targeted concentrations of NO3-: control, 2 mg L-1, 5 mg L-1, 10 mg L-1, and 15 mg L-1. The results showed that: i) when NO3-1; was maintained at high levels: NO3-(1);>= 5 +/- 7 mg L & minus;1 (range of median values), there was no effect of NO3-1 on net P release from the sediment, likely because the positive effects of NO3 & minus; (increasing oxidation) was counteracted by a promotion of phytoplankton growth. ii) after NO3-1 addition was terminated NO3-1; dropped sharply to a low level (NO3- mg L-1), followed by a minor P release in the low N treatments but a significant P release in the high N treatments, which likely reflect that the inhibition effect of NO3-1; on P release de-creased, while the promotion effects at high NO3- concentrations continued. The results thus supported our hypotheses of a dual effect on sediment P release and suggest dose-dependent effect of NO3-; loading on stimulating P release from the sediment, being clear at high NO3 & minus; exceeding 5-7 mg L-1. (C) 2021 Published by Elsevier Ltd.