Oxidation of Ammonium to Nitrite Under Iron-Reducing Conditions in Wetland Soils Laboratory, Field Demonstrations, and Push-Pull Rate Determination
Oxidation of Ammonium to Nitrite Under Iron-Reducing Conditions in Wetland Soils Laboratory, Field Demonstrations, and Push-Pull Rate Determination
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DOI：
10.1097/ss.0b013e3181988fbf
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发表时间：
2009-03-01
期刊：
影响因子：
--
通讯作者：
Jaffe, Peterd R.
中科院分区：
文献类型：
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作者：
Shrestha, Junu;Rich, Jeremy J.;Jaffe, Peterd R.
在多种田间条件下都观察到了土壤中的亚硝酸盐（NO₂⁻）。根据土壤条件的不同，在硝化作用或反硝化作用过程中土壤中都有可能形成NO₂⁻。本研究展示了一系列在不同尺度上进行的实验，这些实验表明在没有初始硝酸盐库的情况下，在铁还原条件下会产生NO₂⁻。这些实验要么是在新泽西州的一个河岸湿地进行的，要么是在实验室中使用来自同一地点的土壤进行的。通过推挽实验原位测定的NO₂⁻和铵（NH₄⁺）的利用速率处于同一数量级，这支持了在这种厌氧条件下存在一个稳态NO₂⁻库的观察结果。用（NH₄⁺）-N - 15进行的同位素实验确凿地表明，在没有初始硝酸盐或NO₂⁻的情况下，在厌氧铁还原条件下存在一条将NH₄⁺与氮气连接起来的途径。这些观察结果表明，在土壤水分饱和时形成的厌氧条件下，湿地土壤中的NH₄⁺有可能被完全去除。
Nitrite (NO2-) in soils has been observed under a variety of field conditions. The formation of NO2- in soils is possible during nitrification or denitrification depending on the soil conditions. This study presents a series of experiments performed at different scales that demonstrate the production of NO2- under iron-reducing conditions, in the absence of an initial nitrate pool. These experiments were performed either in a riparian wetland in New Jersey or in laboratory experiments using soils from the same location. The rates of use of NO2- and ammonium (NH4+) determined in situ by performing push-pull experiments were of the same magnitude, supporting the observation of a steady-state NO2- pool under such anaerobic conditions. An isotope experiment performed with (NH4+)-N-15 conclusively showed an existence of a pathway linking NH4+ to dinitrogen gas under anaerobic iron-reducing conditions, in the absence of initial nitrate or NO2-. Such observations indicate a possibility for the complete removal of NH4+ from wetland Soils under anaerobic conditions that develop when soils are water saturated.