Drying-Rewetting Cycles Affect Nitrate Removal Rates in Woodchip Bioreactors.
Drying-Rewetting Cycles Affect Nitrate Removal Rates in Woodchip Bioreactors.
复制标题
干燥-再润湿循环影响木片生物反应器中硝酸盐的去除率。
DOI：
10.2134/jeq2018.05.0199
复制
发表时间：
2019
影响因子：
2.4
通讯作者：
M. Youssef
中科院分区：
文献类型：
--
作者：
B. Maxwell;F. Birgand;L. Schipper;Laura E. Christianson;S. Tian;M. Helmers;David J. Williams;G. Chescheir;M. Youssef
木片生物反应器被广泛应用于通过反硝化作用控制农业氮素输出。大量证据表明，干湿循环(DRW)可以促进土壤代谢速率的提高。一项287-d的实验研究了每周DRW循环对实验室恒流硝化水木屑柱中硝酸盐(NO)去除的影响。柱子暴露于连续饱和(SAT)或每周8h干燥-再湿(8h好氧后饱和)循环(DRW)。每隔2小时在柱出口用新的多路采样方法与分光光度分析相结合来测量硝酸盐浓度。干湿柱有较大的总有机碳和溶解有机碳的输出，提高了NO的脱除效率。与SAT柱相比，DRW柱对硝酸盐的去除效率提高了高达80%，但在再湿后的3d内，DRW柱的硝酸盐去除速率迅速下降。即使在39个DRW循环后，DRW柱中增加的NO清除量仍在继续，在每周DRW循环中，∼总NO清除量增加33%。本实验收集的数据提供了强有力的证据，表明DRW循环可以显著提高木片生物反应器中NO的去除，碳的可获得性可能是提高效率的一个驱动因素。这些结果对木屑生物反应器的水力管理和其他反硝化实践具有一定的指导意义。
Woodchip bioreactors are widely used to control nitrogen export from agriculture using denitrification. There is abundant evidence that drying-rewetting (DRW) cycles can promote enhanced metabolic rates in soils. A 287-d experiment investigated the effects of weekly DRW cycles on nitrate (NO) removal in woodchip columns in the laboratory receiving constant flow of nitrated water. Columns were exposed to continuous saturation (SAT) or to weekly, 8-h drying-rewetting (8 h of aerobiosis followed by saturation) cycles (DRW). Nitrate concentrations were measured at the column outlets every 2 h using novel multiplexed sampling methods coupled to spectrophotometric analysis. Drying-rewetting columns showed greater export of total and dissolved organic carbon and increased NO removal rates. Nitrate removal rates in DRW columns increased by up to 80%, relative to SAT columns, although DRW removal rates decreased quickly within 3 d after rewetting. Increased NO removal in DRW columns continued even after 39 DRW cycles, with ∼33% higher total NO mass removed over each weekly DRW cycle. Data collected in this experiment provide strong evidence that DRW cycles can dramatically improve NO removal in woodchip bioreactors, with carbon availability being a likely driver of improved efficiency. These results have implications for hydraulic management of woodchip bioreactors and other denitrification practices.
影响因子：
5.2
作者：
Palmer K;Köpp J;Gebauer G;Horn MA
通讯作者：
Horn MA