Gjettermann B, Styczen M, Hansen S, Borggaard O K, Hansen H C B
DHI-Water and Environment, Dep. of Hydrology, Soil and Waste, Agern Allé 11, DK-2970 Hørsholm, Denmark.
J Environ Qual. 2007 Apr 5;36(3):753-63. doi: 10.2134/jeq2006.0081. Print 2007 May-Jun.
Mobility of dissolved organic matter (DOM) strongly affects the export of nitrogen (N) and phosphorus (P) from soils to surface waters. To study the sorption and mobility of dissolved organic C and P (DOC, DOP) in soil, the pH-dependent sorption of DOM to samples from Ap, EB, and Bt horizons from a Danish agricultural Humic Hapludult was investigated and a kinetic model applicable in field-scale models tested. Sorption experiments of 1 to 72 h duration were conducted at two pH levels (pH 5.0 and 7.0) and six initial DOC concentrations (0-4.7 mmol L(-1)). Most sorption/desorption occurred during the first few hours. Dissolved organic carbon and DOP sorption decreased strongly with increased pH and desorption dominated at pH 7, especially for DOC. Due to fractionation during DOM sorption/desorption at DOC concentrations up to 2 mmol L(-1), the solution fraction of DOM was enriched in P indicating preferred leaching of DOP. The kinetics of sorption was expressed as a function of how far the solution DOC or DOP concentrations deviate from "equilibrium." The model was able to simulate the kinetics of DOC and DOP sorption/desorption at all concentrations investigated and at both pH levels making it useful for incorporation in field-scale models for quantifying DOC and DOP dynamics.
溶解性有机物（DOM）的迁移性强烈影响氮（N）和磷（P）从土壤向地表水的输出。为了研究土壤中溶解性有机碳和磷（DOC、DOP）的吸附与迁移，对丹麦一种农业腐殖质湿润老成土的Ap、EB和Bt层样品进行了DOM的pH依赖性吸附研究，并测试了一种适用于田间尺度模型的动力学模型。在两个pH水平（pH 5.0和7.0）以及六个初始DOC浓度（0 - 4.7 mmol L⁻¹）下进行了持续1至72小时的吸附实验。大多数吸附/解吸发生在最初的几个小时内。溶解性有机碳和DOP的吸附随pH升高而显著降低，在pH 7时解吸占主导，尤其是对于DOC。由于在DOC浓度高达2 mmol L⁻¹时DOM吸附/解吸过程中的分馏作用，DOM的溶液部分富含P，表明DOP更易淋溶。吸附动力学表示为溶液中DOC或DOP浓度偏离“平衡”程度的函数。该模型能够模拟所有研究浓度和两个pH水平下DOC和DOP吸附/解吸的动力学，使其可用于纳入田间尺度模型以量化DOC和DOP动态。
