Brilliant Blue sorption characteristics of clay-organic aggregate coatings from Bt horizons
Brilliant Blue sorption characteristics of clay-organic aggregate coatings from Bt horizons
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DOI：
10.1016/j.still.2020.104635
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发表时间：
2020-07
影响因子：
6.5
通讯作者：
S. Beck-Broichsitter;Marisa R. Gerriets;H. Gerke;M. Sobotková;J. Dusek;R. Dohrmann;R. Horn
中科院分区：
文献类型：
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作者：
S. Beck-Broichsitter;Marisa R. Gerriets;H. Gerke;M. Sobotková;J. Dusek;R. Dohrmann;R. Horn
在结构性土壤中，水和活性溶质可以优先通过较大的团聚体间大孔隙(生物孔和裂缝)和较小的团聚体内孔隙。尤其是粘土有机涂层材料对土壤基质和土壤基质中的水和溶质的交换起着重要的作用，它以一种未知的方式影响着土壤基质中的反应运移。本研究的目的是比较粘土有机涂层的吸附和解吸行为，这些涂层来自单性潮土的耕层(T-BT)和黄土(L-BT)衍生的Bt土层，与土壤基质和无涂层的山坡壤土BSH(HL-BSH)土层(CM-PZ)的吸附和解吸行为进行了比较。Qm值高达1100μ摩尔厘米−3，粘土含量高达330g kg-1。这一数值显著高于未涂覆的混合样品(粘土含量为115g·kg~(-1)时的qm值为180μ·−·cm~(-3))。结果表明，铝硅酸盐(粘土矿物)在硅氧烷表面的吸附和土壤有机质与粘土有机复合体的疏水相互作用控制了吸附，涂层和基质的吸附性质的巨大差异表明，混合样品的分析平均值不能用来描述优先流动事件中溶解的活性物质在生物孔道和较大裂隙表面的滞留。
In structured soils, water and reactive solutes can move preferentially through larger inter-aggregate macropores (biopores and cracks) and smaller intra-aggregate pores. Especially clay-organic coating material is of major importance for the exchange of water and solutes between macro- and micropores and the soil matrix by affecting the reactive transport in a yet largely unknown way.The objective of this study was to compare the adsorption and desorption behaviour of clay-organic coatings from samples of till- (T-Bt) and loess- (L-Bt) derived Bt horizons of Haplic Luvisols with those of the soil matrix and a hillslope loam-derived Bsh (HL-Bsh) horizon of a forest Cambisol-Podzol (CM-PZ) without coatings.These coatings are characterized by qm-values of up to 1100 μmol cm−3for clay contents of up to 330 g kg-1. The values are significantly higher than those of mixed samples without coatings (qmof 180 μmol cm−3for clay content of 115 g kg-1). The results indicate two different adsorption mechanisms, i) sorption on siloxane surfaces of the alumosilicates (clay minerals) and ii) adsorption controlled by hydrophobic interaction with soil organic material which is possibly attached to clay-organic complexes.The great difference in sorption properties between coatings and matrix suggests that mean values obtained from analyzing mixed samples cannot be used to describe the retardation of dissolved reactive substances on the surfaces of biopores and larger cracks during preferential flow events.