Phosphate alters the compositional characteristics of humic acid adsorbed onto goethite
Phosphate alters the compositional characteristics of humic acid adsorbed onto goethite
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DOI：
10.1007/s11368-021-02973-4
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发表时间：
2021-05
影响因子：
3.6
通讯作者：
Chunyan Luo;Shuailong Wen;ShiLin An;Yuehan Lu;YingXun Du
中科院分区：
文献类型：
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作者：
Chunyan Luo;Shuailong Wen;ShiLin An;Yuehan Lu;YingXun Du
目的矿物对有机物和磷酸盐的吸附是一种常见的自然过程，对碳和磷的迁移和埋藏具有重要影响。以往的研究主要集中在有机物对磷酸盐吸附的影响。然而，磷酸盐对不同有机物池吸附的影响尚不清楚。本研究评估了在磷酸盐存在下不同有机质库在吸附矿物过程中的变化。材料和方法首先，分别评估了天然有机质（即腐殖酸）和磷酸盐在针铁矿上的吸附行为。其次，将腐植酸和磷酸盐按不同顺序添加到针铁矿中，以阐明磷酸盐对针铁矿吸附的腐植酸组分分级的影响。结果与讨论结果表明，当磷酸盐和腐植酸同时添加时，针铁矿优先与磷酸盐结合。在无磷酸盐存在的情况下，吸附过程中腐植酸溶液的SUVA254降低，溶液的E2/E3增加。腐殖酸的6个EEM-PARAFAC（激发-发射矩阵荧光耦合平行因子分析）组分中，C1、C2和C4（陆地腐殖质类物质）显着下降并表现出较强的吸附性，C3（微生物类黄腐物质）表现出较弱的吸附性，而C5（光降解产物）和C6（类酪氨酸物质）则表现出较强的吸附性。 组分）没有表现出明显的吸附作用。在磷酸盐存在下，磷酸盐抑制并取代了吸附的C1、C2和C4，但促进了C5的吸附，从而增加了腐植酸溶液的芳香性和分子量。结论我们的结果表明，磷酸盐影响吸附在针铁矿上的腐植酸组分的分馏，这表明磷酸盐可以改变与有机物相互作用的天然有机物的化学组成。 矿物质，从而影响矿泉水界面处天然有机物的埋藏和分馏。
PurposeThe adsorption of organic matter and phosphate on minerals is a common natural process that has an important impact on the migration and burial of carbon and phosphorus. Previous studies have focused mainly on the influence of organic matter on the adsorption of phosphate. Yet, the influence of phosphate on the adsorption of different pools of organic matter is not well understood. This study evaluates changes in different organic matter pools during their adsorption to minerals in the presence of phosphate.Materials and methodsFirstly, the adsorption behaviors of natural organic matter (i.e., humic acid) and phosphate on goethite were evaluated separately. Secondly, humic acid and phosphate were added to goethite at different orders to elucidate the effect of phosphate on the fractionation of humic acid components adsorbed to goethite.Results and discussionThe results showed that when phosphate and humic acid were added simultaneously, goethite was preferentially combined with phosphate. In the absence of phosphate, SUVA254of the humic acid solution decreased and E2/E3of the solution increased during the adsorption. Among the six EEM-PARAFAC (excitation-emission matrix fluorescence coupled with parallel factor analysis) components of the humic acid, C1, C2, and C4 (terrestrial humus-like substances) decreased significantly and exhibited strong adsorption, C3 (microbial fulvic-like substance) showed weak adsorption, whereas C5 (photodegradation products) and C6 (tyrosine-like component) did not show evident adsorption. In the presence of phosphate, phosphate inhibited, and replaced the adsorbed C1, C2, and C4, but promoted the adsorption of C5, which increased the aromaticity and the molecular weight of the humic acid solution.ConclusionsOur results reveal that phosphate influences the fractionation of humic acid components adsorbed onto goethite, suggesting that phosphate can alter the chemical composition of natural organic matter interacting with minerals and thus impact the burial and fractionation of natural organic matter at the mineral-water interface.