Understanding major NOM properties controlling its interactions with phosphorus and arsenic at goethite-water interface
Understanding major NOM properties controlling its interactions with phosphorus and arsenic at goethite-water interface
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了解控制其在针铁矿-水界面与磷和砷相互作用的主要 NOM 特性
DOI：
10.1016/j.watres.2019.03.077
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发表时间：
2019
期刊：
影响因子：
12.8
通讯作者：
Chen Yali
中科院分区：
文献类型：
--
作者：
Deng Yingxuan;Weng Liping;Li Yongtao;Ma Jie;Chen Yali
天然有机物（NOM）、含氧阴离子和金属（氢）氧化物之间存在着复杂的相互作用，这种相互作用存在于天然水、陆系统和废水沃茨中。定量研究了7种不同性质的NOM（4种胡敏酸（HA），3种富里酸（FA））对磷酸盐、砷酸盐和亚砷酸盐等含氧阴离子在针铁矿-水界面吸附的影响。结果表明，NOM的存在降低了含氧阴离子在针铁矿上的吸附，尤其是在低pH条件下对磷酸盐和砷酸盐的吸附。总的来说，3种FA的效果相似，在低pH条件下（<6），它们比HA更有效地降低了含氧阴离子在针铁矿上的吸附。四种HA在与含氧阴离子的竞争中存在差异。NOM对磷酸盐、砷酸盐和亚砷酸盐的吸附可以用NOM-CD（CD：Charge Distribution）和LCD（Ligand and Charge Distribution）模型来描述。NOM-CD模型使用相对简单，而LCD模型可以更好地揭示相互作用中的各种因素，包括氧化物表面吸附NOM的空间分布。根据这两个模型：羧基的位密度、羧基的质子化常数和NOM的粒径是NOM决定其对氧阴离子吸附到氧化物上的影响的主要性质。在较低的NOM负载量下，NOM的吸附形态发生了变化，NOM的吸附形态变化程度取决于NOM的粒径、羧基的位密度和芳香度，在较高的NOM负载量下，粒径对相互作用的影响更为重要。结果表明，NOM的存在会显著降低铁氧化物（如针铁矿）对磷酸盐、砷酸盐和亚砷酸盐的固定或去除效率，特别是当NOM中含有酸性基团和芳香基团时。
Among natural organic matter (NOM), oxyanions and metal (hydr)oxides, a complicated interaction exists in natural aquatic and terrestrial systems and in waste waters. Effects of seven types of NOM (four humic acids (HA), three fulvic acids (FA)) that vary in properties on the adsorption of oxyanions, including phosphate, arsenate and arsenite, at goethite-water interface were quantitatively studied. Results show that the adsorption of oxyanions to goethite is decreased by the presence of NOM, especially for phosphate and arsenate at low pH. In general, the effects of the three FA are similar, which are more effective than HA in reducing oxyanion adsorption at low pH (<6). Differences were observed between the four HA in their competition with oxyanions. The adsorption of phosphate, arsenate and arsenite in the presence of NOM are well described with both the NOM-CD (CD: Charge Distribution) and LCD (Ligand and Charge Distribution) model. The NOM-CD model is relatively simple to use, whereas the LCD model can better reveal different factors in the interaction, including the spatial distribution of adsorbed NOM on oxide surface. According to these two models: site density of carboxylic groups, protonation constant of carboxylic groups, and particle size of NOM are major properties of NOM determining its effect on oxyanion adsorption to oxides. At relatively low loadings, morphological change of adsorbed NOM takes place, and the degree of morphological change of adsorbed NOM depends on the particle size, site density of carboxylic groups and aromaticity of NOM. The influence of particle size on the interaction becomes more important at higher NOM loadings. The results suggested that the fixation or removal efficiency of phosphate, arsenate and arsenite with iron oxides (e.g. goethite) can be significantly decreased by the presence of NOM, especially when NOM rich in acidic and aromatic groups.