Environmental Chemistry Letters ( IF 15.7 ) Pub Date : 2020-02-12 , DOI: 10.1007/s10311-020-00964-4 Junho Han , Minhee Kim , Hee-Myong Ro
Oxyanions are ubiquitous in soils, organisms and the environment. Due to their unique chemical structure, oxyanions can be easily transferred into other systems. Carbonate (CO32−), nitrate (NO3−), phosphate (PO43−), silicate (SiO42−) and sulfate (SO42−) are the major oxyanions in organisms and the soil environment, whereas arsenate (AsO43−), antimonate (SbO43−), borate (BO33−), selenate (SeO42−), and tellurate (TeO42−) are generally reported as toxic chemicals found at trace levels. Excessive oxyanions leached from soils into water have caused severe environmental problems. Here, we review the factors affecting the structural configuration of oxyanions and organic acids adsorbed on iron oxides and hydroxides. The configuration of oxyanions on iron (hydr)oxides is controlled by surface loading, pH, sample phase, competing ions and organic acids. Under conditions of low surface loading and low pH at the interface in the absence of competing ions, oxyanions with high affinity possibly form a complex with higher denticity. But an increase in pH decreases the number of sorption sites; thus, a transition from a tri- or bidentate complex to monodentate and outer-sphere complexes occurs.
中文翻译:
改变土壤中氧化铁(氢)氧化物吸附的氧阴离子和有机酸的结构构型的因素。回顾
在土壤,生物和环境中普遍存在含氧离子。由于其独特的化学结构,含氧阴离子可以轻松转移到其他系统中。碳酸盐(CO 3 2-),硝酸根(NO 3 - ),磷酸盐(PO 4 3-),硅酸盐(SIO 4 2-)和硫酸(SO 4 2-)是生物体的主要含氧阴离子和土壤环境,而砷酸盐(AsO 4 3−),锑酸盐(SbO 4 3−),硼酸盐(BO 3 3−),硒酸盐(SeO 4 2−)和碲酸盐(TeO 4 2−)通常报告为痕量水平的有毒化学物质。从土壤中渗入水中的过量氧阴离子造成了严重的环境问题。在这里,我们回顾了影响氧阴离子和有机酸吸附在氧化铁和氢氧化物上的结构构型的因素。羟基氧化铁上的氧阴离子的构型受表面负载,pH,样品相,竞争性离子和有机酸的控制。在没有竞争离子的情况下,在低表面负荷和低pH值的界面上,具有高亲和力的氧阴离子可能会形成具有较高密度的络合物。但是,pH值的增加会减少吸附位点的数量。因此,发生了从三齿或双齿复合物到单齿和外球形复合物的转变。