The hazardous effects of arsenic are closely linked to its speciation and interaction with different soil minerals, which influence both As mobility and bioavailability. Adsorption onto iron (oxyhydr)oxides is one of the main processes controlling the partitioning of arsenite [As(III)] and arsenate [As(V)] between aqueous and solid phases. Arsenic retention can be affected by changes in soil pH and the presence of competing anions, like phosphate. Although competition with inorganic phosphorus (P) for sorption sites on mineral surfaces has been widely studied, little is known about the interactions with organic P (Po ) compounds, in particular inositol phosphates, even though they may represent a large fraction of total soil P. We quantified the effects of myo-inositol hexaphosphate (InsP6) on the adsorption and retention of As(III) and As(V) on goethite as influenced by pH, the order of anion addition, and residence time. The efficiency of InsP6 in displacing adsorbed As(III) decreased with increasing pH values and interaction time, which may be attributed to the increase in bonding strength of the As(III) complexes on the surface of goethite. Adsorption and retention of As(V) by goethite generally decreased with increasing pH, particularly in the presence of InsP6 due to the similar pKa values and the competition for the same binding sites. The addition of InsP6 before, together with, or after adsorption of As(III) and As(V) strongly reduced the amounts of sorbed As, suggesting that the addition of Po -rich matrices to As-contaminated soils may strongly enhance As mobility.

中文翻译：

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有机磷影响亚砷酸盐和砷酸盐在针铁矿上的保留

砷的有害影响与其形态以及与不同土壤矿物质的相互作用密切相关，这会影响砷的迁移率和生物有效性。吸附在铁（氢氧化物）氧化物上是控制亚砷酸盐 [As(III)] 和砷酸盐 [As(V)] 在水相和固相之间分配的主要过程之一。土壤 pH 值的变化和竞争性阴离子（如磷酸盐）的存在会影响砷的保留。尽管已广泛研究与无机磷 (P) 竞争矿物表面的吸附位点，但对与有机磷 (Po) 化合物，尤其是肌醇磷酸盐的相互作用知之甚少，尽管它们可能占土壤总磷的很大一部分。 . 我们量化了肌醇六磷酸 (InsP6) 对针铁矿上 As(III) 和 As(V) 的吸附和保留的影响，受 pH、阴离子添加顺序和停留时间的影响。InsP6 置换吸附的 As(III) 的效率随着 pH 值和相互作用时间的增加而降低，这可能归因于针铁矿表面 As(III) 配合物的结合强度增加。由于相似的 pKa 值和对相同结合位点的竞争，针铁矿对 As(V) 的吸附和保留通常随着 pH 的增加而降低，特别是在 InsP6 存在的情况下。在吸附 As(III) 和 As(V) 之前、同时或之后添加 InsP6 会大大降低吸附 As 的量，