Various iron oxyhydroxide and oxide minerals commonly found in old cast iron pipe scale were shown to exhibit high and similar affinity for arsenate [As(V)] and orthophosphate (PO₄) via adsorption, co-precipitation, and other factors. PO₄ is a common drinking water corrosion inhibitor. This 7.5-year study examined the accumulation and release of As from an old cast iron pipe scale by changing initial As(V) (0, 75, or 180 µg/L as As) and initial PO₄ (0 or 3 mg/L as PO₄) levels in the simulated drinking water. The results showed that sites within the iron scale accumulated As with a large capacity and concentrated 27% of the total amount As in water into the scale during the 7.5-year study. When no PO₄ was added, the As accumulation followed a linear regression model with an accumulation rate of 0.27/hr (R² = 0.80, p < 0.001), and higher initial As level of 180 µg/L (vs 75 µg/L) resulted in 2.3-3 times larger As accumulation rate at 0.25 mg/day (vs 0.084-0.11 mg/day). As much as 44 µg/L As was released back to water following the changes in the initial As and PO₄ concentrations in water. Addition of 3 mg/L PO₄ caused a rapid increase in As release from iron scale that gradually dropped off with time while PO₄ was incorporated into the scale and most PO₄ remained tightly bound to certain iron scale sites. Proactive measures such as sampling for As in the distribution systems following PO₄ corrosion control treatment changes would help identify exposure risks.

旧铸铁管垢中常见的各种羟基氧化铁和氧化物矿物通过吸附、共沉淀和其他因素对砷酸盐 [As(V)] 和正磷酸盐 (PO _{4 ) 表现出高且相似的亲和力。}PO ₄是一种常见的饮用水缓蚀剂。这项为期 7.5 年的研究通过改变初始 As(V)（0、75 或 180 µg/L 作为 As）和初始 PO ₄（0 或 3 mg/L模拟饮用水中的PO _{4 ) 水平。}结果表明，在为期 7.5 年的研究中，铁垢内的位点积累了大量的砷，并将水中总砷含量的 27% 浓缩到了水垢中。当没有 PO ₄添加后，As 积累遵循线性回归模型，积累率为 0.27/hr (R ²  = 0.80, p < 0.001)，初始 As 水平为 180 µg/L（相对于 75 µg/L）更高，结果为 2.3在 0.25 毫克/天（相对于 0.084-0.11 毫克/天）时，As 积累率大 -3 倍。_{随着水中初始 As 和 PO 4}浓度的变化，多达 44 µg/L As 被释放回水中。添加 3 mg/L PO ₄导致铁垢释放的 As 迅速增加，随着时间的推移逐渐下降，而 PO ₄并入铁垢中，大多数 PO ₄仍然与某些铁鳞部位紧密结合。_{在 PO 4}腐蚀控制处理改变后的分配系统中进行 As 取样等主动措施将有助于识别暴露风险。