The coupling of zero-valent iron (ZVI) with common oxidants has recently achieved very rapid and highly efficient removal of Heavy metals from wastewater. However, the uniform activation of ZVI throughout the column and the proportional removal of target contaminants are urgently required for the prevention of premature filter clogging and the extension of the effective column operational time. In this study, we successfully achieved this objective by simply doping granular sand with ZVI at appropriate weight ratios. When pure ZVI packed column was spiked with oxidants, the majority of As trapping occurred between the column inlet and the first sampling point. In a packed column with a 1:20 mixture of ZVI and sand, the average As removal efficiency was 36 (1st), 13.1 (2nd), 18.5 (3rd), 19.2 (4th) and 5.9% (5th outlet). The overall arsenic removal performance of the composite filling system of ZVI/sand was equally as efficient as that of the previous pure ZVI-packed system. Moreover, the leaching of Fe was significantly reduced with an increased sand ratio, resulting in clearer water with less turbidity. The results of X-ray photoelectron spectroscopy (XPS) demonstrated that more than 54% of the arsenic was reduced to As(III). X-ray diffraction (XRD) and scanning electron microscopy (SEM) confirmed the extensive corrosion of the ZVI surface, which resulted in various species of iron oxyhydroxides responsible for the highly efficient sequester of arsenic through reduction, adsorption, and coprecipitation.

零价铁（ZVI）与常见氧化剂的偶联最近实现了非常快速高效的废水中重金属去除。但是，为防止过早的过滤器堵塞和延长有效的色谱柱操作时间，迫切需要整个色谱柱中的ZVI均匀活化并按比例去除目标污染物。在这项研究中，我们通过以适当的重量比简单地将ZVI掺入粒状砂中，成功地实现了这一目标。当纯ZVI填充柱中加有氧化剂时，大部分的As捕集都发生在柱入口和第一个采样点之间。在ZVI和沙子的比例为1:20的填充塔中，平均As去除效率为36（第一），13.1（第二），18.5（第三），19.2（第四）和5.9％（第五出口）。ZVI /砂子复合填充系统的整体除砷性能与以前的纯ZVI填充系统一样有效。此外，随着砂比的增加，铁的浸出显着减少，从而使水更清澈，浊度更低。X射线光电子能谱（XPS）的结果表明，超过54％的砷被还原为As（III）。X射线衍射（XRD）和扫描电子显微镜（SEM）证实了ZVI表面的广泛腐蚀，这导致了各种羟基氧化铁通过还原，吸附和共沉淀而有效地隔离了砷。随着砂比的增加，铁的浸出显着减少，从而使水更清澈，浊度更低。X射线光电子能谱（XPS）的结果表明，超过54％的砷被还原为As（III）。X射线衍射（XRD）和扫描电子显微镜（SEM）证实了ZVI表面的广泛腐蚀，这导致各种羟基氧化铁通过还原，吸附和共沉淀而有效地隔离了砷。铁的浸出随着砂比的增加而显着减少，从而使水更清澈，浊度更低。X射线光电子能谱（XPS）的结果表明，超过54％的砷被还原为As（III）。X射线衍射（XRD）和扫描电子显微镜（SEM）证实了ZVI表面的广泛腐蚀，这导致各种羟基氧化铁通过还原，吸附和共沉淀而有效地隔离了砷。