地下水中阴离子对球磨零价铁除砷影响

研究了不同浓度下几种阴离子（NO₃^-、SO₄^2-、H₂PO₄^-、SiO₃^2-）对球磨零价铁（BZVI）除砷规律的影响，探讨了上述阴离子对BZVI氧化As（Ⅲ）能力的影响，三价砷及五价砷的转化机制，及BZVI腐蚀产物.研究证实，不同浓度的NO₃^-和SO₄^2-对砷去除效率影响不显著，但是随着H₂PO₄^-和SiO₃^2-浓度升高，溶液中As（V）分别由25.1%上升到83.6%和下降到3.8%；通过SEM和拉曼光谱分析发现，H₂PO₄^-促进BZVI的腐蚀，导致As（Ⅲ）氧化能力增强；而铁表面形成二氧化硅聚合物或非晶固相则是SiO₃^2-降低BZVI对砷氧化和吸附能力的主要机制.

Impact of groundwater anions on the arsenic remove by ball milling zero valent iron

The effect of ball milled zero-valent iron (BZVI) on As remove was studied under different concentrations of NO₃^-, SO₄^2-, H₂PO₄^- and SiO₃^2-. The oxidation capacity of BZVI on As(Ⅲ), transformation between As(Ⅲ) and As(V), and the corrosion products of BZVI affected by these anions were studied as well. Arsenic removal efficiency was not significantly changed under varied concentrations of NO₃^- and SO₄^2-. However aqueous As (V) ratio increased from 25.1% to 83.6% accompanied by the increase of H₂PO₄^-, while it decreased from 25.1% to 3.8% with the increase of SiO₃^2-. Results of scanning electron microscopy images and raman spectroscopy showed that H₂PO₄^- promoted the corrosion of BZVI, resulting in the enhanced As (Ⅲ) oxidation capacity. Besides under aqueous SiO₃^2- the formation of silica polymer or amorphous solid phase on iron surface mainly contributed to the weakened As oxidation and adsorption capacity by BZVI.