基于液相色谱-原子荧光光谱法分析脱砷剂在不同介质中的脱砷效果

Analysis of Arsenic Removal Effect of Arsenic Removal Agent in Different Media Based on Liquid Chromatography-Atomic Fluorescence Spectrometry

脱砷剂是一种靶向捕捉砷元素的吸附材料,能将介质中砷元素进行有效脱除。为研究在不同介质体系下,脱砷剂对不同形态砷的脱除效果,利用液相色谱-原子荧光光谱联用仪分析亚砷酸根[As(Ⅲ)]和砷酸根[As(V)]脱除前后的含量,发现脱砷剂的砷脱除效果受到体系pH值的影响明显。脱砷剂对As(Ⅲ)的脱除能力随着pH值增加而提高,对As(V)的脱除能力随着pH值增加而降低。在磷酸、氟硅酸的强酸介质中,脱砷剂对As(Ⅲ)脱除率为50%以上,As(V)脱除率达到90%以上。在pH=2的酸性洗水介质中,脱砷剂对于As(Ⅲ)的脱除率可以达到97.0%,As(V)的脱除率仅为18%以上。当pH值≥5时,脱砷剂对As(Ⅲ)脱除率提升至100%,而对As(V)脱除失效。在强碱性条件下,脱砷剂会溶解,但溶解的脱砷剂具有氧化性,能将As(Ⅲ)氧化成As(V)。在不同介质下,脱砷剂对不同形态砷的脱除效果,体系pH值是最关键的影响因素。

Arsenic removal agent is a kind of adsorptive material that can target arsenic and effectively remove arsenic from the medium.The removal effects of arsenic removal agent on different arsenic speciation in different media systems were studied.The content of arsenite [As(Ⅲ)] and arsenate [As(V)] before and after removal were analyzed by the liquid chromatography atomic fluorescence spectrometer.It was found that the removal effect of the arsenic removal agent was significantly affected by the pH value.With the increase of pH,As(Ⅲ) removal capacity of arsenic removal agent increased,while As(V) removal capacity decreased.In the strong acid medium of phosphoric acid and fluosilicic acid,the removal efficiencies of As(Ⅲ) and As(V) by arsenic removal agent were more than 50% and 90% respectively.In the acidic washing water medium with pH=2,the removal efficiency of arsenic removal agent for As(Ⅲ) reached 97.0%,while the removal efficiency of As(V) was only more than 18%.When the pH value was ≥5,the removal efficiency of As(Ⅲ) increased to 100%,while the removal of As(V) was invalid.Under strong alkaline conditions,the arsenic removal agent dissolved,and it could oxidize As(Ⅲ) to As(V).To investigate the removal effects of the arsenic removal agent on different speciation of arsenic in different media,the pH was the most critical factor.