菱铁矿对砷的吸附解析特性试验研究

The Contrastive study of Siderite and Ferric oxide on the Arsenic Adsorptive-desorptive Behaviour

砷污染是地下水污染中的严重威胁之一。菱铁矿是砷吸附材料的一种,碳酸亚铁是菱铁矿中的主要成分之一。文章将菱铁矿与Fe2O3作对照,分别进行了静态试验和动态试验,初步探究了时间、温度、pH对砷在菱铁矿中的吸附解析行为的影响。结果表明,Fe2O3的吸附明显比菱铁矿好;pH在2到11范围内变化时,菱铁矿对砷的吸附曲线成M形;温度在20℃到40℃范围内变化时,菱铁矿对砷的吸附没有明显的变化;随着时间的变化,在前8个小时内,菱铁矿对砷的吸附速度较快,8小时之后,吸附曲线趋于平缓,说明最佳吸附时间是8小时。在解析实验中,在0.01 mol/L到0.5 mol/L范围内,随着NaOH浓度的增大,砷的解析率逐渐增大,其中在0.5 mol/L的时候达到最大,为50%。

Arsenic contamination of groundwater pollution is a serious threat. Siderite is a kind of arsenic adsorption material, and FeCO3 is one of the major components. We conducted a static and dynamic experiments, and studied the effect of the time, temperature and pH on the adsorptive-desorptive behaviour of Arsenic on siderite. The results show that, Fe2O3 adsorption was significantly better than that of siderite. When pH value changes in the range of 2 to 11, siderite adsorption of arsenic is in the M-shaped curve; when temperature changes in the range of 20℃℃ to 40 ℃ , the adsorption of arsenic on siderite did not change significantly. Over time, in the first 8 hours, siderite fast adsorptived arsenic, and 8 hours later, the adsorption curve leveled off, indicating that the optimum adsorption time is 8 hours. In the desorption study, when NaOH concentrationin changes in the range of O.01 to 0.5 mol/L, arsenic in the resolution increased with the increase of NaOH concentration, which in 0.5mol/L, it reached at the maximum of 50 %. Arsenic adsorption in siderite could be better fitted by Freundlich equation.