铁在含水层介质中的沉积行为研究

为分析铁在含水层介质中的沉积行为,以石英砂为实验材料,研究了铁在石英砂表面的吸附规律,并对接触时间、铁浓度、腐植酸、钙离子等对沉积过程的影响进行了探讨。结果表明:铁在石英砂上的沉积是单分子层沉积,且沉积过程符合准一级动力学模型。低浓度腐殖酸会促进铁在石英砂上的沉积,但受络合作用影响,增加腐植酸浓度会减少铁在石英砂上的沉积。当水中存在阳离子Ca2+和阴离子SO42-时,会促进铁的沉积,NO3-离子的影响较小,而高浓度F-离子会阻碍铁的沉积。

Study on deposition behavior of iron on porous medium

The adsorption of ferric iron on porous medium was conducted by using quartz as model medium.The results show that ferric iron was adsorbed on quartz surface and formed a monolayer,and the adsorption was well fitted with the pseudo-first order kinetic model.The adsorption capacity of ferric iron on quartz sand increased by adding humic acid at low concentration and declined when the humic acid was at high concentration,which was attributed to the chelating effect of humic acid and ferric iron.The cationic Ca^2+ and the anion SO4^2- dramatically promoted the adsorption capacity,while the anion F^- at high concentration presented the opposite effect.NO obvious effect was observed by adding the anion NO3^-.