Fe(Ⅱ)-H2O2不同温度浸润改性活性炭是采用FeSO4·7H2O添加H2O2在温度100℃下纯浸润24 h(Fe(Ⅱ)-24 h)和高温蒸发15 min(Fe(Ⅱ)-15 min)制备.对2类材料进行SEM表征并对其吸附1.1 mg/L砷(Ⅴ)的性能进行比较.SEM显示Fe(Ⅱ)(0.485%)-24 h(0.485%为Fe(Ⅱ)-24 h的铁含量,下同)表面覆盖厚的棒状纳米羟基铁,Fe(Ⅱ)(1.35%)-15 min表面覆盖薄而烧结扭曲羟基铁;高温蒸发15 min有利于铁负载;Fe(Ⅱ)-24 h(108~142 mg/gFe)对砷(Ⅴ)吸附的铁效率是Fe(Ⅱ)-15 min(57~63 mg/gFe)的2倍;
Granular activated carbon(GAC) modified by Fe(Ⅱ)-H2O2 incipient wetness impregnation at different temperatures are prepared by FeSO4·7H2O and hydrogen peroxide(H2O2) via the incipient wetness for 24 h at100 ℃(Fe(Ⅱ)-24 h) and the high temperature evaporation for 15 min(Fe(Ⅱ)-15 min).Fe(Ⅱ)-24 h and Fe(Ⅱ)-15 min are characterized by SEM and are compared for the adsorption behavior of the arsenate(1.1 mg/L).The SEM has shown that nano-iron hydroxides are formed on the surface of Fe(Ⅱ)(0.485 %)-24 h(0.485 % is the iron content of Fe(Ⅱ)-24 h,the same below) and that sintering distorted hydroxides are formed on the surface of Fe(Ⅱ)(1.35 %)-15 min.The high temperature evaporation for 15 min is favorable for iron to load on GAC.The iron use efficiency of Fe(Ⅱ)-24 h(108~142 mg/gFe) is two fold of that of Fe(Ⅱ)-15 min(57~63 mg/gFe).The arsenate equilibrium adsorption capacity of Fe(Ⅱ)(0.485 %)-24 h is better than the Fe(Ⅱ)(1.35 %)-15 min at pH 2~3.5 or 9~12,at the same time,the soluble iron at any particular pH released from the Fe(Ⅱ)(0.485 %)-24 h is less than that released from the Fe(Ⅱ)(1.35 %)-15 min.The presence of SO42-, NO3-, ClO4-, or PO43-inhibit the adsorption of arsenate, especially for phosphate,while the existence of Cl-(100 mg/L)and BrO3-promote the adsorption of arsenate.