稀土掺杂铁炭复合材料处理含砷废水

Treatment of arsenic wastewater with iron-carbon composite material doped with rare earth

针对毒性大、污染严重的含砷废水,采用铁粉和活性炭为原料,加入一定的粘合剂制备铁炭复合材料,然后在复合材料中掺杂二氧化铈(Ce O2)制备了新型铁炭复合材料,研究考察了制备过程中铁炭质量比、二氧化铈质量分数、焙烧温度等3个因素对材料吸附As(Ⅲ)性能的影响,并对吸附过程进行了动力学研究。结果表明,稀土掺杂铁炭复合材料对废水中的As(Ⅲ)具有显著的吸附效果。在铁炭质量比为1∶1、二氧化铈质量分数为3%、焙烧温度为600℃的条件下所制得的稀土掺杂铁炭复合材料对于含As(Ⅲ)浓度为10 mg/L的废水除砷率高达93.39%。动力学研究表明,复合材料对于含As(Ⅲ)浓度为10~30 mg/L的废水具有良好的吸附效果,平衡吸附容量最高可达3.890 mg/g,吸附规律符合Lagergren一级动力学方程和颗粒内扩散模型,吸附过程主要受颗粒内扩散的控制。

To treat the wastewater containing arsenic and with high toxicity and serious pollution, a new iron-carbon composite material was prepared using iron powder, activated carbon, and some binder. The obtained material was doped with ceria （CeO2 ） to get iron-carbon-CeO2 composite material which was usedto treat arsenic contained wastewater. The effects of different iron-carbon mass ratio, mass fraction of ceria, and roast temperature on As （ Ⅲ ） composite material wereinvestigated, the kinetics of the adsorption process was also studied. The results showed that the iron-carbon composite material modified by rare earth had prominent absorption efficiency for As （ Ⅲ ） in the wastewater. The optimal condition for preparation of the composite material was iron-carbon mass ratio of 1 ： 1, ceria mass fractionof 3% , and roasted temperature of 600 ℃. Using the composite material obtained under the optimal condition, the adsorption efficiencyof 10 mg/L As（Ⅲ ） in wastewater could be 93.39%. The kinetic study showed that the material had good absorption efficiency for As（ Ⅲ） in wastewater with 10 mg/L -30 mg/L, the equilibrium adsorption capacity was 3. 890 mg/g. And the Lagergren pseudo-first order kinetic equation and intra-particle diffusion model generated the best agreement with the absorption systems. The intra-particle diffusion was the mainrate-controlling step.