沸石及其改性材料硅炭素处理含铅废水

Lead-Laden Wastewater Treatment with Zeolite and a Modified Material ANJ. SiC

对沸石及其改性材料硅炭素(ANJ.SiC)处理含铅废水进行优化研究,结果表明,当废水中ρ(Pb)为10 mg/L,pH>4.62,吸附剂投加量为5 g/L,25℃处理30 min时,沸石及硅炭素对铅的去除率均可达到90%以上,且硅炭素的处理效果优于沸石.分别采用5种再生剂对饱和的沸石和硅炭素进行再生,NaOH再生效果最佳;经过5次再生,2种吸附剂的饱和容量呈现不同的衰减,硅炭素的再生效果较好,饱和容量从33.9 mg/L衰减到20.5 mg/L.通过扫描电镜(SEM)对沸石和硅炭素吸附前后的表面形貌进行观察发现,二者的除铅机理不尽相同,沸石主要是通过离子交换作用,使铅进入其结构内部;沸石经过改性,表面发生变化,硅炭素主要是通过材料表面与铅离子的反应达到除铅目的.

Optimization studies for lead-laden wastewater treatment with zeolite and a modified material ANJ. SiC were conducted. The experimental results showed that over 90% of the lead could be removed from the wastewater by using these adsorbents under the conditions of initial lead concentration 10 mg/L, pH 〉 4.62, ratio of absorbent to absorbate 5 g/L, reaction time 30 min, and temperature 25 ℃. The ANJ. SiC could remove more lead than the zeolite. Of the five regenerant combinations,NaOH alone was the best for regenerating the saturated zeolite and ANJ. SiC. After regenerating five times, the saturation capacities of the two adsorbents were decreased to different degrees. The regeneration effect of ANJ. SiC was better,with its saturated capacity decreasing from 33.9 mg/L to 20. 5 mg/L. By examining the surface topography of the raw and saturated adsorbents with a Scanning Electronic Microscope （SEM） ,it was found that the two adsorbents differed in the mechanism of removing lead. Lead removal with zeolite was mainly through ion exchange, with the lead being entrapped into its structure. After the modification of the zeolite, the surface of the material was changed. Lead removal with ANJ. SiC was mainly through the surface reaction.