Experimental and modelling studies on fixed bed adsorption of As(III) ions from aqueous solution
Experimental and modelling studies on fixed bed adsorption of As(III) ions from aqueous solution
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DOI：
10.1016/j.seppur.2005.07.035
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发表时间：
2006-03
影响因子：
8.6
通讯作者：
T. Singh;K. Pant
中科院分区：
文献类型：
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作者：
T. Singh;K. Pant
本文研究了活性氧化铝和氧化铁浸渍活性氧化铝（IOIAA）去除饮用水中As（III）离子的试验研究。研究了入口流速、吸附剂床层高度和As（III）初始浓度对吸附效果的影响。通过量的增加，观察到床层高度的增加，而流速和初始As（III）浓度与去除亚砷酸根离子的反比关系，观察到这些吸附剂。与活性氧化铝相比，氧化铁浸渍的活性氧化铝被发现更有效地去除As（III）离子。吸附过程的动力学模型采用床层深度服务时间（BDST）模型和孔扩散模型。吸附速率常数（ka）被认为是增加与流量的增加，表明整个系统的动力学是占主导地位的外部传质在柱中的吸附的初始部分。临界床层深度（Z 0）的增加而增加的流量为两种吸附剂。在相同的流速（0.083cm 3/s）下，观察到IOIAA（0.56cm）与AA（1.12cm）相比，As（III）去除的临界床高相对较低。对于AA和IOIAA，移动单位长度的吸附床所需的时间根据条件在17，280 - 43，920 s（4.8- 12.2 h）和21，240 -54，360 s之间变化。孔扩散模型解释了具有高度相关性的As（III）去除的突破行为。
This paper deals with the experimental investigation on removal of arsenic [As(III)] ions from drinking water by activated alumina and iron oxide impregnated activated alumina (IOIAA). Effect of inlet flow rate, sorbent bed height and initial As(III) concentration on the adsorption of As(III) from aqueous solution were studied. Increase in throughput volume was observed with increase in bed height whereas inverse relationship of flow rate and initial As(III) concentration with removal of arsenite ions was observed by these sorbents. Compared to activated alumina, iron oxide impregnated activated alumina was found more effective in removing As(III) ions. The dynamics of adsorption process was modelled by bed depth service time (BDST) and pore diffusion model. Adsorption rate constant (ka) was found to increase with increase in flow rate indicating the overall system kinetics was dominated by external mass transfer in the initial part of the adsorption in the column. Critical bed depth (Z0) increased with increase in flow rate for both the adsorbent. Relatively lower critical bed height was observed for As(III) removal onto IOIAA (0.56cm) compared to AA (1.12cm) at identical flow rate (0.083cm3/s). Time required for traveling a unit length of adsorber bed varied from 17,280 to 43,920s (4.8–12.2h) and 21,240–54,360s for AA and IOIAA depending upon the conditions. Pore diffusion model explained the breakthrough behaviour for As(III) removal with a high degree of correlation.