Preloading hydrous ferric oxide into granular activated carbon for arsenic removal
Preloading hydrous ferric oxide into granular activated carbon for arsenic removal
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DOI：
10.1021/es7025399
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发表时间：
2008-05-01
影响因子：
11.4
通讯作者：
Cannon, Fred S.
中科院分区：
文献类型：
--
作者：
Jang, Min;Chen, Weifang;Cannon, Fred S.
砷在水处理中因其对健康的影响而受到关注。研究了将含水氧化铁（HFO）掺入颗粒活性炭（GAC）中去除砷的方法。通过初始湿浸渍将铁掺入GAC中，并在60 ~ 90℃的温度下固化，通过x射线衍射和砷吸附随pH值的变化来研究温度对最终氧化铁（氢氧化铁）及其除砷能力的影响。结果表明，当在60℃固化时，该过程成功地在GAC的孔隙中产生了HFO，而在80和90℃的温度下，浸渍的氧化铁表现出更结晶的形式。在合成水柱试验中，60℃条件下制备的负载hfo的GAC也表现出比高温固化介质更高的吸附能力。这些结果表明，在一定的铁含量下，对砷的吸附能力与铁（水合）氧化物的形态密切相关。在天然地下水柱试验中，当进水含砷300 μ g/L时，含铁11.7%的hfo GAC对砷的吸附能力为26 mg As/g。因此，将HFO预压到稳定的GAC介质中提供了在水处理厂或使用点过滤器中使用固定碳床反应器去除砷的机会。
Arsenic is of concern in water treatment because of its health effects. This research focused on incorporating hydrous ferric oxide (HFO) into granular activated carbon (GAC) for the purpose of arsenic removal. Iron was incorporated into GAC via incipient wetness impregnation and cured at temperatures ranging from 60 to 90 degrees C. X-ray diffractions and arsenic sorption as a function of pH were conducted to investigate the effect of temperature on final iron oxide (hydroxide) and their arsenic removal capabilities. Results revealed that when curing at 60 degrees C, the procedure successfully created HFO in the pores of GAC, whereas at temperatures of 80 and 90 degrees C, the impregnated iron oxide manifested a more crystalline form. In the column tests using synthetic water, the HFO-loaded GAC prepared at 60 degrees C also showed higher sorption capacities than media cured at higher temperatures. These results indicated that the adsorption capacity for arsenic was closely related to the form of iron (hydr)oxide for a given iron content. For the column test using a natural groundwater, HFO-loaded GAC (Fe, 11.7%) showed an arsenic sorption capacity of 26 mg As/g when the influent contained 300 mu g/L As. Thus, the preloading of HFO into a stable GAC media offered the opportunity to employ fixed carbon bed reactors in water treatment plants or point-of-use filters for arsenic removal.