Arsenic(III) oxidation/adsorption behaviors on a new bimetal adsorbent of Mn-oxide-doped Al oxide
Arsenic(III) oxidation/adsorption behaviors on a new bimetal adsorbent of Mn-oxide-doped Al oxide
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Mn氧化物掺杂Al氧化物的新型双金属吸附剂上砷(III)的氧化/吸附行为
DOI：
10.1016/j.cej.2012.03.058
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发表时间：
2012-06-01
影响因子：
15.1
通讯作者：
Wang, Xiaochang
中科院分区：
文献类型：
--
作者：
Wu, Kun;Liu, Ting;Wang, Xiaochang
在广泛的条件下，亚砷酸盐[As（III）]比砷酸盐[As（V）]更难去除。几种含锰氧化物的吸附剂对As（III）既有氧化活性，又有吸附活性。然而，很少有信息是可用的As（III）的氧化/吸附行为到铝和锰氧化物的共沉淀物。为了弥补这一差距，结合二氧化锰（MnO 2）和羟基氧化铝（AlOOH）的特征，通过氧化/共沉淀工艺合成了锰氧化物掺杂氧化铝（MODAO）。采用BET、EDAX、SEM和XRD等方法对MODAO进行了表征。表征结果表明：（i）BET面积为44.73 m2/g的粗糙表面，（ii）表面上Al/Mn分布不均匀（Al富集），（iii）无定形结构和MnO 2的存在。此外，一系列的批实验进行了使用MODAO的As（III）去除。动力学结果表明，MODAO能将As（III）氧化为As（V），且数据符合准二级动力学模型，表明MODAO对As（III）的吸附过程主要为一步以上的吸附过程.利用Langmuir模型计算出该树脂对As（III）的最大吸附容量为142.19 mg/g。此外，As（III）的氧化和As（V）的吸附MODAO被抑制的pH值增加超过pH值范围4-10。MODAO与As（III）反应前后的XPS分析结果进一步证实了MODAO吸附As（III）的氧化-吸附机理。(C)2012爱思唯尔有限公司版权所有。
Arsenite [As(III)] is more difficult to remove than arsenate [As(V)] under a wide range of conditions. Several Mn-oxide-containing adsorbents could exhibit both the oxidation and the adsorption activities toward As(III). However, little information is available on the As(III) oxidation/adsorption behaviors onto the coprecipitates of Al and Mn oxides. To bridge this gap, Mn-oxide-doped Al oxide (MODAO) was synthesized by an oxidation/co-precipitation process, combining the features of manganese dioxide (MnO2) and aluminum oxyhydroxide (AlOOH). MODAO was characterized using BET, EDAX, SEM and XRD analyses. The characterization results showed: (i) a rough surface exhibiting a BET area of 44.73 m(2)/g, (ii) an uneven Al/Mn distribution (Al-enriched) on the surface, (iii) an amorphous structure and the existence of MnO2. Additionally, a series of batch experiments were conducted using MODAO for As(III) removal. The kinetic results showed that MODAO could oxidize As(III) to As(V), and the data were best fit using a pseudo-second-order model, confirming that more than one-step adsorption process dominated the rate controlling step. The maximal adsorption capacity As(III) was calculated to be 142.19 mg/g using a Langmuir model. In addition, both As(III) oxidation and As(V) adsorption by MODAO were inhibited by a pH increase over a pH range of 4-10. Furthermore, the XPS analysis results of MODAO before and after reaction with As(III) confirmed the oxidation-sorption mechanism for As(III) uptake by MODAO. (C) 2012 Elsevier B.V. All rights reserved.