摘要: |
以土壤中常见的锰氧化物(水钠锰矿,δ-MnO2)为材料,通过批试验研究了其对溶液中As(Ⅲ)的吸附和氧化机制。研究结果表明:大部分加入的As(Ⅲ)(1.0 mg/L)在反应的数分钟内就可被锰氧化物氧化,氧化产物As(Ⅴ)的释放速度相当快,但还原产物Mn(Ⅱ)的释放速度则相对较慢;在反应的90 min内,当初始质量浓度为0.5、1.0、5.0、10.0和15.0 mg/L时,As(Ⅲ)去除率可分别达到93.59%、92.56%、92.31%、89.15%和87.17%。pH 对锰氧化物氧化As(Ⅲ)的影响较为显著,升高pH有利于锰氧化物对还原产物Mn(Ⅱ)的吸附,但不利于As(Ⅲ)的氧化和对氧化产物As(Ⅴ)的吸附。 |
关键词: 土壤污染 锰氧化物 As (Ⅲ) As(Ⅴ) 氧化 吸附 |
DOI:10.11841/j.issn.1007-4333.2012.05.014 |
投稿时间:2011-11-15 |
基金项目:国家重点基础研究发展计划项目(2004CB418504) |
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As (Ⅲ) adsorption and oxidation by synthetic birnessite |
WANG Nan, LIANG Cheng-hua, DU Li-yu, CUI Hui-ying
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(College of Soil and Environment, Shenyang Agricultural University, Shenyang 110866, China) |
Abstract: |
The mechanism of the reactions between aqueous As (Ⅲ) and synthetic birnessite (δ-MnO2) particles was studied.The experimental results at pH 6 indicate that the depletion of As (Ⅲ) from solution is rapid within a few minutes.The oxidation product As (Ⅴ) is released quickly,while the release of the reduction product Mn (Ⅱ) is slightly slower.Under different initial As (Ⅲ) concentrations of 0.5,1.0,5.0,10.0 and 15 mg/L,the removal rates of As (Ⅲ) can reach 93.59%,92.56%,92.31%,89.15% and 87.17% respectively within 90 minutes during the reaction.High pH favored the adsorption of Mn(Ⅱ),but it disfavored the oxidation of As (Ⅲ) and adsorption of As (Ⅴ). |
Key words: soil pollution manganese oxide As (Ⅲ) As (Ⅴ) oxidation adsorption |