Chemical extraction of arsenic from contaminated soil
Chemical extraction of arsenic from contaminated soil
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DOI：
10.1080/10934520600575036
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发表时间：
2006-01-01
影响因子：
2.1
通讯作者：
Tokunaga, S
中科院分区：
文献类型：
--
作者：
Alam, MGM;Tokunaga, S
采用强化土壤，采用无机酸（盐酸（HCl）、硫酸（H2SO4）、磷酸（H3PO4）、高氯酸（HClO4）或硝酸（HNO3））、有机酸（乙酸（C2H4O2）、柠檬酸（C6H8O7））和碱剂（NaOH）等不同提取液进行了一系列批量提取实验。使用不同的浓度来研究去除效率并优化每种萃取剂的浓度。在本次调查中，使用被亚砷酸盐（As(III)）污染的黑北土壤作为模型土壤。 5% H3PO4 从模型土壤中提取砷的效率最高，最高可达 99% 以上。硫酸也显示出高百分比的萃取效率。另一方面，与 C6H8O7 相比，C2H4O2 和氧化酸（例如 HNO3 和 HClO4）的砷萃取效率较低。尽管与有机酸和氧化酸相比，NaOH 也表现出更高的萃取效率，但主要成分是砷酸盐 (As(V))。在无机酸和碱提取过程中，很大一部分 As(III) 被氧化为 As(V)，并且提取效率也随酸和碱溶液的浓度而变化。
A series of batch extraction experiments were conducted using a fortified soil with different extracting solutions such as inorganic acids (hydrochloric acid (HCl), sulfuric acid (H2SO4), phosphoric acid (H3PO4), perchloric acid (HClO4), or nitric acid (HNO3)), organic acids (acetic acid (C2H4O2), citric acid (C6H8O7)) and alkaline agent (NaOH). Various concentrations were used to investigate the removal efficiency and to optimise the concentration of each extractant. In the present investigation a Kuroboku soil contaminated with arsenite (As(III)) was used as a model soil. Arsenic was extracted most efficiently by 5% H3PO4 with a maximum of more than 99% from the model soil. Sulfuric acid also showed high percentage extraction efficiency. On the other hand, C2H4O2 and oxidizing acids such as HNO3 and HClO4 showed low efficiency of As extraction compared with C6H8O7. Although, NaOH also showed higher extraction efficiencies compared with organic and oxidizing acids but mainly arsenate (As(V)) was found to be the major component. A significant fraction of the As(III) was oxidized to As(V) during mineral acid and alkaline extraction and extraction efficiency also varied with the concentration of the acid and alkali solution.