纳米TiO2协助下As(Ⅲ)在可变电荷土壤中的光催化氧化和吸附 |
摘要点击 2133 全文点击 1965 投稿时间:2007-12-30 修订日期:2008-03-03 |
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中文关键词 TiO2 可变电荷土壤 As(Ⅲ) 光催化氧化 吸附 |
英文关键词 TiO2 variable charge soil As(Ⅲ) photocatalyzed oxidation adsorption |
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中文摘要 |
环境中As(Ⅲ)的毒性和活动性均大于As(Ⅴ),将As(Ⅲ)转化为As(Ⅴ)有利于砷的固定.为此使用自制的光催化装置,采用一次平衡法研究了纳米TiO2协助下As(Ⅲ)在土壤悬液体系中的光催化氧化及土壤对氧化产物的吸附.结果表明,As(Ⅲ)的光催化氧化量随TiO2的加入量和光照时间的增加而增加,当TiO2的加入量为1.0 g·L-1,光照时间为90 min时As(Ⅲ)可以达到很好的转化效果.As(Ⅲ)在土壤中的光催化氧化及土壤对氧化产物的吸附增加了水体中砷的去除量,在Fe/Al氧化物与TiO2体系中也观察到类似的效应.实验结果还表明γ-Al2O3也可诱导As(Ⅲ)的光催化氧化. |
英文摘要 |
Toxicity and mobility of As(Ⅲ) in environments is greater than As(Ⅴ). The transformation of As(Ⅲ) to As(V) is in favor of the adsorption and fixation of arsenic on adsorbents. TiO2photocatalyzed As(Ⅲ) oxidation in the suspension systems of variable charge soils and the adsorption of oxidation products by the soils were investigated with a batch method. The photocatalysis experiments were conducted in a reaction box made by authors. The experiment results show that the photocatalyzed As(Ⅲ) oxidation increased with the increase in the amount of TiO2added and the time of irradiation, and 1.0 g·L-1 of TiO2and 90 min of irradiation were enough for photocatalyzed As(Ⅲ) oxidation in the soil suspension systems. The TiO2photocatalyzed As(Ⅲ) oxidation in the variable charge soils and the adsorption of oxidation products by the soils increased the removal of arsenic from water and the similar processes were observed in TiO2-Fe/Al oxides' systems. The results also indicated that γ-Al2O3was able to induce the photocatalyzed oxidation of As(Ⅲ) in suspension systems. |