| Fe3O4稳定化纳米Pd/Fe对水中2,4-D的催化还原脱氯研究 |
| 摘要点击 3231 全文点击 1423 投稿时间：2013-01-28 修订日期：2013-06-14 |
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| 中文关键词 四氧化三铁 稳定化 纳米Pd/Fe 2,4-D 脱氯 |
| 英文关键词 Fe3O4 stabilization nanoscale Pd/Fe 2,4-D dechlorination |
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| 中文摘要 |
| 采用四氧化三铁(Fe3O4)稳定化纳米Pd/Fe催化脱氯水溶液中的2,4-二氯苯氧乙酸(2,4-D),获得了良好的处理效果. 实验考察了Fe3O4投加量、pH、钯化率、温度、搅拌速率等因素对2,4-D去除的影响. 2,4-D去除率随Fe3O4投加量增加而提高,投加量为4.0 g·L-1时,反应210 min后,2,4-D去除率为93.5%,而未稳定的纳米Pd/Fe,去除率为47.3%. 低pH可促进2,4-D还原脱氯,pH为2.6~4.1时,2,4-D在110 min内几乎完全去除. 2,4-D去除率随钯化率增加而提高. 随着钯化率由0.25%、0.50%增加到0.75%,210 min后,2,4-D的去除率也由51.4%、93.5%提高到99.9%. 温度在16.5~30.0℃范围内,反应210 min后,2,4-D去除率均可超过90.0%. 温度升高到35.0、40.0℃时,去除率显著下降. 2,4-D去除率随着搅拌速率加快而提高. Fe3O4的加入可以使纳米Pd/Fe分散和稳定. 此外,Fe0可通过Fe3O4将电子传递给H+和2,4-D,促进2,4-D的还原脱氯. |
| 英文摘要 |
| Fe3O4-stabilized nanoscale Pd/Fe was used to dechlorinate 2,4-D in aqueous solution and achieved high dechlorination efficiency. The Fe3O4 dosage, pH, Pd loading, temperature and stirring rate were important factors for dechlorination of 2,4-D. The removal rate of 2,4-D increased with the increase of Fe3O4 dosage, and it reached 93.5% after 210 min when the Fe3O4 dosage was 4.0 g·L-1 , while only 47.3% 2,4-D was transformed using bare nanoscale Pd/Fe. Low pH enhanced dechlorination and 2,4-D was almost completely dechlorinated within 110 min when the pH ranged from 2.6 to 4.1. The dechlorination efficiency was significantly influenced by Pd loading. After 210 min, the different Pd loading, 0.25%, 0.50% and 0.75%, resulted in 2,4-D reduction efficiency of 51.4%, 93.5% and 99.9%, respectively. The removal rate was higher than 90.0% after 210 min in the temperature range of 16.5℃ to 30.0℃, while it decreased significantly when the temperature rose to 35.0 and 40.0℃. The dechlorination efficiency was improved with the increasing stirring rate. Fe3O4 prevented the aggregation of nanoscale Pd/Fe particles. In addition, Fe3O4 acted as a medium to promote the electron transfer from Fe0 to H+and 2,4-D, and thus enhanced the reductive dechlorination of 2,4-D. |
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