| 土壤中硝酸盐在非均匀电动力学作用下的迁移与转化 |
| 摘要点击 2220 全文点击 2232 投稿时间：2003-03-26 修订日期：2003-06-30 |
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| 中文关键词 非均匀电动力学 硝酸盐 电迁移 转化 土壤 |
| 英文关键词 non uniform electrokinetics nitrate movement transformation soil |
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| 中文摘要 |
| 以传统的均匀电动力学方法为对照,研究了用非均匀电动力学方法控制土壤中硝酸盐迁移的可行性.结果表明:在外加电压梯度为1.0 V/cm时,受试土壤中NO3-在非均电动力学作用下的电迁移速率为13.5～20.0cm/d,并且迁移速率大小与NO3-浓度和场强分布有关;与均匀电动力学相比,非均电动力学方法更有利于土壤中NO3-向阳极区迁移,而且该方法对土壤性质影响更小,电能消耗更低;切换非均电动力学极性能促使土壤中NO3-转化为NO2-,并进一步降低系统的能耗,但不利于土壤中NO3-相对富集.
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| 英文摘要 |
| Movement and accumulation of nitrate in soil and groundwater has become a serious threat in many cities and agricultural areas. At the same time, application of nitrate as bacterial nitrogenous nutrient in the in situ bioremediation of some organics polluted sites is often required. Laboratory experiments were conducted to examine the feasibility of using non uniform electrokinetics (NUEK) to control the movement of nitrate in unsaturated soil water system. A natural soil taken from woodland was used as experimental soil. Three electrokinetic processes were tested in bench scale cells at a constant potential gradient of 1.0 V/cm: unidirectional NUEK, NUEK with periodic polarity reversal, and conventional uniform electrokinetic (UEK). The tests showed that NUEK drove NO3- through the experimental soil at a rate of 13.5～20cm/d depending upon the concentration of NO3- and the distribution of electric field density. Compared with UEK, NUEK process more effectively concentrated and retained NO3- close to the anode. Moreover, NUEK process maintained soil characteristics and consumed much less electric energy. Reversal the polarity of NUEK weakened the concentration of NO3- to electrodes, but it stimulated the transformation of NO3- to NO2- and further lowered the electric energy consumption. |
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