O_3、O_3/H_2O_2降解TNT的实验研究

On Exploring Better Treatment of 2,4,6-Trinitrotoluene-Polluted Water Using Ozone or Ozone/Hydrogen Peroxide

利用自制装置 ,实验研究了不同反应条件下 ,O3 、O3 /H2 O2 对 TNT的降解规律。结果表明 ,O3 对 TNT具有一定降解功效 ,提高体系的 p H值或添加 H2 O2 均利于 TNT的降解。O3 降解 TNT,可能产生抗氧化性更强的中间产物及其积累 ,而 O3 /H2 O2 作用过程中则没有发生。p H从 1升到 1 2 ,利于 O3 对 TNT降解 ,但超过 1 2时 ,对 O3 作用的影响不再明显 ,p H的最适范围是 1 0～ 1 2 ;O3 /H2 O2作用时 ,1 0为其 p H的临界值 ,当提高或降低 p H都会降低其对 TNT降解能力。维持体系的 p H稳定 ,有利于 O3 降解 TNT,但对 O3 /H2 O2 作用功效的影响不明显。尽管温度对 O3 、O3 /H2 O2 降解 TNT功效的影响较小 ,但温度的提高不利于两者功效的发挥 ,尤其是

Chemical oxidation is one possible option for degradation of 2,4,6-Trinitrotoluene (TNT) in polluted water. We aim to explore both experimentally and theoretically better ways for degrading TNT in polluted water using ozone (O 3) or ozone/hydrogen peroxide (O 3/H 2O 2). In the full paper, we describe and discuss in detail the following topics: (1) experimental method using test set-up developed by us;(2) theoretical analysis of how O 3 or O 3/H 2O 2 degrades TNT in polluted water; (3) test results of degrading TNT using O 3 or O 3/H 2O 2; (4) test results on formation and accumulation of tri-nitro-benzene (except TNT) by-products; (5) the effect of initial pH on degradation efficiency of O 3 or O 3/H 2O 2; (6) test results of the effect of buffer on degradation efficiency of O 3 or O 3/H 2O 2. Here we give only a briefing of our description and discussion. The results show that O 3 has capability to degrade TNT, and can be enhanced by H 2O 2 and pH. During the O 3 process, TNT can not be degraded completely, and tri-nitro-benzene (except TNT) by-products form and accumulate. These by-products form but then disappear without accumulating during O 3/H 2O 2 process. By increasing initial pH from 1 to 12, the efficiency of TNT-degradation by ozone is raised, but over 12, the efficiency begins to fall. For O 3/H 2O 2, its optimum value for initial pH was 10; when pH is below or over 10, its efficiency decreases. Keeping pH steady with buffer helps O 3 but is of no help to O 3/H 2O 2 in degrading TNT. Although beneficial effect of temperature raising is small on the two processes, 40℃ high temperature harms TNT degradation.