Department of Civil and Environmental Engineering, Washington State University, Pullman, WA 99164-2910, United States.
J Contam Hydrol. 2011 Sep 25;126(1-2):1-7. doi: 10.1016/j.jconhyd.2011.05.008. Epub 2011 Jun 7.
Rapid hydrogen peroxide decomposition is the primary limitation of catalyzed H(2)O(2) propagations in situ chemical oxidation (CHP ISCO) remediation of the subsurface. Two stabilizers of hydrogen peroxide, citrate and phytate, were investigated for their effectiveness in one-dimensional columns of iron oxide-coated and manganese oxide-coated sand. Hydrogen peroxide (5%) with and without 25 mM citrate or phytate was applied to the columns and samples were collected at 8 ports spaced 13 cm apart. Citrate was not an effective stabilizer for hydrogen peroxide in iron-coated sand; however, phytate was highly effective, increasing hydrogen peroxide residuals two orders of magnitude over unstabilized hydrogen peroxide. Both citrate and phytate were effective stabilizers for manganese-coated sand, increasing hydrogen peroxide residuals by four-fold over unstabilized hydrogen peroxide. Phytate and citrate did not degrade and were not retarded in the sand columns; furthermore, the addition of the stabilizers increased column flow rates relative to unstabilized columns. These results demonstrate that citrate and phytate are effective stabilizers of hydrogen peroxide under the dynamic conditions of one-dimensional columns, and suggest that citrate and phytate can be added to hydrogen peroxide before injection to the subsurface as an effective means for increasing the radius of influence of CHP ISCO.
过氧化氢的快速分解是原位化学氧化（ISCO）修复地下水中过氧化氢催化自传播的主要限制因素。本文研究了两种过氧化氢稳定剂——柠檬酸盐和植酸盐，以评估它们在氧化铁和氧化锰涂覆砂的一维柱中的有效性。将 5%的过氧化氢（含或不含 25 mM 的柠檬酸盐或植酸盐）施加到柱上，并在 8 个间隔 13 厘米的端口处收集样品。柠檬酸盐不是铁涂覆砂中过氧化氢的有效稳定剂；然而，植酸盐的效果非常显著，使过氧化氢的残留量比未稳定的过氧化氢增加了两个数量级。柠檬酸盐和植酸盐都是锰涂覆砂的有效稳定剂，使过氧化氢的残留量比未稳定的过氧化氢增加了四倍。植酸盐和柠檬酸盐在砂柱中没有降解和被阻滞；此外，添加稳定剂相对于未稳定的柱子增加了柱的流速。这些结果表明，在一维柱的动态条件下，柠檬酸盐和植酸盐是过氧化氢的有效稳定剂，并表明在将过氧化氢注入地下之前，可以将柠檬酸盐和植酸盐添加到过氧化氢中，作为增加 CHP ISCO 影响半径的有效手段。
