Electrolytic Redox and Electrochemical Generated Alkaline Hydrolysis of Hexahydro-1,3,5-trinitro-1,3,5 triazine (RDX) in Sand Columns
Electrolytic Redox and Electrochemical Generated Alkaline Hydrolysis of Hexahydro-1,3,5-trinitro-1,3,5 triazine (RDX) in Sand Columns
复制标题
DOI：
10.1021/es803567s
复制
发表时间：
2009-08-15
影响因子：
11.4
通讯作者：
Alshawabkah, Akram
中科院分区：
文献类型：
--
作者：
Gent, David B.;Wani, Altaf H.;Alshawabkah, Akram
实验室实验中使用砂填充水平流动柱（内径 5 厘米 x 65 厘米）来模拟 RDX 水相分解的原位电解和碱性混合处理区。使用间隔 35 cm 的上升阴极和下降阳极来创建碱性还原条件，然后是含氧、酸性条件，通过碱性水解和直接电解的组合来降解 RDX。采用渗流速度为 30.5 cm/天、电流密度为 9.9 A/m(2) 的初步实验（25 mg/L RDX 进水）来确定处理可行性和 RDX 分解的水产物。在与预柱相同的条件下进行了另外三个柱实验（0.5mg/LRDX 进水），以观察处理过程的重复性和碱处理区的发展。结果表明，在施加的电流密度为 9.9 A/m(2) 的情况下，RDX 在柱中分解了大约 95%。在流出物中检测到含水最终产物甲酸盐、亚硝酸盐和硝酸盐。大约 75% 的 RDX 在阴极附近被破坏（可能是通过电解），其中 23% 在阴极下游通过碱性水解而分解。初步柱伪一级碱性水解速率系数 10.7 x 10(-3) min(-1) 用于估计 RDX 处理的处理区长度小于 100 cm，低于 EPA 饮用水生命周期健康建议 0.002 mg/L。
Sand-packed horizontal flow columns (5 cm i.d. x 65 cm) were used in laboratory experiments to simulate in Situ electrolytic and alkaline hybrid treatment zone for aqueous phase decomposition of RDX. An upgradient cathode and downgradient anode, spaced 35 cm apart were used to create alkaline reducing conditions followed by oxic, acidic conditions to degrade RDX by combination of alkaline hydrolysis and direct electrolysis. A preliminary experiment (25 mg/L RDX influent) with seepage velocity of 30.5 cm/day and current density of 9.9 A/m(2) was used to determine the treatment feasibility and the aqueous products of RDX decomposition. Three additional column experiments (0.5mg/LRDX influent) under the same conditions as the preliminary column were used to observe the treatment process repeatability and the alkaline treatment zone development The results demonstrated approximately 95% decomposition of RDX in the column with an applied current density of 9.9 A/m(2). Aqueous end-products formate, nitrite, and nitrate were detected in the effluent Approximately 75% of the RDX was destroyed near the cathode, presumably by electrolysis, with 23% decomposed downstream of the cathode by alkaline hydrolysis. The preliminary column pseudo first order alkaline hydrolysis rate coefficient of 10.7 x 10(-3) min(-1) was used to estimate a treatment zone length less than 100 cm for RDX treatment below the EPA drinking water lifetime health advisory of 0.002 mg/L.