Yoon Jong Moon, Van Aken Benoit, Schnoor Jerald L
Department of Civil and Environmental Engineering, The University of Iowa, Iowa City, Iowa 52242, USA.
Int J Phytoremediation. 2006;8(1):81-94. doi: 10.1080/15226510500507128.
The uptake and fate of 2,4,6-trinitrotoluene (TNT), hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) by hybrid poplars in hydroponic systems were compared and exposed leaves were leached with water to simulate potential exposure pathways from groundwater in the field. TNT was removed from solution more quickly than nitramine explosives. Most of radioactivity remained in root tissues for 14C-TNT, but in leaves for 14C-RDX and 14C-HMX. Radiolabel recovery for TNT and HMX was over 94%, but that of RDX decreased over time, suggesting a loss of volatile products. A considerable fraction (45.5%) of radioactivity taken up by whole plants exposed to 14C-HMX was released into deionized water, mostly as parent compound after 5 d of leaching. About a quarter (24.0%) and 1.2% were leached for RDX and TNT, respectively, mostly as transformed products. Leached radioactivity from roots was insignificant in all cases (< 2%). This is the first report in which small amounts of transformation products of RDX leach from dried leaves following uptake by poplars. Such behavior for HMX was reported earlier and is reconfirmed here. All three compounds differ substantially in their fate and transport during the leaching process.
比较了杂交杨树在水培系统中对2,4,6-三硝基甲苯（TNT）、六氢-1,3,5-三硝基-1,3,5-三嗪（RDX）和八氢-1,3,5,7-四硝基-1,3,5,7-四氮杂环辛烷（HMX）的吸收和归宿，并用水淋洗暴露的叶片以模拟田间地下水中潜在的暴露途径。TNT从溶液中去除的速度比硝胺炸药更快。14C-TNT的大部分放射性保留在根组织中，但14C-RDX和14C-HMX的放射性则保留在叶片中。TNT和HMX的放射性标记回收率超过94%，但RDX的回收率随时间下降，表明有挥发性产物损失。暴露于14C-HMX的整株植物吸收的放射性中有相当一部分（45.5%）在淋洗5天后释放到去离子水中，大部分为母体化合物。RDX和TNT分别有大约四分之一（24.0%）和1.2%被淋洗出来，大部分为转化产物。在所有情况下，从根部淋洗出的放射性都微不足道（<2%）。这是首次报道杨树吸收RDX后，干燥叶片中有少量转化产物被淋洗出来。HMX的这种行为此前已有报道，在此再次得到证实。在淋洗过程中，这三种化合物在归宿和运输方面有很大差异。
