Abstract：
The efficiency in Cr (III) and Cr (VI) removal by Floating Treatment Wetlands (FTWs) vegetated with Canna indica, metal accumulation in sediment and plants were determined. Plant tolerance and its morphological response to metal were studied. Treatments were 5 and 10 mg L-1 of Cr(III) (5Cr(III) and 10Cr(III), respectively), and 5 and 10 mg L-1 of Cr(VI) (5Cr(VI) and 10Cr(VI), respectively), with and without FTWs, and a biological control (BC: with FTW without Cr addition). After 35 days, Total-Cr removals in treatments with FTW were 99.6 %, 96.9 %, 96.9 % and 81.7 % in 5Cr(III), 10Cr(III), 5Cr(VI) and 10Cr(VI), respectively. In Cr (III) treatments, the sediment from the reactors without FTW accumulated significantly more metal than the sediments with FTW, while the opposite occurred in the Cr(VI) treatments. Chromium in sediment was accumulated mainly bound to organic matter in all treatments (38-64 %). Roots of C. indica were the main Cr accumulator organ in all treatments (76-88 %). In 10Cr(VI) treatment, Cr was translocated to aerial parts resulting in a decrease in plant biomass and Chlorophyll a concentration. C. indica modified its internal and external root morphology as a mechanism to tolerate Cr toxicity, without affecting removal efficiencies. FTWs vegetated with C. indica were efficient in the remediation of water bodies contaminated with Cr. In addition, these systems have an aesthetic value because they use an ornamental species.
摘要：
漂浮处理湿地（FTWs）对Cr（III）和Cr（VI）的去除效率，确定了沉积物和植物中的金属积累。研究了植物的耐性及其对金属的形态响应。处理为5和10mgL-1的Cr（III）（5Cr（III）和10Cr（III），分别)，以及5和10mgL-1的Cr（VI）（5Cr（VI）和10Cr（VI），分别)，有和没有FTW，和生物对照(BC:具有不添加Cr的FTW)。35天后,FTW处理中的总Cr去除率为99.6％，96.9%,5Cr（III）中的96.9%和81.7%，10Cr(III),5Cr（VI）和10Cr（VI），分别。在Cr(III)处理中，来自没有FTW的反应堆的沉积物比具有FTW的沉积物积累了更多的金属，而Cr（VI）处理则相反。在所有处理中，沉积物中的铬主要与有机物结合积累（38-64％）。在所有处理中，in菜的根是主要的Cr积累器官（76-88％）。在10Cr(VI)处理中，Cr转移到地上部分，导致植物生物量和叶绿素a浓度降低。C.indica修饰了其内部和外部根部形态，作为耐受Cr毒性的机制，不影响去除效率。种植C.in的FTW在修复受Cr污染的水体方面是有效的。此外,这些系统具有美学价值，因为它们使用装饰性物种。
