Abstract

Water contamination by hexavalent chromium(Cr) is an emerging issue. The removal of Cr(VI) using phytoremediation via different macrophytes was investigated in this study. To reduce Cr(VI) to the permissible level in irrigation water, the ability of four common macrophytes, viz. Pistia stratiotes (PS), Salvinia minima (SM), Ipomoea aquatica (IA) and Eichhornia crassipes (EC), to remove from 0.5 to 2.0 mg Cr(VI)/L was analyzed. The overall growth of PS was enhanced by 11 to 24%, SM by 36 to 53%, EC by 65 to 101% and IA by 4 to 13% by reducing Cr from 48 to 87% within 29 days of the experiment. In successive experiments, chromium uptake by SM surpassed ∼11.86-, ∼17.17- and ∼94-fold that of PS, EC and IA, respectively, after 15 days of growth in 0.35 to 1.75 mg Cr(VI)/L. The bioconcentration factor of SM surpassed that of PS, IA and EC by 0.64 to 1.73, 1.09 to 4.07 and 0.71 to 1.85 times, while PS exceeded IA and EC by1.71 to 2.35 and 1.07 to 1.11 times, respectively. SM was thus shown to offer efficient removal of Cr(VI), from a level ≅2.0 mg/L, while a suitable combination of SM and PS was efficient at ≤1.0 mg/L.

Novelty It unravels the appropriate macrophytes in terms of biomass production and Cr- uptake pattern under natural condition for phytoremediation of aqueous Cr(VI) and in turn offer services to clean the environment.

摘要

六价铬 (Cr) 对水的污染是一个新出现的问题。本研究研究了通过不同大型植物使用植物修复去除 Cr(VI)。为了将灌溉水中的 Cr(VI) 降低到允许的水平，四种常见大型植物的能力，即。Pistia stratiotes (PS) 、Salvinia minima (SM) 、Ipomoea Aquatica (IA) 和Eichhornia crassipes(EC)，从 0.5 到 2.0 毫克 Cr(VI)/L 被分析。在实验的 29 天内，通过将 Cr 从 48% 降低到 87%，PS 的整体生长提高了 11% 到 24%，SM 增加了 36% 到 53%，EC 增加了 65% 到 101%，IA 增加了 4% 到 13%。在连续的实验中，在 0.35 至 1.75 mg Cr(VI)/L 生长 15 天后，SM 对铬的吸收分别超过 PS、EC 和 IA 的~11.86-、~17.17- 和~94-倍。SM的生物富集因子分别超过PS、IA和EC的0.64-1.73、1.09-4.07和0.71-1.85倍，而PS分别超过IA和EC的1.71-2.35和1.07-1.11倍。因此，SM 被证明可以有效去除 Cr(VI)，从 ≅2.0 mg/L 的水平开始，而 SM 和 PS 的合适组合在≤1.0 mg/L 时是有效的。

新颖性在自然条件下，根据生物量生产和 Cr 吸收模式，解开适当的大型植物，以对水性 Cr(VI) 进行植物修复，进而提供清洁环境的服务。