Abstract

Urban rivers are intensely impacted by pollution with metals resulting from anthropogenic activities, and these elements present in water and sediments can be ecofriendly phytoremediated. This study aimed to evaluate the levels of metals in the sediments and colonizing plants growing in point bars in the channeled bed of the Dilúvio Stream, Southern Brazil. Sediment and plants were sampled at five-point bars with consolidated vegetation. These point bars are formed mainly by sand, with increasing concentrations of clay plus silt, carbon, nitrogen, and metals (Zn, Cu, Cr, Ni, Pb, and Cd) downstream. The concentration of Zn (338 μg/g) and Cu (219 μg/g) in sediments were 1.6 and 1.11 above the probable effect level at the most downstream site. The translocation factor was low in all sites and for all potentially toxic metals evaluated (ranging from 0.01 to 0.63). However, bioaccumulation factor exhibited high values, especially for Cd (average of 2.51), Ni (1.62), Zn (1.49), and Cr (1.25), suggesting that the colonizing plants have more potential for phytostabilization and phytoaccumulation than phytoextraction. These plants can be considered as natural filtering reducing the environmental contamination and the flow of these contaminants in the drainage network.

Statement of novelty: Colonizing plants growing in point bars of urban rivers are common around the world; however, their phytoremediation potential is poorly studied. Colonizing plants may be useful for phytoremediation of water, effluents, and sediments of the Dilúvio Stream (Southern Brazil), polluted by potentially toxic metals that originated from the urbanization.

摘要

城市河流受到人类活动造成的金属污染的严重影响，而这些存在于水和沉积物中的元素可以进行生态友好的植物修复。本研究旨在评估沉积物中的金属含量和生长在巴西南部 Dilúvio 溪流通道床中的点状植物中的定殖植物。沉积物和植物在具有固结植被的五点条上取样。这些点状坝主要由沙子形成，下游的粘土、淤泥、碳、氮和金属（Zn、Cu、Cr、Ni、Pb 和 Cd）的浓度不断增加。沉积物中 Zn (338 μg/g) 和 Cu (219 μg/g) 的浓度分别高于最下游站点的可能影响水平 1.6 和 1.11。所有位点和所有评估的潜在有毒金属的易位因子都很低（范围从 0. 01 至 0.63）。然而，生物累积因子表现出很高的值，尤其是 Cd（平均为 2.51）、Ni（1.62）、Zn（1.49）和 Cr（1.25），这表明定植植物比植物提取具有更大的植物稳定和植物积累潜力。这些植物可以被认为是自然过滤，减少了环境污染和这些污染物在排水网络中的流动。

新颖性声明：在城市河流的点状栅栏上生长的定殖植物在世界各地都很常见；然而，它们的植物修复潜力研究很少。定植植物可能有助于对 Dilúvio Stream（巴西南部）的水、污水和沉积物进行植物修复，这些水、污水和沉积物被源自城市化的潜在有毒金属污染。