Heavy Metal Accumulation in Common Aquatic Plants in Rivers and Lakes in the Taihu Basin.

Li Bai,Jian Hu,Xiao-Long Liu,Cong-Qiang Liu,Si-Liang Li,Guilin Han,Zhong-Liang Wang,Jun Li

doi:10.3390/ijerph15122857

Abstract

We investigated the concentrations of 10 heavy metals in Potamogeton malaianus, Nymphoides peltata, Eichhornia crassipes, and Hydrilla verticillata to evaluate their potential to bioaccumulate heavy metals and related influencing factors in Taihu Lake. Enrichment factor (EF) values of Cu, Cr, Mn, Ni, Zn, Co, Pb, and V were above 2.0, indicating moderate to significant contamination in sediment. Most of Ti, V, Cr, Mn, and Ni in P. malaianus, E. crassipes, and H. verticillata and V in N. peltata were within excess/toxic level in plants, but higher than normal level. Even though no aquatic plants in this study were identified as a hyperaccumulator, relatively higher concentrations in aquatic plants were found in Taihu Lake than have been found in other previous studies. Heavy metal in submerged plants, especially in their stems, seemed to be more closely related to metals in water and sediment than those in floating-leaf plants. Ratios of metals in stem versus leaves in all plants ranged from 0.2 to 25.8, indicating various accumulation capabilities of plant organs. These findings contribute to the application of submerged aquatic plants to heavy metal removal from moderately contaminated lakes.

Highlights

Heavy metals in aquatic environments, such as lakes and rivers, have been studied extensively because of their toxicity, persistence, and tendency to bioaccumulate
Most of the heavy metal concentrations in sediment were higher than background values in local soils, except Ti and Fe
Enrichment factor (EF) values in the sediment indicated that most of the heavy metal concentrations, except Fe and Ti, were represented moderate to significant contamination levels resulting from human activities in the regional lakes and rivers

Summary

Introduction

Heavy metals in aquatic environments, such as lakes and rivers, have been studied extensively because of their toxicity, persistence, and tendency to bioaccumulate. Latifolia) [3], and submerged plants such as Hydrilla verticillata [4,5], Ceratophyllum demersum [5], and Potamogeton malaianus [6] have significant capacities to accumulate heavy metals. Because of their capacity to accumulate heavy metals, several species of aquatic macrophytes such as H. verticillata and water hyacinth have been used to remove heavy metals from waste water.

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