Pollution characteristics and possible sources of seldom monitored trace elements in surface sediments collected from Three Gorges Reservoir, China.

Bo Gao,Huaidong Zhou,Xiaohong Wan,Xin Wei,Hong Hao,Jin Lu

doi:10.1155/2014/170639

Abstract

A geochemical study of Three Gorges Reservoir (TGR) sediments was carried out to analyze the concentrations, distribution, accumulation, and potential sources of the seldom monitored trace elements (SMTEs). The mean concentrations of Li, B, Be, Bi, V, Co, Ga, Sn, Sb, and Tl were 47.08, 2.47, 59.15, 0.50, 119.20, 17.83, 30.31, 3.25, 4.14, and 0.58 mg/kg, respectively. The concentrations of total SMTEs, together with their spatial distribution, showed that the SMTEs were mainly due to anthropogenic inputs in the region of TGR. The assessment by Geoaccumulation Index indicates that Tl, Be, V, Co, and Fe are at the unpolluted level; Bi, Li, Ga, and Sn were at the “uncontaminated to moderately contaminated” level. However, B was classified as “moderately contaminated” level and Sb was ranked as “strongly contaminated” level. The pollution level of the SMTEs is Sb > B > Bi > Li > Ga > Sn > Tl > Be > V > Co > Fe. The results of Correlation Analysis and Principal Component Analysis indicated Be, V, Co, Ga, Sn, Tl, Bi, and Fe in sediments have a natural source. B and Li were positively correlated with each other and mainly attributed into similar anthropogenic input. In addition, Sb has less relationship with other SMTEs, indicating that Sb has another kind of anthropogenic source.

Highlights

River sediment is both the source and sink of the heavy metals in water environment
The concentrations, accumulation, spatial distributions, sources, and ecological assessment of heavy metal pollution resulting from commonly monitored trace elements (i.e., As, Cd, Cr, Cu, Pb, and Hg) in river sediments have been deeply investigated [2, 3]
Our results showed that higher concentrations of Sb and Sn were frequently detected in the downstream of Three Gorges Reservoir (TGR) (Figure 3)

Summary

Introduction

River sediment is both the source and sink of the heavy metals in water environment. It is one of the most important media in water environment to assess the contamination level of aquatic ecosystems [1]. The concentrations, accumulation, spatial distributions, sources, and ecological assessment of heavy metal pollution resulting from commonly monitored trace elements (i.e., As, Cd, Cr, Cu, Pb, and Hg) in river sediments have been deeply investigated [2, 3]. The knowledge of the concentrations, distributions, and enrichment of SMTEs in sediments plays a key role in tracing SMTEs sources and assessing the potential ecological risks of SMTEs in aquatic systems [7, 11]

Objectives

Methods

Results

Conclusion