Spatial distribution and multiple sources of heavy metals in the water of Chaohu Lake, Anhui, China

Abstract

In this study, a survey for the spatial distribution of heavy metals in Chaohu Lake of China was conducted. Sixty-two surface water samples were collected from entire lake including three of its main river entrances. This is the first systematic report concerning the content, distribution, and origin of heavy metals (Cu, Cr, Cd, Hg, Zn, and Ni) in the Chaohu Lake water. The results showed that heavy metals (Cu, Cr, Zn, and Ni) concentrations in the estuary of Nanfei River were relatively higher than those in the other areas, while content of Hg is higher in the southeast lake than northwest lake. Moreover, Cd has locally concentration in the surface water from the entire Chaohu Lake. The heavy metal average concentrations, except Hg, were lower than the cutoff values for the first-grade water quality (China Environment Quality Standard) which was set as the highest standard to protect the social nature reserves. The Hg content is between the grades three and four water quality, and other heavy metals contents are higher than background values. The aquatic environment of Chaohu Lake has apparently been contaminated. Both the cluster analysis (CA) and correlation analysis provide information about the origin of heavy metals in the Lake. Our findings indicated that agricultural activities and adjacent plants chimneys may contribute the most to Cd and Hg contamination of Chaohu Lake, respectively.

Heavy metal contamination, sources, and pollution assessment of surface water in the Tianshan Mountains of China

“…When analyzing the background levels of the sampling sites, the water samples that contained heavy metals in PC 1 and PC 3 often occurred in samples from irrigation channels, rivers and lakes near the townships of the central Urumqi-Akesu and the eastern part of the Balikun-Yiwu sections. Previous studies have shown that heavy metals, such as Zn, Hg, and Mn, are often contained in the emissions from urban and industrial areas and activities (Erdem et al 2004;Karbassi et al 2008;Delgado et al 2010;Kurun et al 2010;Li et al 2012). The water samples that contained a high concentration of heavy metals in PC 2 were often taken from the rivers, lakes, and streams in the mountains and wilderness areas contaminated by little human activity.…”

“…Related literatures suggest they are mainly derived from the natural geological background from rock weathering, dry river floods, etc. Thus, under the power of rains and floods, Co, Cr, As, and Ni can be transferred to bodies of water, such as streams, rivers, and lakes (Qi et al 2002;Karbassi et al 2008;Li et al 2008Li et al , 2012Adhikari et al 2009;Zhang et al 2011;Hu et al 2012). …”

“…Heavy metal contamination of the water caused by this increase in human activity has become a major threat to the health of regional ecosystems (Niao et al 1990;Zenk 1996;Klavinš et al 2000;Qi et al 2002;Karbassi et al 2008). At present, heavy metal concentrations in aquatic environments have become a focus of research of the geographical, water, and environmental sciences and are also important indicators for the evaluation of the state of the regional water supply (Karbassi et al 2008;Adhikari et al 2009;Li et al 2012;Zhang et al 2013a, b).…”

“…Currently, a lot of work has been carried out worldwide concerning heavy metal contamination in the aquatic environment using correlation analysis, principal component analysis, and other related methods to reveal the correlation of mass fraction and to distinguish the source of heavy metals in different aquatic environments (Fourest and Volesky 1995;Canli and Atli 2003;Erdem et al 2004;Bradl 2004;Li et al 2012;Hu et al 2012). Many researchers have also combined the multivariate statistical methods and GIS technology to reveal the patterns of different heavy metals in aquatic environments as well as to create spatial distribution maps to analyze their spatial distributions.…”

Trace metal pollution and potential health risk assessment: a case study of Daye Lake over the past ten years (2000-2009)

“…For instance, Zhang et al (2005) found As contents in plant tissues to be 3.5 times higher in the polluted area than the non-polluted area within the study area. The As is mainly from swine factory (Peng et al, 2014), agriculture fertiliser input (Li et al, 2012), or mining industry (Zhang et al, 2005). Similar research shows that As in Daye Lake is mainly from human activities particularly mining industries (Zhang et al, 2006).…”