Estimation of Source of Heavy Metal Contamination in Sediments of Gomti River (India) using Principal Component Analysis

Abstract

This study explores the extent and possible sources of heavy metal (Cd, Cr, Cu, Fe, Mn, Pb, Zn and Ni) contamination in the bed sediments of the Gomti River performing principal component analysis on the five years (Jan. 1994-Dec. 1998) data set obtained through continuous monitoring of the river water and bed sediments at eight selected sites and water/wastewater of its tributaries/drains. Influence of anthropogenic activities on metal contamination of the bed sediments was evaluated through computing the geoaccumulation index for various metals at studied sites. PCA performed on combined (river bed sediment, water, suspended solids, water/wastewater from tributaries/drains) data set extracted two significant factors explaining more than 58% of total variance. Factor loadings suggested the presence of both natural as well as anthropogenic sources for all these metals in the river bed sediments. Among all the sites, the sites 4 and 5 are more contaminated with Cd, Cu, Cr and Pb, which was supported by the geoaccumulation indices computed for metals. Factor scores revealed presence of seasonal (monsoon-related) differences in metals profiles for river water and suspended solids and absence of seasonal differences for bed sediment and wastewater. Further, the metal contamination of the bed sediment was also evaluated using biological thresholds. Results suggested that the river bed sediments are contaminated with heavy metals, which may contribute to sediment toxicity to the freshwater ecosystem of the Gomti River.

Occurrence, risk assessment, and source apportionment of heavy metals in surface sediments from Khanpur Lake, Pakistan

“…The PCA was performed using varimax normalized rotation on the dataset, and the CA was applied to the standardized matrix of the samples using Ward's method, and the results are reported in the form of dendrograms. PCA and CA complement each other and have been widely used in environmental studies (Gielar et al 2012;Iqbal and Shah 2011;Shah et al 2012;Singh et al 2005).…”

“…Sediments are ecologically sensitive components of the aquatic ecosystems and are also a reservoir of the contaminants, which take part considerably in maintaining the trophic status for any water reservoir (Singh et al 2005). Depending upon the physicochemical conditions, sediments can act both as source and sink for nutrients and heavy metals.…”

Pre and post-monsoon seasonal variation of some heavy metal pollution in sediments of River Gomti in the Vicinity of Lucknow City, India

“…Singh et al, (2005) and Gaur et. al, (2005) also resulted in their study that the Gomti river sediments are in unpolluted from the Fe, Cu, Cd, Mn were in case of other metal Pb its recorded partially to moderate polluted.…”

“…It was noted that the site Sitapur over bridge is least polluted in all the season in all the three years (Table 1-6). Singh et al, (2005) (Table 5), maximum value of Cu was observed at site Dilkusha rail over bridge, whereas in post-monsoon season it was found high at site Dilkusha 32.11 µg g -1 and range was observed between 32.11 13.94 µg g -1 (Table 6). By comparing the guideline for contaminated fresh water sediments (US EPA, 1977) its concluded that site Hanuman setu, Laxaman mela park, Saheed park and Dilkusha were found moderate polluted at most of the sampling time while in term of As and Fe it was found low polluted to unpolluted.…”

Spatial distribution and source identification of heavy metal pollution in roadside surface soil: a study of Dhaka Aricha highway, Bangladesh

“…PCA of the normalized variables was performed to extract significant PCs and to further reduce the contribution of variables with minor significance; these PCs were subjected to varimax rotation with Kaiser Normalization generating VFs (Brumelis et al 2000;Singh et al 2004Singh et al , 2005aLove et al 2004;Abdul-Wahab et al 2005). The factor analysis can be shown by the following equation:…”