Chemometric application in identifying sources of organic contaminants in Langat river basin

Abstract

Increasing urbanization and changes in land use in Langat river basin lead to adverse impacts on the environment compartment. One of the major challenges is in identifying sources of organic contaminants. This study presented the application of selected chemometric techniques: cluster analysis (CA), discriminant analysis (DA), and principal component analysis (PCA) to classify the pollution sources in Langat river basin based on the analysis of water and sediment samples collected from 24 stations, monitored for 14 organic contaminants from polycyclic aromatic hydrocarbons (PAHs), sterols, and pesticides groups. The CA and DA enabled to group 24 monitoring sites into three groups of pollution source (industry and urban socioeconomic, agricultural activity, and urban/domestic sewage) with five major discriminating variables: naphthalene, pyrene, benzo[a]pyrene, coprostanol, and cholesterol. PCA analysis, applied to water data sets, resulted in four latent factors explaining 79.0% of the total variance while sediment samples gave five latent factors with 77.6% explained variance. The varifactors (VFs) obtained from PCA indicated that sterols (coprostanol, cholesterol, stigmasterol, β-sitosterol, and stigmastanol) are strongly correlated to domestic and urban sewage, PAHs (naphthalene, acenaphthene, pyrene, benzo[a]anthracene, and benzo[a]pyrene) from industrial and urban activities and chlorpyrifos correlated to samples nearby agricultural sites. The results demonstrated that chemometric techniques can be used for rapid assessment of water and sediment contaminations.

Spatio-Temporal Variations and Source Apportionment of Water Pollution in Danjiangkou Reservoir Basin, Central China

“…DA is a method to conform the groups found by CA and determines the most significant water quality variables. In this analysis, three different modes of DA, i.e., standard, forward stepwise and backward stepwise, were applied to evaluate both the spatial and temporal variations in water quality [32]. PCA is a powerful pattern recognition method, making use of a small set of independent variables to describe the variance of a relatively large dataset [33].…”

Chemometric Analysis of Selected Organic Contaminants in Surface Water of Langat River Basin

“…Cluster 2, formed by monitoring site (1L09) represents high contamination site located near the city and industrial area. This site is situated in a tributary of Batang Nilai, which carries high pollution flowing through the industrial areas [4]. Cluster 3 represents low contamination sites consisted of three monitoring sites (1L06, 1L07 and 1L08).…”

“…In order to reveal relevant patterns and sources of variation in these large environmental datasets, chemometric analysis has been proposed [2,4]. Massart et al [3] defined chemometrics as a chemical discipline that uses mathematics, statistics and formal logic to design or select optimal experimental procedures; to provide maximum relevant chemical data and to obtain knowledge about chemical systems.…”

“…Many studies have used chemometric techniques to identify the sources and distribution of organic (such as PAHs and sterols) or inorganic (such as heavy metal) contaminantions in environmental compartments such as water, air and sediment [4][5][6][7][8]. The application of chemometric techniques would be helpful in the interpretation of complex datasets and gives a better understanding into the sources of contamination.…”

“…The application of chemometric techniques would be helpful in the interpretation of complex datasets and gives a better understanding into the sources of contamination. Previous study by Osman et al [4] reported the application of this techniques provide a more objective interpretation of the results and able to apply organic contaminants as a chemical markers. Thirteen organic contaminants were analyzed which include polycyclic aromatic hydrocarbons (PAHs), sterols, pesticide (chlorpyrifos) and phenol to evaluate as they are potential chemical marker in the Langat River Basin.…”