Factor analysis of water quality characteristics including trace metal speciation in the coastal environmental system of Chennai Ennore

Abstract

Statistical analysis of water quality parameters including trace metal speciation was undertaken with a view to seeing the interrelationship between different variables and also to identify probable source components in order to explain the pollution status of Chennai Ennore coastal environmental system. Factor analysis has been used in the present work. This is essentially a data reduction technique and will suggest how many variates are important to explain the observed variances in the data. The possible variances in the water quality parameters may be due to either sources of anthropogenic origin or natural variances due to the season or due to different biogeochemical processes that are taking place in the system. When this analysis was carried out with our data on water quality parameters in the above coastal environmental system, we found that the prominent factor or the first factor called the eutrophication factor explained 24.51% of the total variance (comprised of variables like DO, pH, SS, ammonia-N, phosphate and silicate). The second factor called the copper contamination factor explained 10.61% (comprised of variables like labile Cu, total Cu and particulate Cu) and the third factor called metal removal factor explained 10.11% (comprised of variables like particulate Zn, particulate Pb and water temperature) of the variances, respectively. Although there are four more factors, they are all having variances less than 10%. From this study, it is seen that eutrophication is the main source component of pollution to the surface waters of this estuary and its adjacent coastal waters compared to dissolved trace metals.