Multivariate analysis of physico-chemical and microbial parameters of surface water in Kelani river basin

Abstract

Water is essential for the survival of all known forms of life, and there is no substitute for water. Surfacewater pollution may occur in various types such as catchment characteristics, anthropological activities,land use practices and industrial discharges. Such polluting agents may affect physical, chemical andbiological parameters of water. The kelani river is 144 km long and drains an area of 2,230 km2 covers sixdistricts from nallathanniya (nuwara-eliya) to mattakkuliya (colombo). The present study was focused toanalyze the present status of surface water quality in the kelani river basin by means of physico-chemical andmicrobiological parameters using the standard analytical and microbial methods. Heavy metals weredetected using aas. Twenty seven surface water samples were collected from head, transitional andmeandering zones for a period of six months from october 2012 to march 2013. Ph values of most of thesamples of the transitional zone were deviated from the sls drinking water standards and ph of the head andmeandering zones were remained within the sls standards (5.41-8.85). 90% of the samples showed high codvalues (10.33-322.58 ppm) which were exeeded the sls drinking water standards. Bod values in kelani riverbasin ranged between 0.27-10.67 ppm while the conductivity, tds and hardness were within the rangedbetween 9.23-25200.00 μs/cm, 5.91-16381.00 ppm, 2.00-401.33 ppm. Acceptable concentrations ofphosphate and nitrate were detected range between 0.006-0.303 ppm and 0.09-10.42 ppm respectively.Among the sampling locations 80% sampling points in the head and transitional zones and 90% locations inthe meandering zone of the river basin was contaminated with total coliform and feacal coliform bacteria.The cd, al, zn, pb, cr, cu concentrations in surface water was ranged between 0.1183-0.775 ppb, 13.94-255.86 ppb, 1.059-31.44 ppb, 0.078-5.34 ppb, 0.00156-3.50 ppb and 3.11-14.44 ppb respectively. Pcaanalysis showed differentiations between three regions as the pc1 score into one-way anova test did not showsignificant difference between head and transitional regions while the meandering zone showed significantdifference. Factor analysis showed six factors were according to their correlation.

KEYWORDS: Kelani river basin, Surface water, Physico-chemical and microbiological parameters, Heavymetals, PCA and Factor analysis