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

Water is essential for the survival of all known forms of life, and there is no substitute for water. Surface water 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 and biological parameters of water. The kelani river is 144 km long and drains an area of 2,230 km2 covers six districts from nallathanniya (nuwara-eliya) to mattakkuliya (colombo). The present study was focused to analyze the present status of surface water quality in the kelani river basin by means of physico-chemical and microbiological parameters using the standard analytical and microbial methods. Heavy metals were detected using aas. Twenty seven surface water samples were collected from head, transitional and meandering zones for a period of six months from october 2012 to march 2013. Ph values of most of the samples of the transitional zone were deviated from the sls drinking water standards and ph of the head and meandering zones were remained within the sls standards (5.41-8.85). 90% of the samples showed high cod values (10.33-322.58 ppm) which were exeeded the sls drinking water standards. Bod values in kelani river basin ranged between 0.27-10.67 ppm while the conductivity, tds and hardness were within the ranged between 9.23-25200.00 μs/cm, 5.91-16381.00 ppm, 2.00-401.33 ppm. Acceptable concentrations of phosphate 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 in the 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. Pca analysis showed differentiations between three regions as the pc1 score into one-way anova test did not show significant difference between head and transitional regions while the meandering zone showed significant difference. Factor analysis showed six factors were according to their correlation.