WATER QUALITY ASSESSMENT OF KAYAMKULAM LAKE, KERALA, INDIA

The present investigation was carried out in Kayamkulam Lake near National Thermal Power Corporation (NTPC) industrial area, Alappuzha district, Kerala, India, with regard to various Physico -chemical parameters like surface water Temperature, pH, Total Alkalinity (TA), CO2, Dissolved oxygen(DO), Chloride, Total Hardness (TH), Calcium, Phosphate, Sulphate, Nitrate Biochemical Oxygen Demand(BOD), Chemical Oxygen Demand (COD), Silicate and heavy metals viz., Iron, Lead, Zinc, Cadmium and Copper. Monthly variations in physico- chemical parameters were recorded. Surface water Temperature varied from 29.6 to 37ºC, the pH values decreased up to 6.3 and it reached below the permissible limit at site II. The Total Alkalinity of lake water ranged from 20 to160 mg/l and it reached beyond the permissible limit of 120 mg/l. The DO falls up much lower than the desirable limit at site II. The average value of BOD reached beyond the permissible limit at site II . The chloride concentration varied from 47 to1127 mg/l and concentration reaches beyond the permissible limit. The TH of the lake water ranged from 26 to1112 mg/l. Sulphate concentration of the lake water lie within the permissible limit. Heavy metal analysis revealed that sites II and III are much polluted than site I .Results of the study showed that the lake water is not suitable for irrigation and domestic purpose without proper treatment. The results are discussed in the text.