Abstract

SEASONA INFLUENCE ON PHYSICOCHEMICAL PARAMETERS OF YELAHANKA LAKE WATER OF BANGALORE

Narayanaswamy.S.Y.*, Ramachandra Mohan. M.

ABSTRACT

Water quality is a term used here to express the suitability of water to sustain various Uses or processes. The physical and Chemical characteristics of water at Yelahanka lake in Bangalore during the year May 2007-May 2008 have been studied on the concentrations of Toxic substances for drinking water use, or restrictions on temperature and pH ranges for Water supporting invertebrate communities. The pH value of Yelahanka Lake recorded 7.0-8.2; the pH was found above 7.0 in all the lakes making them alkaline. The alkalinity value of Yelahanka Lake ranges from 8.2 NTU – 10.7 NTU. Conductivity is good and rapid measure of the solids recorded ranges from 838μmhos/cm - 1213 μmhos/cm, the values observed in Yelahanka lake values are very much higher than the prescribed standards limits (1400 μmhos/cm) recommended by W.H.O. Conductivity increases with increasing amount and mobility of ions and also can be used an indicator of water pollution.Dissolve oxygen values ranges from 4.0 mg/l – 7.8 mg/l. Salinity is the saltiness or salt dissolved salt content of water body. The iron rangesfrom 0.5 mg/l – 1.8 mg/l, in water it occurs mainly in the divalent or bivalent state (ferrous and ferric). Iron is the surface water is present in the form of ferric state. The fluoride ranges from 0.23 mg/l- 0.63 mg/l, Fluoride in water derives mainly from dissolution of natural minerals in the rocks and soils with which water interacts. The most common fluorine – bearing minerals are lourie, apatite and micas. Fluoride problems therefore tend to occur where the element is most abundant in the host rocks. The changes of the physico-chemical characterstics of lake water due to the runoff water from surrounding agrictural fields and concentration of chemical constituents is partially dried up aquatic environment. Thesvalues for different parameters evaluated fall for below the acceptable limits in the lake studied necessary to drink water after treatment, boiling and filtrations.

Keywords: Fluoride, water, pH.