Abstract:
Nuwara Eliya city has been very attractive due to the scenic beauty of Lake Gregory. But
during the last two decades its beauty has lost due to the waste added. Because the/ land use pattem around the lake has changed a lot with the cultivation increased. This was carried out to determine the polluted areas of the stream Talagala Oya and Lake Gregory observing the parameters BOD, COD, PH, TS, TDS, Phosphate concentration and Nitrate concentration.
Here DO and BOD were measured using the Winkler method. COD was measured using the Potassium dichromate titration method and pH was measured using the PH meter. Phosphate concentration and Nitrate concentration were measured using UV Absorption Spectrophotometer. TS, TDS and TSS were measured using the weight difference.
According to the results, The DO level has decreased from upstream to downstream. BOD and COD values have increased from the first points to the middle and have decreased again when going to last points. Here the Nitrate concentration has been more than the phosphate concentration and increases from upstream to downstream. Most of the occasi ons PT J value was in between 5 and 7. It is in the standard range. TS, TSS and TDS values have also increased from first points to the middle and then have decreased when going to the last.
According to the above results, it can be concluded that the lot of waste is added to the lake when going from upstream to the downstream and some places have diluted up to the lake.And the large amounts of acids and bases are also not added. Further it can be concluded that water is not dissolved with much heavy metals and toxicity of cyanides and sulfides is also less. Normally PH becomes to that range due to organic acids produced by decaying of organic matter. It is concluded that the water in those places is more polluted. Therefore the necessary actions should have been taken to stop the ways of adding wastes to the lake and protect it.
