A Model to Predict Turbidity Levels of Water in Kelani River, Sri Lanka and to Determine the Required Alum Dosage For Settling Suspended Solids

Thoshini Yasanthika Jayaweera


Water turbidity or the murkiness of water caused by suspended solids (SS) is the most common issue related to water sources in Sri Lanka. Murkiness of water is usually treated with alum (Aluminium sulphate). Jar test is used to select the optimum dose of alum, and there is no automated system for dosage calculation.

For the present study, data was collected from the water treatment plant in Biyagama, the right bank water treatment plant of Kelani river. We constructed statistical models for predicting the turbidity levels in Kelani river. Using these models we calculated the required alum dosage for settling SS in raw water. All predictors were significant for these models. We created an efficient and user-friendly automated computer program to calculate the optimum alum dosage.


Water Turbidity, Kelani River, Biyagama Water Treatment Plant, Multiple linear regression model, Excel VBA userform

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