Removal of iron and manganese from drinking water supply

The water treatment plant at the Hingna industrial area receives raw water from Ambazari Lake and supplies drinking water to industrial area, after conventional treatment. The treated water was found to have a pungent odour and yellow colour, which in turn changed from a brown to black precipitate. The water becomes aesthetically unacceptable to consumers. It was observed that a blackish precipitate formation was due to the presence of iron and manganese in lake water, which was not completely removed during treatment. To remove iron and manganese from drinking water, treatment studies were carried out with chlorine and KMnO4 as oxidants. Alum and lime were added for coagulation and pH correction. Jar test studies revealed that treatment with potassium permanganate at pH 7.7-8.0 was effective in the removal of iron, manganese and organics, which were responsible for causing colour and odour to water. The studies helped in improvements in water quality for safe drinking water supply.