THE INFLUENCE OF PH AND COARSE MEDIA ON MANGANESE PRECIPITATION FROM WATER

This technical note represents the initial results of a research project investigating manganese removal from water by filtration through low cost coarse media which may be suitable for rural water treatment in developing countries. A manganese solution of 1 mg/l was shaken with limestone, gravel, crushed brick or with no solid media at various pH values. At a final pH value of 8.5, limestone gave 95% removal of manganese, crushed brick gave 82% removal, gravel gave about 60% removal and the removal for aeration and settlement with no solid media was less than 15%. The results indicate that rough solid media and the presence of carbonate are beneficial in the precipitation of manganese in water.