Quantification of foaming behaviour using foam index

The factors influencing foam index were identified and their effects on foam index were investigated. It was noted that increasing the diameter of the flotation cell led to an increase in foam index. The maximum foam index was found to occur at a constant air/solids ratio when MLSS was varied with time of aeration or airflow. A good degree of correlation was also obtained between filament count and foam index. A small concentration of Surfactants was sufficient to induce foaming. However, further increase in surfactants showed relatively little influence on Foam Index.