that by adding 2-octane to foamed wastewater, 94% of ABS could be removed from the activated sludge through using foam separation techniques. The foam produced during wastewater treatment can either be recycled back into the activated sludge tank within a waste treatment plant, the bacterial organisms that live there have been found to break down ABS when allowed enough time, or extracted and collapsed for disposal. Foam separation has also been found to decrease the chemical oxygen demand when used as secondary treatment technique for wastewater. Heavy metal removal The removal of heavy metal ions from wastewater is important because they accumulate easily in the food chain, ending in animals such as swordfish that humans eat. Foam separation can be used to remove heavy metal ions from wastewater at low costs, especially when used in multistage systems. When performing ion foam separation there are three operational conditions that must be met for optimal production of foam for ion removal: foam formation, flooding, and weeping/dumping. Protein extraction Foam separation can be used for the extraction of proteins from a solution especially to concentrate the protein from a dilute solution. When purifying proteins from solution on an industrial scale, the most cost efficient method is desired. As such, foam separation offers a method with low capital and maintenance costs due to the simple mechanical design; this design also allows for easy operation. However, there are two reasons why using foam separation to extract protein from solution has not been widespread: firstly some proteins denature when going through the foaming process and secondly, control and prediction of foaming is typically difficult to calculate. In order to determine the success of protein extraction through foaming three calculations are used. The Enrichment ratio demonstrates how effective the foaming is in extracting the protein from the solution into the foam, the higher the number the better the affinity the protein has for the foam state. The Separation ratio is similar to the enrichment ratio in that the more effective the extraction of protein from the solution into the foam, the higher the number will be. Recovery is how efficiently the protein is removed from the solution into the foam state, the higher the percentage, the better the process is at recovering protein from solute into the foam state. Foam hydrodynamics as well as many of the variables that affect the success of foaming have limited understanding.