Algae can also act as a sink for carbon dioxide
because they absorb it for photosynthesis. At present
algal biofuel production has not been commercialized
due to high costs associated with production,
harvesting, and preparation for biodiesel. Harvesting
cost is one of the major limitations on viability of this
technology. Algae harvesting in wastewater may be a
significant advance towards reduction in constraints
on economic viability. Utilizing harmful nutrients
(primarily nitrogen and phosphorus) as a food source,
algae hold promise of being able to accomplish
nutrient removal with a net energy savings to water
treatment system.