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Types of Algae in Wastewater

One method for sanitizing wastewater for reuse is by growing algae in ponds and reservoirs where wastewater is collected. Wastewater, which is liquid waste created by residential and commercial sewage and agricultural and industrial runoff, is typically channeled into these reservoirs. The algae growing there cleans the water so that it may be reused as drinking water. Because algae has the potential to provide biofuel or biodiesel for commercial and private energy needs, some companies use these ponds to grow algae that can both clean wastewater and then be converted to biofuel. There are many types of algae that serve these purposes.

Freshwater Algae
- Many green, freshwater types of algae are grown for wastewater treatment. Botryococcus braunii is just one of the types of freshwater algae that is used in wastewater for both sanitizing and biofuel production. It can coexist with wild algae species, which makes it a durable strain. Botryococcus braunii and other algae strains like it are cited as a low-cost, low-energy option for cleaning sludge from wastewater. Its potential as an energy producer makes it doubly efficient.
Brown Water Algae
- Marine brown water algae are another type of algae used in wastewater treatment. Sargassum is a strain of brown water algae that is particularly effective in removing copper from wastewater. It is, like most types of algae, a low-cost alternative to more expensive sanitizing options. Laminaria japonica is another brown water algae that can not only clean sludge but also has potential as a biofuel.
Red and Green Algae
- Many marine red and green algae have also been used to treat wastewater. Both the red algae Corallina officinalis and green algae Codium fragile are grown to remove traces of nickel and cadmium from wastewater.
Microalgae
- Universities, wastewater treatment plants and biofuel companies are also researching the effectiveness of microalgae species in creating biofuel as they clean and sanitize wastewater. These strains of microalgae breakdown phosphate and nitrate waste and reduce toxins. They are then harvested to create biofuel that could potentially be used to run diesel engines. As with other types of algae, microalgae is a low-cost, low-energy alternative to other biofuel options, such as corn, which produces ethanol.

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