Algal Turf Scrubbers

Algal Turf Scrubbers (ATS) are an engineered turf comprising an algal community growing on screens in a shallow basin. Nutrients are removed from the untreated water as it is pumped through the ‘turf’ and the algal community ingests inorganic compounds and, via photosynthesis, releases dissolved oxygen. The ‘treated’ water can then be released back into the water body it was sourced from, resulting in lower nutrient, higher oxygenated waters. In practice, the algae are harvested frequently to remove the nutrients “scrubbed” from the water and to maintain the health and growth of the algal community. ATS biomass production are among the highest of any recorded values for natural or managed ecosystems (Adey & Loveland, 2007). Due to ATS’ extraordinarily fast algae growth rate, it can remove nutrients and produce oxygen at a high rate, and the cost of producing biofuels from the cleaning of wastewaters by ATS can be quite low (R&D to produce ethanol, butanol, and methane is ongoing). ATS design variables include the flow rate of water, the slope of the water basin (i.e., raceway), the loading rate of nutrients in the water, and the type of screen used to grow algae. Here is an example of an Algal Turf Scrubber.