Advanced Sensor Technology for Algal Biotechnology (ASTAB) is an integrated package of water quality and algal physiology sensors designed to enable algae growers to increase significantly productivity and efficiency of their operations, optimize harvesting periods, and avoid losses of “batches” of algae through nutrient deficiencies and/or population shifts. This sensor technology is expected to increase process automation and performance in large-scale algal production facilities.
ASTAB is a neutrally buoyant instrument package (e.g., a sphere) that travels around algal growth systems (e.g. photobioreators, raceways, ponds, bags, and tubes) with water flow. The parameters to be sensed and included in the package cover physical, chemical, and biological areas. Position information, and data on physical and biological parameters in the raceway or pond, is transmitted via a wireless network. Wireless connectivity allows for accurate position reporting, which will enable the creation of 3D maps and detect “dead spots.”
The data are used to control local automatic devices to make appropriate changes to water quality (e.g. nutrient additions, pH controls). The package will determine a suite of important water quality attributes using conventional techniques, while simultaneously determining the photo-physiological state of the algae using PAM (pulse amplitude modulation) fluorometry. PAM fluorometry is an optical technique that provides an immediate assessment of the photosynthetic efficiency (e.g., conversion of light into chemical energy) of algae, or the “health” of the algae. Additionally, the system features solar power, and anti-fouling and/or self-cleaning technologies.
This work was done by Brad Bebout of Ames Research Center.