AQUACULTURAL APPLICATIONS OF AN AUTONOMOUS AQUATIC BIOMASS COLLECTOR

This study focused on testing and optimizing design of an autonomous surface vehicle for collection of aquatic biomass, specifically Lemna minor. Such automated vehicles (ASV) were previously constructed to collect biomass from floating aquatic including duckweek (Lemna minor), water hyacinth (Eichhornia crassipes) and similar aquatic species.  The biomass from these plants are of interest for a number of reasons.  

Three focal interests are in play: 1) many plants have useful properties or chemicals such as lipics or carbohydrates; 2) these plants may be invasive species, so finding sustainable ways to manage them is important and 3) these plants (and their harvest) may improve water quality by removing nitrogenous or other undesirable compounds from the water and by producing oxygen in the water column during photosynthesis.

The ASVs (Figure 1) consisted of a dual-pontoon, dual-paddlewheel devices able to operate in shallow water and guided by an onboard computer or microprocessor.  These were powered by solar energy, guided by GPS and capable of collecting biomass while allowing excess water to drain.  With a speed of approximately 3 mph (4.8 km/hr), each ASV could cover 0.5 acres per hour (2000 sq. meters per hour).  

Testing of single and multiple vehicles has shown that, under appropriate circumstances, these vehicles may be able to capture sustainable levels of biomass performing the functions described above.  Latest results will be presented at the conference.