Towards Sustainable Macroalgae Biorefineries: Experimental Study and Modelling of Ulva Cultivation

Please join us for next Monday departmental seminar on the 8th of November from 15:00 to 16:00 at the Porter Auditorium

 https://tau-ac-il.zoom.us/j/83229921170

Ph.D. Seminar by Meiron Zollmann

Towards Sustainable Macroalgae Biorefineries: Experimental Study and Modelling of Ulva Cultivation

Abstract

Macroalgae biorefineries offer a sustainable alternative source for food, materials and energy, and can alleviate the growing pressure on land and freshwater resources. However, providing a reliable and continuous feedstock supply whilst realizing the potential environmental macroalgae feedstock is still a challenge. This is the focus of this study. Specifically, we look at the green macroalgae Ulva sp., a fast growing, and globally distributed species, which is a potentialbiorefinery feedstock.

We report upon a combination of cultivation experiments and models, resulting in enhanced understanding of the Ulva sp. performance under varying environmental conditions and fertilizing regimes, and in an array of models that can be used to increase the efficiency of Ulva sp. farming. We show that water motion is crucial for high growth rates, and that water aeration/mixing is the top energy consumer of the cultivation process. Fertilization, the second highest energy consumer, is important since it is associated with the environmental and economic damage of coastal eutrophication. We show that fertilizing level, duration, and frequency, affect growth rate, protein content and fertilizing efficiency. Furthermore, we demonstrate the feasibility of Ulva sp. cultivation in low nutrient concentrations, as found offshore the Eastern Mediterranean Sea (EMS) in both deep and surface water. We also demonstrate the feasibility of cultivating Ulva sp. in diluted nitrate-rich desalination brine for nutrient removal purposes.

Finally, we develop and calibrate multiple high-resolution dynamic cultivation models, enabling to simulate biomass production, internal nitrogen content and nitrogen concentration in the environment under various conditions and scales. These models could facilitate improved design, control and management of seaweed farms, with subsequent increased efficiency and improved environmental footprint. Hence, this study lays the foundation for promising precision agriculture applications in the seaweed farming industry, paving the way towards more sustainable and efficient production of food, materials, and energy.