The Bioeconomy & Circular Economy in Southern Arizona: Case Studies

This section of the study, presented as case studies, identifies and explores research and innovative efforts to grow the bioeconomy and circular bioeconomy in Southern Arizona. These case studies help to highlight efforts that are taking place at the intersection of the bioeconomy and circular economy.

The Circular Economy As The Intersection of Bioeconomy and Circular Activities

The Circular Economy as the Intersection of Bioeconomy and Circular Activities

A key theme amongst nearly all case studies is water. In the arid environment of Southern Arizona, it is no surprise that most of the case studies below are in some way tied to water. Several case studies focus on innovative techniques, new technologies, or novel approaches to reduce both land and water requirements for agricultural production, many of which take place in controlled environment agricultural (CEA) systems (Case Studies 6.3, 6.4, 6.5, 6.6, and 6.7). In fact, many of the case studies employ vertical farming techniques with applications in different settings such as urban and peri-urban environments (Case Study 6.3) and underground (Case Study 6.6). Another case study explores the potential for shifting toward low-water-use, drought-tolerant crops that can be used to produce biobased industrial products (Case Study 6.1). Yet another case study (Case Study 6.2) illustrates how local organic material waste can be converted into useful properties to improve soil water and nutrient retention, increase yields, and potentially reduce land and water requirements to sustain crop production.

In many of the case studies, circularity is introduced into the bioeconomy through the use of waste and/or byproducts for productive uses. In Case Study 6.1, the residues generated through rubber production from guayule can be converted into value-added products such as biofuel and materials for making adhesives. In Case Study 6.5, the waste from aquaponics systems (otherwise known as sludge) could potentially make an effective, organic soil amendment, reducing fertilizer and water requirements for crops. In Case Study 6.2, biochar is produced using organic material waste, which is diverted away from landfills.

Another key theme is harnessing biological processes and utilizing technological advancements and specialized equipment to produce useful bioproducts, some of which are created through waste streams (Case Study 6.5, 6.8, 6.9). Case Study 6.8 highlights advancements that have been made to facilitate scaled-up cultivation of microalgae, which can generate high-value bioproducts such as proteins for human consumption, animal feed, nutraceuticals (e.g., omega-3 fatty acids), lipids for biofuels, cosmetic ingredients, and vitamins, among others. Case Study 6.9 illustrates how biological processes can be used to treat wastewater more effectively by removing contaminants of emerging concern. Not only does harnessing the power of plant processes do a more effective job, but it also addresses the concern of waste associated with treated wastewater. The processes proposed here result in valuable plant byproducts that can be used to make fibers, concrete, and myriad other industrial products.

While some of the case studies rely on technological advancements and patented and patent-pending applications, others achieve more efficient resource use by doing things in new and novel ways. For example, Case Study 6.4 illustrates that electrical energy demand for cooling and dehumidification can be reduced in a CEA system by integrating the production of mushrooms into a leafy greens CEA system. This is due to the high C02 emissions from the mushrooms, and the CO2 requirements of leafy greens.

Finally, at the pinnacle of circularity, Case Studies 6.6 and 6.7 explore food production in one of the most resource-scarce environments- in space. Missions to the moon and other planets require sustainable life support systems, including Bioregenerative Life Support Systems (BLSS) that encompass food production by way of engineered controlled environments. In these fully closed systems, 100% of irrigation water and plant nutrients are recycled. The crops produced serve as food for astronauts, and crop production itself can play key roles in air regeneration and water purification, and reuse. Case Study 6.7 illustrates a BLSS through a prototype lunar greenhouse (LGH) while Case Study 6.6 uses underground vertical farming technology.