Insight into Global Issues
Context
Explore the issues we are working to solve with microalgae.
Our Wastewater Crisis
Nutrient Runoff
Freshwater accessibility continues to be a major issue in many countries across the world. While there are a number of global initiatives aimed at increasing the freshwater supply, physical scarcity is not the only factor driving our freshwater crisis.
The agricultural industry is a highly water-dependent sector and is considered to be one of the largest consumers of freshwater worldwide. Within the United States alone, agriculture is responsible for 42% of freshwater withdrawals, and 70% of withdrawals worldwide (“Water and Agriculture,” n.d.). Despite this reliance, agriculture continues to be one of the largest water-polluting industries. Every year, farms and settlements dispose of millions of tons of heavy metals, organic matter, and chemicals such as pesticides and herbicides into bodies of water. Agricultural runoff, which occurs when excess fertilizer leaves fields through surface water runoff, also allows phosphates, nitrates, and pathogens to enter our waterways. The contamination of water due to agricultural runoff can have significant impacts not only on human health, but also that of aquatic ecosystems.
For instance, in the midwest, runoff from farms and livestock operations have resulted in nitrogen rich fertilizers entering the Mississippi River and the Gulf of Mexico. The abundance of nitrogen in the water has created dead zones— areas that cannot support life— as a result of uncontrolled algal blooms (“Gulf of Mexico Dead Zone.,” n.d.).
The effects of nutrient runoff can also be seen locally in Davis. The agriculture and livestock industry is very prominent in Davis, as is the use of nitrogen-based fertilizers. For instance, almonds, which require extensive amounts of nitrogen fertilizer, are a very popular crop grown all over California, including in Davis. Barnyard and manure runoff from the dairy industry also contributes significantly to agricultural waste water and nitrogen leaching. Nitrogen leaching is the percolation of nitrates into groundwater which is a very important source of freshwater for consumers and farmers alike. However, the presence of excess nutrients like nitrogen render it unusable (Hadachek, 2020).
Existing Wastewater Treatment
Currently, physiochemical separation is the most commonly relied upon method to filter agricultural waste worldwide. In this process, solid particles are precipitated out of the water and additional chemicals are added to remove any remaining contaminants. However, the process is energy intensive and the requirement for additional chemicals can be polluting. Struvite filtration, which is a type of physiochemical purification, uses magnesium salt to remove excess nutrients. Although magnesium salt is not as polluting, it can be expensive when considered on an industrial scale (Silkina, 2019).
Man-made wetlands can also effectively treat wastewater. Water moves very slowly through wetlands, so as it flows, sediment in the water settles and gets filtered out. Man-made wetlands are also energy efficient and require minimal maintenance and financial investment. However, there are considerable disadvantages to this filtration method. During the treatment process, carbon and nitrogen extracted from the water can react to form methane and nitrous oxide, two harmful greenhouse gasses. Thus, the environmental benefits of this filtration process are canceled out (VanderZaag, 2010).
It is estimated that the overall cost of removing and managing agricultural wastewater in the United States totals $40,000 per cubic million meter of water each day (Silkina, 2019). Thus, alternative bioremediation methods that encourage harvesting agricultural wastewater are likely better candidates.
A Look at the Eyewear Industry
The current eyewear market is very large and still growing. In 2019, an estimated 600 million eyewear frames were sold worldwide, excluding sunglasses. 51% of the revenue from these sales were from plastic frames, indicating that a very high volume of plastic frames were produced and sold. It is predicted that the market for plastic eyewear will only increase as time progresses (Lüdemann, 2020, p. 8).
The vast majority of sustainable options currently available are not entirely biodegradable. For example, Stella McCartney, known to be a very sustainability-focused brand, has a line of “Bio-Acetate” frames, but these are made up of only approximately 50% bio-based materials. (“Watch the new bio-acetate eyewear campaign: Stella McCartney US,” n.d.) Luxottica, one of the largest eyewear manufacturers in the world, has only advertised one bio-based line of eyewear under the brand Arnette, which is also only made from 50% to 70% bio-based materials (Arnette, n.d.). As for independent sustainable brands, many are made of recycled plastics, exemplified by the brand Sea2See, which retrieves plastic from the ocean and recycles it to make their frames (Sea2See, n.d.). One of the leading sustainable brands is Wires Glasses (Lüdmann, 2020, p. 23), which incorporates bioplastics into its frames. Though they may be more sustainable than most glasses available on the market currently, none of these options are completely biodegradable.
It is not acceptable that the vast majority of glasses frames on the market are not biodegradable, because glasses are not something that people tend to keep for their entire lives. As fashion trends evolve, frames get broken or lens prescriptions become outdated, and so people change their lenses or frames about every 1 to 3 years. In a study on eyewear waste management, only 9% of participants recycled their eyewear (Mentzelou et al., 2019, p. 576), resulting in a mass of unused plastic and aluminum frames. Additionally, it is likely that plastic frames will continue to stay in fashion (Lüdemann, 2020), but the materials that are currently being used are not biodegradable. Therefore, there is a need for 100% biodegradable options in the eyewear industry.
