Why algae could be the next secret weapon in combating plastic pollution
The issue also led the United Nations (UN), which is made up of representatives from 173 nations, to adopt a global resolution on plastic waste.
Even if we took all the necessary measures to end plastic production today, there would still be around 5 billion tonnes in landfills and the environment.
Researchers have shown that plastics can be disintegrated into microplastics – small particles with different shapes, densities, and mechanical and chemical properties.
Microplastics are toxic because of their high surface area and small size.
Scientists have looked to nature as a way to fight the plastic crisis for decades. We could avoid future plastic catastrophes if we take global strategic actions to slow plastic production.
Microalgae are, for example, the most promising candidate based on nature, capable of destroying small plastics. It is a single-celled species that can be found in groups or chains. Their size can vary from a few micrometers to hundreds, depending on the species.
Microalgae are easy to grow because they do not require fertile soil or large amounts of freshwater.
Microalgae can also grow rapidly. Open pond culture is one of the oldest and easiest ways to grow microalgae on a large scale. Others use enclosed photobioreactors, which are bioreactors that contain microalgae.
What microalgae are
Microalgae can interact with plastic to alter its properties, such as biodegradation and density. They may also cause it to sink. Microalgae can also adhere to and collect microplastics that are on the surface of microplastics, no matter how small they may be.
There are four phases of biodegradation. The first step is the attachment of microalgae surfaces. The biodegradation begins, and the surface properties are altered.
Second, there is biodeterioration. The microalgae secrete enzymes that are crucial for the biodegradation of plastic.
Biofragmentation is the third step. The plastic material becomes more fragile and loses its mechanical strength.
Assimilation is the last step, in which microbial filaments are introduced into the plastic and the water, resulting in its decomposition by microorganisms.
There have been many studies that report success stories for algae-based biodegradation of plastics, especially for polyethylene (commonly found in clothing fibres or bottles), low-density plastic or LDPE or BPA chemicals (used to harden plastic) and polyethylene. One of these studies calculated a 58.9% reduction of carbon composition for their LDPE samples.
Need for more action
Indonesia is the largest archipelagic nation with a maritime surface of more than 6.4 million square kilometers. It also has extensive freshwater lakes that have a huge potential for microalgae farming.
According to a 2015 study, microalgae may be an effective solution for Indonesia’s plastic pollution problem.
To support this initiative, more research is needed better to understand the interactions between microalgae microplastics and their effects. Studies on microalgae have so far focused on their potential to be a green resource or their capacity to become an alternative material for plastic.
We need to improve plastic recycling and reuse strategies in order to prevent plastic catastrophes. Regulations and policies must be aligned with The 2018-2015 National Action Plan on Marine Debris, which focuses on Indonesia’s waste handling, plastic substitution, redesigning of plastic products and packaging, and doubling the plastic waste collection rate.