Aerobic Biodegradation of Algae-Derived Bioplastics Under Controlled Composting Conditions

Plastics are versatile polymers that have become critically important materials in many industries. Although plastics are important and useful materials, they account for vast amounts of environmental pollution and climate change contribution. Sustainable bioproducts are becoming increasingly important in the effort to mitigate the impacts of pollution and climate change. The scale of environmental damage caused by plastic pollution highlights the need to implement sustainably sourced biodegradable plastics within the global economy. Bioplastics are materials that may be manufactured from biological materials or can biodegrade under certain conditions. Algae are microorganisms that can be grown using nutrient-rich municipal wastewater; the algae can be used to make bioplastics. Algix, a company based in Meridian, Mississippi, specializes in manufacturing bioplastic products from algae. Algix manufactures bioplastics for many products, including shoes and agricultural mulch films. The Sustainable Waste-to-Bioproducts Engineering Center in Logan, Utah has partnered with Algix and Central Valley Water Reclamation Facility in Salt Lake City, Utah to create a bioplastic using algae grown during a wastewater treatment process. However, Algix has not quantified the biodegradation characteristics of this bioplastic. The purpose of this research is to generate, analyze, and present data concerning the biodegradation of these algae-based bioplastics under composting conditions. In this experiment, bioplastic samples were exposed to a laboratory-scale aerobic composting process for 45 days. The carbon dioxide produced from the biodegradation process was used to measure the biodegradation of the samples. The bioplastic samples were also exposed to industrial-scale aerobic composting conditions for 12 weeks at Central Valley Water Reclamation Facility; in this test, the compost was processed through a sieve to capture remnants of the samples, which were weighed to measure their biodegradation. Under laboratory conditions, approximately 13% of the bioplastic degraded; under industrial-scale conditions, thin-film samples of the plastics completely disintegrated after 12 weeks of aerobic composting. This research will assist in quantifying the biodegradation characteristics of algae-based bioplastics in laboratory-scale and industrial-scale conditions. Furthermore, this research will assist in the integration of renewable and carbon-neutral materials into society.