08. Aug 2018
Study finds Danimer PHA will biodegrade reliably in aerobic or anaerobic environments
Danimer Scientific, a Georgia, USA-based developer and manufacturer of biodegradable plastic products, today announced that its polyhydroxyalkanoate (PHA) material has been recognized as an eco-friendly alternative to petrochemical plastics by University of Georgia (UGA) researchers and members of the UGA New Materials Institute.
The study, published in Environmental Science & Technology, found that PHA effectively biodegrades in aerobic or anaerobic environments, such as a landfill, waste treatment facility or the ocean.
“The results of this study indicate that PHA is a dependable and biodegradable plastic for food packaging and other consumer applications,” said Scott Tuten, chief marketing officer at Danimer. “Many single-use products, such as straws, are under scrutiny or even banned because of their environmental impact at the end of their lifecycle. Our team remains dedicated to helping companies find the quality, sustainable materials that fit their needs. This issue quite literally affects the entire world, so we were grateful for the opportunity to supply UGA with samples of PHA to explore what happens to the material in different environments.”
To determine how PHA biodegrades in a proper waste management scenario, researchers measured the gaseous carbon loss of PHA samples placed in anaerobic sludge after 40 – 60 days of incubation and compared the levels to those of cellulose powder in the same setting. The anaerobic degradation of PHA was not significantly different from that of the cellulose powder. In addition, the methane yields of PHA were found to be similar to food waste, which suggests the material could be effectively processed alongside common organic waste in a landfill.
“As governments and businesses consider alternatives to traditional plastics for everything from straws to food packaging, it is important to have a thorough understanding of the impact that different materials will have on various environments,” said Shunli Wang, Ph.D., postdoctoral research associate in the College of Engineering at UGA. “Our study is among the first to comprehensively examine PHA, and results show that it has a relatively fast anaerobic biodegradation rate.”
Researchers also observed the gaseous carbon loss of PHA in seawater, simulating a situation when plastic waste is deposited in an ocean. The study confirmed that if a solid form of PHA were to end up in such an environment it would begin to biodegrade over the course of six months. Polypropylene pellets, a traditional plastic used as the negative control in the experiment, remained intact and unchanged during the same time period.
The final component of the study investigated the microbial diversity of both experiments to identify the bacteria present when PHA degrades. In anaerobic sludge conditions, Cloacamonales and Thermotogales were the dominant bacteria. In aerobic seawater conditions, Gemmatales and Phycisphaerales were the most enriched forms of bacteria. Researchers concluded that future studies would have to include expanded microbial analysis of PHA degradation, which will ultimately help guide the design of more efficient waste management systems.
The full paper summarizing the study is available on the Environmental Science & Technology website at: https://pubs.acs.org/doi/10.1021/acs.est.7b06688.