As much as we bemoan how plastics have taken over our lives, the truth is that modern societies depend on them for much of their commercial output. Plastics can do marvelous things. They only have two problems — most are derived from petroleum and they take a few hundred years to decompose.
Researchers have been trying for decades to make plastics from plant-based materials. Hydrocarbons are hydrocarbons after all, and don’t much care whether they come from fossil fuels or vegetable matter. But plants require arable land and fresh water to grow — two commodities that are in short supply in many parts of the world. It hardly makes any sense to chop down the Amazon rain forest to grow crops to make biodegradable plastics, does it?
Researchers at Tel Aviv University say they have the solution — a polymer derived from microorganisms that feed on seaweed. The process produces no toxic waste. Better still, the resulting plastic is biodegradable and creates nothing but organic waste when recycled, according to a report in Science Daily.
The polymer was developed jointly by professor Alexander Golberg of the School of Environmental and Earth Sciences and professor Michael Gozin of the School of Chemistry. Their research appears in the January edition of the journal Bioresource Technology.
“Plastics take hundreds of years to decay. So bottles, packaging and bags create plastic ‘continents’ in the oceans, endanger animals and pollute the environment,” says Dr. Golberg. “Plastic is also produced from petroleum products, which has an industrial process that releases chemical contaminants as a byproduct.
“A partial solution to the plastic epidemic is bioplastics, which don’t use petroleum and degrade quickly. But bioplastics also have an environmental price — to grow the plants or the bacteria to make the plastic requires fertile soil and fresh water which many countries, including Israel, don’t have. Our new process produces ‘plastic’ from marine microorganisms that completely recycle into organic waste.”
The two researchers have learned how to harness microorganisms that feed on seaweed to produce a bioplastic polymer called polyhydroxyalkanoate (PHA). “Our raw material was multi-cellular seaweed, cultivated in the sea. These algae were eaten by single celled microorganisms, which also grow in very salty water and produce a polymer that can be used to make bioplastic,” professor Goldberg says.
“There are already factories that produce this type of bioplastic in commercial quantities, but they use plants that require agricultural land and fresh water. The process we propose will enable countries with a shortage of fresh water, such as Israel, China and India, to switch from petroleum-derived plastics to biodegradable plastics.”
The pair will now focus on moving their discovery out of the lab and into commercial use. “Plastic from fossil sources is one of the most polluting factors in the oceans,” Goldberg says. “We have proved it is possible to produce bioplastic completely based on marine resources in a process that is friendly both to the environment and to its residents. We are now conducting basic research to find the best bacteria and algae that would be most suitable for producing polymers for bioplastics with different properties.”
Is this discovery as significant to a sustainable environment as a Tesla automobile or cheap electrical grid storage? Actually, if you consider how plastics have wormed their way into every aspect of human existence and the harm they cause to the environment — particularly the oceans — it could easily overshadow both of them. The scourge of plastics is a symbol of how humanity has turned the Earth into a cesspool. Bioplastics could begin to reverse that trend.
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