Biopolymeric materials subjected to a degradation process, respectively in sea and sand, have shown degradation times comparable to those of non-bio materials. The experiment involved scholars from the National Research Council, the National Institute of Geophysics and Volcanology and the Ligurian Technology District.
If dispersed into the environment, bioplastics also have very long degradation times, comparable to those of non-bio plastic materials. This is demonstrated by the results of an innovative experiment conducted jointly by the National Research Council - involved with the Institute for Chemical-Physical Processes (Cnr-Ipcf) and the Institute of Marine Sciences (Cnr-Ismar), the National Institute of Geophysics and volcanology (INGV) and the Ligurian District for marine technologies (DLTM), with the support of the State Police - La Spezia Nautical and Divers Center (CNeS).
The study, published in the open access journal Polymers, concerned the long-term behavior of different types of virgin plastic granules (resin pellets) used to make commonly used objects.
Two of the most used polymers in plastic objects -HDPE and PP- and two biodegradable plastic polymers -PLA and PBAT- were compared, verifying the degree of aging and degradation respectively in sea water and sand: in both environments, in the space of six months of observation, neither the traditional nor the bio polymers showed any significant degradation. The observation of the samples, together with the outcome of chemical, spectroscopic and thermal analyzes conducted at the Pisan laboratory of the Cnr-Ipfc, coordinated by the researcher Simona Bronco, shows that in the natural environment bioplastics have much longer degradation times compared to those that occur under conditions of industrial composting.
"Given the very high diffusion of these materials, it is important to be aware of the environmental risks that the use of bioplastics poses, if dispersed or not appropriately conferred for disposal: it is necessary to inform correctly", explains the researcher Silvia Merlino of the Cnr-Ismar of Lerici (La Spezia), coordinator of the project.
“This study highlights the importance of correct information regarding biodegradable plastic, especially after the stop to disposable plastic in force in Italy since January 2021 in implementation of the European directive 'Single use plastic', which led to the progressive marketing of disposable products in biodegradable plastic, such as the polymers examined", adds Marina Locritani, INGV researcher and co-coordinator of the study.
The experiment, to date the first of this type carried out entirely in situ, used for the experimental set up the multi-parameter environmental monitoring platform "Lab Mare Coast Station" located at a depth of 10 meters in the Bay of Santa Teresa in the Gulf of Spezia, built as part of the Ligurian District Sea Laboratory project for marine technologies (co-financing by the Liguria Region, PAR-FSC 2007-2013 resources "Fund for development and cohesion"), in which the Marine Hydrographic Institute also collaborates and Aeneas. Here, thanks also to the support of the nautical and diving center of La Spezia and the La Spezia mussel farmers' cooperative, special "cages" designed to contain the plastic samples have been housed; a tank containing sand was also set up, exposed to the elements to simulate the surface of a beach. The experiment is still ongoing and will end in 2023.
Further experiments will concern the study of degradation processes in conditions of greater depth, thanks to the installation of further cages containing plastics and bioplastics in the "Deep Station of the Lab Mare" at a depth of about 400 meters, also in Ligurian waters. Furthermore, in collaboration with the Experimental Zooprophylactic Institute of Piedmont, Liguria and Valle d'Aosta (IZTO), a further study is already underway which provides for the comparative analysis of the state of degradation of the resin pellets in the sea and the presence of chemicals (PAH, PCB, pesticides) dissolved therein and absorbed by them, as well as the comparison with the retention processes of contaminants by mussels, historically considered the "sentinels" of pollution.
If dispersed into the environment, bioplastics also have very long degradation times, comparable to those of non-bio plastic materials. This is demonstrated by the results of an innovative experiment conducted jointly by the National Research Council - involved with the Institute for Chemical-Physical Processes (Cnr-Ipcf) and the Institute of Marine Sciences (Cnr-Ismar), the National Institute of Geophysics and volcanology (INGV) and the Ligurian District for marine technologies (DLTM), with the support of the State Police - La Spezia Nautical and Divers Center (CNeS).
The study, published in the open access journal Polymers, concerned the long-term behavior of different types of virgin plastic granules (resin pellets) used to make commonly used objects.
Two of the most used polymers in plastic objects -HDPE and PP- and two biodegradable plastic polymers -PLA and PBAT- were compared, verifying the degree of aging and degradation respectively in sea water and sand: in both environments, in the space of six months of observation, neither the traditional nor the bio polymers showed any significant degradation. The observation of the samples, together with the outcome of chemical, spectroscopic and thermal analyzes conducted at the Pisan laboratory of the Cnr-Ipfc, coordinated by the researcher Simona Bronco, shows that in the natural environment bioplastics have much longer degradation times compared to those that occur under conditions of industrial composting.
"Given the very high diffusion of these materials, it is important to be aware of the environmental risks that the use of bioplastics poses, if dispersed or not appropriately conferred for disposal: it is necessary to inform correctly", explains the researcher Silvia Merlino of the Cnr-Ismar of Lerici (La Spezia), coordinator of the project.
“This study highlights the importance of correct information regarding biodegradable plastic, especially after the stop to disposable plastic in force in Italy since January 2021 in implementation of the European directive 'Single use plastic', which led to the progressive marketing of disposable products in biodegradable plastic, such as the polymers examined", adds Marina Locritani, INGV researcher and co-coordinator of the study.
The experiment, to date the first of this type carried out entirely in situ, used for the experimental set up the multi-parameter environmental monitoring platform "Lab Mare Coast Station" located at a depth of 10 meters in the Bay of Santa Teresa in the Gulf of Spezia, built as part of the Ligurian District Sea Laboratory project for marine technologies (co-financing by the Liguria Region, PAR-FSC 2007-2013 resources "Fund for development and cohesion"), in which the Marine Hydrographic Institute also collaborates and Aeneas. Here, thanks also to the support of the nautical and diving center of La Spezia and the La Spezia mussel farmers' cooperative, special "cages" designed to contain the plastic samples have been housed; a tank containing sand was also set up, exposed to the elements to simulate the surface of a beach. The experiment is still ongoing and will end in 2023.
Further experiments will concern the study of degradation processes in conditions of greater depth, thanks to the installation of further cages containing plastics and bioplastics in the "Deep Station of the Lab Mare" at a depth of about 400 meters, also in Ligurian waters. Furthermore, in collaboration with the Experimental Zooprophylactic Institute of Piedmont, Liguria and Valle d'Aosta (IZTO), a further study is already underway which provides for the comparative analysis of the state of degradation of the resin pellets in the sea and the presence of chemicals (PAH, PCB, pesticides) dissolved therein and absorbed by them, as well as the comparison with the retention processes of contaminants by mussels, historically considered the "sentinels" of pollution.
Photos: The Bay of Santa Teresa - Gulf of La Spezia
