Pilot project with compostable bags for biodegradable waste successfully completed in Bad Dürkheim, Germany
- District of Bad Dürkheim approves the permanent use of organic waste bags made of the plastic Ecovio FS
Outstanding compost quality
Residents and local waste management companies satisfied
Effective immediately, the district of Bad Dürkheim has approved the permanent use of organic waste bags made of BASF’s compostable plastic Ecovio® FS. Residents and local waste management companies tested the bags over a period of three months. As shown by a survey, the residents of Bad Dürkheim are very satisfied with the new waste bags. And the organic composting plant Grünstadt owned by the waste management company GML Abfallwirtschaftsgesellschaft mbH also rated the results of the pilot project very positively. The bags made of Ecovio FS degrade completely and do not impair the quality of the compost. “The decisive factor for us was the high quality of the compost and the fact that the bags make it easier for residents to separate, collect and dispose of organic waste. This is why we have now approved the Ecovio bags for permanent use,” said Erhard Freunscht, first district councilor for the district of Bad Dürkheim.
Thanks to the Ecovio bags, the disposal of biodegradable garbage is cleaner, more hygienic and less complicated than with paper bags or old newspapers. The bags not only prevent noxious odors and keep out insects, but also mean that it is no longer necessary to wash and clean the container in which the organic waste is collected.
“In 2009, we already demonstrated that the bags degrade in the Grünstadt organic composting plant in a joint project with the environmental services company Veolia Umweltservice West GmbH and the waste management company GML Abfallwirtschaftsgesellschaft, said Jürgen Keck, head of BASF’s global business with biodegradable plastics. “In the latest three-month project, we wanted to find out whether the residents are satisfied with the Ecovio bags. It was also important for us to ensure that the very high quality of the compost in the Bad Dürkheim district is retained when the residents use the Ecovio bags,” explained Jens Hamprecht, responsible for global strategy and innovation management in BASF’s specialty plastics business unit.
At the beginning of the project in early April, the approximately 65,000 households in the district each received 10 bags made of the compostable plastic Ecovio FS. The residents were encouraged to collect their organic garbage in the bags and to dispose of them via the organic waste bin. The independent consulting company IBK-Solutions monitored the pilot project and analyzed the compost at the Grünstadt organic composting plant. In addition, the residents were surveyed about their use of the bags.
Unchanged compost quality
The analysis shows that the biodegradable organic waste bags did not have a detrimental effect on the quality of the compost. The plastic degraded completely. The organic waste bags made of Ecovio FS did not affect the composition of the compost: the density, content of water and salt, pH value, nutrients, percentage of organic matter and other components in the compost all remained unchanged. The appearance of the compost did not change either. These are important critieria because the organic composting plant sells the humus to customers such as winegrowers, fruit farmers and asparagus growers who use it to improve the soil. “Already after three weeks, no residues of the Ecovio film were found any longer in the compost. Moreover, there was no need to change the method normally used at the Grünstadt organic composting plant,” said Frank Schwarz of Veolia Umweltservice. Georg Kosak of IBK-Solutions stated: “Our analyses have demonstrated that Ecovio bags can be used to collect organic waste in the district of Bad Dürkheim without any problems and that this can be implemented in other collection regions and applied to other composting methods after a case-by-case examination.”
The survey revealed that almost 90 percent of the residents were satisfied with the Ecovio bags. More than half of the respondents said that the bags are very helpful for collecting organic garbage. Residents were particularly appreciative of the fact that it was easier to collect organic waste without soggy bags or foul odors. The analysis conducted by IBK-Solutions showed that the filled bags can be stored for at least two weeks without any liquid seeping through. As for the future, residents of the districts expressed a wish for bags in various sizes as well as carrying and closing systems. Additional points of sale were also requested. These suggestions are being studied by the bag manufacturer Weltplast as they introduce the bags on a permanent basis. The compostable Ecovio bags that are familiar to the residents through the pilot project will continue to be available for purchase from various points of sale throughout the district.
A crucial benefit for waste recovery is that the disposal companies do not need to laboriously segregate the organic bags. The bags are converted along with the organic waste into valuable compost, carbon dioxide and water. They help residents in their effort to collect organic waste. Moreover, if more composting is carried out over a larger region, this will reduce the amount of organic waste that ends up in residual waste.
The rate of incorrect disposal, in other words the percentage of unwanted conventional plastics in the organic waste, did not change as a result of the use of the biodegradable plastic bags. During the test, the compost did not contain a larger number of bags made of conventional, non-biodegradable plastics.
Biodegradable plastics: Ecovio and Ecoflex
The biodegradable plastic Ecovio FS is a new BASF development. This material is made of the partially bio-based plastic (polyester) Ecoflex® FS and PLA (polylactic acid), which is obtained from corn starch. Thanks to this combination, the bags used in the Bad Dürkheim pilot project contain more than 50 percent renewable raw materials. Like the biodegradable waste itself, Ecovio is broken down by microorganisms with the aid of enzymes. This degradation process depends only on the structure of the molecules, not on the origin of the raw materials. At the end of the composting process, the microorganisms have completely converted the bags into carbon dioxide, water and biomass.