Home » Tutorials » Plastic Biodegradation in Landfills

Plastic Biodegradation in Landfills

by Galen Killam

 

Plastic is going into landfills in enormous amounts. There are many possible long-term solutions to this problem: some people advocate recycling, while others believe that using plastics that can be composted is the only sound environmental solution. These ideas are important to pursue, but they do not deal realistically with the immediate problem of waste disposal. Millions of tons of plastic waste are carted off to landfills each year, and remain there for an indefinite period of time. We need to find a solution that deals with this reality as it is today, not how we hope it will be in 10-15 years. We need a realistic solution that can be implemented right now, that will make the plastic that is going to the landfills disappear.

The Facts:

20-25% of landfill weight is plastics. Landfills are most common way to dispose of Municipal Solid Waste (MSW) in the US, with an overall increase in MSW consistent with increases in the population.

Plastics made up only 1% of MSW in 1960. This has increased to 12% (30 million tons) in 2008. 43% of this is containers and packaging, 22% is nondurable goods, and 35% is from durable goods. This means that 11.3 million tons of just containers and packaging end up in landfills each year.

Most people agree that recycling is a preferred method of dealing with plastics. However, only 24% of municipal waste is recycled and 9% is composted, for a total of only 33% of waste that is recovered.

What about plastics in particular? Only 7% of plastics that are disposed of are recovered, compared to 55% of paper board. Only 37% of PET soft drink bottles are recycled, and only 28% of HDPE milk containers and large water bottles are recovered. All in all, plastic bottles alone account for about half of the material that appears in dumps that could have been recycled.

Where does waste end up?

Getting people to change their behavior is hard. What we need is a solution that deals with the plastic that ends up in land-fills, instead of simply hoping for a solution that will stop people from throwing away plastic.

What if all of this plastic that goes to landfills could simply disappear? Better yet, what if what was left behind could fuel homes, schools, businesses and industrial compounds?

Can plastic biodegrade in a landfill?

There are a number of plastic products already out there on the market that have passed the ASTM D5511 test for biodegradability. These products range from water bottles to garbage bags to amenities, and are made from traditional plastics in traditional plastics-processing plants. In order to become biodegradable, they use an additive (EcoPure) that is added to the material during the normal manufacturing process. The additive does not affect the strength or clarity of the products. If the product was recyclable to begin with, it remains so. But if placed in a landfill, the product will biodegrade.

What happens when things biodegrade in a landfill?Municipal solid waste contains at least 20% moisture, which is barely enough to react with biomass.Modern landfills use leachate recirculation and bioreactors to incorporate liquid management and pumping systems that maintain higher moisture content.Bioreactor landfills use other liquids to achieve closer to 40% moisture, which is enough for anaerobic bacteria to thrive.One side-effect of this, of course, is the production of “landfill gases”: carbon dioxide and methane.All modern landfills are required to install and operate landfill gas collection and control systems.

Is composting better?

Contrary to popular understanding, compost sites also generate methane. Only in very few cases where the compost sites have adequate controls in place to collect and filter the volatile organic compounds (VOCs) and methane that is generated, would composting be an equivalent or perhaps a better option to landfilling. If the landfill converts the methane to energy, then landfilling will be a better option. Less than 10% of compost sites have adequate controls in place because these controls are so expensive to implement.

It is actually better for the environment to focus on recovering energy from biological material than to try to stabilize organic products.Another concern to think about is emissions during the transportation of waste: since there are far fewer composting sites compared then landfills, the transportation distances are longer.Finally, according to the National Resource Defense Council (NRDC) and earth911.org, only 8% of Americans compost their waste, including residents in cities like San Francisco and Seattle where composting is part of the general waste pickup.Products that incorporate compostable packaging have grown very slowly and have had mixed reviews, and customers are often confused about what to do with compostable materials when they are ready to dispose of them.

Sustainability is good business

93% of CEOs say sustainability is critical to success. Companies with a vision and sustainable solutions achieve above average financial performance. Unlike other sectors of the packaging industry, sustainable packaging has showed growth over the past two years, bucking the economic downturn. Greater awareness about environmental concerns, government initiatives, growing economies, and burgeoning population are identified as the drivers behind this growth. More and more, companies are using sustainable packaging as a marketing tool.

Landfill Gas

Conclusion

The United States is a leader in both the manufacturing and the consumption of plastics. Unfortunately much of this plastic is not recycled and ends up in landfills for indefinite periods of time. There is a solution. EcoPure additive renders plastic biodegradable in a landfill with ASTM D5511 testing to back up the claims. EcoLogic, the company who distributes the product, has aligned itself with the EPA’s Methane to Markets program to encourage landfill gases be recaptured and converted to energy. At the same time, the company encourages source reduction and recycling, both of which will reduce the amount of plastic going into landfills.

Sincerely,

Galen Killam
Director of Business Development
Ecologic, LLC
145 West Wisconsin Ave, Suite F
Neenah, WI 54956

References:

Andersen, J., A. Boldrin, J. Samuelsson, T. H. Christensen, and C. Scheutz, 2010. Quantification of Greenhouse Gas Emissions from Windrow Composting of Garden Waste. J. Environ. Qual., 39:713-724 (2010).

Arsova, L., R. van Haaen, N. Goldstein, S.M. Kaufman, and N. Themelis, 2008. The State of Garbage in America, 16th Nationwide Survey of MSW Management in the U.S., BioCycle, December 2008.

Jackel, U., K., Thummes, P., and Kampfer, 2005. Thermophilic Methane Production and Oxidation in Compost. FEMS Microbiology Ecology 52, 175-184.

SCAQMD, 2001. Ammonia and Volatile Organic Compound (VOC) Emissions from a Greenwaste Composting Operation. Source Test Report 01-171, Conducted at Inland Empire Composting, 1951 W. Key St., Colton, CA 92324. Sept. 27 & Oct. 4, 2001.

Sullivan, P., The Importance of Landfill Gas Capture and Utilization in the U.S., Biocycle Magazine, Earth Engineering Center, Columbia University, April 6, 2010.

Themelis, N., Ulloa, P., 2006, Methane Generation In Landfills, Earth Engineering Center & Deptarment of Earth & Environmental Engineering, Columbia University, August 2, 2006.


Leave a Reply