Biodegradables do more harm than good in landfillsPosted on June 20, 2011 by DrRossH in Plastic Waste News
Reply by Dr RossH
While the comments made in the above link are true with respect to biodegradable plastics biodegrading down and releasing methane or CO2 we ought to consider the larger picture.
At the present time we are headed down a road of substantial plastic waste. We manufactured more plastic in the last 10 years than the previous century. What is it all used for? Mostly in the use of single use disposable plastic items. We are in love with convenience for the now and not spending any thought about tomorrow. The manufacture of plastic items is unregulated so manufacturers will keep on making more and more as long as it is profitable for them. The rest of us must suffer the consequence of this proliferation of plastic. This is filling up our landfills, and making a lot of plastic litter. Sure some of it gets recycled but eventually it will all get discarded and the most common method is to a landfill. Therefore if we can make it biodegrade over time (the time frame I propose is, within our generation or 20 years) then we are not carrying our trash forwards for future generations to deal with. (This is not talking about compostable plastics, as compostable plastics are not worth the effort due to lack of facilities for consumers and no special pickups available for compostable plastic items).
The FTC say the public perception of the time frame for a biodegradable item is 12 months. Therefore they are pushing this short time frame on manufacturers of biodegradable items for them to claim biodegradability. For biodegradation in a landfill this is unrealistic and if enforced would result in no biodegradable plastics being manufactured and our land and landfills full of worthless plastic trash.
However if we do make landfillable biodegradable plastics, and harness the methane coming off as an energy source then that provides two large advantages. The first is that we would be getting rid of all this plastic trash and the second is that the methane provides a clean source of energy that has less carbon emissions per unit of energy than other fuels like coal or diesel. Plus we import less foreign oil which has to be a very good factor. The Altamont facility in California is an example of this. They run all their garbage collection trucks on their own methane so they are not buying fuel from outside the plant.
Within a landfill it has been shown that recycling the leachate will significantly enhance the biodegradation rate. This allows us to have some control as to when the biogas will come off the landfill and to get the biogas out in more commercial quantities. Hence if biodegradable plastics with a longer biodegradation time frame than 12 months can be sanctioned, then that would allow full set up of landfills for energy production and little to no biogas escaping to the atmosphere. Both are desirable.
Therefore in summary, having landfill biodegradable plastics is the right way to go for all of our futures.