| Food: the next frontier in recycling | |
 We all try to do our bit by recycling our cans, glass bottles, cardboard etc and throw everything else away to go to landfill thinking we have done a good job. Now however there is a whole new way of recycling household waste, namely left over food.
In America, namely Minnesota, Duluth, more is being done to help slow down global warming than the usual recycling. The face of composting is changing, now it can and will include left over food, used tissues and much much more.
The Sanitary District in Duluth is now composting all these kitchen left overs by piling them all up into 50 foot long piles that are now called “windrows”. (So called because they look like large rows of hay.) Once erected an electric pump is located at one end of the windrows to blow air through it, this is done to keep a good supply of oxygen for the microorganisms as it is critical in the digestion process. A long thermometer is located in the depths of the pile to monitor the temperature which was observed to be reading 143 Fahrenheit, perfect for the environment needed for composting. The windrows are mostly made up of food waste from hospitals, colleges and restaurants that are delivered daily and leaves and grass from people bringing in their clippings for recycling. For perfect composting the nitrogen and carbon content of everything in the windrow is calculated and the contents adjusted. Duluth has a law in place that requires all big producers of food waste to separate their rubbish and have the food left over’s delivered to the plant. Ginny Black of Minnesota Pollution Control Agency says “Most people don't realize how important recycling is”, she has the job convincing people and businesses to recycle. There has been a direct link made that shows how the amount of rubbish we put in landfills increases greenhouse gases that in turn speed up global warming. One link being that when organic materials decompose in a landfill they do so without oxygen which means methane is released into the atmosphere which is 20 times worse than carbon dioxide. Also, it takes a lot more energy to create new raw materials than it does to recycle, this is true of soil. Soil needs the nutrients and water-retaining benefits that compost supplies. And lastly, compost keeps carbon from going into the atmosphere and increasing global warming when it is returned back into the soil. "Most of what's left after composting is a carbon substance, the organic material," Black says. "So when you incorporate that back into the soil, it's like a bank, it's like a savings account, in this case it's carbon, and we're putting the carbon back in the soil."
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