Anaerobic Digestion of Food Waste
Food waste volumes increased greatly after foot and mouth, and other incidents related to the spread of disease vectors raised public and regulatory awareness to the need for stringent measures to prevent the use of food materials in a way which could jeopardize health. As a result new regulations were brought in, such as the Animal By-Products Regulations to prevent of recurrence of these problems, and these measures eliminated many traditional methods for the re-use of many waste foods.
At the same time rising affluence, the tendency for people to live alone and cook less, and the increase in the number of working mothers with less time to cook at home has increased the amount of pre-processed food bought and wasted.
As a result of this, coupled to a greater casualness to the waste of food, the amount of food waste in our waste has risen faster than overall waste tonnages. Householders should only shop for what they need - they need to take responsibility for what they buy and what they waste. But, in fact the records show that they are not - and all this has contributed to food waste now being a major component, at 15% to 20%, of our municipal solid waste (MSW) by weight.
The first course of action should of course be minimisation - reduce the amount of food becoming waste in the first place.
Even in areas where householders willingly participate in source segregation in the form of paper and packaging recycling schemes, separate collections for food waste are considerably less popular and less well supported than others.
Food has always represented a much bigger percentage of the total weight of waste thrown out by households compared to packaging, but has proved more difficult to get the public to segregate. As a result despite the many advantages of the source separation of food waste, food waste collection is a long way down the priority list for most local authorities.
In fact separate food waste collection is often seen as a problematic area for waste managers and councilors, and few have wanted to promote it, as they see that residents are quick to rebel against it due to the perceived barriers to its collection.
No wonder that the trend within most LA’s Waste Manager’s Depts. has been to look at collecting green and/or garden waste for the tonnage it can generate, while food waste remains largely ignored.
When it comes to food waste, a great deal of attention is put to developing the uptake of relatively cheap home compost units. But even in areas that provide the type of bin that can handle meat, fish and bones, it is generally understood that home composting does not, and will not in the future, make a large impact on the amount of food waste thrown out.
So all this points to an emerging problem with food waste, relative to other recycling, and as the other easier to achieve waste reductions are gradually picked-off, more and more attention will surely have to be paid to the anaerobic digestion of these food waste streams.
Food waste is an excellent feedstock for the new generation of anaerobic digestors, as food waste is readily digested within them. Anaerobic Digestion technology based Waste Treatment Plants which accept a high proportion of food waste will also be, in principle, more economic to run than the equivalent non-food waste fed plants, due to the high methane gas producing potential and the revenue potential of these plants.
So what are you waiting for? The future of Anaerobic Digestion lies in food waste processing. Start experimenting and develop your own proprietary AD Food waste processing system now!
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