According to PlaNYC “New York City sends four million tons of waste to landfill every year. Almost a third of that is food waste”. The relationship between the food waste and climate change occurs when that waste begins to degrade. When it degrades it produces CO and methane, both of which are harmful greenhouse gasses.
To combat these harmful gasses there is Anaerobic Digestion. Anaerobic Digestion is the series of biological process in the microorganisms break down biodegradable material in the absence of oxygen. One of the end products is biogas, which is combusted to generate electricity and heat. Another end product is digestate, which can be land applied, composted and used as a soil amendment or processed into fertilizer pellets.
In fact, it’s different to compost the food waste to biogas and transfer it to heat and power by ourselves. However, we can compost the food waste to the biofertiliser with the simple steps. The basic method to make bio-fertilizer is brown material and the green material under the moist condition. Blend materials continually will heat up the temperature by itself to increase the rate of compost, until it ends compost and dry.
What is brown material?
The brown material which are high in carbon.
- Dries leaves, hay
- Wood chips, straw
- Newspaper, cardboard
- Egg shells and nut shells
What is green material?
The green material which has rich nitrogen. The fresh or green material such as:
- Fruit and vegetable scarps,
- Coffee ground, filter, and paper tea bags
- Stale beans, flour and spices
- Cut or dried flowers
- Fresh grass clipping, fresh leave
But not any food waste can be the material you use for the compost. For example:
- Meat or fish
- Cheese or dairy
- Fats, grease or grease food
Based on the article “Life cycle environmental impacts of substituting food wastes for traditional anaerobic digestion feedstock’s”, it shows that environmental impact for landfill food waste is 94% which is more than 15 times greater than the anaerobic digestion of food waste 6% can cause the climate change.
As a mechanical engineer student, I plan to come up an eco-design product. The product can use biogas to power the machine to make the biofertilizer from the food waste. It should be a small size which can be used in every family house. In addition, the government can reduce cost of recycled food waste.