Food waste recycling (also known as composting) is a method of purposeful biodegradation of organic material, creating compost - the remains of plants and animals that are decomposed.
Compost has been employed for thousands of years as a natural fertilizer or enrichment.
There are 2 principal groups of composting solutions: in-home composting & industrial composting.
At home composting techniques are generally restricted to leftover food and lawn trimmings.
Types of home composting include: Worm Composting: This approach to composting involves the employment of worms and other bugs to generate a combination of decomposed food waste and worm castings.
Worm castings or worm manure are the by-product of the breakdown of organic matter by worms; the castings are nutrient rich and act as a powerful fertilizer.
Bokashi Composting: This method of accelerated composting calls for the fermentation of food scraps using a wheat bran that has been inoculated with specific micro-organisms.
The microorganisms degrade the food and as soon as it's fully fermented, the food waste may be trenched in a garden where it will complete the biodegradation process and will fertilize the soil.
Backyard Composting: This method of organic waste recycling calls for an open pile of organic matter that is turned over to make sure that the proper distribution of heat, humidity, and oxygen in the pile.
The proper balance of moist and dry materials should also be met to make sure that the compost pile will not let off an odor.
This form of food recycling is generally restricted to vegetables, as meat and animal products can bring vermin.
Commercial composting centers can accept discarded food, yard clippings, animal manure, biodegradable food packaging, and most organic matter.
Forms of industrial composting include: Windrow Composting: Windrow composting is a way of generating compost by piling organic matter into extended rows or arc-like piles.
The piles are turned over by large machinery to preserve even levels of heat, humidity, and oxygen content.
Piles will usually range from four to eight feet tall and 14-16 feet in length.
Aerated Static Pile (ASP): ASP organics recycling involves the production of compost heaps which have oxygen pulled through them.
The piles are not turned and may be left open or shut.
Closed piles are covered by heavy duty plastic tarps.
ASPs are generally used by composting facilities processing large amounts of wet organic waste.
In-vessel Composting: In-vessel composting makes compost through the use of enclosed "reactors" that closely monitor temperature and oxygen levels throughout the biodegradation of organic materials.
Production of compost happens rapidly, happening in as little as a few weeks, but organics often need curing for weeks after.
In vessel composting involves larger capital costs than Windrow or Aerated static pile, but needs less land and labour.
Anaerobic Digestion: Anaerobic digesters degrade organic materials without oxygen.
Carbon dioxide and methane are emitted at a roughly 1:1 level and methane is captured and used as an energy source.
Once gas generation and capture is complete, the organic matter is aerobically cured and may be turned into compost.
Capital costs however for anaerobic digesters are significantly more than aerobic food recycling solutions.