Landfill

Landfill is a site used for the discard of waste materials by burial. It is the oldest form of waste treatment. Some modern landfills are better constructed to avoid contamination of neighbouring land and underground water but most of them are not.

The main problem of landfill sites is that they give off gases which are harmful to the environment and human health, and generally unpleasant for neighbours. The worst emissions from waste decomposition at landfills are methane and carbon dioxide, both greenhouse gases, except methane is 20 times more potent than carbon dioxide. Liquid leachate and toxic waste water from landfills also pollute underground water and neighbouring land, harming plants and animals nearby.

Landfills also involve use of car transport of waste materials and car transport itself consumes fossil fuels and emits greenhouse gases.

Some governments have begun taxing landfill sites to encourage mass waste producers to find alternative methods of waste disposal. Reducing availability of land for landfill designation and increasing transportation costs to distant landfills have also led to a shift away from landfills as a waste disposal method.

Incineration

Incineration is the process of burning waste at high temperature inside a specially engineered and purpose-built incinerator until the waste is turned into ash. By incineration, the weight and volume of waste will be greatly reduced by 85% to 95%. However, the ash and gas left behind after incineration are often toxic and harmful to humans as well as the environment.

The incineration process produces not only greenhouse gases, but also harmful dioxin, furan and heavy metals, all known to cause cancer and other health problems in humans. These toxins can also go down our food chain and enter our bodies through the food we take. Dioxin is also known to cause acid rain which destroys vegetation, wildlife, rivers, soils and even architecture. Although modern incinerations are often installed with emission control, these toxins cannot be eliminated completely.

Incineration still leaves ash which needs to be disposed of safely as they may contain dangerous particulates. Such disposal can be costly.

Incineration may be an effective treatment method for clinical wastes and certain hazardous wastes to ensure pathogens and toxins are destroyed. But it is not efficient for food waste treatment as food waste has high moisture content and the moisture must be evaporated prior to burning.

Need for more environmental friendly options

The treatment of food waste through landfills and incineration create more environmental problems than they solve.

Dumping food waste in a landfill causes environmental damage. By volume, it is the largest contributor to methane gas production. Incineration of food waste also creates environmental hazards.

The highly hydrolyzed food waste, however, has a huge potential to be recycled to provide electricity. This potential is not yet fully realized.