FOOD WASTE PROBLEM
In the recent years, the continuous increase of food waste disposal makes the food waste problem more serious. Nowadays, the food waste was sent to the landfills, together with other solid
waste. The disposal of food waste which is classified as an organic waste belongs to the largest category of the municipal solid waste and it leads to rapid decreasing of the limited landfill
The landfills will generate a terrible stench due to the greenhouse gas emissions during the decomposition process of food waste. Besides, the food waste
disposal leads to the problems of wastewater seepage, transportation cost, landfill maintenance, etc., which is a heavy burden to the taxpayer.
Carbon footprint evaluates the impact on the environment by measuring the quantity of greenhouse gas emission. Referring to international research literatures, we now can work out the carbon footprint computation from each ton of food waste disposal. The carbon footprint of the landfill is the largest, which is
about 800kg CO2eq, mainly due to the consumption of diesel fuel during transportation and the release of large amounts of methane by anaerobic decomposition (methane has a warming potential 25 times higher than that of carbon dioxide).
The carbon footprint of composting is 140kg CO2eq
approximately, mainly comes from the transportation gasoline expenditure, power consumption in compost plant and the release of methane and nitrious oxide (nitrous oxide has a warming potential 310 times higher than that of carbon dioxide). However, 40kg CO2eq can be removed through soil carbon storage during
farming, therefore the carbon footprint of compost was down to 100kg CO2eq, which is dramatically lower than landfill. Besides composting, a more significant reduction of carbon footprint can be achieved using our food waste digester, which is only 23kg CO2eq, because of the lower power consumption and minimal transportation.