Before I continue with more strategies, I want to reiterate that there will not be one easy solution to manage all food waste in all its forms, and it will take a combination of technologies and strategies because food waste includes everything from wastewater to misshapen fruits and unbought vegetables to industrial frying oil. Valorization of food waste falls under three main categories: One, the conversion of food waste into repurposed non-food biological products. This would include converting used frying oil into vegetable oil biodiesel to fuel your car. The second is food recovery and salvage which would be if a grocery store were to donate unsold produce to a soup kitchen to use. And the third is waste management through speeding up the process of decomposing. Here are more strategies of bio-transforming food waste!
Incineration
Incineration, while quicker and easier than other strategies, releases smoke from the chimneys which contain nitrogen oxide, particulates, heavy metals, acid gases and the carcinogen dioxin. Incineration also discourages recycling and waste reduction within communities, and burning waste is just not a long-term solution, similar to landfills. But while incineration is not the best long-term solution, there are a few advantages. Incineration can be used to produce thermal energy, also metals can be extracted from ash, and bottom ash can be recycled to be used in the construction industry, which makes incineration a contender for smaller-scale waste valorization.
Vermifilters
A vermifilter or vermi-digester is an aerobic system that filters organic material from wastewater. The process uses aerobic bacteria and composting earthworms. The wastewater is purified by removing pathogens and oxygen demand, and like aerobic digesters, vermifilters are most commonly used for sewage treatment. While sewage is not directly related to food waste, with almost 8 billion people on this earth, all of whom produce feces, it is in the loosest sense “waste from food.” Additionally, vermifilters are very eco friendly and some are even gravity operated which means they require virtually no energy input.
Vermicomposting
Vermicomposting, like vermifilters also use worms to create a mixture of decomposing food waste. The process produces vermicast, which is the product of the breakdown of the organic matter by earthworms, and this vermicast has less contaminants and more nutrients than the organic materials before going through vermicomposting. Although vermicomposting is very efficient, it can be very difficult process. However, there are some few food wastes that vermicomposting cannot compost. Also, if food waste levels become too deep, the bin can start to smell of ammonia. Moisture levels also have to be maintained to support worm respiration and worm life. Right now, vermicomposting is widely used in North America for on-site institutional processing of food scraps, such as in hospitals and shopping malls and is becoming increasingly more common.
Grease interceptors
Grease interceptors are traps that are designed to intercept most greases and solids before they enter a wastewater disposal system. Lots of restaurants and kitchens produce a lot of waste grease and use grease interceptors!
Next week will be part 4 of this series!
