A research team from NTU's Division of Environmental and Water Resources Engineering (School of Civil and Environmental Engineering, CEE) has come up with a cost-effective and environmentally-friendly way of converting food scrapes into valuable natural gases, which are the key components of fertilizer and fuel.
The research team led by Professor Wang Jing-Yuan has received grants from government and private agencies to fund this research project of bioconversion the nutrients in the food waste for better use. The team's two-phase anaerobic digestion system 'digests' the waste without oxygen in bioreactor, producing methane, a key component of natural gas that can be used as fuel. Some 50-60 cubic metres of biogas will eventually be produced for every tonne of food waste.
The team's other project is to recycle sewage sludge (the mud-like substance that remains after treating household and industrial wastes) and food waste. While sludge has high nitrogen and phosphate content - two of the three main nutrients in fertilizer- food waste is high in potassium, the third key nutrient. Prof Wang has come up with a bioconversion process combining both materials to produce a rich fertilizer. In one week, the process stabilizes the sludge and food waste mixture and kills any pathogens. The process also removes heavy metals from the sludge for safe land application.