Normalized potential impacts of the food waste composting system in HongKong (Scenario B1). GW100: global warming (100 years); AC: acidification; NE:nutrient enrichment; POF: photochemical ozone formation; OD: ozone depletion;ETw: ecotoxicity in water; ETs: ecotoxicity in soil; HTa: human toxicity via air; HTw:human toxicity via water; HTs: human toxicity via soil; SETw: stored ecotoxicity inwater; SETs: stored ecotoxicity in soil.