Abstract: The physicochemical characteristics of food waste were of great significance for selecting suitable treatment technology, evaluating environmental impacts, and realizing resource utilization. The physicochemical characteristics of household food waste from source classification and mixed waste in a city of South China were analyzed, and compared with the physicochemical characteristics of restaurant food waste and other food waste. The results showed that the moisture content of all three types of food waste was high, and the carbon-nitrogen ratio was low. Therefore, dehydration and carbon-nitrogen ratio adjustment were necessary before biochemical treatment. The moisture content of the source-segregated household food waste (75.08%) was the lowest and carbon-nitrogen ratio (19.73) was the highest among the three types of food waste. The fat and protein of the source-segregated household food waste were 10.06% and 18.71%, respectively. While those of restaurant food waste were higher, at 27.16% and 25.76%, respectively. The total nutrient content of the three types of food waste all met the limit requirement of NY/T 525—2021 Organic Fertilizer, and the content of heavy metals was all below the limit value of the relevant pollution evaluation standard. The food waste in a city of South China was rich in organic matter and nutrients, with a low risk of heavy metal pollution and high potential for resource utilization.

Key words: 　food waste, source classification； physical and chemical characteristics, resource utilization