Abstract: The disposal of three-phase centrifugal solid residue from food waste treatment facilities presents considerable challenges, and its resource utilization pathways remain limited. This study took the three-phase centrifugal solid residue produced by a kitchen waste treatment plant in Shenzhen as the object, and carried out a continuous operation test of integrated aerobic composting to investigate the operational stability of this technical route, the material reduction effect, and the potential for fertilizer utilization of compost products. A 25-day continuous operation trial was conducted under preset conditions, including intermittent mechanical agitation, forced aeration, auxiliary heating, and the addition of a composite microbial inoculant at a dosage of approximately 1 kg/t. The composting temperature was maintained within the range of 50-60 ℃, and the aeration rate was set at approximately 250 m3/h. During the 25-day continuous operation, the system exhibited stable performance. For the steady-state period from day 15 to day 25, the average daily output was (2.81±0.20) t, and the average mass reduction rate reached 73.8%±1.7%, demonstrating that the three-phase centrifugal solid residue could be continuously and stably reduced in volume under the aforementioned process conditions. After sieving with a 3 mm sieve, the obtained compost product had a moisture content of approximately 12.3%±0.7%. The total nutrient content (N+P2O5+K2O), pH, and heavy metal concentrations all complied with the requirements of NY/T 525—2026 Organic Fertilizers. Seed germination tests revealed that the germination rates of cucumber and carrot seeds treated with 1% and 10% compost extracts were higher than those of the blank controls, with germination indices reaching up to 174.25%±1.21% and 188.93%±15.00%, respectively. These results indicated a satisfactory degree of maturity and the absence of significant phytotoxicity in the composted products. Preliminary economic analysis indicated that the direct operating cost of this process was 35.36 RMB/t relying on the existing public utilities in the factory area, which was lower than the cost of off-site incineration disposal (100 RMB/t). Collectively, this study validated the engineering feasibility of the integrated aerobic composting route for three-phase centrifugal solid residue treatment in terms of continuous operation performance, mass reduction efficacy, product quality, and economic viability. The findings can provide a valuable reference for the reduction and fertilizer-oriented disposal of three-phase centrifugal solid residue in food waste treatment plants.

Key words: food waste, three-phase centrifugation solid residue, aerobic composting, fertilizer utilization, resource utilization