寒区农村户用好氧堆肥系统设计与试验

Design and Experiment of Aerobic Composting System for Rural Households in Cold Regions

摘要:

好氧堆肥适宜处理农村散点堆积的餐厨垃圾、畜禽粪便、农业秸秆等多种有机废弃物，但目前小型户用好氧堆肥系统难以在寒区冬季室外稳定运行，且缺乏配套的通风策略，限制堆肥效果提升。本文联合太阳能蓄热与供电、双舱室和蓄热水箱保温等方式，设计适于寒区农村户用的好氧堆肥系统，研究不同环境温度下好氧堆肥的温升规律及堆肥特性，并探索通风优化策略及臭气减排途径。结果表明：该设计可实现堆肥舱室昼夜温度的有效维持，也可预热通风空气，保证好氧堆肥稳定运行，当环境温度为15~30℃、0~15℃、-25~0℃时，堆肥舱室内实际温度达21.9~45℃、15.7~32.4℃、13.5~23.8℃；好氧堆肥前11d，通风速率25L/（m3·min）时的持续通风最优，当环境温度为15~30℃、0~15℃、-25~0℃时，堆体实际最高温度达62.3、56.4、55.2℃；11d后，通风速率25L/（m3·min）、氧气浓度14%~17%调控下的动态通风更适于-25~0℃的低温环境，堆肥21d时种子发芽率达89.89%，且好氧堆肥过程未产生用电成本；秸秆对堆肥尾气中的氨气具有良好的净化效果，去除率达80%~95%。研究结果可为寒区农村户用好氧堆肥全年稳定运行及生态环境改善提供基础依据。

Abstract:

Aerobic composting is effective for processing various organic wastes, such as kitchen scraps, domesticated animal manure, and agricultural straw, commonly found in rural areas. However, maintaining a stable small-scale household aerobic composting system outdoors during winter in cold regions poses significant challenges, and there is a lack of a suitable ventilation strategy. An aerobic composting system tailored for rural households in the cold regions was designed, integrating solar thermal storage and power supply, double chambers, and an insulated thermal storage tank. The temperature rises and composting characteristics during the aerobic composting process across different ambient temperatures were studied, while exploring optimal ventilation and odor reduction strategies. The results showed that the design effectively maintained stable temperatures in the composting chamber throughout the day and night, while also achieving preheating of the ventilation air, ensuring the stable operation of aerobic composting. The actual temperatures inside the composting chamber reached 21.9~45℃, 15.7~32.4℃, and 13.5~23.8℃ under ambient temperatures of 15~30℃, 0~15℃, and -25~0℃, respectively. A continuous ventilation rate of 25L/(m3·min) proved optimal during the first 11d, with maximum temperatures in the compost pile reaching 62.3℃, 56.4℃, and 55.2℃ at ambient temperatures of 15~30℃, 0~15℃, and -25~0℃, respectively. For low-temperature environments below 0℃ after the initial 11d, implementing a dynamic ventilation strategy with a rate of 25L/(m3·min) and maintaining oxygen concentrations between 14% and 17% proved beneficial. By the end of the 21d aerobic composting at an ambient temperature from -25℃ to 0℃, the germination index reached 89.89%. In addition, the aerobic composting process incurred no electricity costs. Straw effectively purified the ammonia in the exhaust from aerobic composting, achieving a removal rate from 80% to 95%. The findings can serve as a foundation for enhancing the stable operation of aerobic composting and improving the ecological environment for rural households in cold regions.