Abstract:
The conventional aeration method is compulsorily continuous ventilation or aeration at equal intervals, and a uniform aeration rate does not vary during composting. A dynamic on-demand aeration approach based on the diverse oxygen consumption of microorganisms at different composting stages could solve the problems of insufficient oxygen supply or excessive aeration. This study aims to design an aerobic composting system with dynamic aeration, investigate the effects of dynamic aeration on the temperature rise and physicochemical characteristics during the aerobic composting of corn straw and pig manure, and optimise the control parameters of oxygen concentration. Higher temperatures and longer high-temperature durations were achieved under dynamic aeration, thereby accelerating the decomposition of organic compounds. Dynamic aeration effectively reduced the aeration frequency, the convective latent heat and moisture losses, and the power consumption in the middle and later stages of composting. The dynamic aeration regulated according to the oxygen concentration of 14%-17% in the exhaust was optimum. Under the optimal conditions, the period above 50 ℃ lasted 8.5 days, and the highest temperature, organic matter removal, and seed germination index reached 65.82 ℃, 37.59%, and 74.59%, respectively. The power consumption was decreased by 33.58% compared to the traditional intermittent aeration. Dynamic aeration would be a competitive approach for improving aerobic composting characteristics and reducing the power consumption and the hot exhaust gas emissions, especially in the cooling maturation stage, which was of great significance for realising the low-cost production of composting at scale and promoting the blossom of the organic fertiliser industry.
摘要:
常规曝气方式为强制连续通风或等间隔曝气,在堆肥过程中,均匀的曝气速率不会发生变化。基于微生物在不同堆肥阶段的不同耗氧量的动态按需曝气方法可以解决氧气供应不足或过度曝气的问题。本研究旨在设计一种动态曝气的好氧堆肥系统,研究了动态曝气对玉米秸秆和猪粪好氧堆肥过程中温升和理化特性的影响,优化氧气浓度的控制参数。在动态曝气下实现了更高的温度和更长的高温持续时间,从而加速有机化合物的分解。动态曝气有效降低了曝气频率,对流潜热和水分损失,以及堆肥中后期的耗电量。根据排气中氧气浓度14%-17%调节的动态曝气是最佳的。在最优条件下,50℃以上的时间持续了8.5天,最高温度,有机物去除,种子萌发指数达到65.82℃,37.59%,74.59%,分别。与传统的间歇曝气相比,电耗降低了33.58%。动态曝气将是提高好氧堆肥特性,减少能耗和热废气排放的一种有竞争力的方法。尤其是在冷却成熟期,这对于实现规模化堆肥的低成本生产和促进有机肥料产业的蓬勃发展具有重要意义。