This study systematically investigated the evolution law of rheological properties in the anaerobic fermentation system of cow manure (CM) and corn straw (CS) mixtures at varying total solids (TS). Combined with computational fluid dynamics (CFD) simulations, the distribution characteristics of particles within fermentation system were revealed, illustrating the impact mechanisms of agitation strategies. Simulations demonstrated that higher agitation speeds and TS levels increase instantaneous power consumption while altering mixing and sedimentation dynamics. When TS was 6%, 120 r/min required more power than 100 r/min and 80 r/min, but 100 r/min reduced daily energy consumption by 4.30% and 3.19% compared to 80 r/min and 120 r/min. Under conditions of TS=6% and 8%, with maintained process stability, experimental groups increased energy output by 12.42% and 30.41% while reducing energy consumption by 13.60% and 3.39% versus control groups, demonstrating significant overall efficiency gains. Inversely, when TS was 10%, experimental groups decreased energy output by 0.34%, while increasing energy consumption. These findings prove that when TS is below 10%, optimized agitation strategies enable positive net energy output, establish an optimization scheme, and balance biogas production efficiency with economic feasibility.

The annual yield of maize straws is almost exclusively treated by field burning in China. Therefore, exploring the potential utilization value of maize straws is important to further realize modern agriculture in China. Maize straw-based organic degradable seedling bowls, formulated with pig manure and biogas slurry as binding agents, can be utilized for planting seedlings. These seedling bowls serve to supply organic material to the seedlings, thereby aiding in pest prevention and enhancing soil fertility. The vacuum filter suction forming method was proposed to prepare degradable seedling bowls according to its characteristics. Using the theory of fluid flow, drag reduction, and pressure drop control, the fluid model of seedling bowl material in the process of vacuum filtration was established, and the preparation of seedling bowl mold resistance factors was analyzed. The verification test showed that the pressure change interval and the blowing pressure are important factors influencing the formation of the wet body of the seedling bowl. This study provides theoretical support and guidance for the preparation of biodegradable seedling pots.