Before and after the of bio-organic fertilizer granulation, comprehensive harmless treatment is essential to eliminate pathogens, insect eggs, and weed seeds; remove harmful substances; and ensure the viability of microbial strains, compliance with national standards, and overall safety.

First, harmless treatment via high-temperature fermentation at the raw material stage. Utilizing raw materials such as livestock and poultry manure, crop straw, and sewage sludge, a double screws compost turning mahcine is employed to conduct continuous aerobic composting. This process ensures that the pile temperature consistently reaches between 55°C and 70°C and is maintained for a minimum of seven days. Through this high-temperature maturation process, insect eggs, pathogenic bacteria, and weed seeds are naturally eliminated; harmful substances are decomposed; and the activity of residual antibiotics and heavy metals is reduced. Simultaneously, odors are eliminated, thereby achieving fundamental harmlessness.

Second, low-temperature process protection and purification during the organic fertilizer granulator machine stage. Since bio-organic fertilizers contain live microbial strains, they cannot undergo high-temperature drying. Consequently, a "dry-extrusion" granulation method utilizing double-roller presses is typically adopted. This process forms granules at ambient temperature—without raising the temperature—thereby avoiding harm to the microbial strains and generating no waste gas emissions. The entire process is conducted within a closed production system, which minimizes dust generation and external contamination, prevents the secondary introduction of extraneous bacteria and impurities, and ensures the material remains clean and hygienic.

Third, screening, impurity removal, and ingredient ratio control. Both before and after granulation, the material undergoes crushing, screening, and magnetic separation to remove stones, metal impurities, and any uncomposted lumps. The addition of auxiliary materials is strictly controlled; specifically, binders containing heavy metals or harmful additives are prohibited to ensure the purity of the product and compliance with safety standards.

Fourth, post-processing curing and release testing. After granulation, the product is stored in a cool, ventilated environment to undergo natural cooling and curing, thereby preventing "reheating" (spontaneous temperature rise) that could foster bacterial growth. Concurrently, the product is tested for key indicators such as moisture content, viable microbial count, nematode mortality rate, fecal coliform levels, and heavy metal content. Only after passing these quality control tests is the product approved for packaging and release from the facility.

The overall workflow follows a sequence of "maturation first, granulation second," characterized by low-temperature production and a closed-loop purification system. This approach not only achieves effective harmless treatment but also preserves the viability of beneficial microbial strains. The resulting finished fertilizer offers superior efficacy, complies with all regulations, is environmentally friendly, and is highly suitable for widespread application.