Phosphorus (P) is critical for plant growth, but global reserves are exhausting within 250–300 years, therefore enhancing phosphate recycling is crucial for the future. Biogas digestate, rich with nutrients is a promising resource for nutrient recovery. Conventional solid–liquid separation shifts approximately 35 % of the total P in the digestate to the solid phase. Separation trials with additive treatment using a screw press with a 0.75 mm sieve were performed at University of Hohenheim’s full-scale biogas plant. After 22 h, 67.41 % (kieserite treatment) and 52.35 % (strawflour treatment) of total P shifted to the solid phase. Treatment with kieserite enhanced P shift into the solid phase by forming non-labile fractions through a chemical bond between P and Mg2+ ions. Kieserite treatment for 22 h effectively increases the share of total P in the separated solid phase, it also ensures a sustainable nutrient supply and mitigates the risk of nutrient runoff.

中文翻译：

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添加剂对全尺寸沼气厂沼渣固液分离过程中磷向固相转移的影响


磷 （P） 对植物生长至关重要，但全球储量将在 250-300 年内耗尽，因此加强磷酸盐循环对未来至关重要。沼渣富含营养物质，是一种很有前途的营养物回收资源。传统的固液分离将沼渣中约 35% 的总 P 转移到固相。在霍恩海姆大学的大型沼气厂进行了使用带有 0.75 毫米筛子的螺旋压榨机进行添加剂处理的分离试验。22 小时后，67.41 % （硅藻土处理） 和 52.35 % （草粉处理） 的总 P 转移到固相。用硅铁矿处理通过 P 和 Mg2+ 离子之间的化学键形成不不稳定的馏分，从而增强了 P 向固相的转变。硅藻土处理 22 h 可有效增加分离固相中总磷的份额，还确保了可持续的养分供应并降低了养分径流的风险。