Abstract：
This study explores sustainable methods to mitigate nitrogen (N) loss in agriculture amid rising food demands and limited arable land. It examines sewage sludge (SS) as an alternative to synthetic N fertilizers. SS is rich in nitrogen (4.21 ± 0.42 %) and phosphorus (3.60 ± 0.72 %), making it suitable for nutrient recovery and soil enhancement. Unfavorable sludge management methods result in the loss of 950,000 tons of nitrogen, meeting almost 10 % of the EU\'s nitrogen fertilization demand. This research evaluates SS treatment methods, including chemical conversion, thermal treatment, and biological composting, focusing on nitrogen conservation efficiency. Results show nitrogen loss during hydrolysis is minimized at pH 4 to 8 but increases significantly as ammonia (NH3) at pH 9 to 11, ranging from 4.2 % to 9 %. Neutralizing the hydrolysate is crucial; using solid KOH resulted in 13.5 % nitrogen loss, 11 times more than using slightly alkaline ash (1.22 %). Adding ash during drying reduced nitrogen emissions by 30 % compared to traditional drying at 105 °C. Improving the C/N ratio with food residues reduced nitrogen losses by 46.3 % during composting. These findings highlight the importance of pH control in chemical processes and temperature regulation in thermal treatments. Adding residues from other processes, such as biomass combustion waste, enhances SS processing conditions. Understanding nitrogen retention mechanisms is crucial for the environmental sustainability of SS usage. Efficient nitrogen retention strategies improve the fertilization value of SS and reduce its environmental footprint by lowering greenhouse gas emissions, particularly ammonia. Reducing nitrogen loss during SS treatment significantly lowers ammonia emissions, a major contributor to greenhouse gas emissions. These results help determine optimal methods for managing and processing SS to minimize emissions and increase agricultural usability.
摘要：
这项研究探索了在粮食需求增加和耕地有限的情况下减轻农业中氮（N）损失的可持续方法。它检查了污水污泥（SS）作为合成氮肥的替代品。SS富含氮(4.21±0.42%)和磷(3.60±0.72%),使其适合养分恢复和土壤强化。不利的污泥管理方法导致95万吨氮气损失，满足欧盟近10%的氮肥需求。这项研究评估了SS的治疗方法，包括化学转化，热处理,和生物堆肥，注重氮的节约效率。结果显示水解过程中的氮损失在pH4至8下最小化,但随着氨(NH3)在pH9至11下显著增加,范围为4.2%至9%。中和水解产物是至关重要的;使用固体KOH导致13.5%的氮损失,比使用微碱性灰分多11倍(1.22%)。与在105°C下的传统干燥相比，在干燥过程中添加灰分将氮气排放量减少了30％。在堆肥过程中，用食物残渣提高C/N比可减少46.3％的氮损失。这些发现强调了化学过程中pH控制和热处理中温度调节的重要性。添加来自其他过程的残留物，如生物质燃烧废物，增强SS处理条件。了解氮保留机制对于SS使用的环境可持续性至关重要。有效的氮保持策略提高了SS的施肥价值，并通过降低温室气体排放来减少其环境足迹，特别是氨。减少SS处理期间的氮损失显著降低氨排放量，温室气体排放的主要贡献者。这些结果有助于确定管理和处理SS的最佳方法，以最大程度地减少排放并提高农业可用性。
