This study explores a novel multi-stage process for recovering valuable nutrients–nitrogen, phosphorus, and potassium–from real hydrolyzed urine as value-added products. The approach utilizes a combination of membrane contactor, zeolite ion exchange, and mineral precipitation techniques. A closed-loop system was established by reusing the acid regeneration solution from ion exchange as the acid-stripping solution in the hollow fiber membrane contactor (HFMC), thereby minimizing chemical usage. Ammonia recovery using the HFMC achieved over 90 % removal across three cycles from hydrolyzed urine. Zeolite columns of chabazite and clinoptilolite demonstrated consistent potassium recovery from HFMC-treated urine, with slightly higher uptake by chabazite compared with clinoptilolite. This suggests zeolite selection can be based on cost and availability. The regeneration of the potassium-saturated zeolite columns using sulfuric acid exhibited rapid and substantial amounts of potassium desorption. Potassium regeneration remained stable over two cycles, with potassium concentrations reaching up to 14 g/L. The release of other ions, such as sodium, was minor compared with potassium, highlighting the minimal impact of sodium interference. The combined ammonia–potassium liquid fertilizer exhibited a favorable N:K mass ratio (3.6 % N and 0.7 % K), with negligible amounts of other ions, making it suitable for facilitating plant growth. Iron phosphate precipitation, a promising alternative resource for fertilizer or lithium iron phosphate batteries, was successfully achieved. Iron doses were more effective in precipitating phosphate at neutral pH than basic pH, reaching over 90 % phosphate removal. This study provides a promising approach for recovering valuable resources from human urine, promoting a more sustainable approach to wastewater management and nutrient recycling.

中文翻译：

---

从真实人尿液中多阶段回收氨钾液肥和磷酸盐矿物


本研究探索了一种新的多阶段过程，用于从真正的水解尿液中回收有价值的营养物质——氮、磷和钾——作为增值产品。该方法结合了膜接触器、沸石离子交换和矿物沉淀技术。通过将离子交换产生的酸再生溶液再用作中空纤维膜接触器 （HFMC） 中的酸剥离溶液，从而最大限度地减少化学品的使用，建立了一个闭环系统。使用 HFMC 回收氨，在三个循环中从水解尿液中去除了 90% 以上的氨。菱沸石和斜发沸石柱显示出从 HFMC 处理的尿液中一致的钾回收率，与斜发沸石相比，菱沸石的摄取略高。这表明沸石的选择可以基于成本和可用性。使用硫酸再生钾饱和沸石柱表现出快速和大量的钾解吸。钾再生在两个循环中保持稳定，钾浓度高达 14 g/L。与钾相比，其他离子（如钠）的释放量很小，这凸显了钠干扰的影响很小。氨钾混合液体肥料表现出良好的 N：K 质量比（3.6 % N 和 0.7 % K），其他离子的量可以忽略不计，使其适合促进植物生长。磷酸铁沉淀法是肥料或磷酸铁锂电池的一种很有前途的替代资源，已成功实现。铁剂量在中性 pH 值下比碱性 pH 值更有效地沉淀磷酸盐，磷酸盐去除率达到 90% 以上。 这项研究为从人类尿液中回收有价值的资源提供了一种很有前途的方法，促进了更可持续的废水管理和营养物回收方法。