The human urine metabolome is complex, containing a wide range of organic metabolites that affect treatment of urine collected in resource-oriented sanitation systems. In this study, an advanced oxidation process involving heat-activated peroxydisulphate was used to selectively oxidise organic metabolites in urine over urea and chloride. Initial experiments evaluated optimal conditions (peroxydisulphate dose, temperature, time, pH) for activation of peroxydisulphate in unconcentrated, non-hydrolysed synthetic urine and real urine acidified to pH 3.0. Subsequent experiments determined the fate of 268 endogenous organic metabolites (OMs) and removal of COD from unconcentrated and concentrated real urine (80–90% mass reduced by evaporation). The results revealed >90% activation of 60 mM peroxydisulphate in real unconcentrated urine heated to 90 °C for 1 h, resulting in 43% ΣOMs degradation, 22% COD removal and 56% total organic carbon removal, while >94% of total nitrogen and >97% of urea in real unconcentrated urine were recovered. The mechanism of urea degradation was identified to be chemical hydrolysis to ammonia, with the rate constant for this reaction determined to be 1.9 × 10 s at pH 3.0 and 90 °C. Treating concentrated real urine resulted in similar removal of COD, ΣOMs degradation and total nitrogen loss as observed for unconcentrated urine, but with significantly higher chloride oxidation and chemical hydrolysis of urea. Targeted metabolomic analysis revealed that peroxydisulphate treatment degraded 157 organic metabolites in urine, of which 67 metabolites were degraded by >80%. The rate constant for the reaction of sulphate radicals with oxidisable endogenous organic metabolites in urine was estimated to exceed 10 M s. These metabolites were preferentially oxidised over chloride and urea in acidified, non-hydrolysed urine treated with peroxydisulphate. Overall, the findings support the development of emerging urine recycling technologies, including alkaline/acid dehydration and reverse osmosis, where the presence of endogenous organic urine metabolites significantly influences treatment parameters such as energy demand and product purity.

中文翻译：

---

使用基于硫酸根的高级氧化选择性降解酸化新鲜人尿液中的内源性有机代谢物


人类尿液代谢组很复杂，包含多种有机代谢物，这些代谢物影响以资源为导向的卫生系统中收集的尿液的处理。在这项研究中，采用涉及热激活过二硫酸盐的高级氧化过程来选择性氧化尿液中的有机代谢物而不是尿素和氯化物。最初的实验评估了在未浓缩、非水解的合成尿液和酸化至 pH 3.0 的真实尿液中激活过二硫酸盐的最佳条件（过二硫酸盐剂量、温度、时间、pH 值）。随后的实验确定了 268 种内源性有机代谢物 (OM) 的命运以及未浓缩和浓缩真实尿液中 COD 的去除（蒸发导致质量减少 80-90%）。结果显示，在加热至 90 °C 1 小时的真实未浓缩尿液中，60 mM 过二硫酸盐被激活 >90%，导致 43% ΣOM 降解、22% COD 去除和 56% 总有机碳去除，同时 >94% 总氮去除真实未浓缩尿液中尿素的回收率>97%。尿素降解的机制被确定为化学水解成氨，在 pH 3.0 和 90 °C 下，该反应的速率常数确定为 1.9 × 10 s。处理浓缩的真实尿液会导致与未浓缩尿液中观察到的类似的 COD 去除、ΣOM 降解和总氮损失，但氯化物氧化和尿素化学水解明显更高。靶向代谢组学分析显示，过二硫酸盐处理降解了尿液中的 157 种有机代谢物，其中 67 种代谢物降解率 >80%。硫酸根与尿液中可氧化的内源性有机代谢物反应的速率常数估计超过 10 M s。 在用过二硫酸盐处理的酸化、非水解尿液中，这些代谢物比氯化物和尿素优先被氧化。总体而言，这些发现支持新兴尿液回收技术的发展，包括碱/酸脱水和反渗透，其中内源性有机尿液代谢物的存在显着影响能量需求和产品纯度等处理参数。