Electrochemical recovery of nutrients from human urine coupled with biogas upgrading
- The Healthist
- 1月9日
- 讀畢需時 2 分鐘
Hanwoong Kim, Huiju Park, Kwiyong Kim, Changsoo Lee
Department of Civil, Urban, Earth, and Environmental Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea, Graduate School of Carbon Neutrality, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea
H I G H L I G H T S
Hydrolyzed urine (HU) is a promising alternative solvent for biogas upgrading.
Spent urine after biogas upgrading (SU) is more advantageous for nutrient recovery.
Electro-concentration effectively recovered ammonia nitrogen from both HU and SU.
Superior and more energy-efficient electro-concentration was achieved with SU.
Real SU concentrate had a high enough ammonia nitrogen content for fertilizer use.
A B S T R A C T
This study explored the coupling of electrochemical nutrient recovery from human urine with biogas upgrading. Ammonia nitrogen-rich (≥300 mM) and alkaline (≥pH 9) hydrolyzed urine (HU) is a promising alternative CO2 solvent. Spent urine after biogas upgrading (SU), with neutralized pH and increased conductivity resulting from CO2 absorption, is advantageous over HU for recovering total ammonia nitrogen (TAN) through electroconcentration. Experiments using synthetic urine at varying applied current densities (13–77 A/m2) demonstrated effective TAN recovery from both HU and SU, with greater enrichment factors at higher currents (2.1–3.3- fold, 1.2–1.8 M TAN concentrate). Validation experiments using real urine at the optimized current density of 52 A/m2, considering energy consumption, exhibited superior TAN recovery and energy efficiency when using SU (3.7-fold enrichment, 1.6 M TAN concentrate; suitable for liquid fertilizer) compared to HU. These findings offer an advanced strategy for maximizing urine valorization, contributing to a circular economy.
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