Selective Recovery of Ammonia Nitrogen from Wastewaters with Transition Metal-Loaded Polymeric Cation Exchange Adsorbents
Selective Recovery of Ammonia Nitrogen from Wastewaters with Transition Metal-Loaded Polymeric Cation Exchange Adsorbents
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DOI：
10.1002/chem.202002170
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发表时间：
2020-07-16
影响因子：
4.3
通讯作者：
Tarpeh, William A.
中科院分区：
文献类型：
--
作者：
Clark, Brandon;Tarpeh, William A.
利用氮选择性吸附剂从废水中提取有价值的产品可以抵消能源密集型氨生产，重新平衡氮循环，并激励环境修复。从其他废水阳离子（例如，K+, Ca2+）中分离氮(N)作为铵，对从废水中去除N和作为高纯度产品回收N提出了主要挑战。通过负载在聚合物阳离子交换树脂上的氨基络合过渡金属与氨的配体交换，获得了高选择性和高容量。与商业树脂相比，金属配体交换吸附剂在二元等摩尔溶液中表现出更高的氨去除能力（8 mequiv g(-1)）和选择性（N/K（+）平衡选择性为10.1）。考虑到金属配体交换的最佳氨浓度（200-300 mequiv L-1）和pH(9-10)，水解尿液被确定为选择性TAN回收的有希望的候选者。然而，二价阳离子交换增加了过渡金属的洗脱，减少了氨的吸附。最终，金属配体交换吸附剂可以促进废水中氮的选择性分离。
Extracting valuable products from wastewaters with nitrogen-selective adsorbents can offset energy-intensive ammonia production, rebalance the nitrogen cycle, and incentivize environmental remediation. Separating nitrogen (N) as ammonium from other wastewater cations (e.g., K+, Ca2+) presents a major challenge to N removal from wastewater and N recovery as high-purity products. High selectivity and capacity were achieved through ligand exchange of ammonia with ammine-complexing transition metals loaded onto polymeric cation exchange resins. Compared to commercial resins, metal-ligand exchange adsorbents exhibited higher ammonia removal capacity (8 mequiv g(-1)) and selectivity (N/K(+)equilibrium selectivity of 10.1) in binary equimolar solutions. Considering optimal ammonia concentrations (200-300 mequiv L-1) and pH (9-10) for metal-ligand exchange, hydrolyzed urine was identified as a promising candidate for selective TAN recovery. However, divalent cation exchange increased transition metal elution and reduced ammonia adsorption. Ultimately, metal-ligand exchange adsorbents can advance nitrogen-selective separations from wastewaters.