Direct oxidation of ammonia to dinitrogen through persulfate activation by coal-based activated carbon: Selectivity and mechanism

IF 8.1 1区工程技术 Q1 ENGINEERING, CHEMICAL

Separation and Purification Technology Pub Date : 2025-04-02 DOI:10.1016/j.seppur.2025.132752

Yong Liu, Hanling Jiang, Le Zhang, Chenxi Wu, Jianlong Wang

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引用次数: 0

Abstract

Removal of ammonia nitrogen (NH₄⁺-N) from water and wastewater with low C/N ratios by advanced oxidation processes (AOPs) is crucial for guaranteeing the safety of drinking water and preventing eutrophication in aquatic environment. Conventional AOPs tend to over-oxidize NH₄⁺-N to nitrite or nitrate and potentially interfere with the water and wastewater matrix. Herein, we proposed a strategy for direct oxidation of NH₄⁺-N to N₂ through activating persulfate (PS) by coal-based activated carbon (AC) in the presence of MgO. In the AC/MgO/PS process, NH₄⁺-N oxidation mostly occurred via non-radical pathways (¹O₂ and electron transfer). The high selectivity of direct oxidation of NH₄⁺-N was due to the following four reasons: (1) MgO made NH₄⁺-N exist predominantly in the form of NH₃ in solution; (2) electronic shuttle function of AC enhanced the electron transfer from NH₃/N₂H₄ to PS to form N₂; (3) AC surface contains various functional groups, such as C=O, which may catalyze the conversion of N₂H₄ and NO intermediates to form N₂; (4) sulfur components in AC reduced the nitrite/nitrate product to N₂. AC/MgO/PS process could be used to oxidize NH₄⁺-N in polluted groundwater. This work offers a new AOP for chemical treatment of NH₄⁺-containing water and wastewater

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来源期刊

Separation and Purification Technology 工程技术-工程：化工

CiteScore

14.00

自引率

12.80%

发文量

2347

审稿时长

43 days

期刊介绍： Separation and Purification Technology is a premier journal committed to sharing innovative methods for separation and purification in chemical and environmental engineering, encompassing both homogeneous solutions and heterogeneous mixtures. Our scope includes the separation and/or purification of liquids, vapors, and gases, as well as carbon capture and separation techniques. However, it's important to note that methods solely intended for analytical purposes are not within the scope of the journal. Additionally, disciplines such as soil science, polymer science, and metallurgy fall outside the purview of Separation and Purification Technology. Join us in advancing the field of separation and purification methods for sustainable solutions in chemical and environmental engineering.