A new electrifying strategy to enhance nitrogen removal from ammonium-rich saline wastewater: Performance and mechanisms

IF 6.7 2区工程技术 Q1 ENGINEERING, CHEMICAL

Journal of water process engineering Pub Date : 2025-07-18 DOI:10.1016/j.jwpe.2025.108319

Hong Peng , Haotian Lei , Haojie Li, Yuanwei Li, Ganxue Wu, Yingjun Wang, Ying Zhu, Zhenxing Zeng, Hong Xiao

{"title":"A new electrifying strategy to enhance nitrogen removal from ammonium-rich saline wastewater: Performance and mechanisms","authors":"Hong Peng , Haotian Lei , Haojie Li, Yuanwei Li, Ganxue Wu, Yingjun Wang, Ying Zhu, Zhenxing Zeng, Hong Xiao","doi":"10.1016/j.jwpe.2025.108319","DOIUrl":null,"url":null,"abstract":"<div><div>This study explores a novel direct electrical stimulation (ES) system for treating ammonium-rich saline wastewater, using graphite felts as biofilm carriers and conductive materials without separate cathodes and anodes. The concentrations of chemical oxygen demand (COD) and NH₄+-N in the synthetic wastewater were 500 mg/L and 100 mg/L, respectively, with salinity levels ranging from 0.8 % to 1.2 %. Three types of reactors were established under microaerobic conditions: a bio-electrochemical reactor (BER), a biotic control reactor (BC), and an electrochemical control reactor (EC). The BER, charged at 0.9 V, achieved 91.0 ± 2.6 % total nitrogen (TN) removal efficiency at 1.2 % salinity, significantly higher than the BC (79.0 ± 5.5 %), while the EC showed no TN removal. Mechanistically, the ES enhanced microbial salt tolerance, biofilm robustness, and microbial metabolic activity by promoting salt-in strategy, extracellular polymeric substance secretion, and electron transfer. Metagenomic analysis revealed that marine anammox bacteria Candidatus SCAELEC01 and Candidatus Scalindua were enriched in the BER, with relative abundances 2.39 and 2.38 times higher than in the BC, respectively. Functional gene analysis indicated that ES increased the relative abundances of genes narG and narH, enhancing partial denitrification. ES also boosted the relative abundances of genes hzsA, hzsB, hzsC, hdh, and hzo, promoting the anammox process. Meanwhile, genes nirK, norB, and norC decreased. Collectively, these changes may explain the 46.80 % reduction in N₂O emissions. These results highlight direct ES as a promising strategy for treating ammonium-rich saline wastewaters.</div></div>","PeriodicalId":17528,"journal":{"name":"Journal of water process engineering","volume":"77 ","pages":"Article 108319"},"PeriodicalIF":6.7000,"publicationDate":"2025-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of water process engineering","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2214714425013911","RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, CHEMICAL","Score":null,"Total":0}

引用次数: 0

Abstract

This study explores a novel direct electrical stimulation (ES) system for treating ammonium-rich saline wastewater, using graphite felts as biofilm carriers and conductive materials without separate cathodes and anodes. The concentrations of chemical oxygen demand (COD) and NH₄⁺-N in the synthetic wastewater were 500 mg/L and 100 mg/L, respectively, with salinity levels ranging from 0.8 % to 1.2 %. Three types of reactors were established under microaerobic conditions: a bio-electrochemical reactor (BER), a biotic control reactor (BC), and an electrochemical control reactor (EC). The BER, charged at 0.9 V, achieved 91.0 ± 2.6 % total nitrogen (TN) removal efficiency at 1.2 % salinity, significantly higher than the BC (79.0 ± 5.5 %), while the EC showed no TN removal. Mechanistically, the ES enhanced microbial salt tolerance, biofilm robustness, and microbial metabolic activity by promoting salt-in strategy, extracellular polymeric substance secretion, and electron transfer. Metagenomic analysis revealed that marine anammox bacteria Candidatus SCAELEC01 and Candidatus Scalindua were enriched in the BER, with relative abundances 2.39 and 2.38 times higher than in the BC, respectively. Functional gene analysis indicated that ES increased the relative abundances of genes narG and narH, enhancing partial denitrification. ES also boosted the relative abundances of genes hzsA, hzsB, hzsC, hdh, and hzo, promoting the anammox process. Meanwhile, genes nirK, norB, and norC decreased. Collectively, these changes may explain the 46.80 % reduction in N₂O emissions. These results highlight direct ES as a promising strategy for treating ammonium-rich saline wastewaters.

Abstract Image

查看原文本刊更多论文

一种新的电气化策略提高富铵盐水废水的脱氮性能和机理

本研究探索了一种新型的直接电刺激（ES）系统，该系统采用石墨毡作为生物膜载体和导电材料，无需单独的阴极和阳极，用于处理富氨盐废水。合成废水中化学需氧量（COD）和nh4 +-N浓度分别为500 mg/L和100 mg/L，盐度为0.8% ~ 1.2%。在微氧条件下建立了三种反应器：生物电化学反应器（BER）、生物控制反应器（BC）和电化学控制反应器（EC）。充电电压为0.9 V时，在1.2%盐度下，BER的总氮（TN）去除率为91.0±2.6%，显著高于BC(79.0±5.5%)，而EC无TN去除率。从机制上讲，ES通过促进盐入策略、细胞外聚合物质分泌和电子转移，增强了微生物的耐盐性、生物膜稳健性和微生物代谢活性。宏基因组分析显示，海水厌氧氨氧化菌Candidatus SCAELEC01和Candidatus Scalindua在BER中富集，相对丰度分别是BC的2.39倍和2.38倍。功能基因分析表明，ES增加了narG和narH基因的相对丰度，增强了部分反硝化作用。ES还提高了hzsA、hzsB、hzsC、hdh和hzo基因的相对丰度，促进了厌氧氨氧化过程。同时，基因nirK、norB、norC减少。总的来说，这些变化可以解释二氧化碳排放量减少46.80%的原因。这些结果强调了直接ES是处理富铵盐水废水的一种有前途的策略。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Journal of water process engineering Biochemistry, Genetics and Molecular Biology-Biotechnology

CiteScore

10.70

自引率

8.60%

发文量

846

审稿时长

24 days

期刊介绍： The Journal of Water Process Engineering aims to publish refereed, high-quality research papers with significant novelty and impact in all areas of the engineering of water and wastewater processing . Papers on advanced and novel treatment processes and technologies are particularly welcome. The Journal considers papers in areas such as nanotechnology and biotechnology applications in water, novel oxidation and separation processes, membrane processes (except those for desalination) , catalytic processes for the removal of water contaminants, sustainable processes, water reuse and recycling, water use and wastewater minimization, integrated/hybrid technology, process modeling of water treatment and novel treatment processes. Submissions on the subject of adsorbents, including standard measurements of adsorption kinetics and equilibrium will only be considered if there is a genuine case for novelty and contribution, for example highly novel, sustainable adsorbents and their use: papers on activated carbon-type materials derived from natural matter, or surfactant-modified clays and related minerals, would not fulfil this criterion. The Journal particularly welcomes contributions involving environmentally, economically and socially sustainable technology for water treatment, including those which are energy-efficient, with minimal or no chemical consumption, and capable of water recycling and reuse that minimizes the direct disposal of wastewater to the aquatic environment. Papers that describe novel ideas for solving issues related to water quality and availability are also welcome, as are those that show the transfer of techniques from other disciplines. The Journal will consider papers dealing with processes for various water matrices including drinking water (except desalination), domestic, urban and industrial wastewaters, in addition to their residues. It is expected that the journal will be of particular relevance to chemical and process engineers working in the field. The Journal welcomes Full Text papers, Short Communications, State-of-the-Art Reviews and Letters to Editors and Case Studies