Removal Of Ammonium Ions Research Articles

Simultaneous removal and recovery of ammonium and phosphate ions using flow electrode capacitive deionization through the struvite generation mechanism

Removing and recovering nitrogen (N) and phosphorus (P) from water is essential to prevent eutrophication and support sustainable development. Flow electrode capacitive deionization (FCDI) is a promising electrosorption technology often used to remove and recover charged ions from wastewater. This study presents an FCDI system using Mg(OH)2/BC as a flow electrode in a short-circuit closed-cycle (SCC) mode, enhancing the simultaneous removal and recovery of NH4+ and phosphate ions through struvite formation. Results show improved removal of NH4+ and phosphate ions at an optimal Mg(OH)2 amount (M−BC−0.336) and an initial influent pH of 8. The NH4+ and phosphate ions adsorbed into the flow electrode solution can react with Mg2+ ions released from the electrode material, resulting in the formation of struvite nanowires on the surface of the electrode material. This process reduces the back-diffusion effect of NH4+ and phosphate ions, thereby enhancing the performance of FCDI in removing N and P. In actual domestic sewage treatment, the system achieves high removal efficiency for N (64.6 %) and P (87.3 %) while consuming low energy (0.46 kWh/kg for NH4+-N and 4.1 kWh/kg for PO43−-P). Our study demonstrates an efficient method for removing and recovering N and P from wastewater while producing struvite-rich biochar.

Increasing the stability and efficiency of an electrochemical ammonium separation system via state-of-charge (SoC) control

Ammonium ions in wastewater can induce toxicity in aquatic organisms and accelerate eutrophication. Therefore, the efficient removal of ammonium ions is necessary. The electrochemical ion separation method, based on an electrode with selectivity for ammonium ions, is a promising recovery technique that can efficiently adsorb and desorb ammonium ions. In this system, the electrode is composed of copper hexacyanoferrate (CuHCF) and silver (Ag), and ammonium ions are captured by the CuHCF electrode. However, the stability of the CuHCF electrode is not sufficient for continuous ammonium ion removal. We aim to report an improvement in the stability of this system realized through the use of the state-of-charge (SoC) control method. The stability of the system can be enhanced by using SoC control at only 60 % of the maximum capacity. After 300 cycles, the discharge capacity for the 60 % SoC approach remained at 55.8 %, showing a 10 % improvement in stability compared to the 100 % SoC method (45.8 %). Furthermore, in concentrated solutions with a ratio similar to that of domestic wastewater, the 60 % SoC control strategy exhibited ammonium removal capacity and selectivity comparable to that with 100 % SoC control but with higher energy efficiency (77 % reduction in energy consumption). These results indicate that the state-of-charge (SoC) control method can enhance both the stability and the efficiency of the electrochemical ammonium separation system.

Synergistic chemical traction and pre-intercalation strategies enable high-quality MnO2 composites for efficient ammonium capture

The δ-MnO2 exhibits an ideal capacitive deionization (CDI) electrode for the efficient removal of ammonium ions (NH4+), owing to its unique layered structure that facilitates effective insertion and extraction of ions. However, MnO2 is constrained by self-aggregation, inadequate electrical conductivity, and sluggish reaction kinetics in practical applications, leading to subpar ammonium removal performance. Here, the polyaniline (PANI) intercalated MnO2 and carbon nanotubes (CNTs) composites (P/M-C-X) were synthesized by a straightforward and swift one-step inorganic/organic interface reaction using the chemical traction effect of aniline. The synergistic effect of the increased layer spacing and the introduced oxygen vacancy after PANI intercalated and the 1D/2D conductive interconnect structure constructed by CNTs can effectively improve the electrical conductivity, promote ions/electrons diffusion, and enhance the charge reaction kinetics. As results, P/M-C-50 exhibits excellent NH4+ removal performance, including the maximum salt adsorption capacity (SAC) (160.0 mg g−1), ultra-high salt adsorption rate (SAR) (1.07 mg g−1 s−1), and good cyclic stability. Furthermore, the comprehension of NH4+ storage mechanism has been enhanced through structural characterization, electrochemical analysis, and theoretical calculation. This study shows that P/M-C-50 has broad potential as a CDI ammonium removal electrode, and lays a solid foundation for the effective recovery and reuse of ammonium resources.

Exploring ammonia adsorption and filtration efficiency of ceramic membranes derived from weathered basalt: Fabrication analysis and application in wastewater treatment

This study aims to develop an innovative ceramic membrane derived from naturally-occurring weathered basalt (NWB) for the effective adsorption and filtration of ammonium ions (NH+4) from wastewater. The NWB was subjected to calcination to produce CWB-750 and further combined with activated carbon to form CWB-AC-950. Comprehensive characterization using Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD), Fourier-Transform Infrared Spectroscopy (FT-IR), and Brunauer-Emmett-Teller (BET) analysis revealed that CWB-AC-950 possessed a significantly high surface area of 121.7 m²/g and a minimal pore volume of 6.2 nm, indicating its enhanced adsorption capabilities. In practical filtration tests, CWB-AC-950 demonstrated a remarkable reduction in NH+4 concentration, decreasing it from an initial 30 mg/L to 15.25 mg/L. This substantial decrease underscores the membrane's efficiency in adsorbing and removing ammonium ions from contaminated water. Furthermore, the integration of activated carbon with calcined basalt not only improved the adsorption performance but also maintained the structural integrity and reusability of the membrane. These findings illustrate the potential of CWB-AC-950 as a promising and cost-effective medium for adsorption and filtration in wastewater treatment applications.The development of CWB-AC-950 contributes significantly to environmental remediation efforts by offering an efficient and low-cost alternative to conventional filtration materials. Its ability to maintain performance across multiple cycles underscores its potential for practical applications in large-scale wastewater treatment facilities, thus providing a sustainable solution to address the growing global water pollution crisis.

An extended S-heterocyclic organic compound with enhanced redox active sites for efficient and stable ammonium ion removal via capacitive deionization

Innovations in electrode materials profoundly impact the performance breakthroughs of capacitive deionization (CDI) technology. Organic compounds with electrochemical activity constitute a significant family of electrode materials for CDI systems. However, many of them face challenges such as insufficient active sites and dissolution in the aqueous electrolyte during the electrosorption processes. The present study focuses on molecular engineering design of a novel sulfur heterocyclic organic compound, dibenzo[b,i]thianthrene-5,7,12,14-tetraone (DTT) through an in situ sulfidation reaction. The DTT molecule extends the π-conjugated plane of the previous 2,3-dichloro-1,4-naphthoquinone (2,3-d-1,4-NQ) through CS bonding, enhancing structural stability and significantly reducing the band gap (3.96 to 2.29 eV). Additionally, the number of redox-active groups (C=O) has doubled from 2 to 4, thereby resulting in the improved capability of pseudocapacitive interactions with NH4+. In situ Raman spectroscopy, combined with relevant ex situ characterization, has verified the redox mechanism of multiple CO in DTT. As electrode, DTT exhibits a high specific capacitance of 614.8 F g−1 (280 cycles at 1 A g−1) and maintains a capacitance retention of 91.8 % after 10,000 cycles at 10 A g−1. Additionally, DTT is applied in CDI for the NH4+ capturing, which exhibits a high NH4+ adsorption capacity of 72.1 mg g−1 and a rapid NH4+ removal rate of up to 9.2 mg g−1 min−1 (at 1.2 V) in CDI devices. The stable cyclic regeneration and favorable specific energy consumption promote the potential of DTT as a Faradaic electrode material for CDI applications.

Performance Evaluation of a Romanian Zeolite: A Sustainable Material for Removing Ammonium Ions from Water

Ammonium ion is a chemical species that is found in abundance in natural waters, whether underground or surface, but also in wastewater resulting from agricultural and industrial activities. Even if the removal of the ammonium ion from water has been studied for a very long time, it has been found that its removal is far from being solved. In this study, we evaluated the performance of the ammonium ion adsorption process on two adsorbents, zeolite clinoptilolite, ZR, a sustainable material (manufacturer: Zeolite Development SRL, Rupea, Brasov, Romania), and the other granular activated carbon type, Norit GAC 830 W. Zeolite ZR is found in very large deposits in Romania; it is a natural, cheap material with costs between 50 and 100 EUR/ton, compared to other adsorbents that cost over 500 EUR/ton and which can be regenerated and reused in the technological process of water treatment and purification, but also after exhaustion, as an amendment for the soil. In the first step, this paper presents the mineralogic (XRD) and structural (SEM and EDX) characterization of the ZR and the determination of the pH zero-point charge, pHZPC, for all the adsorbents. Studies were carried out in equilibrium and kinetic conditions. The efficiency of the adsorbent was investigated in different experimental conditions by varying the initial concentration, particle size, temperature, pH, ionic strength, and contact time. The mathematical models and parameters specific to the adsorption isotherms that best describe the experimental results were identified. Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich mathematical models were used for comparison. The Langmuir isotherm proved to be the most appropriate to describe the adsorption of ammonium ions on all types of adsorbents used. The adsorption capacity of ammonium ions from synthetic solutions at 20 °C, pH = 6.09, for the range of initial concentrations 0–50 mg/L for Rupea zeolite is in the range of 10.46 mg/g−12.34 mg/g, and for granular activated carbon GAC W830, it is 16.64 mg/g. It was found that the adsorption capacity of the ammonium ion on both activated carbon and zeolite increases with increasing temperature and pH. Also, it was observed that as the ionic strength increases, the adsorption capacity decreases for all four adsorbents. Kinetic models were also identified that best describe the experimental processes. In this sense, pseudo-first order, pseudo-second order, intra-particle diffusion and the Elovich model were used. The results of the investigation showed that second-order kinetics governs the adsorption process on ZR, and pseudo-first order governs activated carbon.

Ammonium ion removal from contaminated water using Cikancra natural zeolite

Abstract Water quality in water bodies is deteriorating due to human activities such as industries, agriculture, and households. These activities have been reported to increase the levels of nitrogen species in water bodies, including ammonium (NH4 +). Various processes have been used to reduce NH4 + concentration in water, including adsorption and ion exchange using zeolite which is renowned as an excellent adsorbent and ion exchange material. In this study, we assessed the ability of Cikancra natural zeolite to reduce the NH4 + concentration in water. Heat pre-treatment was carried out on the zeolite to reveal its effect on the NH4 + removal rate. Furthermore, several factors such as contact time, grain size, and initial NH4 + concentration were evaluated to determine the optimum absorption condition. The experimental results reveal that heat-pretreated natural zeolite can reduce the NH4 + concentration by up to 84% after 60 minutes of contact time. Furthermore, the absorption capacity of the zeolite is reaching 2.37 mg/g at an initial NH4 + concentration of 50 mg/L. The evaluation using Freundlich and Langmuir isotherm models indicates that the process occurs physically due to Van Der Waals interaction between the adsorbate and the adsorbent.

Removal of Phosphate and Ammonium Ion from Domestic Wastewater Using Clay Feldspar in Wupa Sewage Treatment Plant Abuja

The aim of this study is centered on the sustainability of feldspar as an adsorbent as opposed to other clay minerals such as plastic clay, red clay and barite. Brauner-Emmert-Teller (BET) analysis of the clay minerals considered in this study revealed that raw feldspar had the highest surface area and pore volume of 332.8 m²/g and 0.218 cc/g respectively. Similarly, the clay minerals were used in adsorption study with feldspar producing the best removal efficiency of 90.00%and 73.96% for ammonium and phosphate ions respectively. The BET results and the adsorption test showed that feldspar was a better adsorbent than the other adsorbents. Thermal activation of feldspar was carried out at temperatures of 500–700 ◦C using muffle furnace. The BET results of the thermal activation revealed that feldspar activated at 600 ◦C has the highest surface area and pore volume of 533.9 m²/g and 0.272 cc/g respectively. The Fourier’s transformed infrared (FT-IR) results indicated that several functional groups were involved in the adsorption process of the phosphate and ammonium ions some of which were O-H, N-H and C-O groups. The results showed that irregular-layered structures of the raw feldspar became smooth and regular after thermal activation. The effects of pH, adsorbent dosage, temperature, contact time and initial PO₄3− and NH₄⁺ concentrations on the adsorption of phosphate ions and ammonium ions were investigated using atomic adsorption spectroscopy (ASS). The adsorption studies of phosphate ion and ammonium ion onto feldspar increased with contact time, adsorbent dosage and temperatures until optimum values were reached.

Efficient Ammonium Ion Removal from the State Company of Fertilizers Wastewater through Nano Zeolite Treatment

Efficient Ammonium Ion Removal from the State Company of Fertilizers Wastewater through Nano Zeolite Treatment

Study on harmless treatment of electrolytic manganese residue by low temperature thermochemical method.

The Electrolytic Manganese Residue (EMR) is a by-product of the electrolytic manganese metal (EMM) industry, containing high concentrations of potential pollutants such as NH4+-N and soluble Mn2+. These components pose a serious threat to the ecological environment. To explore accurate, efficient, and harmless treatment methods for EMR, this study proposes a low-temperature thermochemical approach. The orthogonal experiment design investigates the effects of reaction temperature, reaction time, quicklime (CaO), sodium carbonate (Na2CO3), sodium phosphate (Na3PO4) (Reviewer #3), and water consumption on manganese solidified and ammonia removal from EMR. The results indicate that optimal conditions are a reaction temperature of 60 ℃ (Reviewer #3) and a reaction time of 10min. CaO precipitates Mn2+ as manganese hydroxide (Mn(OH)2) (Reviewer #3), achieving effective manganese solidified and ammonia removal. The addition of Na2CO3 causes Mn2+ to form manganesecarbonate (MnCO3) (Reviewer #3)precipitate, while Na3PO4 makes Mn2+ form Manganese phosphate trihydrate (Mn3(PO4)2·3H2O) (Reviewer #3). Increased water consumption enhances the interaction adequacy between ions. Under optimal conditions (CaO 10%, Na2CO3 1%, Na3PO4 0.5%, and 80% water consumption), the removal rate of ammonium ions reaches 98.5%, and the solidification rate of soluble Mn2+ is 99.9%. The order of influence on ammonium ion removal is CaO > water consumption > Na3PO4 > Na2CO3. Therefore, this study provides a new method for low-cost process disposal and efficient harmless treatment of EMR (Reviewer #3).

Imine-based conjugated polymer enables efficient removal of ammonium ion via capacitive deionization

The design of innovative faradaic electrode materials is crucial for improving the removal efficiency of contaminants in hybrid capacitive deionization (HCDI) systems. Organic compounds are a promising choice for faraday electrodes due to the sustainable production and tunable molecular structure. However, their high solubility in aqueous media and limited availability of redox-active sites for deionization greatly constrain the HCDI applications. Herein, we intentionally construct a conjugated polymer (IMP) with abundant imine groups, in which the strategic integration of N-heteroaromatic rings within the π-conjugated framework effectively prevents the disintegration of redox-active entities, while honing the energy bandgap and electronic characteristics. The copious redox-active CN sites within the imine groups along the polymeric chain markedly improve its capacity for the high-efficiency (de)intercalation of NH4+ ions. As an electrode material, the IMP polymer exhibits a significant NH4+-storage capacitance of 257.1 F g−1 at 2 A g−1 and maintains an ultra-cycle stability of 96.1 % after 10,000 cycles (4 A g−1), as evidenced by the in-situ spectral analysis of electrolyte. For real applications, a HCDI configuration has been constructed with a high specific NH4+ adsorption capacity of 119.0 mg g−1 and a fast removal rate of 27.0 mg g−1 min−1 with stable regeneration performance.

Ammonium ion removal from aqueous solutions in the presence of organic compounds, using biochar from banana leaves. Competitive isotherm models

BackgroundIndustrial, e.g. food industrial and domestic wastewaters contain huge amount of compounds causing eutrophication, and should be removed with high cost during wastewater treatment. However, these compounds could be utilized as fertilizers too. Biochar can remove a wide range of pollutants from water, such as ammonium, which can be found in relatively high concentration in dairy wastewaters. However, adsorption performance may be affected by the presence of other wastewater pollutants. Thus, this study aims to determine the efficiency of biochar as an adsorbent of ammonium in aqueous solutions in the presence of some selected organic compounds of typical dairy wastewaters such as bovine serum albumin (BSA), lactose, and acetic acid. Methods: The biochar was produced from banana leaves at 300 °C, modified with NaOH, and characterized by Scanning Electron Microscope – Energy Dispersive X-Ray Spectroscopy (SEM-EDX), Fourier-transform infrared spectra (FTIR) analysis, and specific surface area measurements. Batch experiments were carried out to investigate the ammonium adsorption capacity and the ion competitive adsorption mechanism. Significant Findings: Results show that the surface structure of the biochar derived from banana leaves is different from other biochars previously studied; although the specific surface area is not very considerable and despite having nitrogen within the elemental composition, the biochar studied is capable of adsorbing 2.60 mg NH4+/m2, the highest ammonium removal in 2 h occurs at pH 9 and 500 mg biochar dose. Langmuir model in the monolayer phase analysis fits better for all scenarios and the maximum NH4+ adsorption capacity was 0.97 mg/g without organic compounds. In the multilayer adsorption phase, the isotherm model that best fits the data obtained is the Harkins-Jura model without organic compounds. The presence of organic compounds in the aqueous solution significantly impacts the adsorption of ammonium by biochar since it improves the adsorption capacity (1.132 mg/g BSA, 0.975 mg/g lactose, and 1.874 mg/g acetic acid). The Aranovich-Donohue isotherm model fitted the data obtained during ion competitive adsorption experiments well.

Prussian blue analogue based integrated membrane electrodes for desalination and selective removal of ammonium ions in a rocking-chair capacitive deionization

Capacitive deionization (CDI) technology has shown significant promise in selective removal of nutrients from wastewater. In this study, a novel inorganic integrated membrane electrodes (i-IMEs) were developed with Prussian blue analogues (PBAs), cation insertion materials, as a coating on activated carbon (AC) electrode to replace cation exchange membrane. When the i-IMEs were operated in a rocking-chair CDI (RCDI) system for continuous desalination, a high specific adsorption capacity (SAC) of 42.7 mg/g and an impressive charge efficiency of 71.6 % were obtained. Moreover, taking advantage of PBAs' ion-selective properties for monovalent cations especially NH4+, this IME-RCDI achieved highly selective removal of cations compared to a RCDI with bare AC electrodes. The selectivity coefficients (Si/j) of NH4+ to divalent cations (such as Ca2+) and monovalent cations (such as Na+) were determined to be 2.15 and 1.95, respectively. These values are much higher than those obtained for AC electrodes, which were 0.3 and 1.07, respectively. Overall, this work demonstrates that the incorporation of PBAs in the i-IME-RCDI configuration offers superior desalination performance and selective removal capabilities for specific ions such as NH4+.

Removal of eutrophication agents from wastewater using glauconite-based sorbents

Excessive phosphorus and nitrogen in water and sediment may cause eutrophication, which poses a potential risk to drinking water safety and the sustainability of aquatic ecosystems. The research focuses on the removal of phosphates and ammonium ions from aqueous solutions using a new thermally and microwave-treated glauconite. The surface morphology of the samples was studied by SEM. BET surface area, pore volume, and pore size distribution were measured. Adsorption studies were carried out in static and dynamic conditions. The best fit for adsorption of both pollutants is given by the Langmuir-Freundlich and BET models. The calcined sample showed the lowest adsorption capacity for phosphate (1.78 mg/g) but the highest capacity for ammonium (20.67 mg/g). For the microwave-irradiated sample, the adsorption capacity for ammonium increases from 0.723 to 4.37 mg/g, while that for phosphate remains almost at the same level (101.21 mg/g). In dynamic conditions, phosphorus was most efficiently retained by natural glauconite (more than 60% retention rate), and ammonium nitrogen by glauconite that was thermally treated in a muffle furnace (more than 80% retention rate after 3 h).

Modelling clogging dynamics in groundwater systems using multiscale homogenized physics informed neural network (MHPINN)

Groundwater systems, or also commonly known as large-scale closed and saturated porous media systems in general, are important sources of potable water, especially in arid countries. However, maintenance of groundwater systems is operationally expensive and time-consuming, hence requiring field engineers to optimally predict the system’s breakthrough phase. To address this engineering challenge, this study developed an alternative physics informed machine learning model, termed as multiscale homogenized physics informed neural network (MHPINN), to model and predict the effluent discharge concentrations from closed and saturated porous media systems when removing different contaminants. The proposed MHPINN model mainly exploits the homogenization theory, coupled with multiscale perturbation analysis, for hydrodynamic modelling to extract important model input features pertaining to the pore-scale clogging behavior in porous media. Together with available experimental data, the extracted model features then set the input layer for training neural network model to predict the discharge concentration of emulated porous media groundwater systems. At the same time, the model training is performed with modified mean square error (MSE) cost function, based upon homogenized mathematical representations derived from a series of rigorous mathematical constructs and formulations, to better facilitate the model’s learning, especially under sparse data constraint. To verify the proposed methodology, MPINN is trained (and validated) with data obtained from five historical experimental studies, which emulated porous media systems to remove ammonium ions and fine-scaled colloids, to model and predict the discharge concentration in each study. Overall, MHPINN outperformed other conventional machine learning models (random forest, support vector machines, etc.) by obtaining higher predictive accuracy of around 4% on average from the model’s validation step across the five different experimental studies. Therefore, the predictive analysis underscored the effectiveness of MHPINN to combine both physics-based modelling and machine learning to model complex porous media systems, under sparse experimental data constraints, hence demonstrating the potential of the proposed methodology to extend to other physical systems.

Treatment and recovery of phosphate from submerged anaerobic membrane bioreactor effluent using thermally treated biowaste and powder activated carbon

This study presents a novel treatment system using a submerged anaerobic membrane bioreactor (SAnMBR) followed by adsorption onto thermally treated biowaste, and ending with a final treatment using powdered activated carbon (PAC). Despite limited phosphate and ammonium ion removal during SAnMBR operation, thermally treated eggshell (EGSL) and seagrass (SG) received SAnMBR effluent and enhanced phosphate recovery, achieving removal rates of 71.8–99.9% and 60.5–78.0%, respectively. The SAnMBR achieved an 85% COD removal, which was slightly reduced further by biowaste treatment. However, significant further reductions in COD to 20.2 ± 5.2 mg/L for EGSL effluent and 57.0 ± 13.3 mg/L for SG effluent were achieved with PAC. Phytotoxicity tests showed the SAnMBR effluent after PAC treatment notably improved seed growth compared to untreated wastewater. In addition, volatile organic compounds (VOCs) were significantly reduced in the system, including common wastewater contaminants such as dimethyl disulfide, dimethyl trisulfide, phenol, p-cresol, nonanal, and decanal. Fractionation analysis of the solid fraction, post-adsorption from both synthetic and domestic wastewater, indicated that for SG, 77.3%–94% of the total phosphorus (TP) was inorganically bound, while for EGSL, it ranged from 94% to 95.3%. This study represents the first attempt at a proof-of-concept for simultaneous treatment of domestic wastewater and phosphorus recovery using this integrated system.

Effect of Desilication on Indonesian Natural Zeolite for the Enhancement of Ammonium Ion Removal from Aqueous Solutions

Effect of Desilication on Indonesian Natural Zeolite for the Enhancement of Ammonium Ion Removal from Aqueous Solutions

Novel composite membrane(PES/Clay/Zeolite) for ammonium and sulfide ions removal from Sour water

Novel composite membrane(PES/Clay/Zeolite) for ammonium and sulfide ions removal from Sour water

Selective removal of ammonium ions with transition metal hexacyanoferrate (MHCF) electrodes

This study investigated the potential of using transition metal hexacyanoferrates (MHCF) to selectively capture NH4+ over Na+ in brine for nutrient recovery from wastewater. The electrochemical characteristics of five different MHCF (M is Ni, Cu, Fe, Co or Zn), known as Prussian blue analogues (PBA), was investigated using a hybrid capacitive deionization device, and their desalting capacity, stability and energy consumption were evaluated. By adjusting the mass ratio of electrodes, applied voltage, and ion concentration, the relationship between NH4+ removal and selectivity was explored. Results showed that all five MHCF electrodes exhibited high selectivity (> 4) for NH4+ over Na+, but the selectivity is not stable due to comprehensive factors (such as the structural stability of electrode, solution composition, and current density, etc.). Among them, the NiHCF electrode showing the best performance in terms of specific desalination capacity (∼1.23 mmol/g), charge efficiency (>80%), and stability (82.5% capacity retention after 50 cycles). This study demonstrates that PBA has promising potential as NH4+ selective electrodes for nutrient removal and recovery in wastewater.

CNT/copper hexacyanoferrate: A superior Faradic electrode for ammonium ion removal with stable performance and high capacity

The discharge of ammonium ion (NH4+) not only seriously threatens the ecological safety of the environment, but also causes the waste of valuable resources. Capacitive deionization (CDI) is an environmentally friendly and efficient NH4+ ion treatment and recovery technology. Herein, the NH4+-rich copper hexacyanoferrate (N-CuHCF) and carbon nanotube (CNT) complex (CNT/N-CuHCF) was formed by a simple and fast co-precipitation-ion exchange method, and used as the Faradic electrode to store NH4+ in the hybrid capacitive deionization (HCDI) system. Intriguingly, the etching efficiency of the ion exchange process produces the interconnected nanonetwork structure, endows the prepared material with larger surface area and abundant redox active sites, guarantees high pseudocapacitance contribution and reversible NH4+ intercalation/deintercalation, thus enabling an excellent ammonium ion removal performance. The CNT/N-CuHCF demonstrates a superior specific adsorption capacity (SAC) of 120.2 mg g−1, a low specific energy consumption (126.1 kJ molNH4Cl−1), and remarkable cycling stability. In addition, compared with Na+ and Mg2+, CNT/N-CuHCF has better affinity and selectivity for NH4+. The NH4+ intercalation mechanism and structure stabilization mechanism of N-CuHCF were revealed through a series of ex situ characterizations. This work provides some new illuminating insights for the design of high-performance ammonium ion removal CDI electrodes, and lays a foundation for the recovery of ammonium resources.