Additional Energy Input Research Articles

Magnetic recyclable Fe3O4@Ti3C2TX nanoparticles for high-efficiency solar membrane distillation

Over the last few years, solar energy has emerged as a sustainable energy which can replace traditional fossil energy sources. Solar evaporation systems are very dependent on the concentration of light-absorbing particles. However, solar evaporation systems have low water production rates and the used nanofluids usually causes secondary pollution. These problems seriously limit the wide application of solar evaporation techniques. In this work, we established a novel solar direct contact membrane distillation system combining Fe3O4@MXene light absorbing particles (Fe3O4 nanoparticles modified with Ti3C2Tx MXene) and membrane distillation, which could improve the water production rates and the used light-absorbing nanoparticles were easily separated by magnetic field for reuse. In this system, Fe3O4@MXene acts as an efficient photothermal conversion particle that heats the feedwater for membrane distillation by absorbing sunlight, eliminating the additional energy input. The test results showed that the water production rate of this system was superior to that of most published solar membrane distillation systems, which the flux could reach 2.26 kg/m2/h, and the nanoparticles could be almost completely recycled. The work not only provides a useful method of desalination using solar energy and membrane distillation, but also to reduce the materials consumption and overall operating cost.

Efficient air water harvesting of TpPa-1 COFs@LiCl composite driven by solar energy

Adsorbent-assisted air water harvesting (AWH) may help alleviate the current global freshwater scarcity crisis. However, the weak sorption capacity of various adsorbents and the high energy required to release water are two long-standing problems. Herein, we propose a class of green and clean adsorbent, TpPa-1@LiCl composite, whose sorption capacity is greatly improved to 0.37 and 0.80 ​g ​g−1 under 30% and 90% relative humidity (RH), respectively, and which has excellent stability, showing only a slight decrease (0.79%) after 10 sorption–desorption cycles (1400 ​min). This TpPa-1@LiCl composite can reach equilibrium within 2 ​h and undergo complete desorption in 30 ​min under air mass 1.5 ​G irradiation. A corresponding solar-driven AWH device can complete up to 4 sorption–desorption cycles per day, with each cycle capable of collecting 0.34 ​g ​g−1 water without additional energy input, which implies TpPa-1@LiCl composite has the potential for achieving sorption-assisted AWH with high efficiency and rapid cycling.

Liquid-gas phase transition enables microbial electrolysis cell to treat organic pollution and synchronously remediate nitrate-contaminated groundwater via hydrogenotrophic denitrification

Groundwater denitrification is challenged by a lack of electron donors and usually requires additional energy input or chemical agents. MEC can convert organic pollution into clean electron donor (hydrogen) through a gas-liquid phase transition. In this study, the MEC was combined with permeable bio-reactive barrier (PRB) as a hybrid system to achieved simultaneous organic waste removal, hydrogen production and groundwater remadition via long-distance hydrogenotrophic denitrification by biogas. The semi-hydrophobic PTFE-coated granular activated carbons (GAC) and hydrophilic GAC were filled as two kinds of biocarriers in PRBs, in which the hydrophobic PTFE surface coating improved hydrogen utilization. The PTFE-coated GAC maked the denitrification performance of PRB insensitive to hydrogen partial pressure within the tested range of 0.01–0.04 MPa and achieved effluent nitrate concentration of <20 mg L−1 within 12 h (The Water Quality Standard for Drinking Water Sources in China). The gas production in MECs was actively pumped to PRBs and spontaneously achieve negative pressure on the MEC side and positive pressure on the PRB side. The actively pumping of biogas induced negative pressure in MEC and positive pressure in PRB. The negative pressure improved current density by 18.6 ± 0.7% in MECs and the MEC-PRB hybrid system achieved a nitrate removal of 85.0 ± 0.8% in actual groundwater with an effluent concentration of 15.0 ± 0.8 mg L−1 at 72 h. This work demonstrated the feasibility of matching MEC and PRB as a novel hybrid system for organic pollution degradation and effective nitrogen removal in electron-donor-lacking groundwater.

A Review on Active Heat Transfer Enhancement Techniques within Latent Heat Thermal Energy Storage Systems

Renewable energy resources require energy storage techniques to curb problems with intermittency. One potential solution is the use of phase change materials (PCMs) in latent heat thermal energy storage (LHTES) systems. Despite the high energy storage density of PCMs, their thermal response rate is restricted by low thermal conductivity. The topic of heat transfer enhancement techniques for increasing thermal performance of LHTES systems has mainly focused on passive heat transfer enhancement techniques with less attention towards active methods. Active heat transfer enhancement techniques require external power supplied to the system. In this paper, recent advances in active heat transfer enhancement techniques within LHTES systems are reviewed, including mechanical aids, vibration, jet impingement, injection, and external fields. The pertinent findings related to the field are summarized in relation to the charging and discharging processes of PCMs. Suggestions for future research are proposed, and the importance of additional energy input for storage is discussed.

Spatial Development of Strong Storm-Induced Ionospheric Perturbations during 25–27 August 2018

The 25–27 August 2018 geomagnetic storm was the third largest storm in the 24th solar cycle. It was a surprising space event that originated from low-level solar activity. This study provides an overview of the temporal–spatial behaviors of plasma irregularities as functions of geographic longitude, latitude, and altitude using ground-based (GNSS receivers and ionosonde) instruments and space-borne Swarm satellites. The results not only reveal enhanced equatorial ionization anomaly (EIA) and hemispheric asymmetry over the Asian–Australian and American sectors at a particular time but also hemispheric asymmetric features of global ROT in the main and recovery phases. Additionally, this storm triggered positive plasma irregularities in altitudes of 100 to 150 km near the Auroral zone, and the changed ratio of bottom-side plasma irregularities exceeded 250%. This finding has been cross-validated by other instruments and models. Furthermore, the storm significantly affected the thermospheric O/N2 density ratio, equatorial electrojet, and vertical E×B drifts. The equatorial and mid-latitude plasma irregularities may be a combined action of thermospheric composition change, equatorial electrojet, and vertical E×B drifts. Finally, the storm induced positive Joule heating irregularities in the Auroral ionosphere in altitudes of 100 to 400 km with a maximum changed ratio of over 200%, as well as enhanced cross-Polar voltage to ~90 kv. The Polar ionospheric irregularities may be associated with additional energy input through particle precipitation, Joule heating, and ionospheric current intensification.

Enhancement of solar distiller performance by photovoltaic heating system

This study aims to improve the productivity of traditional multi-slope solar stills, which are still employed in isolated villages with no power and no clean drinking water. The conventional multi-slope solar still was equipped with a photovoltaic array system that heated the water through an electric heater submerged in the basin to increase the productivity of the conventional solar stills. This study analyzed and compared the productivity of a PV-coupled solar still (PVSS) with a solar still basin area of 0.64 m2 to that of a conventional solar still (CSS). The results showed that the productivity of the PVSS improved more than triple times (9.39–10.9 L/m2.day) during active mode compared to the CSS, which had a daytime solar still production without a PV system (passive mode) that varied between 2.2–2.34 L/m2.day. The daily efficiency of the passive mode without any additional external energy input was around 27%, which resulted in a distilled water yield of 1.4 L. However, when operated in active mode with supplementary energy inputs, such as electrical heating elements that were powered by solar panels, the daily efficiency of the solar still was approximately 44.8%, resulting in a distilled water yield of 6 liters. The payback period for PVSS was found to be two years. The main observation is that the PVSS has demonstrated its applicability for distillation improvement and a significant increase in production for the entire day when employing a clean energy source.

The “tornado” effect induced by magnetohydrodynamic convection in an electrolytic cell with a wire-electrode

High energy consumption is the key problem to be solved in water electrolysis for hydrogen production. Imposing magnetic field during electrolysis is proved to be a research-worthy method to reduce the required electrical energy, since the magnetohydrodynamic convection can be induced without additional energy input. Considering the structure of commercial electrolyzers, the magnetic field perpendicular to the electrode surface is most likely to be applied in practical engineering. But there is still a lack of research on the gas-liquid two-phase flow in the electrolytic cell under this condition. To avoid mutual blocking between a large number of bubbles and obtain clear two-phase flow images of the electrolysis process, a wire electrode is used as cathode to generate hydrogen bubbles in this work. The cell voltage is obviously reduced by external magnetic field, and an interesting “bubble tornado” is formed under the action of induced magnetohydrodynamic convection. The numerical simulation results and theoretical analysis indicate that: (1) the formation of the bubble chain is caused by low-pressure region along the vertical axis; (2) the unstable low-pressure region is the key factor leading to the formation of continuously deformed bubble chain; (3) the bubble dispersion may be related to Kelvin-Helmholtz flow instability. We anticipate our work being a starting point for the application of magnetic field in practical engineering.

Synergizing Electron and Heat Flows in Photocatalyst for Direct Conversion of Captured CO2

AbstractWe report a ternary hybrid photocatalyst architecture with tailored interfaces that boost the utilization of solar energy for photochemical CO2 reduction by synergizing electron and heat flows in the photocatalyst. The photocatalyst comprises cobalt phthalocyanine (CoPc) molecules assembled on multiwalled carbon nanotubes (CNTs) that are decorated with nearly monodispersed cadmium sulfide quantum dots (CdS QDs). The CdS QDs absorb visible light and generate electron‐hole pairs. The CNTs rapidly transfer the photogenerated electrons from CdS to CoPc. The CoPc molecules then selectively reduce CO2 to CO. The interfacial dynamics and catalytic behavior are clearly revealed by time‐resolved and in situ vibrational spectroscopies. In addition to serving as electron highways, the black body property of the CNT component can create local photothermal heating to activate amine‐captured CO2, namely carbamates, for direct photochemical conversion without additional energy input.

Synergizing Electron and Heat Flows in Photocatalyst for Direct Conversion of Captured CO2.

We report a ternary hybrid photocatalyst architecture with tailored interfaces that boost the utilization of solar energy for photochemical CO2 reduction by synergizing electron and heat flows in the photocatalyst. The photocatalyst comprises cobalt phthalocyanine (CoPc) molecules assembled on multiwalled carbon nanotubes (CNTs) that are decorated with nearly monodispersed cadmium sulfide quantum dots (CdS QDs). The CdS QDs absorb visible light and generate electron-hole pairs. The CNTs rapidly transfer the photogenerated electrons from CdS to CoPc. The CoPc molecules then selectively reduce CO2 to CO. The interfacial dynamics and catalytic behavior are clearly revealed by time-resolved and in situ vibrational spectroscopies. In addition to serving as electron highways, the black body property of the CNT component can create local photothermal heating to activate amine-captured CO2 , namely carbamates, for direct photochemical conversion without additional energy input.

Regulation of droplet impacting on superhydrophobic surfaces: Coupled effects of macrostructures, wettability patterns, and surface motion

Superhydrophobic surfaces have shown great application prospects due to their excellent water repellency in many applications involving fluid–surface interactions. As a ubiquitous fluid–surface interaction phenomenon, droplet impacting dynamics has a crucial effect on the application of superhydrophobic surfaces. In this Perspective, we summarize the basic process of droplet impacting on superhydrophobic surfaces and introduce the two most concerned parameters that describe the droplet impacting dynamics, i.e., the maximum spreading coefficient and the contact time. We then review two improvement strategies for superhydrophobic surfaces: one is to construct macrostructures and the other is to set wettability patterns on the surface. The former strategy shows great potential in reducing the droplet contact time, and the latter one can accurately regulate the behavior of impacting droplets. The motion of superhydrophobic surfaces also changes the droplet impacting dynamics due to the additional aerodynamic effect or energy input, which arouses attention recently. However, only the individual influence of each factor (e.g., macrostructures, wettability patterns, or surface motion) on the droplet impacting dynamics has been focused in literature, so we write this Perspective to emphasize the importance and urgency of studying the coupled effects of these three factors.

Surfactant sorption on a single air bubble in an ultrasonic standing acoustic wave field

Ultrasound application presents a promising non-intrusive way to enhance and facilitate mass transfer in aqueous systems. This enhanced mass transfer can influence the sorption processes in multiphase flows. Previous studies investigating the impact of ultrasound on sorption, have reported an increase in either desorption due to the rise in liquid temperature or adsorption due to the additional convective mass transfer resulting from acoustic streaming. In this study, low intensity ultrasound with a frequency of 36kHz was deployed to evaluate the sorption process of Triton X-100 on the surface of a single bubble, placed along the standing acoustic wave using profile analysis tensiometry. Furthermore, microscopic particle image velocimetry was used to understand the role acoustic streaming might play during different stages of the sorption process. Contrary to expectations, the results showed no considerable change in surface tension and sorption dynamics after sonicating both fresh and surfactant-loaded bubbles. The results of this study suggest that the observations from previous studies may be attributed to the additional energy input of the acoustic wave into the system rather than the presence of an external acoustic field.

Energetics of Shock-triggered Supersubstorms (SML < −2500 nT)

The solar wind energy input and dissipation in the magnetospheric–ionospheric systems of 17 supersubstorms (SSSs: SML < −2500 nT) triggered by interplanetary shocks during solar cycles 23 and 24 are studied in detail. The SSS events had durations ranging from ∼42 minutes to ∼6 hr, and SML intensities ranging from −2522 nT to −4143 nT. Shock compression greatly strengthens the upstream interplanetary magnetic field southward component (B s), and thus, through magnetic reconnection at the Earth’s dayside magnetopause, greatly enhances the solar wind energy input into the magnetosphere and ionosphere during the SSS events studied. The additional solar wind magnetic reconnection energy input supplements the ∼1.5 hr precursor (growth-phase) energy input and both supply the necessary energy for the high-intensity, long-duration SSS events. Some of the solar wind energy is immediately deposited in the magnetosphere/ionosphere system, and some is stored in the magnetosphere/magnetotail system. During the SSS events, the major part of the solar wind input energy is dissipated into Joule heating (∼30%), with substantially less energy dissipation in auroral precipitation (∼3%) and ring current energy (∼2%). The remainder of the solar wind energy input is probably lost down the magnetotail. It is found that during the SSS events, the dayside Joule heating is comparable to that of the nightside Joule heating, giving a picture of the global energy dissipation in the magnetospheric/ionospheric system, not simply a nightside-sector substorm effect. Several cases are shown where an SSS is the only substorm that occurs during a magnetic storm, essentially equating the two phenomena for these cases.

Photolysis of chlorite by solar light: An overlooked mitigation pathway for chlorite and micropollutants

Chlorite (ClO2−) is an undesirable toxic byproduct commonly produced in the chlorine dioxide and ultraviolet/chlorine dioxide oxidation processes. Various methods have been developed to remove ClO2− but require additional chemicals or energy input. In this study, an overlooked mitigation pathway of ClO2− by solar light photolysis with a bonus for simultaneous removal of micropollutant co-present was reported. ClO2− could be efficiently decomposed to chloride (Cl−) and chlorate by simulated solar light (SSL) at water-relevant pHs with Cl− yield up to 65% at neutral pH. Multiple reactive species including hydroxyl radical (•OH), ozone (O3), chloride radical (Cl•), and chlorine oxide radical (ClO•) were generated in the SSL/ClO2− system with the steady-state concentrations following the order of O3 (≈ 0.8 μΜ) > ClO• (≈ 4.4 × 10−6 μΜ)> •OH (≈ 1.1 × 10−7 μΜ)> Cl• (≈ 6.8 × 10−8 μΜ) at neutral pH under investigated condition. Bezafibrate (BZF) as well as the selected six other micropollutants was efficiently degraded by the SSL/ClO2− system with pseudofirst-order rate constants ranging from 0.057 to 0.21 min−1 at pH 7.0, while most of them were negligibly degraded by SSL or ClO2− treatment alone. Kinetic modeling of BZF degradation by SSL/ClO2− at pHs 6.0 – 8.0 suggested that •OH contributed the most, followed by Cl•, O3, and ClO•. The presence of water background components (i.e., humic acid, bicarbonate, and chloride) exhibited negative effects on BZF degradation by the SSL/ClO2− system, mainly due to their competitive scavenging of reactive species therein. The mitigation of ClO2− and BZF under photolysis by natural solar light or in realistic waters was also confirmed. This study discovered an overlooked natural mitigation pathway for ClO2− and micropollutants, which has significant implications for understanding their fate in natural environments.

Evaporator fabricated with accessible photothermal material derived from waste fallen leaves for highly efficient desalination

Direct solar steam generation (DSSG) has been considered to be one of the most promising technologies to alleviate the significant threat of freshwater scarcity worldwide. Among these, the solar-thermal evaporator based on carbonized natural materials is a very promising and environmentally friendly alternative. However, due to the high energy consumption and expensive equipment requirements in the preparation of conventional carbon-based materials, developing simple and low-cost material preparation methods without additional energy input is still challenging. Fallen leave is a widely distributed and renewable waste biomass that is easily accessible, which can be made into evaporators for desalination. Herein, the biomass waste fallen leaves were selected as raw material to synthesize carbonized fallen leaves (CFL) by simple sulfuric acid carbonization without energy input. Then the CFL were sprayed onto artificial deerskin towels (ADT), and finally, the portable CFL@ADT evaporators were constructed. Our CFL@ADT evaporator with 1 wing shows a solar absorptance of 97.4 % and an evaporation rate of 1.50 kg m−2h−1 in water with an evaporation efficiency of up to 95 %. The CFL@ADT evaporators provide an attractive alternative to conducting biomass waste resource utilization as well as achieving efficient and economical desalination during the day and self-cleaning at night.

Molecular basis of eIF5A-dependent CAT tailing in eukaryotic ribosome-associated quality control.

Ribosome-associated quality control (RQC) is a conserved process degrading potentially toxic truncated nascent peptides whose malfunction underlies neurodegeneration and proteostasis decline in aging. During RQC, dissociation of stalled ribosomes is followed by elongation of the nascent peptide with alanine and threonine residues, driven by Rqc2 independently of mRNA, the small ribosomal subunit and guanosine triphosphate (GTP)-hydrolyzing factors. The resulting CAT tails (carboxy-terminal tails) and ubiquitination by Ltn1 mark nascent peptides for proteasomal degradation. Here we present ten cryogenic electron microscopy (cryo-EM) structures, revealing the mechanistic basis of individual steps of the CAT tailing cycle covering initiation, decoding, peptidyl transfer, and tRNA translocation. We discovered eIF5A as a crucial eukaryotic RQC factor enabling peptidyl transfer. Moreover, we observed dynamic behavior of RQC factors and tRNAs allowing for processivity of the CAT tailing cycle without additional energy input. Together, these results elucidate key differences as well as common principles between CAT tailing and canonical translation.

Application of Vortex Induced Vibration Systems to Improve Vertical Mixing and Create Light/Dark Cycles for Enhanced Algal Biomass Productivity in Raceway Ponds

Limited light availability due to insufficient vertical mixing is one of the main drawbacks of raceway ponds (RWPs), the most common type of microalgae cultivation system. In this study, we have investigated the application of vortex induced vibration (VIV) systems to improve vertical mixing in order to enhance algal biomass productivity. The system consists of a cylinder submerged parallel to the bottom in the pond with two springs attached at its ends. The cylinder oscillates perpendicularly to the flow direction at the pond to increase vertical mixing. A VIV system, which requires no additional energy input, was installed in a 0.3 m deep raceway pond and continuous cylinder oscillation was successfully achieved. Cylinder oscillation frequency of 1.24 s−1 and amplitude of 6.5 cm have been obtained experimentally for 0.3 m s−1 flow velocity. Numerical simulations were carried out with experimental parameters using CFD code and were in good accordance with experimental results. Numerical analysis revealed that it is possible to create high frequency light/dark cycles; mean light/dark cycle frequencies were found to be 2.33 s−1, 5.28 s−1 and 21.17 s−1, at lowermost, middle and uppermost cylinder positions, respectively. Enhanced velocity magnitude of 0.3 m s−1 was achieved in the vertical direction; vertical motion of flow resulting from cylinder oscillation covers about two thirds of pond depth. Effectiveness of the VIV system on biomass growth was also verified by comparative Chlorella vulgaris cultivation under outdoor conditions. It has been observed that the VIV system installed reactor enhanced biomass production capacity by over 20% compared to the control pond. These results indicate that the presented method possesses a potential for enhanced algal biomass production without significant increase in installation and operating costs.

Qualitative Considerations on the Influence of the Gases Water Vapor and Carbon Dioxide on the Global Environmental Temperature from the Point of View of Textbook Knowledge

The solar radiation that hits the Earth conditions the dynamic equilibrium that prevails on our planet. Consideration of basic physical-chemical knowledge shows that this equilibrium can be changed only by additional energy input or prolongation of the interaction time solar radiation—Earth matter. The contribution of H2O(g) and CO2 to the protection of the earth against excessive warming is experimentally and by basic laws of nature secured. For a greenhouse effect, a part of the earth radiation must be radiated back to the earth and then into space. If one understands the earth radiation as radiation of a black body with the average global environmental temperature, from all vibrations normal modes of the gases H2O(g) and CO2 only the bending mode of CO2 with 4% of the solar constant can contribute beside the rotational modes of the water to the greenhouse effect. The contributions of the normal modes of H2O(g) and CO2 to the heat capacity of the atmosphere are negligible. Therefore, in agreement with studies by K. Ångström, CO2 contributes only to the stabilization of the global environmental temperature. Whether the use of renewable energies can actually at least mitigate the increase of the environmental temperature is by no means certain but must be examined for each individual case. With certainty, this goal can only be achieved by reducing the energy consumption of mankind.

A membrane-based seawater electrolyser for hydrogen generation.

Electrochemical saline water electrolysis using renewable energy as input is a highly desirable and sustainable method for the mass production of green hydrogen1-7; however, its practical viability is seriously challenged by insufficient durability because of the electrode side reactions and corrosion issues arising from the complex components of seawater. Although catalyst engineering using polyanion coatings to suppress corrosion by chloride ions or creating highly selective electrocatalysts has been extensively exploited with modest success, it is still far from satisfactory for practical applications8-14. Indirect seawater splitting by using a pre-desalination process can avoid side-reaction and corrosion problems15-21, but it requires additional energy input, making it economically less attractive. In addition, the independent bulky desalination system makes seawater electrolysis systems less flexible in terms of size. Here we propose a direct seawater electrolysis method for hydrogen production that radically addresses the side-reaction and corrosion problems. A demonstration system was stably operated at a current density of 250 milliamperes per square centimetre for over 3,200 hours under practical application conditions without failure. This strategy realizes efficient, size-flexible and scalable direct seawater electrolysis in a way similar to freshwater splitting without a notable increase in operation cost, and has high potential for practical application. Importantly, this configuration and mechanism promises further applications in simultaneous water-based effluent treatment and resource recovery and hydrogen generation in one step.

Solar desalination chimneys: Investigation on the feasibility of integrating solar chimneys with humidification–dehumidification systems

The feasibility of integrating a solar chimney with a humidification–dehumidification desalination system resulting in a solar desalination chimney is examined in this work using combined validated mathematical models. In the proposed system, the solar energy is used to create buoyant hot air that flows through a humidification and dehumidification system. A small turbine can be housed in the chimney to provide energy for pumping water if there is sufficient airflow. This integrated solar desalination chimney uses solar irradiation as an energy source for buoyant air motion and might not require additional energy input. Data available in the literature for experimental solar chimney setups were examined to evaluate the potential of this novel desalination approach which utilizes solar energy. A validated humidification–dehumidification model is used to investigate desalination capacity. Based on the integrated model, a large-scale solar chimney power plant in Manzanares, as an example, could operate efficiently with a turbine providing power to operate the desalination system and provide freshwater for over 800 households. Moreover, numerical simulation shows that small-scale integrated solar chimney desalination systems could be placed on the roof of a residential building and produce about 600 liters of freshwater daily to satisfy freshwater of a household.

Low-energy ammonium recovery by a combined bio-electrochemical and electrochemical system

Bio-electrochemical systems (BESs) can recover ammonium at low specific energy inputs and can produce hydrogen gas. A reason hampering development of large-scale applications for ammonium recovery is the general instability of the bio-generated current and the thereby variable TAN (ammonia and ammonium) effluent concentrations. Electrochemical systems for ammonium recovery, such as the hydrogen recycling electrochemical system (HRES), can fine-tune the applied current, but require higher specific energy inputs than BES, and may require an additional external hydrogen supply in case of HRES. This research presents for the first time an integrated BES and HRES system for ammonium recovery to combine the advantages of both types of systems to achieve high TAN removal efficiency at low specific energy input. The HRES was able to partially compensate for BES instability, which resulted in an overall high TAN removal efficiency (89–95 %) at an increased energy demand of 5.2–10.2 MJ/kgN. When the BES was performing stably and efficiently, the HRES removed almost all of remaining TAN at up to 99.8 % overall TAN removal efficiency, requiring 9.2 MJ/kgN. The combined system can remove TAN down to much lower effluent concentrations at little to no additional energy input. These results indicate that combining BES and HRES in one system can result in TAN recovery that is more efficient than in each system separately, which could facilitate new application possibilities for (bio-)electrochemical ammonium recovery.