Salt Adsorption Research Articles

Graphene oxide modulation of lignin-derived porous nanosheets for efficient desalination

Carbon nanomaterials derived from biomass have focused much attention due to their porous nanostructures and large specific surface area. This is more in line with the concept of sustainable development. Herein, the carbon nanosheets (GALC) derived from modulating lignin by graphene oxide (GO) are successfully assembled via simple confinement template action. The confined template effect of GO efficiently assembles lignin molecules into two-dimensional nanosheet structures. The interaction of oxygen-containing groups on the surface of GO with the NH2 groups of lignin makes the generated porous nanostructures more stable. The adsorption performance is further improved. The GALC shows the optimum electrochemical bilayer characteristics with a specific capacitance of 133 F·g−1. The desalination amount reaches 20.97 mg·g−1 with an average salt adsorption rate of 1.82 mg·g−1·min−1 during desalination process. The retention of desalination capacity is 90.18 %. This work strengthens the green chemistry implications of synthesizing porous carbon nanomaterials using biomass resource.

Influence mechanism of Fe(II/III) doping on the adsorption of methylamine salts on kaolinite surfaces elucidated through DFT calculations

To investigate the effect of Fe(II/III) doping on the microscopic mechanism of methylamine salt hydrophobic modifiers on kaolinite surfaces, the adsorption characteristics of various methylamine cations on Fe(II/III)-doped kaolinite (denoted as Fe(II/III)-Kao) surfaces are calculated by density functional theory (DFT). The simulation results, including the Fukui index, adsorption energy, Mulliken bond populations, and charge analysis, reveal that Fe(II/III) doping enhances the surface activity of kaolinite, with significant effects observed in proximity to the doping site. Consequently, Fe(II/III) doping strengthens the interaction between methylamine cations and kaolinite surfaces. The adsorption mechanism of various methylamine cations on Fe(II/III)-Kao surfaces is attributed to a combination of hydrogen bonding and electrostatic attraction, with electrostatic attraction dominating the adsorption process. By comparing the adsorption energy of methylamine cations and alkyl carbon chains on Fe(II/III)-Kao surfaces, it becomes evident that the alkyl carbon chain has minimal impact on the adsorption of the hydrophobic modifier on Fe(II/III)-Kao surfaces. This finding confirms that the ammonium salt hydrophobic modifier primarily adsorbs onto Fe(II/III)-Kao surfaces through its polar head groups. The research results establish a theoretical foundation for further investigations on fine clay particle interface control and hydrophobic modifier design, ultimately guiding practical production processes.

Mesopore-enhanced graphene electrodes with modified hydrophilicity for ultrahigh capacitive deionization

Capacitive deionization (CDI) technology represents a potent approach towards energy-efficient and sustainable access to potable water, with minimal environmental impact. However, the ion removal capacity of CDI systems remains inadequate for desalination of saline water. Herein, mesopore-enhanced graphene foam with modified hydrophilicity via O2-plasma treatment (MGFP) is proposed for ultrahigh CDI. This developed MGFP encompasses abundant mesopores, outstanding electrical conductivity and good hydrophilicity, enabling fast ions migration, efficient solution/pores contact and high adsorption capacity. As such, MGEP delivers a high specific capacitance of 156.64 F g−1 at 1 mV s−1, and a maximum salt adsorption capacity (SAC) up to 40.76 mg g−1 (1000 mg L−1, 1.2 V), much higher than most of the CDI systems leveraging the carbon-based materials. What's more, MGFP can be employed in the treatment of wastewaters containing various heavy metals, with the SAC of 89.96, 83.38, and 91.80 mg g−1, as for CuCl2, CoCl2, and NiCl2 (1000 mg L−1, 1.6 V), respectively. This well-developed MGFP undoubtedly presents a promising material platform within the CDI system, effectively tackling the pressing concern of water scarcity.

Enhanced hybrid capacitive deionization performance by the mass balance of electrodes

The ion removal capacity of carbon based capacitive deionization (CDI) is limited by the double-layer mechanism. Replacing one electrode of the conventional carbon-based symmetric CDI with a battery-like ion insertion material to obtain hybrid capacitive deionization (HCDI) can significantly improve the adsorption capacity. Various ion insertion materials have been adopted for HCDI, however, how to optimize the performance of the HCDI system by matching the two electrodes with different ions removal mechanism remains challenging. In this work, a HCDI desalination cell was demonstrated by using NaTi2 (PO4)3/reduced graphene oxide composites (NTP-rGO-700) as the cathode and activated carbon (AC) as the anode. Based on the mass balance strategy of electrodes and the electrochemical behavior of hybrid capacitors with different AC:NTP-rGO-700 mass ratios, the HCDI desalination cell was assembled with the optimal AC:NTP-rGO-700 mass ratio of 2:1. At an operating voltage of 1.6 V and a current density of 125 mA·g−1, the specific adsorption capacity (SAC) of the HCDI cell can reach 51 mg·g−1 with an average salt adsorption rate (ASAR) of 2 mg·g−1·min−1, and the energy consumption (Em) is 136.53 kJ·mol−1. This work provides an efficient approach for developing high performance HCDI cell.

Unraveling the Ion Uptake Capacitive Deionization of Sea- and Highly Saline-Water by Sulfur and Nitrogen Co-Doped Porous Carbon Modified with Molybdenum Sulfide.

In parallel to the depletion of potable water reservoirs, novel technologies have been developed for seawater softening, as it is the most abundant source for generating deionized water. Although salt removal at subosmotic pressures and ambient temperatures by applying low-operating potentials with high energy efficiency made capacitive deionization (CDI) an advantageous water-softening process, its practical application is limited by insufficient ion removal capacity and low concentration influent. The performance of a CDI system is in progress with engineering the electrode active materials, also facilitating the advance design in highly saline- and seawater study. Herein, an innovative strategy was developed to provide high-performance CDI systems based on efficient and electrochemical ion-uptake active materials with a simple initial preparation. Nitrogen-doped porous carbons (N-pCs) received benefits from a high specific surface area and good surface wettability. The N-pCs were modified with molybdenum oxide/sulfide intercalative array and developed as CDI electrode active materials for desalination of both low/medium saline- and seawater. The MoS2/S,N-pC electrode materials exhibited perfect optimized salt adsorption capacity (SACs) of 47.9 mg g-1 when compared to N-pC (37.9 mg g-1) and MoO3/N-pC (39.6 mg g-1) counterparts at 1.4 V in a 750 ppm NaCl solution. In addition, the assembled CDI cells exhibited reasonable cycle stability and retained 96.7% of their initial SAC in continuous CDI cycles for 128,000 s. The fabricated CDI cell rendered an excellent salt removal efficiency (SRE, %) of 13.34% from the real seawater sample at 1.2 V. In detail, the SRE % of the NaCl, KCl, MgCl2, and CaCl2 soluble salts with respect to seawater sample exhibited a remarkable SRE % of 30.8%, 36%, 32.6%, and 19.3%, respectively. These SRE % values (>13.34%) provide convincing evidence on the reasonable ion uptake capability of the fabricated CDI cells for removing Na+, K+, Mg2+, and Ca2+ ions compared to other soluble component. The advanced cell design parallel to the promising outcomes provided herein makes these CDI systems immensely propitious for efficient water softening.

Structure of microemulsions in the continuous phase channel

We have studied the microemulsion and lamellar phases of two of the most commonly described systems based on nonionic C12E5 and ionic AOT surfactants. We show that C12E5 is best described by the symmetric disordered open connected lamellar model (DOC-lamellar), contrary to the more commonly employed standard flexible model. In the case of AOT, the bicontinuous microemulsion structure is best described by the standard flexible model at high temperatures. Around room temperature, connected cylinders in a molten cubic crystal phase are the only description which corresponds to the data. In the lamellar phase, around one third of the available surface area is lost in fluctuations and defects. Comparing structurally predictive models with results from conductivity measurements show that salt adsorption in the hydrated ethoxy groups is dominant for C12E5 (nonionic). For AOT, our conductivity measurements clarify the role of tortuosity versus cation absorption.

Boosting capacitive deionization of monovalent and hardness ions using Ti3C2Tx MXene as an intercalation-type pseudocapacitive electrode

MXene is a promising electrode material for energy storage and capacitive deionization (CDI) applications. In this study, a viable approach was developed to synthesize Ti3C2Tx at different LiF/Ti3AlC2 mass ratios of 0.5 – 2.0 for the enhanced CDI to remove different cations including hardness (Mg2+ and Ca2+), salt (Na+), and ammonium (NH4+) ions. The Ti3C2Tx was fabricated using the hydrothermal method in the presence of LiF and HCl. The optimal mass ratio of 1.0 results in the formation of hydrophilic and well-delaminated nanosheets. Moreover, the Ti3C2Tx-1 shows an interconnected meso-macroporous structure with a specific surface area of 48.4 m2/g. The Ti3C2Tx MXene exhibits an exceptional electrochemical performance with a specific capacitance of 540 F g−1 at 5 mV s−1 in the presence of 1 M H2SO4. A remarkable desalination performance with the salt adsorption capacity (SAC) of 39.7 mg g−1 is obtained. The well-suited lattice fringe and inter-connected porous structure of the Ti3C2Tx nanosheets accelerate the electron transport, which can maintain the cyclability over 50 cycles. This enhanced electron transport leads to an improved deionization capability during the CDI process. Moreover, the Ti3C2Tx-based CDI device exhibits prominent selectivity for hardness ions with SACs of 43.8 and 39.5 mg g−1 for Ca2+ and Mg2+, respectively. The SAC of NH4+ can also be up of 39.7 mg g−1 at 1000 mg L−1. Results in this study clearly elaborate the promising potentiality for the utilization of MXene as an effective electrode material for desalination and other electrochemical applications.

Friedel’s Salts Synthesis and Adsorption Applications in the Removal of As(III) and Se(IV) from Desulfurization Wastewater

Friedel’s Salts Synthesis and Adsorption Applications in the Removal of As(III) and Se(IV) from Desulfurization Wastewater

In Vitro Lipid Lowering Effect of Mixed Carboxymethyl Dietary Fiber from Rosa sterilis Pomace

AbstractThe carboxymethylation of the soluble and insoluble dietary fiber (DF) of Rosa sterilis pomace (RSP) can improve their properties. In this study, the carboxymethyl soluble DF (CSDF) and carboxymethyl insoluble DF (CIDF) of RSP are mixed to prepare the CTDF1/3 (CSDF:CIDF = 1:3) based on previous research, and the lipid lowering effect of CTDF1/3 is evaluated by the cholesterol and bile salt adsorption capacity in vitro. Results show that the cholesterol adsorption content (50.82 mg g−1) of CTDF1/3 is higher than that (35.18 mg g−1) of the RTDF1/3 (RSP soluble dietary fiber:RSP insoluble dietary fiber = 1:3). The adsorption content of CTDF1/3 for sodium taurocholate, sodium deoxycholate, sodium glycocholate, sodium cholate is 55.38%, 21.95%, 39.26%, 100.0% higher than that of RTDF1/3. The adsorption rate of cholesterol and bile salts increases with the CTDF1/3 addition and the adsorption time and finally reaches equilibrium. The initial stage of adsorption (0–20 min) belongs to the rapid adsorption stage, which is followed by equilibrium. At more than 120 mg of CTDF1/3, CTDF1/3 has little effect on the cholesterol and bile salt adsorption rate. The cholesterol and bile salts adsorption content decrease gradually with the increase of CTDF1/3 addition and tend to adsorption balance.

Tailoring B, N-Enriched Carbon Nanosheets via a Gelation-Assisted Strategy for High-Capacity and Fast-Response Capacitive Desalination.

Designing high-performance carbonous electrodes for capacitive deionization with remarkable salt adsorption capacity (SAC) and outstanding salt adsorption rate (SAR) is quite significant yet challenging for brackish water desalination. Herein, a unique gelation-assisted strategy is proposed to tailor two-dimensional B and N-enriched carbon nanosheets (BNCTs) for efficient desalination. During the synthesis process, boric acid and polyvinyl alcohol were cross-linked to form a gelation template for the carbon precursor (polyethyleneimine), which endows BNCTs with ultrathin thickness (∼2 nm) and ultrahigh heteroatoms doping level (14.5 atom % of B and 14.8 atom % of N) after freeze-drying and pyrolysis. The laminar B, N-doped carbon enables an excellent SAC of 42.5 mg g-1 and fast SAR of 4.25 mg g-1 min-1 in 500 mg L-1 NaCl solution, both of which are four times as much as those of activated carbon. Moreover, the density functional theory (DFT) calculation demonstrates that the dual doping of B and N atoms firmly enhances the adsorption capacity of Na+, leading to a prominent chemical SAC for brackish water. This work paves a new way to rationally integrate both conducive surface morphology and systematic effects of B, N doping to construct high-efficiency carbonaceous electrodes for desalination.

Novel low-cost steel slag porous ceramic-based composite phase change material: An innovative strategy for comprehensive utilization of steel slag resources

This work creatively proposes a novel and low-cost steel slag porous ceramic (SSPC)-based NaNO3 salt composite phase change material (PCM) using industrial solid waste steel slag as the main raw material. In this study, the foaming-gel casting process prepares SSPC with high porosity (77–83%) and mechanical strength (0.36–1.13 MPa), which shows good adsorption of NaNO3 salts. The spontaneous infiltration method prepares and characterizes the NaNO3/SSPC composite PCM by performance properties. The results show that the NaNO3 salt is uniformly adsorbed in the pores of SSPC with good chemical compatibility, and the maximum filling rate reaches 86.26%. The porous media can effectively prevent the leakage of molten NaNO3 salt. The prepared composite PCMs have lower melting and freezing temperatures, lower subcooling by 5.47 °C, and higher thermal conductivity by 121.6% compared to pure NaNO3 salt. The latent heat retention of the composite after 50 thermal cycles is more than 96%, with good thermal reliability. Finally, a prospective process of using steel slag to prepare composite PCMs for collecting and storing waste heat from the steel industry is proposed. Reusing steel slag and storing waste heat from the steel industry are realized, both beneficial for sustainable development.

Maximum salt adsorption tracking in capacitive deionization cell powered by photovoltaic solar panel

Photovoltaic (PV) systems are considered as a support unit and eco-friendly energy source for the desalination system. If the surface of the desalination plant is covered by PV cells, it is possible to produce self energized desalination plants. Capacitive deionization (CDI) is a water purification technology known for its reduced energetic footprint. The cells are supplied with Direct current (DC) power which makes the application of the PV panels logically intuitive. Conventional existing PV maximum power point trackers (MPPT) are similar to each other in hardware as electrically DC modulated and operated, but different in software. Through different algorithms, existing PV power trackers aims battery charging or grid-tie exportation as application. In this study, a new power tracking using the water flow control is presented as an adapted solution for water desalination using the solar power. The developed algorithm is based on Maximum Salt Adsorption Tracking (MSAT). The proposed algorithm shows a comparative performance as other tracking algorithms under varying radiations. Besides, MSAT brings considerable lower costs by eliminating the need of any storage unit and any DC to DC converters. The developed controller is described in detail and comparative simulated/experimental analysis and performance evaluation are presented.

N, P-doped carbon nanorings for high-performance capacitive deionization

The developments of efficient carbonaceous materials are of significant importance to break through the bottlenecks of the traditional electrodes for capacitive deionization (CDI). Herein, we reported a simultaneous MOF-on-MOF growth combined with the MOF-etching strategy for the tailoring of MOF/MOF nanorings. Afterwards, N, P co-doped carbon rings (NPC-Rings) was synthesized through the thermal transformation of MOF/MOF nanorings and followed by the phosphidation activation. Taking advantage of such hierarchically porous structures, the NPC-Rings exhibited a high adsorption capacity of 43.0 mg g−1 in a 500 mg L−1 NaCl solution, fast salt adsorption rate, and superior capacity retention stability of 90.4% after 100 cycles. Finite element simulations further revealed that the unique structure of the NPC-Rings considerably promoted the current density and generates charge migration, thereby providing stronger salt adsorption capacity.

Faster bipolar capacitive deionization with flow-through electrodes

Capacitive deionization (CDI) is an emerging technology in water cleaning applications. Bipolar electrode modules are promising for upscaling CDI systems by applying a high voltage over a stack of cells. Previous experiments indicate around 3 times faster removal rate can be achieved with a 5-cell stack of flow-between electrodes. In this work, we present the first flow-through bipolar CDI design. Surprisingly, the effective average salt adsorption rate (ASAR) of a 5-cell stack was around 10 times higher per electrode mass. The flow-through design allows for faster ion transport to match the higher charging rate. Also, the floating electrodes discharge near-instantaneous by internal short-circuit upon the removal of potential, leaving almost twice as much time for charging in a cycle. Resistance is lowered due to the removal of internal compartments in the design, and the benefits of flow-through devices outweigh any potential higher energy cost of mass transport. The high voltage at the extreme electrodes poses a risk of electrode oxidation but optimized device operation controls this risk by constraining the voltage locally. For the same reason, the device is best adapted for the deionization of moderate to low ionic concentrations, such as river water, well water, or municipal water. In summary, this work provides a simpler yet highly effective way of scaling up CDI for water-cleaning applications.

Gas exfoliation induced N, S-doped porous 2D carbon nanosheets for effective removal of copper ions by capacitive deionization

Using capacitive deionization to remove heavy metal ions from water has received much attention, but the inferior salt adsorption capacity (SAC) of electrode materials has always limited its practical application. Herein, N, S co-doped two-dimensional (2D) porous glucose derived carbon nanosheets (NSPGC) was successfully fabricated, utilizing the gas exfoliation by calcination of thiourea. The NSPGC demonstrates distinct 2D lamellas, high specific surface area (2529 m2 g−1), hierarchical pore structure and high wettability. In electrochemical tests, a high specific capacitance (127 F g−1) and electrons/ions transport performance can be achieved in the NSPGC, moreover it showed a prominent SAC of 206.57 mg g−1 and recoverability in 100 mg L−1 CuSO4 solution. Moreover, the density functional theory (DFT) calculation manifested the intrinsic affinity of Cu2+ improved by N, S co-doping, which played an essential role in enhancing the Cu2+ removal performance of CDI. Our work provided a new insight into the preparation of high-performance CDI electrode materials for Cu2+ removal and promoted the application of CDI in heavy metal wastewater.

High-performance nitrogen-doped porous carbon electrode materials for capacitive deionization of Industrial salt-contaminated wastewater

The increasing demand for efficient and sustainable solutions in the field of energy storage and water desalination has sparked research in the development of supercapacitors and capacitive deionization (CDI) cells. This study presents a scalable and eco-friendly process for the preparation of N-doped polyhedral macrotube carbon arrays with a multihole cross-sectional profile. These arrays were synthesized from lotus stems (N-ALS) through carbonization at 500 °C and activation at 700 °C. The resulting material offers a high density of adsorption sites and good conductivity, making it suitable for use as electrodes in both supercapacitors and CDI cells. The N-ALS electrodes exhibit a high specific capacitance of 221.34 F g−1 at a scan rate of 2 mV s−1 and excellent cycling stability, as well as a salt adsorption capacity (SAC) of 26.07 mg g−1 at an applied voltage of 1.4 V and 85 % retention after 50 desalination-regeneration cycles in CDI cells, outperforming traditional activated carbon electrodes.

Carbon-based electrode materials with ion exchange membranes for enhanced membrane capacitive deionization

Potable clean water is in high demand for human life. Numerous technologies like reverse osmosis, flash distillation and electrodialysis are employed and explored to overcome the scarcity of potable water. Last decade has witnessed great attraction of researchers towards membrane capacitive deionization (MCDI) as an alternative technology for water desalination. MCDI holds ability to compete with benchmark desalination techniques as it involves adsorption of ions by porous carbon material on application of low voltage (<1.4 V). Ions are desorbed back into the stream on reversing the potential hence, regenerating the electrodes. Addition of ion exchange membranes enhances the desalination efficiency by reducing the effect of co-ions, which is not possible in traditional capacitive deionization (CDI). Present study aims to synthesize and explore the best fit carbon-based material for MCDI. SPEEK and QPPO polymers were used for CEM and AEM preparation over the porous carbon materials respectively. SEM, XRD and Raman spectroscopy were used to investigate the structural information about carbon materials. Nyquist plots were obtained to analyze diffusive behavior and formation of electrolyte double layer (EDL) on electrode-electrolyte interface. Capacitive behavior of the electrodes was analyzed through cyclic voltammetry (CV) and Galvanostatic charge discharge (GCD). Water desalination performance of membrane coated carbon materials was observed through batch-mode MCDI set-up. Important CDI parameters like salt adsorption capacity (SAC) and specific capacitance were also calculated to evaluate performance of the prepared MCDI electrodes. Among all four synthesized materials, CMGO (carbon spheres modified graphene oxide) reports highest SAC value i.e. 22.5 mg g−1 which suggest CMGO as a promising material for large scale MCDI application.

The successive infiltration of various saline waters accelerates the infiltration processes and enhances the salt leaching in a coastal saline soil

AbstractThe local saline water resource has been widely used for soil water and salt managements in saline‐alkali area. The soil desalinization is strongly affected by the infiltration mode, and the melting saline ice infiltration can obtain soil salt leaching effectively. In this work, four melting sections (S1, S2, S3, and S4) were divided artificially according to the changes in meltwater from 5 (W5), 10 (W10), and 15 g L−1 (W15) ice. Various saline water samples of the above four sections with different salinities and volumes were prepared and infiltrated successively into soil columns that were packed with the coastal saline soils. The infiltration parameters, distribution patterns of soil moisture, salt, and sodium adsorption ratio (SAR), and soil desalinization in different sections were investigated and analyzed. Results showed that the infiltration of higher salinity water in the initial section increased the infiltration rates of slightly saline and fresh water in the last section. A greater infiltration rate, cumulative infiltration, and infiltration depth were ranked as W5 &lt; W10 &lt; W15. Moreover, the faster infiltration process obtained higher soil water contents throughout the S1, S1 + S2, and S1 + S2 + S3 sections, and more water was ultimately distributed in the deeper soil layer (S1 + S2 + S3 + S4 section). Both the soil salt and SAR increased initially (Section S1) and then decreased in the following sections; &gt;80% of the total leached salt loads occurred in the S2 section for all treatments. Lower levels of soil salt contents and SAR developed within the later infiltration sections. Ultimately, the 30 cm desalinization layer was obtained among all treatments, and the treatments corresponding to the saline ice with higher salinity acquired lower salt contents and SAR values. These results indicate that the successive infiltration of water with various salinity levels, characterized by meltwater from saline ice, accelerated the infiltration process, and resulted in an obvious soil desalinization effect on the coastal saline soil.

Study on the adsorption mechanism of the sodium lignosulphonate on the surface of the selected plastics as a potential solution for plastics waste management

Separating different components of a plastic mixture is crucial in its recycling. Among the different separation techniques, flotation was selected as a cheap, non-toxic, and efficient process. Basis of the technique refers to the selective adsorption of a depressant on the plastics surface which cause the alteration in the surface energy of the plastic. Adsorption of the lignosulfonic acid sodium salt (SL) on the surface of the selected available plastics in the waste stream was studied. Plastics used in this study were Polyvinylchloride (PVC), acrylonitrile-butadiene-styrene polymer (ABS), polystyrene (PS), polypropylene (PP), polyoxymethylene (POM), and polycarbonate PC. It results showed that SL adsorbed on the surface of the selected plastics considerably. It was evidenced by the measured equilibrium adsorption capacities ( [Formula: see text] ) of the SL and also, the SEM and AFM images. SL adsorbed on the plastic surface in the sequence of [Formula: see text]. Also, the parameters of the Freundlich and Langmuir adsorption models were derived. Experimental data fit with the mentioned models appropriately. However, for the most studied plastics, the Freundlich model was more suitable. As important conclusion, PP separated from plastics mix using the flotation separation technique with the aid of SL as a depressant.

A Comparison of Capacitive Deionization and Membrane Capacitive Deionization Using Novel Fabricated Ion Exchange Membranes.

Another technique for desalination, known as membrane capacitive deionization (MCDI), has been investigated as an alternative. This approach has the potential to lower the voltage that is required, in addition to improving the ability to renew the electrodes. In this study, the desalination effectiveness of capacitive deionization (CDI) was compared to that of MCDI, employing newly produced cellulose acetate ion exchange membranes (IEMs), which were utilized for the very first time in MCDI. As expected, the salt adsorption and charge efficiency of MCDI were shown to be higher than those of CDI. Despite this, the unique electrosorption behavior of the former reveals that ion transport via the IEMs is a crucial rate-controlling step in the desalination process. We monitored the concentration of salt in the CDI and MCDI effluent streams, but we also evaluated the pH of the effluent stream in each of these systems and investigated the factors that may have caused these shifts. The significant change in pH that takes place during one adsorption and desorption cycle in CDI (pH range: 2.3-11.6) may cause problems in feed water that already contains components that are prone to scaling. In the case of MCDI, the fall in pH was only slightly more noticeable. Based on these findings, it appears that CDI and MCDI are promising new desalination techniques that has the potential to be more ecologically friendly and efficient than conventional methods of desalination. MCDI has some advantages over CDI in its higher salt removal efficiency, faster regeneration, and longer lifetime, but it is also more expensive and complex. The best choice for a particular application will depend on the specific requirements.