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This study investigates the removal efficiency of the toxic element antimony (Sb(V)) using a combined system incorporating ion exchange resins and ion exchange membranes to form an Electrodeionization (EDI) cell. The impact of various operational parameters, including applied potential, flow rate, Na₂SO₄ concentration in the electrode compartment, and the presence of interfering ions, on Sb(V) removal was systematically examined. Results indicate that increasing the applied potential significantly enhances Sb(V) removal, achieving a maximum removal rate of 99% at 40 V and 50 V, with the residual Sb(V) concentrations reducing to 60 μg/L and 9 μg/L, respectively. Variation in flow rate from 1 L/h to 3 L/h showed that removal efficiency peaks at 99% for flow rates of 2 L/h and above. Adjusting the Na₂SO₄ concentration from 0.005 M to 0.05 M in the electrode compartment also improves removal efficiency, maintaining a rate of 99%. Furthermore, the presence of low concentrations of Cl⁻, SO₄ 2 ⁻, NO₃⁻, and PO₄³⁻ ions resulted in achieving a 99% removal efficiency of Sb(V). These findings demonstrate the system's robustness and potential for effective Sb(V) removal from aqueous solutions under varying operational conditions., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2025 Elsevier Ltd. All rights reserved.)

This study showcases the remarkable efficacy of quaternary ammonium-modified cellulose as a highly sustainable biosorbent for removing Sunset Yellow (SY) dye from water. Detailed analysis was conducted using infrared (FTIR) spectroscopy for structural changes and Scanning Electron Microscopy (SEM) for morphological changes. A minimal yet highly effective dose of 0.05 g was identified through dedicated optimization experiments, achieving near-complete removal (99 %) of SY. The biosorbent demonstrated exceptional performance across a broad pH range (2-10), accomplishing remarkable removal within just 5 min. Langmuir modeling uncovered a monolayer sorption mechanism with a high maximum capacity (107.08 mg g -1 ), and thermodynamic analysis affirmed the spontaneity and favorability of the sorption process. Noteworthy is the biosorbent's impressive regeneration capabilities (up to 95 %) using 1.0 M NaOH or HCl solutions and its sustained performance over three sorption-regeneration cycles, highlighting its exceptional stability and reusability. The modified cellulose exhibited remarkable resistance to common interfering ions (chloride, nitrate, and sulfate) at 10 and 100 mg L -1 concentrations. These combined features position quaternary ammonium-modified cellulose as a promising, sustainable, and efficient option for dye wastewater treatment., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2025 Elsevier B.V. All rights reserved.)

This study introduces a highly efficient tripolyphosphate -tethered cellulose sorbent for cadmium (Cd 2 ⁺) removal from aqueous solutions. Characterization through FTIR and SEM revealed the material's structural properties. The sorbent achieved 99% Cd 2 ⁺ removal even at a minimal dosage of 0.05 g. Optimal sorption occurred within the pH range of 4-6, influenced by the sorbent's weak acidic functional groups. Rapid kinetics, reaching equilibrium within a minute, and a high sorption capacity (up to 18.03 mg/g at 50 °C) were observed. Langmuir isotherm modeling confirmed monolayer sorption, and thermodynamic studies indicated a spontaneous, endothermic process with increased randomness at the solid-liquid interface. Selectivity studies demonstrated strong Cd 2 ⁺ removal performance in the presence of competing ions, with minimal interference from monovalent ions but notable effects from divalent ions. The sorbent exhibited consistent reusability over multiple cycles. XPS analysis conclusively established an ion exchange mechanism between Cd 2 ⁺ and negatively charged P 3 O 10 5- groups as the primary removal pathway. This research highlights the potential of TPP-tethered cellulose as a promising sorbent for effective Cd 2 ⁺ remediation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Herein, tannic acid-tethered cellulose was developed as an efficient and selective sorbent for Mn 2 ⁺ removal from aqueous solutions. The modified cellulose was characterized through scanning electron microscopy, infrared spectroscopy, and elemental analyses. Sorption performance was evaluated using various parameters, including pH, initial Mn 2 ⁺ concentration, contact time, and the presence of interfering ions. Results indicated that Mn 2 ⁺ removal was highly pH-dependent, with removal efficiency increasing from 8% at pH 2 to99% at pH 9, achieving a remarkable 99% removal rate within only 30 min, highlighting the rapidity of the cellulose sorption kinetics. The results of isotherm studies confirmed that the sorption conformed to the Langmuir model with a monolayer sorption mechanism. Using a sorbent dose of 0.05 g, 99% of Mn 2 ⁺ could be effectively eliminated from water, achieving a maximum sorption capacity of 32.2 mg/g dry-sorbent. The modified cellulose could be effectively regenerated using 0.5-M HCl or 0.1-M H₂SO₄, with no considerable deterioration in sorption performance after three sorption-regeneration cycles. The presence of Na⁺ and K⁺ had minimal impact on Mn 2 ⁺ removal, whereas the presence of Ca 2 ⁺ and Mg 2 ⁺ at low concentrations facilitated moderate-level Mn 2 ⁺ removal., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

In batch-scale operations, biosorption employing phosphorylated hazelnut shell waste (FHS) revealed excellent lithium removal and recovery efficiency. Scaling up and implementing packed bed column systems necessitates further design and performance optimization. Lithium biosorption via FHS was investigated utilizing a continuous-flow packed-bed column operated under various flow rates and bed heights to remove Li to ultra-low levels and recover it. The Li biosorption capacity of the FHS column was unaffected by the bed height, however, when the flow rate was increased, the capacity of the FHS column decreased. The breakthrough time, exhaustion time, and uptake capacity of the column bed increased with increasing column bed height, whereas they decreased with increasing influent flow rate. At flow rates of 0.25, 0.5, and 1.0 mL/min, bed volumes (BVs, mL solution/mL biosorbent) at the breakthrough point were found to be 477, 369, and 347, respectively, with the required BVs for total saturation point of 941, 911, and 829, while the total capacity was calculated as 22.29, 20.07, and 17.69 mg Li/g sorbent. In the 1.0, 1.5, and 2.0 cm height columns filled with FHS, the breakthrough times were 282, 366, and 433 min, respectively, whereas the periods required for saturation were 781, 897, and 1033 min. The three conventional breakthrough models of the Thomas, Yoon-Nelson, and Modified Dose-Response (MDR) were used to properly estimate the whole breakthrough behavior of the FHS column and the characteristic model parameters. Li's extremely favorable separation utilizing FHS was evidenced by the steep S-shape of the breakthrough curves for both parameters flow rate and bed height. The reusability of FHS was demonstrated by operating the packed bed column in multi-cycle mode, with no appreciable loss in column performance., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Asli YUKSEL reports financial support was provided by Scientific and Technological Research Council of Turkey. Asli Yuksel reports a relationship with Scientific and Technological Research Council of Turkey that includes: funding grants. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Bromate (BrO 3 - ) is a disinfection byproduct formed during the chemical oxidation of water containing bromide. Due to the carcinogenic effect of bromate, its maximum permissible concentration in drinking water has been set to 10 μg/L by the World Health Organization. In this study, the removal of BrO 3 - ions from aqueous solutions via electrodeionization (EDI) was investigated. The removal rate of BrO 3 - varied with the applied potential, and at 10 V, a removal rate of 99% was achieved. However, further increasing the applied potential to 30 V had a negative effect on the removal rate. Additionally, a low bromate concentration in the product water was achieved by reducing Na 2 SO 4 conductivity in the electrode compartment. The removal of BrO 3 - is pH dependent, and at pH 1, only 17.5% was removed. However, increasing the pH of the solution to 5 increased the removal rate to 99.6%. Increasing the operating time and number of cells in the EDI stack improved the removal rate of BrO 3 - , and its concentration decreased from 5 mg/L to 1.4 μg/L. The calculated flux for BrO 3 - was 2.17 × 10 -5  mol/m 2 s, specific power consumption was 89.98-W/hg KBrO 3 , and mass-transfer coefficient was 5.4 × 10 -4  m/s at 10 V., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

In this study, electrodeionization (EDI) in bath mode was tested regarding its capability to remove phosphate (PO 4 3- ) ions from aqueous solutions. Various parameters affecting the phosphate removal rate via EDI were determined. The results showed that the phosphate removal rate depends on the applied voltage and that the optimum potential was 15 V, corresponding to a phosphate removal rate of 97%. Changing the stream rate of the phosphate-containing solution also affected the phosphate removal rate. Changing the pH of the phosphate-containing solution from 2 to 6 enhanced the phosphate removal rate from 80% to 97%. The presence of Cl - , NO 3 - , and SO 4 2- ions did not affect the phosphate removal rate. The highest mass transfer coefficient (k) of phosphate was calculated to be 7.85 × 10 -4  m/s, and the flux was calculated to be 3.72 × 10 -4  mol/m 2  s 1 at a flow velocity of 3 L/h. Thus, the study results showed the feasibility of EDI as an alternative membrane process for removing phosphate from aqueous solutions. PRACTITIONER POINTS: Electrodeionization was employed for the removal of phosphate. The removal of phosphate exhibited dependence on applied potential. EDI demonstrated a remarkable 97% efficiency in phosphate removal. The pH of the solution was found to influence the removal rate., (© 2023 Water Environment Federation.)

In this work, usage of a hybrid polymeric ion exchange resin and a polymeric ion exchange membrane in the same unit to remove Li + from aqueous solutions was reported. The effects of the applied potential difference to the electrodes, the flow rate of the Li-containing solution, the presence of coexisting ions (Na + , K + , Ca 2+ , Ba 2+ , and Mg 2+ ), and the influence of the electrolyte concentration in the anode and cathode chambers on Li + removal were investigated. At 20 V, 99% of Li + was removed from the Li-containing solution. In addition, a decrease in the flow rate of the Li-containing solution from 2 to 1 L/h resulted in a decrease in the removal rate from 99 to 94%. Similar results were obtained when the concentration of Na 2 SO 4 was decreased from 0.01 to 0.005 M. The selectivity test showed that the simultaneous presence of monovalent ions such as Na + and K + did not change the removal rate of Li + . However, the presence of divalent ions, Ca 2+ , Mg 2+ , and Ba 2+ , reduced the removal rate of Li + . Under optimal conditions, the mass transport coefficient of Li + was found as 5.39 × 10 -4 m/s, and the specific energy consumption was found as 106.2 W h/g LiCl. Electrodeionization provided stable performance in terms of the removal rate and transport of Li + from the central compartment to the cathode compartment., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Published by American Chemical Society.)

Addressing antimony (Sb) contamination, which is caused by the use of Sb compounds in various industries, is crucial. This study aims to compare two different Sb removal mechanisms: ion exchange and chelation. Therefore, two different water-soluble polymers-glycidyl methacrylate-N-methyl-D-glucamine and poly 2-(acryloyloxy)ethyl trimethylammonium chloride-were synthesized and used to remove Sb(III) and Sb(V) using the polymer-enhanced ultrafiltration (PEUF) method. The removal of Sb(III) was pH-dependent and extremely difficult at a pH of 1.2. However, when the pH of the solution was increased to 11, the Sb(III) removal rate increased to 77%. The Sb(III) removal rate was 28% at an Sb(III):polymer mole ratio of 1:5, which increased to 77% at a mole ratio of 1:20. Sb(III) removal was discovered to be unaffected by the low concentrations of Na + , K + , Ca 2+ , and Mg 2+ ions in the solution, maintaining a Sb(III) removal rate of 77%. The test parameters showed different characteristics for Sb(V) removal. Increasing the pH of the solution from 1 to 9 correspondingly increased the removal rate from 0% to 45%, but increasing it further to 11 decreased the removal rate to 14%. The removal rate of Sb(V) was 67% at a Sb(V):polymer mole ratio of 1:60. Sb(V) removal was discovered to be unaffected by low concentrations of SO 4 2- , NO 3 - , and PO 4 3- anions in the solution. However, notably, the Sb(V) removal rate decreased from 67% to 58% in the presence of Cl - ions. The results demonstrate that Sb removal via chelation was more effective than by ion exchange, and it remained unaffected by the presence of interfering ions., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Inc. All rights reserved.)

A novel sulfonated cellulose-magnetite (Fe 3 O 4 ) composite sorbent was prepared and applied for the removal of Cu 2+ ions from an aqueous solution. It was characterized by infrared spectroscopy, X-ray fluorescence, elemental analysis, SEM, VSM and X-ray photoelectron spectroscopy. The effect of the sorbent dose, initial solution pH, and temperature on Cu 2+ removal were studied. The removal of the Cu 2+ was completed in 15 min, and the sorption kinetics of Cu 2+ was found to follow a pseudo-second-order kinetic model. An equilibrium test demonstrated that sorption of Cu 2+ onto a hybrid sorbent agreed well with the Langmuir adsorption model for a maximum adsorption capacity of 4.2 mg/g. Moreover, the optimum pH for Cu 2+ removal was found to be ≥4. Furthermore, the thermodynamic parameters reveal the feasibility, spontaneity and endothermic nature of the sorption process. In addition, Cu 2+ ions can be desorbed from the sorbent with a 0.5 M H 2 SO 4 solution.