Cationic Ions Research Articles

Synthesis and characterization of novel chitosan-sodium pyruvate polymer and its derivatives for corrosion feature evaluation of Cu-Ni alloy

In this research, developing a novel chitosan-Schiff base and its derivatives is a distinct and appealing synthetic route for green corrosion inhibitors to lower the rate of Cu-Ni alloy industrial corrosion. Cu-Ni alloy is a material of choice for condensers and heat exchangers, where seawater is used as a coolant and in desalination plants. Therefore, a novel chitosan-sodium pyruvate (Chi-SP) polymer was successfully prepared through the condensation reaction of chitosan with sodium pyruvate. (Chi-SP) polymer is tailored into the hydrophobic core of β-cyclodextrin (CD) by two routes (chemically and physically) to give a novel Chi-SP/β-CD inclusion complex (IC), Chi-SP/β-CD physical mixture (PM), respectively. Further, A composite of Chi-SP encapsulating titanium oxide (TiO2) with nanometer size has been synthesized by a one-pot reaction. The physicochemical properties and the corrosion inhibition efficiency (CIE) of Chi-SP, Chi-SP/β-CDIC, Chi-SP/β-CD PM, and Chi-SP/TiO2 were performed. The corrosion rate (CR) and inhibitor efficiency (IE) of Cu-Ni alloy in HCl (1 M) using Chi-SP, PM, IC, and the nanocomposite were found to be (82.53, 61.63, 65.56, and 62.94) % and (54.1, 65.7, 63.5, and 65)%, respectively. These findings reveal that the Chi-SP/TiO2 molecules have many polar hydroxyl groups which can contribute to the chemisorption and physisorption of the inhibitor on the alloy surface. As well as, the TiO2 in an aqueous solution convert into Ti4+ (cation ions) adsorbed on the negatively charged electrode surface, which increases the adsorption of the nanocomposite on the electrode surface and increases the protection layer.

Positively charged thin-film composite hollow fiber nanofiltration membrane via interfacial polymerization and branch polyethyleneimine modification for Mg2+/Li+ separation

It is a vital technical challenge to extract lithium from salt-lake brine which has very high Mg2+ / Li+ mass ratio via green and low-cost methods, as these two cations have quite similar ionic hydration radius. Positively charged nanofiltration membranes can separate Li+ and Mg2+ through Donnan exclusion. In this work, a kind of hollow fiber nanofiltration membrane with positively charged skin layer was successfully fabricated via interfacial polymerization followed by a surface modification with branched polyethyleneimine (BPEI). The resultant membrane has a large number of amine groups, and thus shows positively charged surface with high rejection for divalent cation ions via Donnan exclusion. This gives it very high selectivity for the separation of Li+ ions from salt-lake brine. Under optimized conditions, it achieves a water permeance of up to 126.2 L m-2 h-1 MPa−1 at a transmembrane pressure difference of 4 bar, and a MgCl2 rejection of 94.6% with 2000 mg L-1 aqueous MgCl2 solution as feed. Meanwhile, it achieves a Mg2+ / Li+ selectivity of nearly 24 for MgCl2 and LiCl salt mixture solution with an overall concentration of 2000 mg L-1 and a Mg2+ / Li+ mass ratio of 150 : 1 as feed, which is high as compared with most of the literature, demonstrating its potential in the practical application of Mg2+ and Li+ separation.

Ion-pairing extraction and their reaction modeling of anionic M-Cl species with cationic NTAamide(C6) extractant and comparison with density functional theory calculations

Solvent extraction is conducted using a total of 20 di-, tri-, and tetravalent metals, revealing high stability constants with Cl− and the N,N,N′,N′,N″,N″-hexahexyl-nitrilotriacetamide (NTAamide(C6)) extractant. The metals used here may behave as anions at high Cl− concentrations, and NTAamide(C6), which contains a tertiary N atom, is protonated under acidic conditions. Most of the metal ions in this study display higher distribution ratios (D(M)) from HCl than those from HNO3, although NO3− hardly forms metal-complexes, and exhibit 1:1 stoichiometries with NTAamide, based on the slopes of acid and metal extraction. The high D(M) may be due to ion-pair extraction based on the combination of cationic extractants and anionic metal-chloride ions. Following the experimental results, the association constants and distribution coefficients of the group 12 elements are calculated via ion-pair extraction modeling using density functional theory calculations, and the simulations of D yield calculated values with the same trend as that of the measured values. In the future, it will be possible to calculate the distribution ratio precisely by considering the size effect in the exosphere of metal and chloride ions and the HSAB rule.

Microscopic mechanism of nucleation and growth of helium bubbles in monovacancy in tungsten: helium regulates the charged states of tungsten atoms

In fusion reactor, tungsten (W) has been selected as a candidate for plasma-facing materials due to its excellent properties. However, W-PFMs suffer from helium (He) bubbles where He atoms are produced during deuterium tritium fusion in fusion reactors. To date, there have been few contributions to uncovering the formation of He bubbles from the perspective of the microscopic electronic structure of He-mediated tungsten. In this work, we develop a tight-binding potential model for the W–He interaction to study He atom aggregation and nucleation in the electronic ground state as well as in different electronic excited states. The most important finding of this paper is that caused by the He atoms in the vacancy, some d-orbital electrons of the W atoms at the inner wall of the vacancy are transferred to the W atoms farther away from the vacancy, leading to the feature of positively charged W ions at the inner wall of the vacancy. As the number of He atoms in the vacancy increases, these W ions become more cationic. Under the repulsion between these adjacent cationic ions, the volume of vacancies increases, and more He atoms tend to gather and nucleate there. At the same time, the enhancement of the electronic excitation can also promote the abovementioned electron transfer between W atoms and further increase the vacancy volume, which increases the self-aggregation of the He atoms in the vacancy. Our results shed new light on understanding He self-aggregation in many different metal materials.

Effect of charge and solvation shell on non-radiative decay processes in s-block cationic metal ion water clusters.

Intermolecular Coulombic decay or electron transfer-mediated decay are the autoionization processes through which a molecule can relax. This relaxation is only possible if the inner valence's ionization potential (IP) exceeds the system's double ionization potential (DIP). To study the effects of charge and solvation shell, we have calculated the IP, DIP values, and lifetime of Na-2s and Mg-2s temporary bound states in various optimized structures of Na+-(H2O)n and Mg2+-(H2O)n (n = 1-5) micro-solvated clusters, where n water molecules are distributed in a way that some are directly bound to the metal ion and the rest to the water molecules. The first and second solvation shells are the names for the former and the latter water-binding positions, respectively. For a given n, the lifetime of decaying states is longer when water molecules are in the second solvation shell. We found that the Mg-2p state can decay for all n values in Mg2+-(H2O)n clusters, whereas the Na-2p state's decay is possible for n ≥ 2 in Na+-(H2O)n clusters. Our findings highlight the influence of metal ions' charge, different solvation shell structures, and the number of water molecules on the decay rate. These systems are relevant to the human body, which makes this study significant.

Simultaneous remediation of Cr and Ni from waste water using efficient Schiff-base resin bis(2-methoxy-1-napthaldehy)-O-phenylene diimine as an adsorbent

In this study, we report the synthesis of a Schiff base, bis(2-methoxy-1-napthaldehy)-o-phenylene diimine (BMNOPhen), and a Schiff-base resin, bis-2-methoxy-1-napthaldehy-o-phenylenediimine (PMBMNOPhen). The materials were characterized via different spectroscopic techniques; CHN analysis, FT-IR, TGA, EDS, SEM, and XRD to analyze the structure and surface morphology and crystallographic evolution of the polymeric resin. The synthesized resin was used for uptake studies with Ni(II) and Cr(VI) ions. The optimum conditions were determined by different parameters used to describe the effects of uptake including initial concentration, temperature, time, and pH through batch adsorption methods. Different functional groups like azomethine, OH, and amine present in the Schiff-based resin structure contain donor N and O atoms which can coordinate cationic metal ions, supported by the active adsorption of chromium(VI) and nickel(II). The isotherm data are informative and useful for calculating and modeling adsorption capacity and exploring the mechanism of removal by the adsorbent Different types of adsorption isotherms like Langmuir, Freundlich, and kinetic studies were used on environmental water samples. The polymeric resin PMBMNOPhen was used for elimination of Cr(VI) and Ni(II) ions in real water samples from different agricultural cities of Sindh (Province of Pakistan) such as Sanghar, Tando-Adam, Kotri, and Jamshoro.

Removal of Cationic and Anionic Heavy Metal Ions From Aqueous Phase by a HGMS and Magnetized Zeolite

A magnetic separation study was conducted employing magnetized zeolite and a high gradient magnetic separation system (HGMS) for removal of both cationic and anionic heavy metals. Magnetized zeolite Y was prepared with variable iron contents ranged from 1.2-22.8% based on surface concentration. The magnetized zeolite showed decreased adsorption capacity for cations while the adsorption capacity of the adsorbent for anion increased and the adsorption capacity was proportional to the iron contents. The captured rate of dispersed adsorbents after use for removal of contaminants is a very important factor in water treatment processes. The magnetic separation system recovered more than 98% of magnetized zeolite at 3 T of magnetic field. Current result indicates the combination of magnetized zeolite and HGMS separation could be an efficient alternative for simultaneous removal of cationic and anionic heavy metal from water phase.

Novel approach to grow nanosized BiFeO3, CoFe2O4 and NiFe2O4 on Amberlyst-15 for efficient sorption of Cd2+ ions

The current study deals with the growing the ferrites of bismuth, cobalt, and nickel on the surface of cationic ion exchanger Amberlyst-15. To evaluate the effect of surface modification, bare Amb-15 was also used for the comparative study of Cd+2 ions removal. The surface charge, phase identification, surface area, pore size distribution, desired functionalities, morphology, and composition of the bare and modified sorbents were evaluated via an array of analytical techniques. The efficacy of each absorbent was investigated under the influence of pH, contact time, temperature, adsorbents dosage, and concentration of adsorbate. The results showed that modified sorbents have remarkable removal efficiency of Cd+2 from 80 to 91 %. The adsorption of Cd+2 ions followed Langmuir and pseudo-second-order kinetic model indicating the physiochemical nature of the sorption process. The maximum sorption capacity (qm) of 21.79 mg/g, 32.37 mg/g, 221.23 mg/g and 304.87 mg/g was obtained for Amb-15, Amb@BFO, Amb@NFO and Amb@CFO respectively. Additionally, desorption and selectivity study of bare and modified adsorbents were also carried out and the findings showed that adsorbents can be reused up to four cycles. The selectivity study shows that Amb@CFO is the best candidate for the uptake of Cd+2 ions.

Structural Elucidations of derivatized Sterols using Electrospray Ionization/Atmospheric Pressure Chemical Ionization-Quadrupole Ion Trap-Mass spectrometry

Free sterols are neutral molecules that are difficult to ionize by Electrospray Ionization (ESI) or Atmospheric Pressure Chemical Ionization (APCI). Therefore, in order to increase their ionization efficiency, sterols were converted into their corresponding picolinyl esters. In this study we examined the possibility of analyzing picolinyl ester of sterols derivatives using flow injection ESI-quadrupole ion trap (QIT) MS and APCI-QIT MS and we investigated their fragmentation pathways using low energy collision induced dissociation-tandem mass spectrometry (CID-MS2). This study also aimed to examine the possibility of using ESI-QIT MS3 to identify sterol isomers. The picolinyl esters readily formed protonated molecular ions ([M+H]+) in ESI and APCI sources except for the picolinyl ester of 7-dehydrocholesterol which was detected as the radical cation ion [M].+ using APCI-QIT MS. The ester bonds of picolinyl esters cleaved during CID MS2, resulting in diagnostic fragments corresponding to steryl cation moieties [M+H-C6H5NO2]+. The CID MS3 of [M+H]+ → [M+H-C6H5NO2]+ of picolinyl esters was found to be useful for structural elucidation and for distinguishing among steryl isomers.

Open Linear Polymer Host-Guest Interactions Sensed by Luminescent Silver Nanodots.

The selectivity of the linear polymer chain toward its binding moieties has been considered negligible; thus, a clear demonstration showing the best-fit binding of a linear polymer to its guest counterpart is still unknown. Luminescent poly(acrylic acid) (PAA)-stabilized silver nanodots (PAA-AgNDs) have been applied as a turn-on sensor to monitor the interaction between the PAA chain and its binding cations. The binding of cations ions to the PAA chain may cross-link the linear PAA chain via coordination with carboxylate, which increases the rigidity of the polymer chain, retards the nonradiative decay of PAA-AgNDs, and consequently enhances the emission of silver nanodots while inducing a blue-shift of its emission spectrum. For the first time, we have demonstrated that a linear polymer chain can act as an open host to selectively bind to its best-matching cations. Specifically, among Group 2 cations (Mg2+, Ca2+, Sr2+, Ba2+), calcium ions show the strongest bonding to the PAA polymer chain. Our research suggests that, with extra rigidity, the polymer improves its chemical stability as calcium ions cross-linked the linear polymer. Meanwhile, it has also been demonstrated that luminescent silver nanodots can be excellent probes for the detection of polymer activities with straightforward and simple visualization methods.

Experimental Evaluation of Stiffness Properties of a Quicklime-Stabilized Clay Subgrade Using a Resistivity Plate Loading Testing Device

Quicklime-mixing in soil stabilization applications for subgrade construction is crucial to its engineering performance and controlling quicklime and water content. Modern construction quality control devices and methods have improved construction quality control substantially. Certain devices, meanwhile, still need to be studied more thoroughly. This study used the resistivity plate loading device to assess the physical and stiffness properties of compacted quicklime-stabilized subgrade instantaneously and simultaneously for compaction quality control. The Taguchi L9 orthogonal array was used to design the experiment considering the dry density, test time, quicklime, and water content at various input factor levels. The pH, cation exchange capacity, conductivity, X-ray diffraction analysis (XRD), and scanning electron microscope (SEM) tests were further conducted. Analysis of the Taguchi experiment shows that the average soil electrical resistivity responses increased with dry density, test time, and quicklime content, and were highest at low water content. Whether the dry density, quicklime content, and test time are positively or negatively related to the average subgrade reaction modulus depends on the level of the water content. Regression equations are proposed to predict the average subgrade reaction modulus and soil electrical resistivity. The tested soils’ pH, conductivity, and cation ion exchange capacity properties were directly related to the test time, water, and quicklime content. The XRD showed nearly similar X-ray diffraction peaks. The SEM analysis confirmed marked changes in the microstructure of the samples that explained the changes in electrical resistivity and subgrade reaction modulus responses. The test results show that the resistivity plate loading device efficiently assesses compacted quicklime’s stiffness and physical properties at ease and instantaneously.

Elaborating the mechanism of lead adsorption by biochar: Considering the impacts of water-washing and freeze-drying in preparing biochar

This paper examined the impacts of different pretreatments on the characteristics of biochar and its adsorption behavior for Pb2+. Biochar with combined pretreatment of water-washing and freeze-drying (W-FD-PB) performed a maximum adsorption capacity for Pb2+ of 406.99 mg/g, higher than that of 266.02 mg/g on water-washing pretreated biochar (W-PB) and 188.21 mg/g on directly pyrolyzed biochar (PB). This is because the water-washing process partially removed the K and Na, resulting in the relatively enriched Ca and Mg on W-FD-PB. And the freeze-drying pretreatment broke the fiber structure of pomelo peel, favoring the development of a fluffy surface and large specific surface area during pyrolysis. Quantitative mechanism analysis implied that cation ion exchange and precipitation were the driving forces in Pb2+ adsorption on biochar, and both mechanisms were enhanced during Pb2+ adsorption on W-FD-PB. Furthermore, adding W-FD-PB to Pb-contaminated soil increased the soil pH and significantly reduced the availability of Pb.

Effects of microstructure on radiolytic degradation of nuclear grade cationic resins: Gel versus macro-porous

A study was undertaken to evaluate the effect of gamma radiation on the physico-chemical and functional properties of strong cationic ion exchange resins with varying microstructures i.e., gel and macro-porous type, used in purification systems of water-cooled nuclear reactors. The effect of metal ion loading on degradation behavior was probed to simulate the in-situ irradiation scenario in used resin. The resins are expected to undergo physico-chemical and functional degradation due to different oxidizing and reducing species from water radiolysis. Nevertheless, evaluating the extent of degradation based on the morphological and structural differences was of interest. The extent of resin degradation was estimated by analyzing the change in pH, conductivity, total organic carbon (TOC), chemical oxygen demand (COD) and the extent of reactive site loss from the leached ions. Leaching of SO42− ions and the formation of lower organic acids resulted in decreased pH and increased conductivity, TOC and COD values. The change in exchange capacity and physical and structural changes in the irradiated resin's surface was probed with X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared spectroscopy (FT-IR) and Field emission scanning electron microscopy (FE-SEM). Gel resin showed more significant functional group loss, while hydrogen generation was more from macroporous resin due to its more rigid and dense structure.

Rhodamine 6G derivative for the selective copper detection and remediation using nanoporous diatomaceous earth-engineered functional receptor

A rhodamine-derived receptor was synthesized and comprehensively characterized for structural confirmation. The receptor was able to distinguish the copper ions (Cu2+) from other competing cations. The yellow color of the receptor changed to pink upon adding Cu2+ ions, however, other competing cations ions were impotent towards any color variation. The UV–visible titration studies revealed the binding stoichiometry of a 1:1 ratio with a detection limit of 9.663 × 10−8 M. Additionally, a novel idea of the work resides in the use of diatom for the practical application, where the receptor has been tethered on nanoporous diatomaceous earth microparticles (P2D) to remove Cu2+ ions. The results confirmed that 50 mg receptor functionalized DE could adsorb 10 mL of 1 ppm Cu2+ ions from water. Furthermore, a proof-of-concept device that is inexpensive, simple to operate, and continuously removes Cu2+ ions from water has been developed. The efficiency of the device in Cu2+ ion removal could be realized through the naked eye by observing the color change of P2D particles, which has excellent potential for application in remote locations where water contamination is a significant issue.

Ionic-Nanophase Hybridization of Nafion by Supramolecular Patching for Enhanced Proton Selectivity in Redox Flow Batteries.

Nafion, as the mostly used proton exchange membrane material in vanadium redox flow batteries (VRFBs), encounters serious vanadium permeation problems due to the large size difference between its anionic nanophase (3-5 nm) and cationic vanadium ions (∼0.6 nm). Bulk hybridization usually suppresses the vanadium permeation at the expense of proton conductivity since conventional additives tend to randomly agglomerate and damage the nanophase continuity from unsuitable sizes and intrinsic incompatibility. Here, we report the ionic-nanophase hybridization strategy of Nafion membranes by using fluorinated block copolymers (FBCs) and polyoxometalates (POMs) as supramolecular patching additives. The cooperative noncovalent interactions among Nafion, interfacial-active FBCs, and POMs can construct a 1 nm-shrunk ionic nanophase with abundant proton transport sites, preserved continuity, and efficient vanadium screeners, which leads to a comprehensive enhancement in proton conductivity, selectivity, and VRFB performance. These results demonstrate the intriguing potential of the supramolecular patching strategy in precisely tuning nanostructured electrolyte membranes for improved performance.

Effect of TeO2 on optical and 1.06 µm emission in Nd3+-doped phosphate glass for high-power lasers

In this work, we deal with glass composition, 29P2O5+(60−x)ZnO+10Na2O+xTeO2 (x=5−40mol.%) doped with 1 mol.% of Nd2O3. The samples are characterized by x ray diffraction, micro-Raman, optical absorption, and photoluminescence techniques. Refractive index (n) linearly increased with TeO2 content, as well as the optical basicity (Λ) due to the strengthening of the covalent bond between cation and oxide ions. Such information was corroborated by Raman spectra via an increase of non-bridging oxygens. The maximum phonon energy is approximately 1010cm−1, which is lower than reported for P2O5−ZnO−Na2O phosphate glass (1164cm−1). Detailed spectroscopic and luminescent properties based on TeO2 content are discussed. From luminescence spectra, laser parameters were estimated, viz., radiative transition probabilities, radiative lifetimes, branching ratios, and emission cross sections. The results show that the optimal laser emission parameters are obtained for TeO2 content equal to 20 mol.%, which evinces this glass composition as a promising host material for 1.06 µm high-power laser applications.

Gold Nanoparticles as Exquisite Colorimetric Transducers for Water Pollutant Detection.

Gold nanoparticles (AuNPs) are useful nanomaterials as transducers for colorimetric sensors because of their high extinction coefficient and ability to change color depending on aggregation status. Therefore, over the past few decades, AuNP-based colorimetric sensors have been widely applied in several environmental and biological applications, including the detection of water pollutants. According to various studies, water pollutants are classified into heavy metals or cationic metal ions, toxins, and pesticides. Notably, many researchers have been interested in AuNP that detect water pollutants with high sensitivity and selectivity, while offering no adverse environmental issues in terms of AuNP use. This review provides a representative overview of AuNP-based colorimetric sensors for detecting several water pollutants. In particular, we emphasize the advantages of AuNP as colorimetric transducers for water pollutant detection in terms of their low toxicity, high stability, facile processability, and unique optical properties. Next, we discuss the status quo and future prospects of AuNP-based colorimetric sensors for the detection of water pollutants. We believe that this review will promote research and development of AuNP as next-generation colorimetric transducers for water pollutant detection.

Can the mix-charged NF membrane directly obtained by the interfacial polymerization of PIP and TMC?

Currently, most nanofiltration membranes exhibit satisfactory separation performance on the anions or cations, and few membranes could concurrently separate anion and cation. Therefore, preparing nanofiltration membranes with excellent separation performance for both anionic and cationic ions remains a challenge. Herein, we have developed a series of nanofiltration membranes using conventional interfacial polymerization with different ratios of trimesoyl chloride (TMC) and piperazine (PIP) concentrations. In the interface polymerization process, the amine groups carried by PIP imparted a positive charge, while the hydrolysis of acyl chloride groups resulted in the generation of carboxylic acid groups that introduced a negative charge. The mix-charged nanofiltration membrane could be fabricated by varying PIP/TMC concentration ratios. The optimized membrane exhibited high rejection rates for bivalent ions (Na2SO4 rejection of 96.6 %, MgCl2 rejection of 93.0 %), and its selectivity for Mg2+/Li+ mixed solution was improved significantly. This work provides a novel approach for the development of nanofiltration membranes capable of effectively separating mono-/divalent ions.

Transcriptomics Reveal Molecular Differences in Equine Oocytes Vitrified before and after In Vitro Maturation.

In the last decade, in vitro embryo production in horses has become an established clinical practice, but blastocyst rates from vitrified equine oocytes remain low. Cryopreservation impairs the oocyte developmental potential, which may be reflected in the messenger RNA (mRNA) profile. Therefore, this study aimed to compare the transcriptome profiles of metaphase II equine oocytes vitrified before and after in vitro maturation. To do so, three groups were analyzed with RNA sequencing: (1) fresh in vitro matured oocytes as a control (FR), (2) oocytes vitrified after in vitro maturation (VMAT), and (3) oocytes vitrified immature, warmed, and in vitro matured (VIM). In comparison with fresh oocytes, VIM resulted in 46 differentially expressed (DE) genes (14 upregulated and 32 downregulated), while VMAT showed 36 DE genes (18 in each category). A comparison of VIM vs. VMAT resulted in 44 DE genes (20 upregulated and 24 downregulated). Pathway analyses highlighted cytoskeleton, spindle formation, and calcium and cation ion transport and homeostasis as the main affected pathways in vitrified oocytes. The vitrification of in vitro matured oocytes presented subtle advantages in terms of the mRNA profile over the vitrification of immature oocytes. Therefore, this study provides a new perspective for understanding the impact of vitrification on equine oocytes and can be the basis for further improvements in the efficiency of equine oocyte vitrification.

Buoyancy control of Microcystis using different light regimes combined with extracellular polysaccharides and cationic ions

ABSTRACT Cyanobacterial blooms are widely known to cause problems in the aquatic environment, and their appearance has become more frequent due to global warming. Microcystis is one of the most widespread and dominant bloom-forming cyanobacterial genera, largely because Microcystis has the ability to control its buoyancy. A buoyancy experiment conducted on Microcystis sp. isolated from cyanobacterial blooms in Lake Senba, Japan, showed that buoyancy could be controlled using a combination of preculture under the dark conditions and the addition of powdered tightly bound extracellular polysaccharides (TB-EPS) and metal cations (Ca2+ and Mg2+). Preculture under the dark conditions, 96 h in length were the most effective treatment to reduce the cellular carbohydrate content of Microcystis and simultaneously increase its buoyancy. The addition of TB-EPS, Ca2+ and Mg2+ ions increased the colony size of Microcystis and enhanced buoyancy in precultures under both dark and light conditions. Thus, the buoyancy of Microcystis can be controlled by reducing its cellular carbohydrate content by preculturing it in dark conditions for 96 h and increasing the colony size with the addition of 100 mg l−1 EPS, 80 mg l−1 Ca2+ and 80 mg l−1 Mg2+. This study contributes to establishing a novel removal method for cyanobacterial blooms dominated by Microcystis, especially in water treatment facilities.