scholarly journals Understanding of Adsorption and Desorption Mechanisms of Anthocyanins and Proanthocyanidins on Heterogeneous and Homogeneous Cation-Exchange Membranes

Membranes ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 136
Author(s):  
Véronique Perreault ◽  
Veronika Sarapulova ◽  
Ksenia Tsygurina ◽  
Natalia Pismenskaya ◽  
Laurent Bazinet
Keyword(s):  
Ion Exchange ◽  
Cation Exchange ◽  
Membrane Fouling ◽  
Electrostatic Interactions ◽  
Exchange Capacity ◽  
Type Ii ◽  
Cranberry Juice ◽  
Membrane Processes ◽  
Adsorption And Desorption ◽  
The Impact

The presence of membrane fouling is the main drawback in membrane processes, and it is related to the premature use and high cost for the replacement of membranes. Polyphenols in cranberry juice are associated with ion-exchange membrane fouling, and it results in a loss of these beneficial compounds in the juice when treated by membrane processes such as electrodialysis. In the present work, four heterogeneous or pseudohomogeneous cation-exchange membranes (CSE-fg, MK-40, CEM Type-II, and CJMC-5), different in terms of the polymer matrix (aromatic, aliphatic), exchange capacity, size, and location of meso and macropores, were studied to understand the impact of the membrane structure and physico-chemical properties on adsorption and desorption of phenolic compounds (anthocyanins and proanthocyanidins) from cranberry juice. It appeared from these results that MK-40, CEM Type-II, and CSE-fg were more prone to fouling due to their high ion-exchange capacity, their thickness, and the presence of meso and macropores in their structure. Indeed, electrostatic interactions occurred between fixed groups of membranes and polyphenolic ions. Desorption of the entire membrane and cryogenic grinding with pH adjusted to 10 allowed a better recovery of anthocyanins and proanthocyanidins (PACs), respectively, since hydroxide ions competed with polyphenols and membrane that induced desorption of polyphenols. In the future, this new knowledge will become the basis for a more sensible choice of membranes and for the development of protocols for extending their life cycle.

scholarly journals Assessing the ageing process of cation exchange membranes in bioelectrochemical systems

2019 ◽  
Author(s):  
M. Isabel San-Martín ◽  
Francisco Javier Carmona ◽  
Pedro Prádanos ◽  
Antonio Morán ◽  
Adrián Escapa
Keyword(s):  
Ion Exchange ◽  
Electrochemical Properties ◽  
Cation Exchange ◽  
Exchange Capacity ◽  
Economic Feasibility ◽  
Bioelectrochemical Systems ◽  
Term Operation ◽  
Force Microscopy ◽  
Exchange Membrane ◽  
The Impact

Bioelectrochemical systems (BES) encompass a group of biobased technologies capable of directly converting organic matter into electricity. In these systems, which are derived from conventional electrochemical systems, the ion exchange membrane represents a key element because of its influence on the economic feasibility and on the performance of BES. This study examines the impact of long-term operation of a BES on the mechanical, chemical and electrochemical properties of five different kind of cation exchange membranes (Nafion-117, CMI-7001, Zirfon UTP 500, FKE and FKB) through several techniques: (i) scanning electron microscopy (SEM) and atomic force microscopy (AFM) to assess the changes on the membranes surface, (ii) thermogravimetric analysis (TGA) to evaluate the structural stability of the membranes, and (iii) ion exchange capacity (IEC) to monitor any change in their electrochemical properties. Results confirmed that there is not an ideal membrane for BES. While Nafion and CMI-7000 exhibited the strongest chemical structure, they also underwent the highest fouling as revealed by a fast increase in surface roughness.

Studies on Sodium lauryl sulphate supported Thorium(IV) phosphate: A New Surfactant supported Cation exchange resin, Useful in Water Purification

2021 ◽  
Vol 17 ◽  
Author(s):  
Amita Somya ◽  
Mamata Singh
Keyword(s):  
Ion Exchange ◽  
Cation Exchange ◽  
Water Purification ◽  
Sol Gel ◽  
Synthesis Method ◽  
Cation Exchange Resin ◽  
Exchange Capacity ◽  
Sodium Lauryl Sulphate ◽  
Infrared Study ◽  
Chemical Studies

Background: With increasing population and decreased quality of drinking water, there is a great demand for the development of new materials and methods that can find applications in the purification of water. This paper presents our small effort from pollution to solution by presenting the synthesis method of new sodium lauryl sulphate supported thorium(IV) phosphate, its characterization, and disquisition of analytical applications by executing some dual separations of calcium. Methods: Sodium lauryl sulphate thorium(IV) phosphate was synthesized by sol gel method. The synthesized exchanger was characterized by some physico-chemical studies like powdered X-ray diffraction, Scanning electron microscopy, Thermo gravimetric-differential thermal analysis, EDAX and Fourier transform-infrared study and was also checked for its competency towards the ion exchange processes and in analytical chemistry. Results: The prominent characteristic of Sodium lauryl sulphate supported Thorium(IV) phosphate has been its tremendously high ion exchange capacity for sodium ions (3.10 meq/g) which is almost two and half times more than the exchange capacity of Thorium(IV) phosphate (ThP), i.e., 1.3 meq/g. The material was resulted in fibrous sheet which is quite thermally, mechanically stable and poorly crystalline. The material has shown selectivity towards Ca2+ and Hg2+ ions. Conclusion: The synthesized cation exchange material has been found quite thermally stable, showing drastically high exchange capacity and selectivity towards Hg2+ and Ca2+ metal ions which might be because of the use of an anionic surfactant, sodium lauryl sulphate while synthesis of Th(IV) phosphate which has played a key role in enhancing the exchange capacity and adsorption of specific metals as well. Therefore, based on the results obtained, the above said materials can find applications in water purification processes and also, in environmental pollution control where removal of Hg2+ and Ca2+ is required.

The Impact of Plant Hedgerow in Three Gorges on the Soil Chemicophysical Properties and Soil Erosion

2012 ◽  
Vol 500 ◽  
pp. 142-148 ◽  
Author(s):  
Wen Xing Lü ◽  
Hong Jiang Zhang ◽  
Yu He Wu ◽  
Jin Hua Cheng ◽  
Jian Qiang Li ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Erosion ◽  
Cation Exchange ◽  
Cation Exchange Capacity ◽  
Exchange Capacity ◽  
Citrus Reticulata ◽  
Three Gorges ◽  
Zanthoxylum Bungeanum ◽  
The Impact ◽  
Nitrogen Phosphorus

Through the research and sampling analysis on different plant hedgerow in sloped farmland in Three Gorges reservoir area, we will conduct research on the impact of plant hedgerow in Three Gorges on the chemicophysical properties of soil and soil erosion. The results show that the plant hedgerow mainly composed by Morus alba, Citrus reticulata, Zanthoxylum bungeanum, Vitex negundoand Begonia fimbristipula can decrease the soil density as well as sand content and increase soil porosity, soil water content, silt content and clay content to some extent. The organic matter, nitrogen, phosphorus, potassium and cation exchange capacity and other chemical indices of soil in different locations in plant hedgerow indicate as maximum in on-band, minimum in inter-band, middle both upper-band and below-band. In the same slop with no plant hedgerow, the organic matter, nitrogen, phosphorus, potassium and cation exchange capacity and other chemical indices of soil show a trend of increasing from the top to the bottom of the slop, which reveals that these substances own a feature of accumulation by moving to the bottom. The strength of soil anti-corrosion in different plant hedgerow is: Vitex negundoand (79.2%)> Citrus reticulata (36.4%)> Morus alb (22.4%)> Zanthoxylum bungeanum (18.9%)> Begonia fimbristipula (15.3%)> CK (8.7%), and the soil anti-corrosion indices in plant hedgerow are decreasing with the increase of soil immersion time, besides, the former and the latter are 3 times polynomial function. For those 5 plant hedgerows, Vitex negundoand owns the best impact on improving soil chemicophysical properties and reducing soil erosion.

scholarly journals Biologically active ion exchange (BIEX) for NOM removal and membrane fouling prevention

2017 ◽  
Vol 17 (4) ◽  
pp. 1178-1184 ◽  
Author(s):  
M. Schulz ◽  
J. Winter ◽  
H. Wray ◽  
B. Barbeau ◽  
P. Bérubé
Keyword(s):  
Molecular Weight ◽  
Biological Activity ◽  
Ion Exchange ◽  
Membrane Fouling ◽  
Building Blocks ◽  
Biologically Active ◽  
Low Molecular Weight ◽  
Effective Removal ◽  
Pre Treatment ◽  
The Impact

The natural organic matter (NOM) removal efficiency and regeneration behavior of ion-exchange filters with promoted biological activity (BIEX) was compared to operation where biological activity was suppressed (i.e. abiotic conditions). The impact of BIEX pre-treatment on fouling in subsequent ultrafiltration was also investigated. Biological operation enhanced NOM removal by approximately 50% due to an additional degradation of smaller humic substances, building blocks and low molecular weight acids. Promotion of biological activity significantly increased the time to breakthrough of the filters and, therefore, is expected to lower the regeneration frequency as well as the amount of regenerate of which to dispose. Pre-treatment using BIEX filters resulted in a significant decrease in total and irreversible fouling during subsequent ultrafiltration. The decrease was attributed to the effective removal of medium and low molecular weight NOM fractions. The results indicate that BIEX filtration is a robust, affordable and easy-to-operate pre-treatment approach to minimize fouling in ultrafiltration systems and enhance the quality of the produced permeate.

scholarly journals Impact of sediment–seawater cation exchange on Himalayan chemical weathering fluxes

2016 ◽  
Vol 4 (3) ◽  
pp. 675-684 ◽  
Author(s):  
Maarten Lupker ◽  
Christian France-Lanord ◽  
Bruno Lartiges
Keyword(s):  
Cation Exchange ◽  
Chemical Weathering ◽  
Sediment Load ◽  
Relative Proportion ◽  
River System ◽  
Exchange Capacity ◽  
Sediment Flux ◽  
Continental Scale ◽  
The Impact

Abstract. Continental-scale chemical weathering budgets are commonly assessed based on the flux of dissolved elements carried by large rivers to the oceans. However, the interaction between sediments and seawater in estuaries can lead to additional cation exchange fluxes that have been very poorly constrained so far. We constrained the magnitude of cation exchange fluxes from the Ganga–Brahmaputra river system based on cation exchange capacity (CEC) measurements of riverine sediments. CEC values of sediments are variable throughout the river water column as a result of hydrological sorting of minerals with depth that control grain sizes and surface area. The average CEC of the integrated sediment load of the Ganga–Brahmaputra is estimated ca. 6.5 meq 100 g−1. The cationic charge of sediments in the river is dominated by bivalent ions Ca2+ (76 %) and Mg2+ (16 %) followed by monovalent K+ (6 %) and Na+ (2 %), and the relative proportion of these ions is constant among all samples and both rivers. Assuming a total exchange of exchangeable Ca2+ for marine Na+ yields a maximal additional Ca2+ flux of 28  ×  109 mol yr−1 of calcium to the ocean, which represents an increase of ca. 6 % of the actual river dissolved Ca2+ flux. In the more likely event that only a fraction of the adsorbed riverine Ca2+ is exchanged, not only for marine Na+ but also Mg2+ and K+, estuarine cation exchange for the Ganga–Brahmaputra is responsible for an additional Ca2+ flux of 23  ×  109 mol yr−1, while ca. 27  ×  109 mol yr−1 of Na+, 8  ×  109 mol yr−1 of Mg2+ and 4  ×  109 mol yr−1 of K+ are re-absorbed in the estuaries. This represents an additional riverine Ca2+ flux to the ocean of 5 % compared to the measured dissolved flux. About 15 % of the dissolved Na+ flux, 8 % of the dissolved K+ flux and 4 % of the Mg2+ are reabsorbed by the sediments in the estuaries. The impact of estuarine sediment–seawater cation exchange appears to be limited when evaluated in the context of the long-term carbon cycle and its main effect is the sequestration of a significant fraction of the riverine Na flux to the oceans. The limited exchange fluxes of the Ganga–Brahmaputra relate to the lower than average CEC of its sediment load that do not counterbalance the high sediment flux to the oceans. This can be attributed to the nature of Himalayan river sediment such as low proportion of clays and organic matter.

The Use of Some Ion-Exchange Sorbing Tracer Cations in Insitu Experiments in High Saline Groundwaters

1994 ◽  
Vol 353 ◽  
Author(s):  
J. Byegård ◽  
G. Skarnemark ◽  
M. Skålberg
Keyword(s):  
Ion Exchange ◽  
Cation Exchange ◽  
Cation Exchange Capacity ◽  
Alkali Metals ◽  
Alkaline Earth ◽  
Exchange Capacity ◽  
Alkaline Earth Metals ◽  
Crushed Granite ◽  
The Difference

AbstractThe possibility to use alkali metals and alkaline earth metals as slightly sorbing tracers in in-situ sorption experiments in high saline groundwaters has been investigated. The cation exchange characteristics of granite and some fracture minerals (chlorite and calcite) have been studied using the proposed cations as tracers. The results show low Kd’s for Na, Ca and Sr (∽0.1 ml/g), while the sorption is higher for the more electropositive cations (Rb, Cs and Ba). A higher contribution of irreversible sorption can also be observed for the latter group of cations. For calcite the sorption of all the tracers, except Ca, is lower compared to the corresponding sorption to granite and chlorite. Differences in selectivity coefficients and cation exchange capacity are obtained when using different size fractions of crushed granite. The difference is even more pronounced when comparing crushed granite to intact granite.

Ion Exchange Functional Nanofibers

2009 ◽  
Vol 1240 ◽  
Author(s):  
Prabir K Patra ◽  
Sukalyan Sengupta
Keyword(s):  
Ion Exchange ◽  
Cation Exchange ◽  
Average Diameter ◽  
Strong Acid ◽  
Weak Acid ◽  
Exchange Capacity ◽  
Orifice Diameter ◽  
Pump Speed ◽  
Acid Cation ◽  
Weak Base Anion Exchange

AbstractWe have synthesized a series of ion exchange functionalized fibers (IXF) from polystyrene (PS) and polyacrylonitrile (PAN). To obtain strong-acid cation exchange fibers, polystyrene was sulfonated using specific sulfonation protocols. Micron sized fibers (average diameter of 100m) were then produced from the functionalized polystyrene using a single-screw extruder equipped with a 30 hole spinneret with orifice diameter of 0.5 mm with a precise screw speed of 5 rpm, pump speed of 15 rpm, and with a feed rate of 2.4 cc/min. The extruder zone temperature was kept at 250 – 270 °C. Fiber was drawn at 120 degree with a draw ratio of 2. Electrospinning of functionalized polystyrene was also carried out to produce ultrafine functionalized fibers of 100 nm in average diameter. We have also electrospun polystyrene and polyisoprene blended nanofibers to increase the strength of the resulting blend nanofibers compared to pure PS nanofibers. To synthesize weak-acid cation exchange fibers polyacrylonitrile (PAN) was electrospun and the nanofibers obtained were alkaline hydrolyzed with 2 N NaOH for 20 minutes at room temperature to convert nitrile bonds to carboxylate. Cation exchange capacity (CEC) of the microfibers and nanofibers was determined. Sulfonated PS microfibers show high CEC of 4.0 meq/gm compared to that of nanofibers with 2.5 meq/gm. CEC of blended nanofibers of PS and polyisoprene was 2.0 meq/gm. In case of PAN fibers, nanosized electrospun fibers were found to show a CEC of 1.5 meq/gm. Weak-base anion exchange fiber synthesis was undertaken using appropriate protocol and its CEC was measured. For all IXF synthesized, fiber diameter was measured using SEM, degree of functionalization was qualitatively determined using FTIR and ion exchange capacity was computed after mass balance on a binary exchange system after equilibrium.

Impacts of whole-tree harvesting and winter windrowing on soil pH and base status of clayey sites of northwestern Quebec

1995 ◽  
Vol 25 (6) ◽  
pp. 997-1007 ◽  
Author(s):  
S. Brais ◽  
C. Camiré ◽  
D. Paré
Keyword(s):  
Cation Exchange ◽  
Soil Ph ◽  
Forest Floor ◽  
Cation Exchange Capacity ◽  
Exchange Capacity ◽  
Exchangeable Ca ◽  
Whole Tree Harvesting ◽  
The Impact ◽  
Whole Tree ◽  
Tree Harvesting

To assess the impact of forest operations on soil nutrient status, modifications to forest floor, to 0–10 and 10–20 cm mineral soil base status, and to pH were evaluated 5–12 years following whole-tree harvesting and winter windrowing on dry to fresh and moist clayey sites in the clay belt region of northwestern Quebec. Whole-tree harvesting had few impacts on base concentrations and soil pH of dry to fresh sites. On moist sites, significant decreases in pH (−0.60 to −0.84 units), exchangeable Ca, total Ca, and, exchangeable Mg concentrations, base saturation, and effective cation exchange capacity were observed following harvesting. On dry to fresh sites, a decrease in the forest floor weight (−55%) accounted for significant reductions in exchangeable Ca (−55%), total Ca (−61%), and exchangeable K (−40%) pools in this layer, while reserves of both mineral layers were not affected. On moist sites, significant decreases in exchangeable Ca (−42 to −65%) and Mg (−35 to −56%) reserves occurred in all soil layers, while forest floor reserves of total Ca, Mg, and K decreased by 67, 48, and 40%, respectively. These reductions were caused by a loss of substrate in the forest floor (−44%) and a decrease in effective cation exchange capacity, exchangeable Ca saturation, and total Ca concentrations. Impacts of windrowing following whole-tree harvesting were limited to a reduction in reserves of exchangeable Ca (−22%), exchangeable Mg (−27%), total Ca (−20%), and total Mg (−29%) pools of the forest floor of moist sites. Values reported here are much greater than values generally predicted by a balance sheet approach and underline the need for more process-oriented studies. Impacts of these losses on long-term site productivity remain to be investigated.

scholarly journals Preliminary Study on Enzymatic-Based Cleaning of Cation-Exchange Membranes Used in Electrodialysis System in Red Wine Production

Membranes ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 114 ◽  
Author(s):  
Bdiri ◽  
Bensghaier ◽  
Chaabane ◽  
Kozmai ◽  
Baklouti ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Contact Angle ◽  
Ion Exchange ◽  
Cation Exchange ◽  
Red Wine ◽  
Exchange Capacity ◽  
Operating Conditions ◽  
Cleaning Efficiency ◽  
Wine Production ◽  
Ion Exchange Capacity

The use of enzymatic agents as biological solutions for cleaning ion-exchange membranes fouled by organic compounds during electrodialysis (ED) treatments in the food industry could be an interesting alternative to chemical cleanings implemented at an industrial scale. This paper is focused on testing the cleaning efficiency of three enzyme classes (β-glucanase, protease, and polyphenol oxidase) chosen for their specific actions on polysaccharides, proteins, and phenolic compounds, respectively, fouled on a homogeneous cation-exchange membrane (referred CMX-Sb) used for tartaric stabilization of red wine by ED in industry. First, enzymatic cleaning tests were performed using each enzyme solution separately with two different concentrations (0.1 and 1.0 g/L) at different incubation temperatures (30, 35, 40, 45, and 50 °C). The evolution of membrane parameters (electrical conductivity, ion-exchange capacity, and contact angle) was determined to estimate the efficiency of the membrane′s principal action as well as its side activities. Based on these tests, we determined the optimal operating conditions for optimal recovery of the studied characteristics. Then, cleaning with three successive enzyme solutions or the use of two enzymes simultaneously in an enzyme mixture were tested taking into account the optimal conditions of their enzymatic activity (concentration, temperatures, and pH). This study led to significant results, indicating effective external and internal cleaning by the studied enzymes (a recovery of at least 25% of the electrical conductivity, 14% of the ion-exchange capacity, and 12% of the contact angle), and demonstrated the presence of possible enzyme combinations for the enhancement of the global cleaning efficiency or reducing cleaning durations. These results prove, for the first time, the applicability of enzymatic cleanings to membranes, the inertia of their action towards polymer matrix to the extent that the choice of enzymes is specific to the fouling substrates.

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