Ion Exchange Resin Adsorption Research Articles

Efficient removal of alkali and alkaline earth metals from biodiesel using Ion-exchange resin: Performance and mechanism

Raw materials, production process, and other factors cause several metal ions to exist in biodiesel. Furthermore, the existence of alkali and alkaline earth metals seriously affects the quality and performance of biodiesel. To improve fuel quality, a 732 ion-exchange resin was used to reduce the contents of alkali and alkaline earth metal ions in Jatropha biodiesel. The adsorption efficiency of the ion-exchange resin for alkali and alkaline earth metal ions in biodiesel was evaluated using ion chromatography, while the adsorption mechanism of ion change resin on alkali and alkaline earth metal ions in biodiesel was elucidated via FTIR and XPS. In addition, the effects of ion-exchange resin on several key physiochemical properties of biodiesel, including oxidation stability, corrosivity, heat value and kinematic viscosity, were also explored. The results showed that the total content of alkali and alkaline earth metal ions in biodiesel was reduced by 88.19%, and the K+, Na+, Mg2+, and Ca2+ contents were reduced to 0.11 mg/kg, 0.89 mg/kg, 0.53 mg/kg, and 0.78 mg/kg, respectively, after removing the ion-exchange resin. In the removal process, the hydroxyl group of sulfonic acid group on the ion-exchange resin is broken, and the substitution adsorption reaction between H+ and the alkali and alkaline earth metal ions in biodiesel is carried out. Moreover, the oxidation induction period of biodiesel was prolonged by 40.8% owing to the reduction in the content of alkali and alkaline earth metal ions, which significantly blocked the decomposition pathways of unstable oxidation intermediates in biodiesel. The degree of copper corrosion in biodiesel did not change significantly before and after ion-exchange resin adsorption during short-term corrosion (3 h); however, the copper corrosion grade decreased from 2c to 1b after ion-exchange resin adsorption during long term corrosion (240 h). Nevertheless, the heat value and kinematic viscosity of biodiesel were observed to be independent of the ionic metal content.

Study on gel properties of lysozyme-free egg white before and after Lactiplantibacillus plantarum fermentation.

Isolation of lysozyme from egg white (EW) using ion exchange resin adsorption method generates large quantities of lysozyme-free egg white (LFEW) with poor gelling property. To maximize the applications of LFEW, the effect of Lactiplantibacillus plantarum fermentation on the gel properties of LFEW was investigated in this study. The fermentation efficiency of LFEW with lysozyme removed was significantly improved, and the sugar removal rate (2g kg-1 Lactiplantibacillus plantarum, 37 °C, 7h) was more than 90%. Removal of lysozyme resulted in increased stability and surface hydrophobicity of EW. After Lactiplantibacillus plantarum fermentation, the stability of EW decreased, and the average particle size and surface hydrophobicity increased. In addition, by comparing the gel properties of EW and LFEW before and after fermentation at different pH, it was found that the hardness, elasticity, and water holding capacity (WHC) of EW gel increased significantly. The removal of lysozyme effectively improved the WHC and springiness of the EW gel and promoted the formation of a denser network structure with smaller pores. After Lactiplantibacillus plantarum fermentation treatment, LFEW gel hardness decreased, with loose and porous network structure, no browning occurred after autoclaving. This study provided the direction and theoretical basis for producing a fermented LFEW gel with pleasing texture and appearance. © 2022 Society of Chemical Industry.

The kinetics of heparin adsorption with Dowex 1x1 ion exchange resin

The recovery of heparin from the porcine intestinal mucosa by using the ion exchange resin was studied. The procedure involved the following steps: alkaline hydrolysis, ion exchange resin adsorption, and elution. The activity of heparin was measured by an antifactor Xa assay. The ammonium chloride/ammonium hydroxide was used as a buffer, and the effect of salt concentration on the adsorption efficiency was evaluated. The results showed that the highest heparin yield (86.17%) was achieved at the lowest concentration of ammonium chloride. The pseudo-first-order model was shown as more adequate to describe heparin adsorption onto the resin.

Effect of pH on effluent organic matter removal in hybrid process of magnetic ion-exchange resin adsorption and ozonation.

It is essential to mitigate the risk of exposure to effluent organic matter (EfOM) in aquatic environments to ensure safe wastewater recycling. Magnetic ion-exchange (MIEX) resin adsorption combined with ozonation could provide EfOM removal. However, the poor understanding of the influences of the parameters and mechanisms in the hybrid process has restricted the applications. In this study, the response surface methodology was used to reveal the interactions of the major operation parameters. The degradation behaviour of the EfOM was investigated by using spectroscopy combined with mathematical methods. The effect of the pH on the EfOM removal was also analysed. The maximum efficiency of the removal of dissolved organic carbon (DOC) was 59.77% at the optimal MIEX resin dosage of 7.97 mL/L, ozone concentration of 8 mg/L, agitation speed of 199.84 r/min, and pH of 9.98. The ozonation was superior to resin adsorption in the removal of 1054-Da compounds, while the resin adsorption was advantageous in the removal of 4168-Da compounds. Three fluorescent components (C1, C2, and C3) were more easily subjected to external perturbation than the DOC and ultraviolet absorbance at 254 nm in the oxidation processes. The MIEX resin exhibited low efficiencies of removal of the fluorescent substances. A synchronous fluorescence analysis coupled with a two-dimensional correlation analysis revealed that the variation in EfOM followed the order of fulvic-to humic-like substances in the hybrid process of MIEX and the following ozonation. The pH was the most significant influencing factor in the hybrid process.

Sustainable utilization of cane molasses by an integrated separation process: Interplay between adsorption and nanofiltration

Molasses-based fermentation produces a large amount of wastewater with high salinity and recalcitrant pigments, and thus alternative strategies to efficiently utilize molasses are required. In this study, the clarified molasses were treated by nonpolar resin adsorption to recover caramel pigments, and this operation also greatly alleviated fouling formation on loose nanofiltration (NF) membranes used for molasses decolorization, especially the polyethersulphone (PES) membrane. PES1 membrane (molecular weight cut-off ∼1000 Da, AMFOR) was selected as a substitute for NF5 membrane (340–460 Da, self-made) with a polyamide (PA) separation layer thanks to its stronger long-term chlorine resistance than NF5. The short-term chlorine cleaning at pH 12 could improve the hydrophilicity of PES1 and mitigate its irreversible fouling formation, but such effect decreased color retention by PES1 because the fouling-induced pore narrowing was weakened. The decolorized molasses (the PES1 permeate) were further treated by a tight NF and ion exchange resin adsorption, and the tight NF could not only separate sucrose and reducing sugar, but also retain most divalent ions and residual pigments lessening the burden of the subsequent resin adsorption. The sucrose-rich liquid could be used for sugar crystallization while the desalted reducing sugar was expected to be concentrated to produce syrup. This work offered a complete technological route for green and sustainable utilization of cane molasses from practical application point of view.

Removal of iodine from the salt water used for caustic soda production by ion-exchange resin adsorption

A lower concentration of iodine (<0.2 mg/L) in the salt water used for caustic soda production is crucial to prolong the service life of ionic membrane and decrease the cost of production. The removal of iodine from salt water by resin adsorption was carried out in this work. It was found that the existing species of iodine is the key factor to affect the adsorption, and I2 is the optimal adsorbed species in salt water through the reaction between I2 and Cl− in the resin to form (ClI2)−. A simple pre-treatment method was developed to transform different iodine species in salt water into I2 by adjusting the solution to pH 1.5–2.5 and redox potential (Eh) 530–560 mV. A novel purification system for the removal of iodine from salt water was subsequently developed and constructed based on the pre-treatment method and the adsorption thermokinetics of I2. The stability and reliability of this developed method and system were demonstrated by a scale-up experiment to remove iodine from the refined salt water used for caustic soda production, by which the concentration of iodine can be stably decreased to far <0.2 mg/L.

Extraction of matrine from Sophora flavescens Ait. and evaluation of its inhibitory effects on human nasopharyngeal carcinoma CNE-2 cells

Abstract The present study investigated the extraction and purification technology of matrine from Sophora flavescens Ait. and the inhibitory effects of matrine on human nasopharyngeal carcinoma (NPC) CNE-2 cells. The matrine was extracted from Sophora flavescens Ait. by decocting using ethanol-aqueous solution as the solvent, followed by purification using ion exchange resin adsorption. The extraction and purification conditions were investigated. The effects of matrine on growth, cell apoptosis and cycle of CNE-2 cells and expressions of Bac-2 and caspase-3 protein in cells were detected. Results showed that, the optimal extraction and purification technologies of matrine from Sophora flavescens Ait. were obtained, under which the purity of matrine was 81.56%. Matrine could obtain inhibit the growth of CNE-2 cells, promote the cell apoptosis, and arrest most cells in G0/G1 phase. In addition, after treated matrine, the relative expression level of Bcl-2 protein in CNE-2 cells was decreased, and the expression level of Caspase-3 protein was increased. In conclusion, matrine has inhibitory effects on human NPC CNE-2 cells. The mechanism may be related to its down-regulation of Bcl-2 protein and up-regulation of Caspase-3 protein expression.

Effect of integrated pretreatment technologies on RO membrane fouling for treating textile secondary effluent: Laboratory and pilot-scale experiments

In this study, effect of pretreatment on reverse osmosis (RO) fouling was investigated for treating textile secondary effluent (SE), including coagulation, ultrafiltration (UF), magnetic ion exchange resin adsorption (MIEX) and their integrations. Laboratory-scale experiments exhibited that organics removal was highest by MIEX, followed by UF and coagulation; the integration of coagulation and MIEX was the most effective pretreatment to mitigate RO fouling. The effect of integrated pretreatment methods on RO fouling was also conducted in pilot-scale experiments. The same result with that of laboratory-scale experiments was obtained that coagulation+sand filter+MIEX as RO pretreatment was superior to coagulation+sand filter+UF. The results of gel permeation chromatograph (GPC) and excitation and emission matrix fluorescence (EEM) showed that the foulants on RO membrane were mainly composed of high molecule weight (MW) protein and soluble microbial products (SMP)-like matter. UF could remove the RO foulants effectively, but mitigation of RO fouling was at the expense of UF fouling. Besides, SEM shown that fouling layer on RO surface became more compact and peak heights of organics were higher on GPC spectra after UF pretreatment than MIEX likely due to the easily deposition of low MW organics in the valleys of RO membrane. Consequently, the integrated coagulation+MIEX was a promising pretreatment method prior to RO for treating textile SE.

A Review of Thiosulfate Leaching of Gold: Focus on Thiosulfate Consumption and Gold Recovery from Pregnant Solution

Thiosulfate leaching is a promising alternative to cyanidation, and the main hindrances for its wide commercial application are the high thiosulfate consumption and the difficult recovery of dissolved gold. In this review, the four solutions to reduce the consumption of thiosulfate, including the control of reaction conditions, the use of additives, the generation of thiosulfate in situ, and the replacement of traditional cupric-ammonia catalysis, are introduced and evaluated after the presentation of background knowledge about thiosulfate consumption. The replacement of cupric-ammonia catalysis with other metals, such as nickel- and cobalt-based catalysts, is proposed. The reason is that it not only reduces thiosulfate consumption observably via decreasing the redox potential of leach solution significantly but also is beneficial to gold recovery mainly owing to eliminating the interference of cuprous thiosulfate [Cu(S2O3)3]5−. Based on the comparative analysis for five common recovery techniques of rare-noble metals from pregnant leach solution, ion-exchange resin adsorption is considered to be the most appropriate to recover aurothiosulfate [Au(S2O3)2]3− because the resin can be employed in the form of resin-in-leach/pulp and, furthermore, is able to be eluted and regenerated simultaneously at ambient temperature. At last, how to reduce the process cost of the resin adsorption technique is discussed. In order to simplify the complex two-stage elution process for loaded resins, the traditional catalysis is suggested to be replaced.

The analysis of ion exchange resin adsorb Li from ash solution

PurposeThis paper aims to take the four resin as adsorbent and coal ash alkaline solution as the material and use the single factor experimental method to study absorption influence factors for each resin to absorb lithium. At the same time, the authors got the special properties of some kinds of resin and compared the test results of each resin at the optimum factors.Design/methodology/approachBecause many factors affect the test, this study uses the method of comparison and control variables. This method study on the influencing factors of ion exchange resin adsorption Li+.FindingsIn these adsorption experiments, the basic resin adsorption effect is more obvious. The optimum adsorption conditions are as follows: resin quality is 0.1 g, the volume of fly ash solution is 100 ml, magnetic stirrer speed is 140 r/min and the adsorption time is 60 min. Under these conditions, the adsorption rate of Li+ could reach 25.17 per cent aluminum.Originality/valueLi extracted from coal ash can not only relieve the lithium resources in short supply but can also provide a new mode to the field of coal resources in recycling economy and transition economy. At the same time, the extraction of Li resources will provide an important reserve of raw materials for the future of nuclear power plant.

Study on Preparation of Zn/Al Double Metal Oxide by Ion Exchange Method

The optimum reaction conditions of D113 type ion exchange resin adsorption on Zn/Al ions and the microstructure of Zn/Al double metal oxide were researched with weight method and scanning electron microscopy. The results showed that when Zn/Al molar ratio was 2:1, the number of moles per unit mass of resin adsorption was biggest and the microstructure was better; with the increase of pH value and temperature, the number of moles per unit mass of resin adsorption increased. When the PH value was 3.89, the microstructure of calcined product was best, and the effect of temperature on the calcined product microstructure was little. EDS data and XRD spectra indicated that there were two kinds of ZnO and Al2O3products.

Purification of Hemicelluloses in Pre-Hydrolysis Liquor of Kraft-Based Dissolving Pulp Production Process Using Activated Carbon and Ion-Exchange Resin Adsorption Followed by Nanofiltration

Purification of Hemicelluloses in Pre-Hydrolysis Liquor of Kraft-Based Dissolving Pulp Production Process Using Activated Carbon and Ion-Exchange Resin Adsorption Followed by Nanofiltration

Research Status of Gold Recovery from Thiosulfate Leaching Solution

The main recovery methods of gold from thiosulfate leaching solution are introduced, such as replacement precipitation, carbon adsorption, ionexchange resin adsorption, and solvent extraction. Research status of different process and their advantages/disadvantages are reviewed briefly. The research prospects on the methods are also given.

Study on the influence of humic acid of different molecular weight on basic ion exchange resin's adsorption capacity

In this paper, humic acid (HA) was ultra-filtered into different molecular weight sections and was characterized by multi-element analysis, UV 254/TOC, FT-IR and three-dimensional fluorescence spectrometric. Since humic acids of different molecular weights have different hydrophilic and molecular size, the maximum adsorption capacity of basic ion exchange resins appears on the humic acid whose molecular weight ranges from 6000 to 10,000 Da.

Soil Nutrient Availability Assessed by In Situ Ion-exchange Resin Bags as a Predictor of Growth of Swedish Coniferous Forests

Assessment of site fertility is usually based on measurements of the growth of the present stand or the composition of the field vegetation. In this study, the soil nutrient availability, assessed using in situ ion-exchange resin (IER) bags, was tested as a possible predictor of forest production. Ten Scots pine sites and five Norway spruce sites, distributed throughout Sweden, were included in the study. At the pine sites, the amounts of NO3 adsorbed by the IER correlated best to forest production ( pB 0.001), although the abundance of this ion was low. Only a weak correlation with production was found for K+ (pB 0.1). The IER adsorption of PO4 was low at the pine sites in southern Sweden.

Soil Nutrient Availability Assessed by In Situ Ion-exchange Resin Bags as a Predictor of Growth of Swedish Coniferous Forests

Assessment of site fertility is usually based on measurements of the growth of the present stand or the composition of the field vegetation. In this study, the soil nutrient availability, assessed using in situ ion-exchange resin (IER) bags, was tested as a possible predictor of forest production. Ten Scots pine sites and five Norway spruce sites, distributed throughout Sweden, were included in the study. At the pine sites, the amounts of NO3 adsorbed by the IER correlated best to forest production ( pB 0.001), although the abundance of this ion was low. Only a weak correlation with production was found for K+ (pB 0.1). The IER adsorption of PO4 was low at the pine sites in southern Sweden.

Production of citric acid from molasses integrated with in-situ product separation by ion-exchange resin adsorption

A novel method of citric acid production from beet molasses was developed, in which an anion-exchange resin packed-column was connected to a fermenter for separation of citric acid from fermentation broth. The experimental results indicated that, as compared with conventional batch, the new fermentation techniques increased the citric acid productivity and sugar conversion from 0.338 g/l h and 82.2% to 0.543 g/l h and 94.8%, respectively.

A method for the quantitative determination of individual free fatty acids in milk by ion exchange resin adsorption and gas-liquid chromatography

SummaryA quantitative method for rapid routine analysis of individual free fatty acids (FFA) in milk was developed. Lipid was extracted from milk in ether and FFA were recovered by shaking the extract with anion exchange resin Amberlyst 26. The resin-bound FFA were methylated directly and the individual acids quantified, using internal standards, by gas-liquid chromatography. The properties of the resin were measured. The validity of the method was established by extraction of FFA mixtures and milk. Individual acids were, on average, found to be within 6% of the actual concentration present in the mixture. An average coefficient of variation of 4·3% was achieved for the major individual fatty acids on repeated extraction of a single milk sample.

Polyphenol Oxidation by Leaf Peroxidases in Nicotiana

Peroxidase allozymes from mature leaves of Nicotiana tabacum L. cv. Burley 21 and Hicks, N. Sylvestris, and N. tomentosiformis were partially purified by ion-exchange resin adsorption and then separated into four groups by polyacrylamide gel electrophoresis. The allozymes were fast- or slow- migrating anodic or cathodic forms. All allozyme groups showed pH optima from pH 5 to 6. Certain anions, cations chelators, enzyme inhibitors, and other compounds affected the oxidative capability of the allozymes; a greater difference in sensitivity to these compounds was found between anodic and cathodic groups than between allozymes migrating to the same pole. Tobacco polyphenols chlorogenic acid, caffeic acid, rutin, and quercetin were readily oxidized by the fast-migrating anodic peroxidases, less so by the slow-migrating anodic peroxidases, and least by the cathodic ones. Similarities in catalytic properties between the cultivars and the putative progenitors support their phylogenetic affinity. Tests of in vitro interaction for oxidative capability between the anodic groups of different species showed enhancement for most of them. Polyphoenol oxidation by peroxidase produced soluble brown substances and con-comitantly resulted in a loss of the oxidase. Results suggest that peroxidases in tobacco leaf may contribute iron and protein units to brown pigments.

The ion-exchange resin adsorption of thallium(I) and (III)

The adsorption of small concentrations of radiothallium(III) on the cation-exchange resin Amberlite IR-120(H) begins to decrease at 8 and 32°C when the concentrations of hydrochloric and hydrobromic acids in the solution are about 10 −3 and 10 −2 and 10 −4 and 10 −3 M respectively. The adsorption of tracer thallium at 25°C on the anion-exchange resin Dowex 1-X8 is at a maximum when the concentration of hydrochloric acid in the solution is about 10 −1 and 1 M for the (III) and (I) oxidation states respectively. The presence of perchloric acid depresses markedly the adsorption of tracer thallium(III) on Dowex-1 from hydrochloric acid media.