Chelating Resin Research Articles

Iron limitation by transferrin promotes simultaneous cheating of pyoverdine and exoprotease in Pseudomonas aeruginosa.

Pseudomonas aeruginosa is a primary bacterial model to study cooperative behaviors because it yields exoproducts such as siderophores and exoproteases that act as public goods and can be exploited by selfish nonproducers behaving as social cheaters. Iron-limited growth medium, mainly casamino acids medium supplemented with transferrin, is typically used to isolate and study nonproducer mutants of the siderophore pyoverdine. However, using a protein as the iron chelator could inadvertently select mutants unable to produce exoproteases, since these enzymes can degrade the transferrin to facilitate iron release. Here we investigated the evolutionary dynamics of pyoverdine and exoprotease production in media in which iron was limited by using either transferrin or a cation chelating resin. We show that concomitant loss of pyoverdine and exoprotease production readily develops in media containing transferrin, whereas only pyoverdine loss emerges in medium treated with the resin. Characterization of exoprotease- and pyoverdine-less mutants revealed loss in motility, different mutations, and large genome deletions (13-33 kb) including Quorum Sensing (lasR, rsal, and lasI) and flagellar genes. Our work shows that using transferrin as an iron chelator imposes simultaneous selective pressure for the loss of pyoverdine and exoprotease production. The unintended effect of transferrin uncovered by our experiments can help to inform the design of similar studies.

Synchronous reduction-fixation of reducible heavy metals from aqueous solutions: Application of novel mesoporous MFT/SBA-15 composite materials

The usual treatment for Cr(VI)-contaminated wastewater primarily included reduction, adsorption, and the subsequent separation of the Cr-laden adsorbent. Among these factors, the adsorbent is the most critical factor in determining Cr removal efficiency. In this study, a novel melamine-formaldehyde-thiourea (MFT) chelating resin/mesoporous silica composite material (MFT/SBA-15) was synthesized via a co-condensation method and used for the reduction and fixation of Cr(VI)-contaminated water. Cr(VI) adsorption onto MFT/SBA-15 obeyed the pseudo-second-order model, and the chemical adsorption was the rate-limiting step in the adsorption process. Also it followed the Langmuir adsorption model, with single molecular layer adsorption characteristics. The organic components within MFT/SBA-15 were the core functional groups for Cr(VI) adsorption, and the formation of a coordination bond (CS→Cr) between the lone electron pairs of the S atom and Cr during the adsorption process led to the synchronous reduction-fixation processes of Cr(VI). These synchronous effects were further demonstrated for other reducible heavy metals, including As(V) and Cu(II), but negligibly observed in chemically stable elements, such as Zn(II), Ni(II), Pb(II), Cd(II), and As(III). The novel mesoporous MFT/SBA-15 materials combine the advantages of the chelating resin and mesoporous silica and have excellent potential for the wastewater treatment of reducible heavy metals through synchronous reduction-fixation.

The impact of an Amberlite XAD-16-based chelating resin for the removal of aqueous Cd(II) and Pb(II)ions

The main objective of this study is to investigate the influence of the Amberlite XAD-16-based chelating resin, 1,8-(3,6-dithiaoctyl)-4-polyvinylbenzenesulphonate (dpvbs), for the removal of the highly lethal Pb(II) and Cd(II) from aqueous solutions. The extractor`s behavior is examined, as adsorbent as well as coordinating agent showing structural changes upon the interaction with the targeted metal ions. Elemental analyses, FTIR, electronic spectra, EDS and XPS were used to provide a close image of the composition, structural and morphological changes upon the interaction with Pb(II) and Cd(II). Thermal behavior of the sorption products, compared with the coordinating resin, were also, studied and the estimated thermodynamic parameters indicated an endothermic spontaneous sorption mechanism. The BET surface area, BJH desorption volume and the pore diameters increased upon chelation with Cd(II) and Pb(II), indicating the destruction of the cross-linking of the free resin. SEM and AFM studies confirmed the surface morphological change of dpvbs, after sorption processes. The sorption effectiveness was examined utilizing batch and column methods, showing high removal efficiency with an average sorption of 99.9%. dpvbs was tested for the removal of metal ions from tap watershowing a metal uptake of almost the same after 3 cycles, with an efficiency of 98–99%.

Recovery of uranium from ferruginous Shale mineralization from Um Bogma formation, Egypt, via Duolite ES‐467 chelating resin

AbstractThe ferruginous shale iron content (27.5 %) is a serious problem that prevents the separation of uranium. Chemical dissolution of the ferruginous shale from Um Bogma Formation, Egypt, has been studied for the recovery of uranium using the acidic leaching method. Um Bogma representative sample assays 700 ppm of uranium as the element of interest. The effective dissolution parameters such as acid concentrations, solid/liquid addition ratio, leaching time, and leaching temperature were planned to investigate. It was found that The dissolution rate was greatly influenced by the studied dissolution factors. Analysis of the kinetic data showed that the dissolution mechanism is fitted well to shrinking core model within chemical reaction as a rate determining step. It was found that the recorded activation energy (Ea) of uranium dissolution is 205 kJ/mol. The uranium dissolution efficiency of 95.2 % has been achieved with optimized conditions of 250 g/L H2SO4; 1 : 7 (S/L) phase ratio; 250 °C for 7 hours. Finally, the best‐controlling factors were applied for uranium separation from Um Bogma leach liquor to produce a uranium concentrate with 69.985 % uranium purity.

Removal of fluoride from sodium sulfate brine by zirconium pre-loaded chelating resins with amino-methyl phosphonic acid functionality

Fluoride can be removed from brine by loading it onto an aluminum pre-loaded chelating cation exchange resin. In this work, zirconium pre-loaded chelating resin with amino methyl phosphonic acid (AMPA) functional group was investigated and compared with the resin in aluminum pre-loaded form to remove fluoride (<25 mg/L) from sodium sulfate electrodialysis brine solution. With the resin in zirconium pre-loaded form, a series of batch isotherm studies suggested that a change in Na2SO4 brine concentration (6–24 wt%) resulted in a negligible effect on fluoride adsorption. Solution pH in the range of 3–9 was observed to be optimal, and further increase in pH resulted in significant decrease in fluoride loading capacity. Increase in temperature (303−333 K) resulted in lower fluoride loading capacity. Cyclical load-regenerate column studies with zirconium pre-loading solution resin regeneration method showed that a noticeable improvement in the fluoride adsorption was attainable. Notably, for every load-regenerate cycle, fluoride concentration of below 1 mg/L was achieved in effluent. Zirconium concentration in the product solutions were less than 1 mg/L Zr, suggesting that displacement of zirconium from the resin is minimal. This result therefore demonstrated the outstanding stability of zirconium with the AMPA resin.

Adsorption of lanthanum and cerium on chelating ion exchange resins: kinetic and thermodynamic studies

ABSTRACT As the demand for rare earth elements (REE) increases in the coming years, techniques to obtain these elements from different sources may be explored. A hydrometallurgical route may achieve the sustainable approaches signed by countries. For this, separation techniques need to be explored, and chelating ion exchange resins are the most prominent. For this reason, to enhance the possibilities for REE separation, the main focus of this work was to study kinetics models and the thermodynamics of lanthanum and cerium adsorption at laboratory scale under industrially operating conditions. Three different functional groups were evaluated through the chelating resins M4195, TP207, and XUS43605. The effect of pH and resin dosage were evaluated, as well as the kinetic models (pseudo-first-order, pseudo-second-order, Elovich, and intraparticle diffusion) and thermodynamic parameters. The results presented here could be used for industrial applications. Pseudo-second order provided a better fit for both M4195 and TP207, and the intraparticle diffusion fitted better for XUS43605. Thermodynamic experiments have shown that the adsorption of lanthanum and cerium are spontaneous and endothermic. These findings represent the novelty of the present study since it could be used in selective separation of lanthanum and cerium onto chelating resins from primary and secondary sources.

Surface-Activated Chelating Resins Containing N-Methyl-D-Glucamine Functional Groups for Desalination of Geothermal Water Aimed for Removal of Boron and Arsenic

ABSTRACT Within the present study, novel chelating resins containing a layer loaded with N-methyl-D-glucamine functionalities were synthesized. The procedure involved impregnation of macroporous Amberlite XAD-4 adsorbent using mixture of vinylbenzyl chloride (VBC) and divinylbenzene (DVB) further subjected to free radical suspension polymerization. The so-obtained 1PTN and 2PTN adsorbents were characterized by expanded-gel or microporous structure of VBC-co-DVB layer, respectively. The both materials were used in desalination of geothermal water aimed to decrease levels of boron and arsenic. As a part of this, he research on boron and arsenic removal included batch adsorption and kinetic studies. The results have shown that the resin 1PTN showed maximum boron removal of 64% and arsenic removal of 18% from the geothermal water. The resin 2PTN exhibited competitive boron removal performance as compared to the commercial Diaion CRB 05 resin, reaching its efficiency by removing over 96% of boron. Also, the sample 2PTN outmatched Diaion CRB 05, removing 97% of arsenic and leading to decrease of its concentration to permissible level.

Applicability of Internal Standardization with Yttrium to the Solid-phase Extraction of Trace Elements in Groundwater and Wastewater Using an Aminocarboxylic Acid-type Chelating Resin.

Internal standardization was applied to the solid-phase extraction of trace elements using the following commercially available aminocarboxylic acid-type chelating resins: InertSep ME-2, NOBIAS Chelate PA-1, and Presep PolyChelate. The concentration of the trace elements in initial sample solution can be calculated by using the ratio of the added amount of the internal standard element, Y, in the initial sample solution to that in the final solution after the solid-phase extraction, which is proportional to the volume of the sample solution passed through the cartridge, and the ratio of the volume of the initial sample solution to that of a blank solution for preparing the calibration curve. In this solid-phase extraction, strict control of the volumes of the sample solution passed through the cartridge and the final solution after the solid-phase extraction is not needed because these are not used in the calculation of the trace element concentration. The solid-phase extraction with the internal standardization using Y could be applied to the separation and preconcentration of some trace elements, namely Cd, Co, Cu, Fe, Ni, Pb, Ti, and Zn in an artificial seawater spiked with the elements and some certified reference materials, EnviroMAT ES-L-1 Ground Water and EU-L-3 Waste Water, without any interference.

Sequential separation of Cu(II)/Ni(II)/Fe(II) from strong-acidic pickling wastewater with a two-stage process based on a bi-pyridine chelating resin

A self-synthesized bi-pyridine chelating resin (PAPY) could separate Cu(II)/Ni(II)/Fe(II) sequentially from strong-acidic pickling wastewater by a two-stage pH-adjusted process, in which Cu(II), Ni(II), and Fe(II) were successively preferred by PAPY. In the first stage (pH 1.0), the separation factor of Cu(II) over Ni(II) reached 61.43 in Cu(II)-Ni(II)-Fe(II) systems. In the second stage (pH 2.0), the separation factor of Ni(II) over Fe(II) reached 92.82 in Ni(II)-Fe(II) systems. Emphasis was placed on the selective separation of Cu(II) and Ni(II) in the first-stage. The adsorption amounts of Cu(II) onto PAPY were 1.2 mmol/g in the first stage, while those of Ni(II) and Fe(II) were lower than 0.3 mmol/g. Cu(II) adsorption was hardly affected by Ni(II) with the presence of dense Fe(II), but Cu(II) inhibited Ni(II) adsorption strongly. Part of preloaded Ni(II) could be replaced by Cu(II) based on the replacement effect. Compared with the absence of Fe(II), dense Fe(II) could obviously enhance the separation of Cu(II)-Ni(II). More than 95.0% of Cu(II) could be removed in the former 240 BV (BV for bed volume of the adsorbent) in the fixed-bed adsorption column process with the flow rate of 2.5 BV/h. As proved by X-ray photoelectron spectrometry (XPS) and density functional theory (DFT) analyses, Cu(II) exerted a much stronger deprotonation and chelation ability toward PAPY than Ni(II) and Fe(II). Thus, the work shows a great potential in the separation and purification of heavy metal resources from strong-acidic pickling wastewaters.

Determination of Rare Earth Elements in Pore Water Samples of Marine Sediments Using an Offline Preconcentration Method.

The concentrations of dissolved yttrium and rare earth elements (REY) in sediment pore water provide important geochemical information. However, due to the low REY concentration, complex matrix, and limited sample volume (often only a few milliliters), analysis of the REY in pore water often is highly challenging. In this study, a method was established to determine the dissolved REY in pore water of marine sediments using an offline preconcentration step with the ethylenediaminetriacetate chelating resin, followed by inductively coupled plasma-mass spectrometry. In addition, using a commercially available automated trace-element preconcentration system, the preconcentration step can be fully automated, saving labor and providing a better control of the final elution volume. The experimental conditions (pH, elution volume, elution acid concentration, and organic complexation effect) were assessed, and the optimal conditions were chosen. In particular, the organic complexation effect was found to be negligible. The procedure blank and limit of detection were satisfactory for studying REY in pore water of marine sediments, and the method also yielded satisfactory recoveries for the REY elements (83-110%). The method was then applied to analyze the dissolved REY concentrations of pore water samples collected in a sediment core (~ 30cm) in the central Indian Ocean. The vertical distribution, dissolved REY concentration, and the average Post Archean Australian Shale-normalized pattern of the REY showed similarities to the previously published pore water REY data. This method provides an accurate yet facile approach for the analysis of all 15 REY in marine pore water samples using the sample volume of only ~ 5mL.

Removal of ammonia nitrogen from copper-loaded resin based on ligand adsorption

A ligand adsorbent with strong selectivity towards ammonia nitrogen in solution was prepared by loading Cu onto the chelating resin of iminediacetic acid. The static adsorption results showed that the removal rate of ammonia nitrogen reached the maximum when the equilibrium pH of solution was 9.5-10. The presence of competing cations, such as Na+ and Ca2+, had no obvious effect on the optimal equilibrium pH, but had a certain inhibitory effect on the adsorption of ammonia nitrogen and Ca2+> Na+. The adsorption of ammonia nitrogen by copper-loaded resin was in line with the Langmuir isothermal equation, and the maximum adsorption capacity of ammonia nitrogen was 44mg/g(dried copper-loaded resin).

Desorption and recovery of fluoride adsorbed by the aluminum-loaded chelating resin

Desorption and recovery of fluoride adsorbed by the aluminum-loaded chelating resin

Speciation and separation of platinum(iv) polynuclear complexes in concentrated nitric acid solutions.

Understanding the solution chemistry of Pt(iv) is crucial for the hydrometallurgy of precious metals. To gain such an understanding, the speciation and separation of Pt(iv) complexes in concentrated HNO3 solutions were investigated via Pt LIII edge X-ray absorption fine structure (XAFS) spectroscopy. The XAFS results for concentrated HNO3 solutions of Na2Pt(OH)6 revealed the dominant presence of Pt polynuclear complexes, wherein the formation of Pt(iv) polynuclear complexes depended on the metal concentration and the Na2Pt(OH)6 dissolution temperature. The dominant species present in a heated nitrate solution of 0.90 g-Pt L-1 and a non-heated nitrate solution of 3.2 g-Pt L-1 were dinuclear Pt(iv) complexes, whereas those in a heated solution of 3.0 g-Pt L-1 were predominantly larger polynuclear complexes, such as, tetra- and hexa-nuclear complexes. The presence of larger Pt(iv) complexes was confirmed via XAFS spectroscopy, wherein the adsorption of Pt(iv) ions from a 10 M HNO3 solution by a chelating resin functionalised with iminodiacetic acid and a strongly basic anion-exchange resin bearing trimethyl ammonium nitrate was examined. The adsorption of 50 mg L-1 of Pt(iv) by the two resins was tested using aqueous solutions diluted from heated HNO3 solutions with varying metal concentrations, and also from a non-heated solution. We found that Pt(iv) complexes from heating solutions containing high Pt(iv) concentrations displayed high adsorption percentages. In addition, the selective adsorption of Pt(iv) over Pd(ii), Ag(i), Cu(ii), Ni(ii), and Fe(iii) from a 10 M HNO3 solution was achieved using a strongly basic anion-exchange resin.

Pd–In bimetallic nanoparticles supported on chelating resin for nitrate removal from water: high efficiency and low NH4+ selectivity

The supported Cu/Pd bimetallic catalyst could prestore hydrogen and no additional reducing agent is required during the nitrate reduction process. High nitrate removal efficiency (96%) and low NH4+ selectivity (&lt;2%) were achieved.

Adsorption Properties for La(III), Ce(III), and Y(III) with Poly(6-acryloylamino-hexyl hydroxamic acid) Resin.

Using polyacrylic resin followed by the substitution reaction with 6-aminohexyl hydroxamic acid, poly(6-acryloylamino-hexyl hydroxamic acid) resin (PAMHA) was successfully synthesized. PAMHA, a spherical resin with the particle size of 0.4 mm, is a novel polyamide hydroxamic acid chelating resin containing acylamino and hydroxamic acid functional groups. A series of influences (pH, contact time, temperature, and the initial concentrations of rare earth ions) were investigated to determine the adsorption properties. The adsorption capacity for La(III), Ce(III), and Y(III) ions were 1.030, 0.962, and 1.450 mmol·g−1, respectively. Thermodynamic and kinetic studies were also carried out to show that the uptake of rare earth ions onto PAMHA fitted well the pseudo-second-order model and Langmuir isotherm, and the adsorption process was spontaneous endothermic. In addition, desorption of rare earth ions was achieved by using 2 mol·L−1 HNO3 and desorption efficiencies for La(III), Ce(III), and Y(III) ions were 98.4, 99.1, and 98.8%, respectively. Properties of PAMHA resin were characterized by scanning electron microscope (SEM), Fourier transform infrared spectrometry (FTIR), and X-ray photoelectron spectrometer (XPS). The results showed that there was coordination between the rare earth ions with PAMHA and rare metal ions were chemically adsorbed on the surface of the PAMHA.

Flow injection analysis method with on-line resin separation for determining trace Fe(II) and Fe(II + III) using catalytic spectrophotometry

A simple and sensitive flow injection analysis method using catalytic spectrometry was developed to measure sub-nanomolar levels of Fe(II) and Fe(II + III) in seawater using N,N-dimethyl-p-phenylenediamine dihydrochloride (DPD). Even without a preconcentration step, the minimum detection limit was 43 pmol/L, which was comparable to the limit of methods using a preconcentration step. DPD solutions were prepared using sodium sulfite as an antioxidant to increase the stability and extend the shelf-life of the reagent. The linear determination range was 6.0 nmol/L, and the relative standard deviation for sample measurements in 0.61 nmol/L Fe(II + III) was 4.4% (n = 14). The salinity and seawater matrix had a negligible impact on the results. The analytical results of the certified reference seawater NASS-5 (3.81 ± 0.21 nmol/L) agreed with the certified value (3.71 ± 0.63 nmol/L). The accuracy was further verified by measuring GEOTRACES Atlantic Ocean reference seawater samples. By adopting a nitrilotriacetic acid (NTA) Superflow chelating resin, the method was used for the on-line separation of the Fe(III)/Fe(II + III) redox pair. The method was used to assay dissolved Fe (<0.45 μm) in samples collected from the South East Asia Time-Series station in the South China Sea.

Preparation of a novel Poly-chloromethyl styrene chelating resin containing heterofluorenone pendant groups for the removal of Cu (II), Pb (II), and Ni (II) from wastewaters

Poly-chloromethyl styrene (CPS) was used as a carrier to synthesize a poly-chloromethyl styrene chelating resin (CPS-DI) containing heterofluorenone side groups with 4, 5-diazafluoren-9-one. The adsorption performance of the chelating resin on Cu (II), Ni (II), and Pb (II) was studied by batch experiments. Results show that CPS-DI chelating resin has a high affinity for Cu (II), Pb (II), and Ni (II) ions. The maximum adsorption capacities of Cu (II), Pb (II), and Ni (II) are 2.55, 1.34 and 0.94 mmol/g resin, respectively. The parameters on thermodynamic give the adsorption process spontaneous, and a higher temperature is beneficial to the adsorption process. CPS-DI chelating resin has excellent reusability. The column experiment simulates the adsorption process of CPS-DI chelating resin to metal ions, indicating that CPS-DI chelating resin can treat and recover heavy metal ions such as Cu (II), Pb (II), and Ni (II), effectively solve the problem of advanced treatment of wastewater containing heavy metal ions.

Comparative study of selective copper recovery techniques from nickel laterite leach waste towards a competitive sustainable extractive process

The launch of the 17 SDGs in 2015 cast a light in the challenges on sustainable development impacting directly all industrial process, including extractives. As a result, distinct raw materials, even residues, and industrial routes are being rethought to achieve the objectives. The main challenge of nickel limonite processing is the selective separation of target elements due to high-iron content, which is not well explored in the literature, making this material being considered as a waste Different techniques are explored for selective separation of copper, nickel, and cobalt. So, the motivation of the present work was to compare the ion exchange resin (Dowex XUS43605) and precipitation (sodium dithionite) for copper recovery. Batch experiments were carried in a multi-elementary system. Kinetic and thermodynamic parameters were evaluated focusing on industrial modeling. Results showed that the precipitation using sodium dithionite was more selective than chelating resin. On the other hand, sulfide hydrogen may be released making it dangerous for handling; furthermore, the ion exchange process is normally performed as continuous unlike precipitation, which is more suitable for industrial applications. Copper adsorption fitted better to Langmuir isotherm and pseudo second-order. The present study concludes that chelating resin is recommended to reach the SDGs goals.

In Situ Preparation of Copper-Loaded Carbon-Based Catalyst with Chelate Resin and Its Application on Persulfate Activation for X-3B Degradation

Under the guidance of the idea of “treating waste with waste”, copper-loaded carbon-based catalysts were prepared in situ using waste chelating resin with adsorbed copper. The effect of the catalyst activation temperature on dye brilliant red (X-3B) degradation was investigated and the characterization of the catalysts was analyzed. The results show that a catalyst activated at 800 °C (Cu-AC-800) has the largest specific surface area and abundant pore structure and the highest proportion of Cu under low valence states, which leads to the best performance in adsorbing and degrading X-3B. The influences of operation conditions and inorganic salt anions on persulfate (PS) activation were also investigated. Moreover, the degradation mechanism was preliminarily explored by quenching reactions. The main active free radicals in the system were determined as sulfate radicals (•SO4−). Given its use in solid waste recycling, copper-loaded carbon-based catalyst may provide some new insights for the remediation of wastewater.

Use of a Polymer Inclusion Membrane and a Chelating Resin for the Flow-Based Sequential Determination of Copper(II) and Zinc(II) in Natural Waters and Soil Leachates.

A bi-parametric sequential injection method for the determination of copper(II) and zinc(II) when present together in aqueous samples was developed. This was achieved by using a non-specific colorimetric reagent (4-(2-pyridylazo)resorcinol, PAR) together with two ion-exchange polymeric materials to discriminate between the two metal ions. A polymer inclusion membrane (PIM) and a chelating resin (Chelex 100) were the chosen materials to retain zinc(II) and copper(II), respectively. The influence of the flow system parameters, such as composition of the reagent solutions, flow rates and standard/sample volume, on the method sensitivity were studied. The interference of several common metal ions was assessed, and no significant interferences were observed (<10% signal deviation). The limits of detection were 3.1 and 5.6 µg L−1 for copper(II) and zinc(II), respectively; the dynamic working range was from 10 to 40 µg L−1 for both analytes. The newly developed sequential injection analysis (SIA) system was applied to natural waters and soil leachates, and the results were in agreement with those obtained with the reference procedure.