Aqueous Source Research Articles

Calix[4]pyrrole‐based Crosslinked Polymer Networks for Highly Effective Iodine Adsorption from Water

AbstractA series of calix[4]pyrrole‐based crosslinked polymer networks designed for iodine capture is reported. These materials were prepared by Sonogashira coupling of α,α,α,α‐tetra(4‐alkynylphenyl)calix[4]pyrrole with bishalide building blocks with different electronic properties and molecular sizes. Despite their low Brunauer–Emmett–Teller surface areas, iodine vapor adsorption capacities of up to 3.38 g g−1 were seen, a finding ascribed to the presence of a large number of effective sorption sites including macrocyclic π‐rich cavities, aryl units, and alkyne groups within the material. One particular system, C[4]P‐BTP, was found to be highly effective at iodine capture from water (uptake capacity of 3.24 g g−1 from a concentrated aqueous KI/I2 solution at ambient temperature). Fast capture kinetics (kobs=7.814 g g−1 min−1) were seen. Flow‐through adsorption experiments revealed that C[4]P‐BTP is able to remove 93.2 % of iodine from an aqueous source phase at a flow rate of 1 mL min−1.

Correction to “Recovery of Critical Metals from Aqueous Sources”

ADVERTISEMENT RETURN TO ISSUEPREVCorrectionNEXTORIGINAL ARTICLEThis notice is a correctionCorrection to “Recovery of Critical Metals from Aqueous Sources”Serife E. Can SenerSerife E. Can SenerMore by Serife E. Can Senerhttps://orcid.org/0000-0002-8085-7367, Valerie M. ThomasValerie M. ThomasMore by Valerie M. Thomashttps://orcid.org/0000-0002-0968-8863, David E. HoganDavid E. HoganMore by David E. Hogan, Raina M. MaierRaina M. MaierMore by Raina M. Maierhttps://orcid.org/0000-0002-0421-4677, Michael Carbajales-DaleMichael Carbajales-DaleMore by Michael Carbajales-Dale, Mark D. BartonMark D. BartonMore by Mark D. Barton, Tanju KaranfilTanju KaranfilMore by Tanju Karanfilhttps://orcid.org/0000-0003-0986-5628, John C. CrittendenJohn C. CrittendenMore by John C. Crittendenhttps://orcid.org/0000-0002-9048-7208, and Gary L. AmyGary L. AmyMore by Gary L. AmyCite this: ACS Sustainable Chem. Eng. 2021, 9, 44, 15072Publication Date (Web):October 26, 2021Publication History Received6 October 2021Published online26 October 2021Published inissue 8 November 2021https://doi.org/10.1021/acssuschemeng.1c06821Copyright © 2021 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views298Altmetric-Citations-LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (489 KB) Get e-AlertsSUBJECTS:Seawater,Coal,Power,Manufacturing,Water Get e-Alerts

Recovery of Critical Metals from Aqueous Sources.

Critical metals, identified from supply, demand, imports, and market factors, include rare earth elements (REE), platinum group metals, precious metals, and other valuable metals such as lithium, cobalt, nickel, and uranium. Extraction of metals from U.S. saline aqueous, emphasizing saline, sources is explored as an alternative to hardrock ore mining. Potential aqueous sources include seawater, desalination brines, oil-and-gas produced waters, geothermal aquifers, and acid mine drainage, among others. A feasibility assessment reveals opportunities for recovery of lithium, strontium, magnesium, and several REE from select sources, in quantities significant for U.S. manufacturing and for reduction of U.S. reliance on international supply chains. This is a conservative assessment given that water quality data are lacking for a significant number of critical metals in certain sources. The technology landscape for extraction and recovery of critical metals from aqueous sources is explored, identifying relevant processes along with knowledge gaps. Our analysis indicates that aqueous mining would result in much lower environmental impacts on water, air, and land than ore mining. Preliminary assessments of the economics and energy consumption of recovery show potential for recovery of critical metals.

Application of Plasticized Cellulose Triacetate Membranes for Recovery and Separation of Cerium(III) and Lanthanum(III)

Abstract This work explains the application of plasticized cellulose triacetate (CTA) membranes with Cyanex 272 di(2,4,4-(trimethylpentyl)phosphinic acid) and Cyanex 301 (di(2,4,4-trimethylpentyl)dithiophosphinic acid) as the ion carriers of lanthanum(III) and cerium(III). CTA is used as a support for the preparation of polymer inclusion membrane (PIM). This membrane separates the aqueous source phase containing metal ions and the receiving phase. 1M H2SO4 is applied as the receiving phase in this process. The separation properties of the plasticized membranes with Cyanex 272 and Cyanex 301 are compared. The results show that the transport of cerium(III) through PIM with Cyanex 272 is more efficient and selective than lanthanum(III).

Enhanced removal of humic acid from aqueous solution by combined alternating current electrocoagulation and sulfate radical.

Application of alternating current in electrocoagulation and activation of persulfate (AEC-PS) for the effective removal of humic acid (HA) from aqueous solution was evaluated. In order to optimize the removal efficiency HA by the AEC-PS process, several influencing parameters such as pH, reaction time, PS dose, current density (CD), concentration of NaCl, initial concentration of HA, and coexisting cations and anions influence were investigated. From the batch experiments, the highest HA removal efficiency obtained was 99.4±0.5% at pH of 5, reaction time of 25min, CD of 4.5mA/cm2, PS dose of 200mg/L, and NaCl concentration of 0.75g/L for an initial HA concentration of 30mg/L. When CD increased from 1.25 to 4.5mA/cm2, the HA removal efficiency was improved from 88.8±4.4% to 96.1±1.5%. In addition, the type of coexisting cations and anions exerted a significant role, leading to a reduction in the removal efficiency of HA. To investigate the dominant free activated radical, radical scavengers such as tert-butyl alcohol and ethanol were employed. It was observed that both OH and SO4- radicals substantially contributed to the removal of HA, and the contribution of SO4- radical was higher than that of OH radical, suggesting that AEC-PS process could serve as a novel and effective treatment technique for the removal of organic matters from aqueous sources.

Changing the conventional clarification method in metal sulfide precipitation by a membrane-based filtration process

The metal sulfide precipitation process is a widely studied technology used to recover metals or remove pollutants from different aqueous sources. However, the conventional clarification stage used to separate the generated precipitates cannot effectively remove them from recovered solutions. Taking this into account, the current study focuses on developing a new separation method applied in metal sulfide precipitates, based on a membrane filtration process. Different operating conditions and metal concentration in the feed solution were evaluated for the separation of copper sulfide precipitates formed from synthetic cyanide solutions in ceramic microfiltration membranes. Results showed attractive values of flux and copper recovery. Flux results ranged between 0.9 L/m2s and 1.2 L/m2s for copper concentrations above 500 mg/L, and copper recoveries resulted closer to 100% at the determined optimal operating conditions (4.5 pH, 120% NaHS stoichiometric dosage, and 2 bar feed pressure). These flux values decreased up to one order of magnitude for diluted copper concentrations, due to a change of aggregation capacity of precipitates. This study has demonstrated that the membrane filtration process can be a suitable alternative for the conventional gravitational clarification, promoting better performance results in terms of equipment capacity, metal recovery, and process safety.

Separation of methylparaben from aqueous source stream by pseudo-emulsion hollow fiber membrane strip dispersion technique: Optimization of process parameters using Grey-Taguchi method

Parabens are the esters of p-hydroxybenzoic acid extensively used as antimicrobial preservatives in food, pharmaceuticals and personal care products. These compounds have been reported to have estrogenic and antiandrogenic properties. The separation of methylparaben from water by hollow fiber supported liquid membrane (HFSLM) and pseudo-emulsion hollow fiber membrane strip dispersion (PEHFSD) technique was studied. Output responses: permeability and stripping percentage were maximized by Grey-Taguchi technique. Concentrations of methylparaben in the three phases at equilibrium were in good agreement with the values calculated from the material balance. Stripping percentage for HFSLM and PEHFSD system were 67% and 90.52% respectively at a contact time of 90 minutes. The estimated permeability was 3.8859 × 10−5 and 7.8041 × 10−5 cm/sec for HFSLM and PEHFSD system respectively.

Detection and removal of arsenic contamination from aqueous media using nanomaterials

Compounds containing Arsenic (As) have been contaminating the ground water not only in India, but also in other countries of the world. Millions of people are affected by various Arsenic-related diseases, such as skin diseases, cardiovascular diseases, neurological disorders, etc. Due to these reasons, extensive research is being carried for detection and removal of arsenic-containing compounds by various research groups. Numerous arsenic moieties, such as As(III) containing H3AsO3, H2AsO3−, HAsO32−; As(V) containing H3AsO4, H2AsO4−, HAsO42− as well as organoarsenic compounds are being actively studied in order to detect these from different aqueous sources. Several research groups are also investigating methods for removal of these ions and compounds using nanomaterials. Herein, we briefly recount the recent and diverse research activities, carried out by various researchers, in this important area in the past few years.

NaI cubic detector full-energy peak efficiency, including coincidence and self-absorption corrections for rectangular sources using analytical method

Low activities of radionuclides in environmental and occupational samples demand for the lower detection limits of the measuring system, which can be achieved by minimizing the source-to-detector distance. Analytical technique to calculate full-energy peak efficiency and total efficiency, self-absorption of sources and a coincidence factor of the NaI cubic scintillation detector with rectangular cavity for rectangular source have been derived. The photon path length of the volumetric sources calculated and determined source self-absorption. The photon attention by rectangular sources and detector cap materials is also calculated. In the experiments gamma aqueous source containing Eu-152 radionuclide covering range from 121 to 1408 keV was used. By comparison analytical method for calculating the full energy peak efficiency and the corrected experimental efficiency values are in good a agreement.

Lead service lines and Parkinson’s disease prevalence in U.S. States

IntroductionWe recently showed that the prevalence of Parkinson’s Disease (PD) in U.S. states is positively associated with the quantity of acid rain. Acid rain could play an etiologic role in PD by mobilizing metals, e.g., lead, from watersheds and pipes into drinking water. We assessed the correlation of PD with lead service lines, the underground pipes that connect homes to municipal water sources, which are a major aqueous source of lead. MethodsWe used multiple regression techniques to examine PD prevalence rates by state relative to the number of lead service lines. We included known or suspected aqueous risk factors, e.g., the Acid Precipitation Index (a measure of acid rain) and well water use. ResultsAge-, race-, and sex-adjusted prevalence rates for PD were significantly and positively correlated with the log number of lead service lines (p = 0.0004). The effect of lead service lines remained significant after adjusting for the effects of acid rain and well water use (p = 0.0019). ConclusionThese findings are consistent with a role for lead in the etiology of PD. Studies of lead service line exposure in relation to PD at the individual level are warranted.

Emergent Self-Assembly of a Multicomponent Capsule via Iodine Capture.

Described here is a three-component self-assembly system that displays emergent behavior that differs from that of its constituents. The system comprises an all-hydrocarbon octaaryl macrocycle cyclo[8](1,3-(4,6-dimethyl)benzene (D4d-CDMB-8), corannulene (Cora), and I2. No appreciable interaction is seen between any pair of these three-components, either in cyclohexane or under various crystallization conditions. On the other hand, when all three-components are mixed in cyclohexane and allowed to undergo crystallization, a supramolecular iodine-containing capsule, ((D4d-CDMB-8)3⊃(Cora)2)⊃I2, is obtained. This all-hydrocarbon capsule consists of three D4d-CDMB-8 and two Cora subunits and contains a centrally bound I2 molecule as inferred from single-crystal and powder X-ray diffraction studies as well as solid-state 13C NMR and Raman spectroscopy. These analyses were complemented by solution-phase 1H NMR and UV-vis spectroscopic studies. No evidence of I2 escape from the capsule is seen, even at high temperatures (e.g., up to 418 K). The bound I2 is likewise protected from reaction with alkali or standard reductants in aqueous solution (e.g., saturated NaOH(aq) or aqueous Na2S2O3). It was also found that a mixed powder containing D4d-CDMB-8 and Cora in a 3:2 molar ratio could capture saturated I2 vapor or iodine from aqueous sources (e.g., 1.0 mM I2 in NaCl (35 wt %) or I2 + NaI(aq) (1.0 mM each)). The present system displays structural and functional features that go beyond what would be expected on the basis of a simple sum-of-the-components analysis. As such, it illustrates a new approach to creating self-assembled ensembles with emergent features.

Liquid-liquid extraction and facilitated membrane transport of Pb2+ using a lipophilic acridono-crown ether as carrier

Studies on liquid-liquid extraction and bulk liquid membrane (BLM) technique-based metal ion separation by a previously published Pb2+-selective acridono-18-crown-6 ether selector molecule were performed. The effects of the stirring speed, the quality of apolar organic membrane, the counterions of Pb2+, the pH of the aqueous phase, the concentration of the source phase, the concentration of the carrier in the BLM and the temperature on the Pb2+-separation were investigated. Moreover, the effects of the competitive inhibition due to the presence of Ag+, Ca2+, Co2+, Cu2+, K+, Mg2+, Na+ and Zn2+ as competing ions in a multicomponent aqueous source phase of different ion-concentrations were also studied. After a proper dilution of the multicomponent aqueous source phase, excellent Pb2+-selectivity was achieved without a significant reduction in the efficiency compared to the liquid membrane transport of single-component systems. Based on the BLM-cell studies the applied selector molecule proved to be suitable for the development of liquid membrane-based Pb2+-selective separation methods, which can be greatly aided by the analysis of the effects on the separation and by the optimization of the parameters of the process discussed here.

Positively charged nanofiltration membrane synthesis, transport models, and lanthanides separation

The design and understanding of rejection mechanisms for both positively and negatively charged nanofiltration (NF) membranes are needed for the development of highly selective separation of multivalent ions. In this study, positively charged nanofiltration membranes were created via an addition of commercially available polyallylamine hydrochloride (PAH) by conventional interfacial polymerization technique. Demonstration of real increase in surface zeta potential, along with other characterization methods, confirmed the addition of weak basic functional groups from PAH. Both positively and negatively charged NF membranes were tested for evaluating their potential as a technology for the recovery or separation of lanthanide cations (neodymium and lanthanum chloride as model salts) from aqueous sources. The NF membranes with added PAH performed high and stable lanthanides retentions, with values around 99.3% in mixtures with high ionic strength (100 mM, equivalent to ~6000 ppm), 99.3% rejection at 85% water recovery (and high Na+/La3+ selectivity, with 0% Na+ rejection starting at 65% recovery), and both constant lanthanum rejection and permeate flux at even pH 2.7. Donnan steric pore model with dielectric exclusion elucidated the transport mechanism of lanthanides and sodium, proving the potential of high selective separation at low permeate fluxes using positively charged NF membranes.

The Fat of the Land: Cuticle Formation in Terrestrial Plants.

In a world surrounded by a vast expanse of gaseous air, water is constantly evaporating from aqueous sources to their surroundings. This is a major problem for microscopic cells containing water essential for life. The genetic and chemical components that help to prevent water loss by creating a

Application of the Taguchi Method and Central Composite Design for the Highly Selective and Efficient Extraction of Cu(II) ions from an Aqueous Solution Containing Mn(II), Co(II), Ni(II), Zn(II), Cu(II), and Pb(II) ions Mixture Using Benzyl Bis(thiosemicarbazone)

A simple method was developed for the highly selective and efficient extraction of Cu(II) ions from an aqueous source solution containing Mn(II), Co(II), Ni(II), Cu(II), Zn(II), and Pb(II) ions using benzyl bis(thiosemicarbazone) (LH2) as the chelating agent. The parameters involved in selectivity and efficiency of extraction were concurrently investigated by multivariate optimization methods with rapidity and reliability. First, the organic solvent (A = Chloroform, 1,2-dichloroethane, dichloromethane, nitrobenzene), extraction time (B = 2, 6, 10, 14 h), pH (C = 3.6), shacking rate (D = 320,560 rpm), and LH2 concentration (F = 0.0001, 0.0005 mol/L) influence on selectivity of the system were investigated using the Taguchi design. The obtained results reveal that B, D, and F have notable effects on the selectivity of the extraction procedure, whereas the A and C presented little influence. Then, to maximize the percentage of Cu(II) ion extraction, the significant parameters were further optimized using central composite design (CCD). Eventually, optimum conditions were achieved as dichloromethane, 12 h, 6, 400 rpm, and 1 × 10−3 mol/L for A, B, C, D, and F, respectively. At the above-specified conditions, Cu(ΙΙ) ion with acceptable high recoveries was extracted from the mixed cations solution, while other cations remained in the source phase. In this work, by the right choice of the extraction conditions, a general chelating agent has been converted to a highly selective and efficient chelating agent for Cu(II) ions. The high selectivity and efficiency of this method make it suitable for the successful extraction of Cu(ΙΙ) ion in various real samples with the recoveries ranged from 91.27 to 99.20%.

Surface interaction of cadmium and zinc metal ions on Al2O3 nanoparticles in aqueous solution

ABSTRACT The adsorbent ability of Al2O3 nanoparticles (ANPs) was examined to remove Cd2+ and Zn2+ from aqueous solution. The sorption of Cd2+ and Zn2+ on ANPs as a function of pH, ionic strength (IS), humic acid (HA), contact time, foreign ions and the temperature were investigated. It was observed that physico-chemical factors (pH and ionic strength) strongly affect the sorption of Cd2+ and Zn2+ on ANPs. Comparatively, the sorption of Cd2+ and Zn2+ dominated by surface complexation of the outer sphere at low pH values (pH < 8.0), while surface complexation of the inner sphere was the major sorption mechanism at elevated pH values (pH > 8.0). The maximum sorption capacity of Cd2+ and Zn2+ on ANPs calculated from the Langmuir model was 8.40 and 9.00 mg g–1 respectively at 303 K, exhibiting higher efficiency for Zn2+ sorption than Cd2+.The thermodynamic parameters (∆H0, ∆S0 and ∆G0) showed that the adsorption of Cd2+ and Zn2+ was endothermic and spontaneous. This investigation exhibited that ANP is an efficient, inexpensive process and thereby reasonable technology for the elimination of metal ions from the contaminated aqueous source.

Preparation of Xanthan Magnetic Biocompatible Nano-Composite for Removal of Ni^2+ from Aqueous Solution

This study investigates the uptake of the nickel (II) metal ions from aqueous sources using the xanthan magnetic biocompatible nano-composites. The desired nano-sorbent was first synthesized, analysed, and evaluated by scanning electron microscope (SEM) and Fourier transform infrared spectroscopy and (FT-IR), then used as adsorbent for removing the nickel from aqueous solution. Then the effect of different parameters such as contact time, adsorbent amount, pH, initial concentration, and temperature on the adsorption rate was investigated. The equilibrium time for the stirring state was 60 min and the optimum adsorbent value was 0.1 g and the acidity of 4 was the best pH. The highest removal efficiency was obtained at 97.6%. The kinetic studies of nickel removal by the synthesized adsorbent were performed and the results obtained for batch experiments follow the pseudo-quadratic kinetic model with (R2=0.9987). Equilibrium adsorption studies also revealed that, the adsorption process was in better agreement with the Freundlich isotherm (R2=0.9978). The positive Gibbs free energy (15.08 KJ/mole-1) showed that the process was spontaneous. Also the entropy changes was positive (0.03 KJ/mole-1), indicated an increase in entropy during the adsorption process in the system. Therefore, the adsorption process was associated with increasing the disorder.

Functionalized Polymer Thin Films for Plutonium Capture and Isotopic Screening from Aqueous Sources.

The rapid screening of plutonium from aqueous sources remains a critical challenge for nuclear nonproliferation efforts. The determination of trace-level Pu isotopes in water requires offsite sample preparation and analysis; therefore, new methods that combine plutonium purification, concentration, and isotopic screening in a fieldable detection system will provide an invaluable tool for nuclear safeguards. This contribution describes the development and characterization of thin polymer-ligand films for the isolation and concentration of waterborne Pu for direct spectroscopic analyses. Submicron thin films were prepared through spin coating onto Si wafers and consisted of combinations of polystyrene (PS) with dibenzoylmethane, thenoyltrifluoroacetone, and di(2-ethylhexyl)phosphoric acid (HDEHP). Pu uptake studies from solutions at pH from 2.3 to 6.3 indicated that only films containing HDEHP exhibited significant recovery of Pu. High alpha spectroscopy peak energy resolutions were achieved for PS-HDEHP films over a range of film thicknesses from 30 to 250 nm. A separate study was performed to evaluate uptake from a primarily Pu(V) solution where it was observed that doubling the HDEHP loading in the film increased uptake of Pu by an order of magnitude. X-ray photoelectron spectroscopy (XPS) analysis revealed that HDEHP was highly concentrated within the first few nanometers of the film at the higher loading. XPS analysis also revealed that, in the presence of water, HDEHP was stripped from the surface layer of the film at circumneutral pH. While significant losses of ligand were seen in all samples, higher loadings of HDEHP resulted in measurable amounts of ligand retained after a 12-h soak in water. Findings of this study are being used to guide the development of thin-film composite membrane-based detection methods for the rapid, fieldable analysis of Pu in water.

Crown ethers “clicked” on fibrous polyglycidyl methacrylate for selective Li+ retrieval from aqueous sources

Increase in lithium (Li) demand has motivated the development of simple yet very effective materials for its recovery from aqueous resources. In this work, a microfibrous (MF) composite Li+ adsorbent tethered with dibenzo-14-crown-ether-4 (DB14CE4) as ligand was successfully fabricated. Polyglycidyl methacrylate (PGMA) was electrospun as MF support, rich with epoxy groups as reactive sites for DB14CE4 functionalization. PGMA MF was subsequently azidated (N3-PGMA) and covalently attached with alkyne terminated DB14CE4 (PPL-DB14CE4) via azide-alkyne cyclo-addition “click” chemistry. Characterization results confirm successful preparation of the final adsorbent DB14CE/PGMA MF. The Li+ adsorption mechanism is well described by Redlich-Peterson, Hill (nH ∼ 1) and Langmuir isotherm models with capacity qm ∼ 12.45 mg g−1. The Li+ uptake rate follows a pseudo-second order model. DB14CE4/PGMA MF preferentially captures Li+ in different aqueous sources (seawater, simulated rubber wastewater, simulated leachates from coal fly ash and lithium-ion battery waste). Li+ uptakes ranged qe ∼ 345–1428 μmol g−1 against competing ions (Na+, K+, Ba2+, Mg2+, Ca2+ Zn2+, Co2+, Cu2+, Al3+) having qe values < 16 μmol g−1. DB14CE4/PGMA MF is regenerable and highly stable with consistent performance in cycled adsorption/desorption runs. Overall results demonstrate the reliability of DB14CE4/PGMA MF for selective Li+ mining in complex aqueous sources.

Photopeak Efficiency and Coincidence Summing Factors for HPGe Detectors Using Bulk Sources.

In the field of gamma-ray spectroscopy with high-purity germanium detectors, used to measure the activity when the sample to be measured has low radioactivity, volumetric sources are widely used. To determine the sample activity, the full-energy peak efficiency is needed. Bulk sources are very common for low-level radioactivity measurements in activation analysis and environmental samples. The main problem with these measurements is that coincidence effects are large for close source-detector geometries. Ignoring these effects can lead to an error typically of a factor of 2 in the determination of Co and Y activity, which was used in this work in the calibration process. Extensive experimental readings have been carried out, and bulk gamma aqueous sources containing several radionuclides covering the energy range from 60 to 1,840 keV were used. By comparison, the experimental (present work) and theoretical (published) full-energy peak efficiency values are in good agreement; the overall percentage error is less than 6%.