Heavy Ion Research Articles

Nanocomposite membrane for simultaneous removal of dye and heavy metal ions from wastewater.

A catalytic 2D nanocomposite membrane (CNC) was fabricated and used for the simultaneous removal of methylene blue (MB) and heavy metal ions in aqueous solution. Both molybdenum disulfide (MoS2) and graphene oxide (GO) were incorporated in a chitosan polymer matrix, and the fabricated CNC membrane exhibited performance as a nanofiltration membrane. Here MoS2 activated H2O2 to generate very reactive oxygen species (ROS), such as hydroxyl radicals, allowing the catalytic breakdown of the organic dye contaminants and reducing heavy metal ions. Greater than 99% efficiencies were achieved for the simultaneous removal of methylene blue (MB) and the heavy metal Co2+. Moreover, significant removal efficiencies in the 89-96% range were demonstrated for other heavy metal ions of Cu2+, Pb2+, and Ni2+. The generated ROS were trapped by terephthalic acid (TA) and confirmed by fluorescence emission spectroscopy. The used membrane was regenerated and reused with a flux recovery rate of more than 91% after 4 experimental cycles. These promising results indicated that the novel catalytic 2D nanocomposite membrane showed a high potential for the simultaneous removal of organic contraminants and heavy metal ions from textile industry wastewater.

Advances in deep eutectic Solvent-Based synthesis of nanomaterials for environmental remediation

The application of eco-friendly deep eutectic solvents (DES) in the functionalization and synthesis of adsorbent materials has gained significant research interest in recent times. These materials, employed for treating polluted water primarily through degradation or adsorption, are emerging as sustainable alternatives to traditional technologies. However, the information regarding the functionalization and synthesis of adsorbent materials using DES is dispersed throughout the literature. This review aims to consolidate and clarify the extensive information available on the synthesis and functionalization of DES-based adsorbents, their application in water treatment as nanomaterials, and the future prospects of such technologies. DES presents an ideal alternative to conventional solvents for modifying and functionalizing adsorbents due to their lower toxicity, cost-effectiveness, and environmental friendliness. Most DESs effectively introduce desired functionalities and enhance the surface area of adsorbents, thereby greatly enhancing the removal of pollutants. This review compiles recent literature on the synthesis and modification of graphene oxides, carbon nanotubes, metal oxides, and other materials for the degradation/adsorption of pharmaceuticals, herbicides, dyes, pesticides, heavy metal ions, and other water contaminants. Besides this, DES-based nanomaterials have potential future applications in nanotechnology, nanofluids, nanocatalysts, biosensors, environmental remediation, among others. The anticipated exponential growth in these areas underscores the urgent need for such a review.

A novel amidoxime-functionalized covalent organic framework adsorbent for efficient lead ion removal: synthesis and adsorption mechanism

Lead ions are highly toxic heavy metal ions and Pb(Ⅱ) in wastewater threatened seriously human health and environment. Therefore, an effective adsorbent must be developed to remove lead ions from wastewater. In this study, a polycrystalline amidoxime covalent organic framework (DBCC-NHOH) is synthesized by a post-modification method for the elimination of lead (II) from wastewater. The successful preparation of adsorbent (DBCC-NHOH) is demonstrated by the oxygen appearance in SEM-EDS pattern and conversion of -CN to C=N-O and C-N in the FT-IR pattern. DBCC-NHOH is a crystalline porous material and its pore size, specific surface area and pore volume are 3.419nm, 28.154 m2/g and 4.2ⅹ10-8 m3/g respectively. The optimum conditions for the adsorption of Pb(II) by DBCC-NHOH are temperature 298K, time 180min, and pH 5. The maximum adsorption of DBCC-NHOH was 221.37mg/g. Kinetic and thermodynamic investigations indicate that adsorption of Pb(II) by DBCC-NHOH is a monolayer chemisorption and exothermic process. Selectivity experiments indicate that DBCC-NHOH can adsorb Pb(II) efficiently and selectively in complex multi-ion systems. In addition, the adsorption percentage of DBCC-NHOH remained up to 83.20% after five adsorption-desorption experiments. The XPS and FT-IR analyses and DFT results indicated that DBCC-NHOH utilized amidoxime function group to realize the high efficiency of Pb(II) adsorption by electrostatic attraction and chelation.

Fixation behavior of oceanic manganese nodule-sodium alginate composite microspheres for heavy metal release during manganese nodule mining

Research on the environmental impact of deep-sea mining is crucial, particularly for fragile deep-sea ecosystems. This research focuses on the issue of heavy metal release during mining activities. Through simulation experiments, we investigated the release of Cu2+, Co2+, and Ni2+ from sediments under disturbance conditions and the fixation behavior during the deployment of ocean manganese nodule-sodium alginate composite microspheres (OMN@SA). The experimental results revealed that mining disturbances cause the release of 0.291% of Cu2+, 7.34% of Co2+, and 4.13% of Ni2+ from sediments into the water, primarily in the form of exchangeable metals. Compared with the bottom adsorption, OMN@SA has a faster adsorption rate in the slow settling process. The removal rates of Cu2+, Co2+ and Ni2+ reached 54.0%, 78.3% and 61.8% for 5 h adsorption, and the bottom adsorption removal rates reached 96.4%, 97.8% and 95.1% for 30 d adsorption, which has a good removal effect. In addition, OMN@SA can effectively block the diffusion of Cu2+, Co2+, and Ni2+ from interstitial water to overlying water, and reduce the influence of interstitial water on overlying water. SEM-EDS, FTIR, and XRD analyses revealed that OMN@SA adsorbs heavy metal ions through its abundant -OH groups and incorporates Cu2+, Co2+, and Ni2+ into the crystal lattices of vernadite and todorokite via substitution or intercalation. This study provides guidance for the remediation of heavy metal release from deep-sea mining using adsorption methods and demonstrates the promising application prospects of OMN@SA.

Preparation of cellulose nanofiber/polyvinyl alcohol-based composite films for metal ion detection by starch/disodium calcium ethylenediaminetetraacetate synergistic complexation effect

Heavy metal pollution causes irreversible damage to plants, animals, and humans. Therefore, it is meaningful to develop facile, fast, and efficient strategies for heavy metal ion (HMI) detection. Here, a portable composite film (CPSE) was designed for HMI detection with high sensitivity and wide detection range. The CPSE was prepared by using cellulose nanofibers (CNF)/polyvinyl alcohol (PVA) as the matrix and utilizing modified starch (HPS) to assist disodium calcium ethylenediaminetetraacetate (EDTA-Ca) to form stable complexes with HMI. The R, G and B values (the three primary colors of light) were captured using an image acquisition system to produce an HMI standard color card successfully. Specifically, the composite film can effectively distinguish Cu2+, Pb2+ and Fe3+. The response time of the composite film to HMI was 2–4 s, and the detection ranges of Cu2+ and Fe3+ were 5–700 ppm and 10–1000 ppm, respectively. Additionally, the synergistic effect of HPS and EDTA-Ca led to the increase in tensile strength (1.59–1.71 times), tear strength (3.29–3.57 times), and glass transition temperature (~ 6 °C) compared to CNF/PVA/HPS and CNF/PVA/EDTA-Ca films. This study confirms the value of CPSE films as materials for HMI detection and suggests innovative ideas for designing similar biomass detection materials in the future.

Three-dimensionally assembled polyelectrolyte multilayers-functionalized silica nanowire membrane for highly-efficient adsorptive separation of copper ions from water

High-performance materials for heavy metal ion removal are highly demanded in environmental treatment. Membrane adsorption has the advantages of being easy to operate and avoiding secondary pollution. It remains challenging to prepare adsorption membranes with both high removal rate and high permeability. Here, we present a novel strategy for preparing poly(acrylic acid) (PAA) and polyethyleneimine (PEI) multilayer-assembled silica nanowires (SiO2 NWs) membrane with abundant, multiple functional groups on a highly porous network for Cu(II) capture. The SiO2 NWs in the hybrid membranes serve as a rigid 3D framework to improve membrane porosity and water flux, while the polyelectrolyte multilayers assembled on the SiO2 NWs provide abundant, highly accessible adsorption sites for Cu(II) uptake. The adsorption capacity of the membranes can be tuned by changing the dosage of the assembled SiO2 NWs and the PAA/PEI pair layers. The maximum adsorption capacity of the active polyelectrolyte layer for SiO2 NWs@(PAA/PEI)4 composite membrane was 272.5 mg/g toward Cu(II), outperforming the counterpart (PAA/PEI)4 membrane (97.5 mg/g) after removal of the SiO2 NWs framework. The hybrid membrane shows excellent adsorption performance for the removal of low concentrations of Cu(II) in a dynamic adsorption mode, and the removal rate is maintained at above 90% after eight recycles.

A multifunctional coconut shell biochar modified by titanium dioxide for heavy metal removal in water/soil and tetracycline degradation

Heavy metals and tetracycline pollute the environment and endanger human health. This work prepared a multifunctional coconut shell biochar (Ti-XBC) through NaHCO3 activation and TiO2 modification. The modified coconut shell biochar was characterized by various methods. Ti-4BC exhibited excellent removal performance for heavy metals. The maximum adsorption capacity of Ti-4BC on Cd2+, Pb2+, Cr3+, and Cr6+ reached 104.2, 136.8, 101.2, 112.4 mg/g in water. The adsorption of Ti-4BC for four metal ions had a competitive effect in the binary metal system. It also reduced the mobility of four heavy metal ions in soil. Density functional theory (DFT) calculations were employed to explain the mechanism of heavy metal removal. Additionally, the degradation performance and mechanism of Ti-4BC towards tetracycline were investigated. The results indicated that the maximum degradation rate was 99.4%. Overall, this work developed a multifunctional material capable of both removing heavy metals and degrading antibiotics, addressing the issue of single-function in biochar. This provided a novel approach for tackling complex and diverse environmental pollution scenarios.

Enhancing Tannic Acid-Arginine Complex Loading in Ultraporous PA6 Nanofibers through NH3 Foaming for Efficient Heavy Metal Removal from Textile Wastewater.

Metal-containing dyes in the textile industry release heavy metal ions into wastewater, posing significant environmental risks and complicating treatment processes. Among various removal methods, chemical adsorption through functional groups that form stable complexes is one of the most effective. Tannic acid (TA), renowned for its strong chelation of metal ions via phenolic hydroxyl groups, faces challenges in operation and recycling in its powdered form. Electrospun polyamide 6 (PA6) nanofiber membranes, characterized by high surface area and structural stability, offer a promising platform. However, achieving an optimal TA loading remains a technical hurdle for industrial applications. To address this, we developed an arginine (l-Arg) bridging strategy to enhance the TA loading on PA6 nanofibers. Additionally, we implemented an NH3 escape foaming technique to increase membrane porosity by 20% and quadruple pore size, enhancing surface roughness and resulting in a 70% increase in TA loading. The optimized adsorbent demonstrated the effective removal of various heavy metal ions, achieving over 95% removal efficiency for five different metals. Even after five adsorption-desorption cycles, the membrane retained over 92% efficiency, translating to a treatment capacity of 12.5 tons of wastewater per kilogram of foaming fiber, underscoring its potential for practical wastewater treatment applications.

Machine learning the in-medium correction factor on nucleon-nucleon elastic cross section

Abstract The nuclear equation of state cannot be directly measured in the heavy-ion collision experiments; it is usually inferred from the comparison between transport model simulations and experimental measurements. The in-medium correction factor (F , which is defined as the ratio of the cross section in the nuclear medium to that in free space) on the nucleon-nucleon elastic cross section is one of the important inputs of the transport model, and its magnitude is still debated. The advent of Machine Learning (ML) has profoundly influenced the way scientists study the natural world and has provided a new paradigm that merges traditional investigation with advanced datadriven techniques. The aim of this work is to present a ML-based method to study the in-medium correction factor F . The ultra-relativistic quantum molecular dynamics (UrQMD) transport model is used to simulate 132Sn + 124Sn collisions at beam energy of 0.27 GeV/nucleon with different impact parameters. The value of F is randomly selected from 0.4 to 0.8 for the simulation of each event. Several observables simulated by the UrQMD model with different F , which are thought to be probably sensitive to the in-medium nucleon-nucleon cross sections, are fed into the LightGBM (Light Gradient Boosting Machine, which is a modern decision tree-based ML algorithm) to establish the mapping between the observables and F . The mean absolute error (MAE), which is the absolute difference between the true and the predicted F , is about 0.080 and 0.021 by using event-by-event and 40-event summed observables, respectively. It indicates that ML can recognize information about the F factor. Furthermore, according to the results of Shapley Additive exPlanations (SHAP), an interpretability analysis method in ML, features that have the greatest effect on the F are identified. ML combined with the transport model may open a new venue to study the F factor. In addition, the interpretability analysis of the ML algorithm may also offer valuable insights for subsequent research.

Interaction of the Prominence Plasma within the Magnetic Cloud of an Interplanetary Coronal Mass Ejection with the Earth’s Bow Shock

The magnetic cloud within an interplanetary coronal mass ejection (ICME) is characterized by high magnetic field intensities. In this study, we investigate the interaction of a magnetic cloud carrying a density structure with the Earth’s bow shock during the ICME event on 2023 April 24. Elevated abundances of cold protons and heavier ions, namely, alpha particles and singly charged helium ions, associated with the prominence plasma are observed within this structure. The plasma downstream of the bow shock exhibits an irregular compression pattern, which could be due to the presence of heavy ions. Heavy ions carry a significant fraction of the upstream flow energy; however, due to their different mass-per-charge ratio and rigidity, they are less scattered by the electromagnetic and electrostatic waves at the shock. We find that downstream of the shock, while the ion thermal energy is only a small fraction of the background magnetic energy, nevertheless increased ion fluxes reduce the characteristic wave speeds in that region. As such, we observe a transition state of an unstable bow shock in which the plasma flow is super Alfvénic both upstream and downstream of the bow shock. Our findings help with the understanding of the intense space weather impacts of such events.

Isotropization by shock waves generation in anisotropic hydrodynamics

Anisotropic hydrodynamics (aHydro) has proven successful in modeling the evolution of quark-gluon matter created in heavy-ion collisions. The hydrodynamic description of quark-gluon plasma has also been widely used to study sound phenomena, such as shock waves. It has recently been shown that initial fluctuations in energy density and supersonic partons can generate fairly strong shock waves. However, significant anisotropic properties of the system due to the rapid longitudinal expansion of matter have not been taken into account in such studies. Moreover, the process of isotropization and its characteristic time-scales were not considered along with the question of the shock waves formation. Previous studies on shock discontinuous solutions in anisotropic hydrodynamics assumed constant anisotropy, leading to flow refraction towards the anisotropy axis and flow acceleration, characteristics of rarefaction waves, indicating limitations in this approach. This paper investigates discontinuous solutions for normal shock waves without flow refraction, introducing two compression parameters for longitudinal and transverse pressures. The resulting analytical solutions, as well as numerical computations, provide an isotropization mechanism of the system.

Remediation of Cd and Cu compound contaminated soil with ryegrass (Lolium perenne L.) combined with electrokinetics

ABSTRACT The process of ryegrass combined with electrokinetics (REK) was developed to remediate the soil contaminated with Cd and Cu. The effects of voltage gradient, soil moisture content, and heavy metal concentration on the remediation efficiency of the process were investigated. Three voltage gradients (1.0, 2.0, 3.0 V/cm), three moisture contents (20%, 40%, 60%), and two heavy metal concentrations (Cd: 100 mg/kg, Cu: 150 mg/kg; Cd: 200 mg/kg, Cu: 300 mg/kg) were set. The ryegrass calculated for 5 d with uniform growth was selected, and directed-current (DC) was supplied and energized for 8 h/d for 5 d. The results showed that heavy metal ions migrated to the root system of ryegrass and the vicinity of the cathode under the action of an electric field, and were absorbed, degraded, and enriched to achieve the purpose of removal. The 3 factors had a significant impact on the remediation of REK. When the voltage gradient was 2.0 V/cm, the moisture content was 40%, and the concentration of heavy metals was low, the growth status of ryegrass was best. After remediation, the height of ryegrass increases by 4.4 cm, reaching a maximum of 13.5 cm. The fresh weight and dry weight of ryegrass were 0.68 g and 0.122 g. At this time, the removal rates of Cd and Cu in soil were 37.0% and 13.0%, respectively. It demonstrated that the application of ryegrass combined with electrokinetic technology in the remediation of heavy metal contaminated soil was promising.

Physicochemical and Heavy Metal Analysis in Industrial Wastewater: Impact on Biodiversity in Morang District, Koshi Province, Nepal

This study investigates the concentration of heavy metal ions in wastewater samples collected from various industrial facilities located in the Biratnagar-Rangeli corridor of Morang district. The physical and chemical parameters, such as pH, electrical conductivity (EC), biological oxygen demand (BOD), and chemical oxygen demand (COD) were measured, and the presence of heavy metals, including iron (Fe), Zinc (Zn), Chromium (Cr), Nickel (Ni), Lead (Pb), and Arsenic (As), was assessed. Atomic Absorption Spectrophotometer (AAS) (Thermo Scientific, ice3000 series, Thermo Fischer, USA) was used to measure heavy metals. The findings reveal elevated levels of these pollutants, particularly Iron (Fe) and Zinc (Zn), which exceed acceptable safety limits. The study also identifies potential impacts on biodiversity, human health, and the local ecosystem, with significant risks associated with long-term exposure.

Magnetic nanoparticles for efficient heavy metal removal: synthesis, adsorption capacity, and key experimental parameters

Abstract Heavy metals are toxic, non-biodegradable pollutants that pose serious risks to human health and the environment, even at trace concentrations. The contamination of drinking water and groundwater by heavy metals requires urgent attention. Nanotechnology has advanced significantly over the past decade, offering innovative solutions for water purification, particularly through the adsorption of heavy metal ions using nanomaterials. This study focuses on the synthesis of magnetic nanoparticles, their adsorption capacity, and the desorption process. Additionally, the effects of key experimental parameters – such as contact time, ion concentration, pH, temperature, ionic strength, and adsorbent dose – on the removal efficiency of metal ions are examined. The findings underscore the potential of magnetic nanoparticles for effective heavy metal remediation in water.

Electric conductivity of QCD matter and dilepton spectra in heavy-ion collisions

The electric conductivity, σel, is a fundamental transport coefficient of QCD matter that can be related to the zero-energy limit of the electromagnetic (EM) spectral function at vanishing three-momentum in the medium. The EM spectral function is also the central quantity to describe the thermal emission rates and pertinent spectra of photon and dilepton radiation in heavy-ion collisions. Employing a model for dilepton rates that combines hadronic many-body theory with nonperturbative QGP emission constrained by lattice QCD which describes existing dilepton measurements in heavy-ion collisions, I investigate the sensitivity of low-mass dilepton spectra in Pb-Pb collisions at the CERN Large Hadron Collider (LHC) to σel. In particular, I separately evaluate the contributions from QGP and hadronic emission, and identify signatures that can help to extract σel from high-precision experimental data expected to be attainable with future detector systems at the LHC. Published by the American Physical Society 2024

Direct quarkonium production in DIS from a joint CGC and NRQCD framework

We compute the differential cross section for direct quarkonium production in high-energy electron-nucleus collisions at small x. Our computation is performed within the nonrelativistic QCD factorization formalism that separates the calculation into short distance coefficients and long distance matrix elements that depend on the color and spin of the state. We obtain the short distance coefficients of the production of the heavy quark pair within the framework of the color glass condensate effective field theory, which resums coherent multiple interactions of the heavy quark pair with the nucleus to all orders. Our results are expressed as the convolution of perturbatively calculable functions with multipoint lightlike Wilson line correlators. In the correlation limit, we establish the correspondence between our color glass condensate formulation with calculations employing the transverse momentum dependent (TMD) framework. We extend this correspondence by resumming kinematic power corrections within the improved TMD framework, which interpolates between the TMD formalism and k⊥-factorization formalism. We present a detailed numerical analysis, focusing on J/ψ production in the kinematics accessible at the future Electron-Ion Collider, highlighting the importance of genuine higher-order saturation contributions when the electron collides with a large nucleus. Our results are also valid in the photoproduction limit where we expect the largest contribution from genuine higher-order saturation contributions which could be accessed in ultraperipheral collisions of relativistic heavy ions. Published by the American Physical Society 2024

The Role of Metal Tolerance Proteins (MTPs) Associated with the Homeostasis of Divalent Mineral Elements in Ga-Treated Rice Plants.

Mineral elements typically act as transported substrates for metal tolerance proteins (MTPs). The chelation of MTPs with heavy metal ions is a suggestive detoxification pathway in plants; therefore, the trade-off between transporting mineral elements and chelating excess toxic metal ions is inevitable. Gallium (Ga) is an emerging pollutant associated with high-tech industries. This study investigated the impact of Ga stress on MTPs, subsequently altering the transport and distribution of mineral elements. Gallium exposure reduced rice seedling biomass, with roots accumulating more Ga than shoots. Ga stress also changed the rice plants' subcellular mineral element distribution. PCR assays showed that Ga stress negatively affected all genes belonging to the Mn group, except OsMTP9. While Mn accumulation in the rice cellular compartments did not respond positively to Ga stress, OsMTP8, OsMTP8.1, OsMTP11, and OsMTP11.1 were found to be intimately connected to Mn transport and repressed by increased Ga accumulation in roots. Mg and Cu accumulated in the cytosol and organelles of Ga-treated rice plants, while OsMTP9 expression increased, demonstrating its importance in transporting Mg and Cu. A positive link between Ga stress and Zn accumulation in the cytosol and organelles was found, and OsMTP7 and OsMTP12 expression was positive, suggesting that Ga stress did not impair their Zn transport. Notably, Ga exposure down-regulated Fe-transporting OsMTP1 and OsMTP6, wherein the subcellular concentrations of Fe showed negative responses to Ga accumulation. These findings provide valuable insights into elucidating the roles of OsMTPs in Ga tolerance and the transport of these mineral elements.

Effect of vorticity on the dynamical magnetic fields in heavy-ion collisions

Magnetic fields in heavy-ion collisions are pivotal and subject to diverse factors. In this study, we quantitatively investigate the impact of fluid vorticity on the evolution of magnetic fields in the 20%–50% centrality class in Au+Au collisions, with collision energies of sNN=(7.7,14.5,19.6,27,39,62.4,200) GeV. Our results indicate that fluid vorticity leads to a delay in the evolution of the magnetic field, in which this effect becomes more pronounced as the collision energy decreases. Additionally, we have calculated the mean magnetic field values on the freeze-out hypersurface for various collision energies. Our simulation results align with the values inferred from experimental data of Λ¯−Λ, within the error margins. Published by the American Physical Society 2024

Field redefinitions and evolutions in relativistic Navier-Stokes

In recent years the equations of relativistic first-order viscous hydrodynamics, that is, the relativistic version of Navier-Stokes, have been shown to be well posed and causal under appropriate field redefinitions, also known as hydrodynamic frames. We perform real-time evolutions of these equations for a conformal fluid and explore, quantitatively, the consequences of using different causal frames for different sets of initial data. By defining specific criteria, we make precise and provide evidence for the statement that the arbitrarily chosen frame does not affect the physics up to first order, as long as the system is in the effective field theory regime. Motivated by the physics of the quark-gluon plasma created in heavy-ion collisions we also explore systems which are marginally in the effective field theory regime, finding that even under these circumstances the first order physics is robust under field redefinitions.

Ligand-Responsive Artificial Protein-Protein Communication for Field-Deployable Cell-Free Biosensing.

Natural protein-protein communications, such as those between transcription factors (TFs) and RNA polymerases/ribosomes, underpin cell-free biosensing systems operating on the transcription/translation (TXTL) paradigm. However, their deployment in field analysis is hampered by the delayed response (hour-level) and the complex composition of in vitro TXTL systems. For this purpose, we present a de novo-designed ligand-responsive artificial protein-protein communication (LIRAC) by redefining the connection between TFs and non-interacting CRISPR/Cas enzymes. By rationally designing a chimeric DNA adaptor and precisely regulating its binding affinities to both proteins, LIRAC immediately transduces target-induced TF allostery into rapid CRISPR/Cas enzyme activation within a homogenous system. Consequently, LIRAC obviates the need for RNA/protein biosynthesis inherent to conventional TXTL-based cell-free systems, substantially reducing reaction complexity and time (from hours to 10 minutes) with improved sensitivity and tunable dynamic range. Moreover, LIRAC exhibits excellent versatility and programmability for rapidly and sensitively detecting diverse contaminants, including antibiotics, heavy metal ions, and preservatives. It also enables the creation of a multi-protein communication-based tristate logic for the intelligent detection of multiple contaminants. Integrated with portable devices, LIRAC has been proven effective in the field analysis of environmental samples and personal care products, showcasing its potential for environmental and health monitoring.