Ion Precipitation Research Articles

Precipitation and flotation concentration of neodymium, erbium, and thulium ions by alkylbenzenesulfonic acid

The possibility of using the commercially produced anionic surfactant alkylbenzenesulfonic acid for the precipitation and flotation extraction of neodymium(III), erbium(III), and thulium(III) ions was investigated. The effects of concentration and ratio of reacting components, content of sulfuric acid, and sodium hydroxide on the precipitation efficiency of metal ions were considered. The composition of the resulting compounds was determined and their conditional solubility products were calculated. Flotation conditions for metal ions with alkylbenzenesulfonic acid were optimized.

MsDUF3700 overexpression enhances aluminum tolerance in alfalfa shoots.

This study identified a gene associated with aluminum stress through GWAS, which regulates aluminum tolerance in alfalfa by contributing to the antioxidant system. Aluminum (Al) ions precipitate in acidic soils with a pH < 5.5, where they are absorbed alongside other nutrients by plants, negatively impacting plant growth. Alfalfa, the most widely grown perennial legume forage in the world, is especially vulnerable to acidic soil conditions. Our research pinpointed MsDUF3700 as a potential gene linked to Al-response traits via genome-wide association analysis in Medicago sativa. MsDUF3700 encodes the domain of unknown function (DUF). We observed higher expression of MsDUF3700 in Al-tolerant alfalfa compared to Al-sensitive ecotypes. MsDUF3700-overexpressing transgenic alfalfa (MsDUF3700-OE) showed shorter root elongation and higher Al accumulation in roots than wild type (WT) under Al conditions. However, the shoots of MsDUF3700-OE lines showed enhanced growth rates under both normal and Al stress conditions. Under Al stress, MsDUF3700-OE lines showed increased H2O2 and malondialdehyde (MDA) levels in the roots, alongside reduced catalase activity, In contrast, the shoots showed an inverse trend. In addition, we found that MsDUF3700-OE alfalfa plants had high Al accumulation in the roots and low Al accumulation in the shoots. Transcripts of MsALS3 and MsPALT1, homologs of Al translocation in alfalfa, were downregulated, while MsNrat1, a homolog of transporters absorb Al, was upregulated in the roots of MsDUF3700-OE in alfalfa. Our research indicates that MsDUF3700 plays a role in aluminum stress by participating in antioxidative defense and facilitating aluminum transport from roots to shoots.

Ru0.1Mn0.9Ox Electrocatalyst for Durable Oxygen Evolution in Acid Seawater

AbstractCurrently, direct electrolysis of seawater for green hydrogen production is primarily focused on neutral and alkaline systems. However, the precipitation of calcium and magnesium ions restricts the advancement of this technology. An acidic system can effectively address this issue. Given that Ru/Ir‐based catalysts with high oxygen evolution reaction (OER) activity also exhibit high chlorine evolution reaction (CER) activity, acid seawater splitting requires anodes with higher selectivity and stability compared to the other two systems. In this study, we propose a non‐precious Ru0.1Mn0.9Ox as the active anode for direct acid seawater electrolysis, which exhibits a high OER selectivity and remarkable stability for more than 1200 hours. Different from the Cl−‐free system, *Cl occupied on Ru sites could shift the OER active center to Mn on Ru0.1Mn0.9Ox, which prevents the lattice oxygen consumed on Ru and hinders the metal site dissolution. As the CER‐insensitive catalytic center, Mn activated by the introduction of Ru can adsorb a substantial amount of *OH, creating an OER‐favored local environment that inhibits CER. We introduce Cl−‐assisted transfer of OER active sites to CER‐insensitive Mn as a fundamental strategy for achieving highly selective and durable oxygen evolution in acidic seawater.

Implementation of an Asymmetric Internal Field in the Comprehensive Inner Magnetosphere‐Ionosphere (CIMI) Model

AbstractA Comprehensive Inner Magnetosphere‐Ionosphere (CIMI) model has been developed to study the dynamics of the cold plasmasphere and the energetic plasmas in the inner magnetosphere, as well as their couplings with each other and with the ionosphere. The CIMI model is able to predict the cold plasma density and energetic electron and ion fluxes in geospace. Furthermore, CIMI is capable of predicting the Region 2 currents, penetration electric field, electron and ion precipitation and magnetospheric heat flux into the ionosphere. The CIMI model includes a realistic magnetic field configuration with a combination of an internal field and an external field imposed by the interaction of the solar wind with the magnetosphere. The internal field has previously been assumed to be a dipole. Recently, the International Geomagnetic Reference Field (IGRF) has been implemented. This new capability enables studies of north‐south and longitudinal dependences in particle precipitation and heat flux, as well as the corresponding asymmetries in ionospheric and thermospheric responses. In this paper, we will briefly review the CIMI equations and model output. Then we will describe the new implementation of the IGRF model into CIMI and how to estimate the north‐south asymmetry in precipitating fluxes from the differences in field strength between magnetic conjugate points. The inclusion of a realistic internal field leads CIMI into a better position to couple with sophisticated ionosphere‐thermosphere models, most of which are using the IGRF model.

Ru0.1Mn0.9Ox Electrocatalyst for Durable Oxygen Evolution in Acid Seawater.

Currently, direct electrolysis of seawater for green hydrogen production is primarily focused on neutral and alkaline systems. However, the precipitation of calcium and magnesium ions restricts the advancement of this technology. An acidic system can effectively address this issue. Given that Ru/Ir-based catalysts with high oxygen evolution reaction (OER) activity also exhibit high chlorine evolution reaction (CER) activity, acid seawater splitting requires anodes with higher selectivity and stability compared to the other two systems. In this study, we propose a non-precious Ru0.1Mn0.9Ox as the active anode for direct acid seawater electrolysis, which exhibits a high OER selectivity and remarkable stability for more than 1200 hours. Different from the Cl--free system, *Cl occupied on Ru sites could shift the OER active center to Mn on Ru0.1Mn0.9Ox, which prevents the lattice oxygen consumed on Ru and hinders the metal site dissolution. As the CER-insensitive catalytic center, Mn activated by the introduction of Ru can adsorb a substantial amount of *OH, creating an OER-favored local environment that inhibits CER. We introduce Cl--assisted transfer of OER active sites to CER-insensitive Mn as a fundamental strategy for achieving highly selective and durable oxygen evolution in acidic seawater.

Effect of inorganic component of biochar on lead adsorption performance and the enhancement by MgO modification.

Biomass-derived biochar has enormous potential for sustainable and low-cost treatment of lead-contained wastewater. In this study, corncob and cow dung-derived biochar were prepared. The increase in pyrolysis temperature could improve the porous structures, surface area, functional groups and alkalinity, and further provide a higher Pb2+ capacity in both biochars. Cow dung biochar performed better than corncob for its higher inorganic mineral content and more alkaline surface. Among them, CDB-600 performed the Langmuir maximum capacity of 357.1 mg/g, with a high surface area of 144.3 m2/g; ion exchange and precipitate were the main adsorption mechanisms. After further MgO modification, the M-CDB displayed a high surface area of 166 m2/g, and ion exchangeability and precipitate-promoting effects were improved. M-CDB performed a Langmuir maximum capacity of 833.3 mg/g. The pHpzc was found to be 10 and the adsorbents portray a very good Pb2+ adsorption selectivity among coexisting ions in the solution. The adsorption process was found to be endothermic, feasible, spontaneous and chemisorption. The fixed lead on CDB-600 was stable in water. The immobilized lead could be desorbed by acid wash. CDB-600 performed better in terms of sustainability in use, which could support its continuous application ability.

Novel biocompatible magnetron-sputtered silver coating for enhanced antibacterial properties and osteogenesis in vitro

Peri-implant infection is a serious complication in orthopedic surgery. This study aimed to reduce the incidence of peri-implant infection by developing a durable and safe antibacterial silver coating. We compared the antibacterial properties and process controllability of various coating techniques to identify the most effective method for silver coating. We refined substrate treatment techniques and coating thicknesses through antibacterial and scratch tests. Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) were used to analyze the coating’s morphology and composition. Micron-sized magnetron sputtering silver coating samples underwent in vitro antibacterial testing, cytotoxicity testing, silver ion release testing, and osteogenic testing using membrane contact culture, CCK-8 assay, inductively coupled plasma (ICP) detection, and alkaline phosphatase (ALP) activity/osteogenic gene PCR. Magnetron sputtering demonstrated superior antibacterial properties, uniformity, and process controllability compared to alternative techniques. The optimal adhesion strength was achieved with a 0.5 μm coating thickness and a 400 mesh sandpaper pretreatment process, without compromising antibacterial efficacy. The coating showed near-perfect antiseptic results in antibacterial and anti-biofilm tests. Fibroblasts cultured in silver ion precipitation medium exhibited growth rates of 89% on day 30 and 88% on day 90, compared to 95% in the control group. The osteogenic test indicated that the magnetron sputtering silver coating promotes osteogenesis effectively. Our study demonstrated that micron-sized magnetron sputtering silver coating has potential for clinical use to prevent peri-implant infections in the future.

The Effects of Model Insoluble Copper Compounds in a Sedimentary Environment on Denitrifying Anaerobic Methane Oxidation (DAMO) Enrichment.

The contribution of denitrifying anaerobic methane oxidation (DAMO) as a methane sink across different habitats, especially those affected by anthropogenic activities, remains unclear. Mining and industrial and domestic use of metals/metal-containing compounds can all cause metal contamination in freshwater ecosystems. Precipitation of metal ions often limits their toxicity to local microorganisms, yet microbial activity may also cause the redissolution of various precipitates. In contrast to most other studies that apply soluble metal compounds, this study investigated the responses of enriched DAMO culture to model insoluble copper compounds, malachite and covellite, in simulated sedimentary environments. Copper ≤ 0.22 µm from covellite appeared to cause immediate inhibition in 10 h. Long-term tests (54 days) showed that apparent methane consumption was less impacted by various levels of malachite and covellite than soluble copper. However, the medium-/high-level malachite and covellite caused a 46.6-77.4% decline in denitrification and also induced significant death of the representative DAMO microorganisms. Some enriched species, such as Methylobacter tundripaludum, may have conducted DAMO or they may have oxidized methane aerobically using oxygen released by DAMO bacteria. Quantitative polymerase chain reaction analysis suggests that Candidatus Methanoperedens spp. were less affected by covellite as compared to malachite while Candidatus Methylomirabilis spp. responded similarly to the two compounds. Under the stress induced by copper, DAMO archaea, Planctomycetes spp. or Phenylobacterium spp. synthesized PHA/PHB-like compounds, rendering incomplete methane oxidation. Overall, the findings suggest that while DAMO activity may persist in ecosystems previously exposed to copper pollution, long-term methane abatement capability may be impaired due to a shift of the microbial community or the inhibition of representative DAMO microorganisms.

A retarded foam acid fluid system for low-temperature dolomite geothermal reservoir stimulation and its action mechanisms

Acidizing improves geothermal reservoir productivity by dissolving rocks to increase formation permeability, which is achieved by injecting acid fluids into reservoir formations. However, conventional acid fluids either can not achieve effective acidizing or cause geothermal reservoir damages. Foam acid fluids, which have been applied for oil-gas reservoir stimulation, can realize effective acidizing by retarding acid-rock reactions, and can protect reservoirs. Here, a foam acid fluid system is proposed, aiming at achieving efficient acidizing and reservoir protection in low-temperature dolomite geothermal reservoirs. Formic acid (FA) and acetic acid (HAc) are used to replace a portion of hydrochloride (HCl) acid. Alkyl glycine surfactant AGS-12 is added for foaming, while xanthan gum and nano silica particles are used to stabilize foams. Corrosion inhibitor and ferric ion stabilizer are added to inhibit acid corrosion of steel and ferric ion precipitations. The acidizing effect was evaluated through foam stability, dissolution performance, corrosion inhibition performance, and compatibility. Microscopic observation, field emission scanning electron microscope, and numerical simulation were applied to reveal the mechanisms of temporal evolution of foams and acid dissolution behaviors. Results show that the foam acid fluid with 5 wt% FA, 5 wt% HAc and 10 wt% HCl acid has the best foam stability and retardation effect. Compared to non-foam acid fluid, the decrease degree of the cuttings mass change rate in foam acid fluids exceeds 50 %, and foaming primarily retards acid-rock reactions. Simulation results is consistent with the experiment results, demonstrating that the cuttings dissolve less in FA and HAc. Calcium (Ca) content on the cuttings surfaces after acid-rock reactions in foam acid fluids with FA and HAc is less than that after acid-rock reactions in foam acid fluid with sole HCl acid, indicating that FA and HAc inhibit Ca-bearing mineral precipitations, as formate and acetate ions can chelate with Ca2+. The replacement of HCl acid by FA and HAc contributes to a low corrosivity and good compatibility of the foam acid fluids due to a reduced hydrogen ions resulted from partial dissociation of weak acids. This study shows the feasibility of foam acid fluids during geothermal reservoir stimulation with eliminated reservoir damages.

Experiment and modelling of degradation mechanism of cement mortar with graphene oxide nanosheets under sulfate attack

Degradation of cementitious materials caused by sulfate attack poses a significantly challenge to their durability. Using nano-additives to enhance the mechanical and durability properties of cementitious materials is a promising solution; however, the impact of graphene oxide (GO) on the sulfate resistance is not yet fully understood. While efforts have been made to study the degradation mechanism through accelerated indoor tests with high sulfate concentrations, these methods fail to accurately replicate real-world field exposure conditions. To better understand the degradation mechanism of GO-modified mortars under actual field conditions, this study examines the long-term degradation (over 24 months) of GO-modified mortars exposed to sulfate solutions with varying concentrations: 0 % (reference), 2.1 % (field condition), 5 % (laboratory condition), and 15 % (high-concentration condition). Additionally, a comprehensive chemo-mechanical model that considers multiple factors and time-varying boundary conditions was proposed. The study thoroughly discusses the effects of GO dosage, sulfate concentration, and exposure time on the degradation mechanism. Comparison with experimental data revealed that cement mortar degradation under sulfate attack is primarily driven by the crystallization pressure related to ettringite formation in diluted sulfate solutions, while the precipitation of alkali ions from mortar pore solutions occurs in concentrated sulfate solutions. In real-field conditions, cement mortar degradation primarily involves gypsum precipitation rather than ettringite formation. This study demonstrates that well-dispersed GO nanosheets can significantly enhance durability of cementitious materials against sulfate attack, offering valuable insights for strategic applications of GO nanosheets in cementitious materials.

Metal-modified biochars prepared from blue algae and their ability of adsorbing phosphates from water and utilization as soil amendment

The problem of blue algae accumulation can be alleviated by utilizing blue algae as biomass for resource utilization, which can remove excess phosphates from water to alleviate eutrophication. Herein, Magnesium (Mg) and/or lanthanum (La) were used to modify biochar via high-temperature slow pyrolysis with blue algae as the raw biomass. These modified biochars exhibited abundant carbon (18.0 %-50.3 %), oxygen content (17.4 %-49.1 %), along with a high specific surface area (82.26–233.80 m2/g). The surface of metal-modified biochar was enriched with hydroxyl and carboxyl groups and metal elements were efficiently incorporated into biochars. Adsorption kinetic and isotherm experiments were conducted under the optimal pyrolysis temperature of 600 °C, pH of 6.0, and adsorbent dosage of 2.0 g/L. The adsorption kinetics studies by metal-modified biochars for phosphate fitted well pseudo-second-order model Redlich-Peterson isotherm model. Biochar modified by Mg and La exhibited the highest removal efficiency (97.8 %) for phosphate at adsorption equilibrium. The adsorption mechanism involved the electrostatic interaction between hydroxylated metal oxides and negatively charged phosphate ions and the precipitation of phosphate ions through chemical reactions with metal oxides in the solution. After phosphate adsorption, the pristine and metal-modified biochars derived from blue algae were applied as the soil amendment. Biochar adsorbed phosphate apparently improved the germination rate of seeds facilitated the height, width, weight, and chlorophyll content of vegetable seedlings, and induced oxidative stress, which proved that the biochar recovered after adsorption was a high-quality soil amendment. This study provides a new approach for the treatment of phosphate wastewater and the algae application.

Comparative Evaluation of Ion Release and Uptake of Fluoride Varnish Containing Dicalcium Phosphate Dihydrate and Casein Phosphopeptide-Amorphous Calcium Phosphate – An Experimental Approach.

The effectiveness of fluoride varnish may be restricted due to inadequate bioavailability of phosphate and calcium ions in the oral cavity. Dicalcium phosphate dihydrate and Casein phosphopeptide–amorphous calcium phosphate have exhibited ability to enhance absorption of calcium and fluoride. The present study aims to compare the remineralization potential of fluoride varnishes containing DCPD and CPP-ACP. Materials and Method: The ion release, precipitation and surface microhardness of enamel blocks were compared following topical application of various Floride varnishes. Thirty enamel blocks were divided into 3 groups following randomization that included: NaF varnish (Group A), CPP-ACP NaF varnish (Group B) and DCPD- NaF varnish (Group C). Pre- and post-treatment microhardness was evaluated using Vickers Microhardness Tester. UV-Vis Spectroscopy assessed the fluoride release at 2 hrs, 4 hrs and 6 hrs. The uptake of fluoride, calcium and phosphates were determined using SEM-EDX. The statistical significance was tested with One-way ANOVA variance for normality followed by post-hoc tests (p ≤ 0.05). Results: All the groups showed statistically significant increase in microhardness post-treatment (Group A: p=0.03, Group B, C: p=0.00). The mean increase in VHN was Group B (53.67) &gt; Group C (34.75) &gt; Group A (27.40). No significant difference in the F release was noted over time (p=0.00). The fluoride release over all three time intervals was Group C &gt; Group B &gt; Group C. Fluoride, Calcium and Phosphates showed highly significant differences between groups (p=0.00) with Group C &gt; Group A&gt; Group B. Conclusion: The novel NaF-DCPD Varnish displayed a promising remineralization potential, however it cannot be conclusively considered to be superior to the commercially available NaF-CPP ACP Varnish. Further in-vivo investigations need to be undertaken to determine the efficacy of NaF-DCPD varnish to determine its feasibility in clinical practice.

Utilization of Schiff base ligands to chelate Ag+ for highly specific and sensitive Hg2+/Ag+ immunoassay

In this study, a planar benzothiazole Schiff base derivative ZX1 was designed and synthesized to selectively precipitate silver ions, in conjunction with the immunoassay detection of Hg2+ ions. The silver chelation process was highly effective in the pH range of 7–10, with a silver ion precipitation ratio of 99.9 %. The coordination behavior of ZX1 with Ag+ was studied using a series of spectroscopic measurements, topography analysis and DFT calculation. The shortest bond distances were 2.251 and 2.254 Å between nitrogen atom of thiazole and Ag+. Weak interactions were analyzed using the interaction region indicator (IRI) method and VMD. The immunoassay was developed through an anti-Hg2+/Ag+ monoclonal antibody, which showed similar sensitivities for Ag+ and Hg2+. The selectivity and anti-interference ability of the Schiff base ligands were tested for some hard metal ions and several anions. With co-existence of interference ion Ag+, Hg2+ was detected in rice matrix solution with 77 %∼123.5 % recovery by addition of ZX1 as the masking reagent and 90.3 %∼115 % for wheat matrix. This research provides a promising immunoassay strategy for simultaneous detection of silver ions and mercury ions in food matrix by utilization of Schiff base ligands. This novel Schiff base ligand was then used as the pre-treatment reagent to remove silver ions within 5 min for detection of Hg2+ or detection of both Ag+ and Hg2+ based on a novel bi-specific heavy metal antibody.

Carbon dioxide sequestration through mineralization from seawater: The interplay of alkalinity, pH, and dissolved inorganic carbon

Marine carbon dioxide removal technologies rely on the equilibration of seawater with atmospheric CO2, where a pH increase can facilitate CO2 removal either through increased absorption capacity of CO2, or precipitation of minerals. Here, we focus on explicitly defining the governing factors that influence seawater alkalinity with respect to CaCO3 mineralization and atmospheric CO2 uptake. We utilize an electrochemical setup and different water types, such as near-shore Mediterranean seawater and Red Sea Salt water. The setup allows us to separate mineralization from alkalinity enhancement via an electrochemical membrane cell, with a second compartment that allows evaluation of the interplay of ion concentration, precipitation, pH, DIC concentration, and total alkalinity under a controlled evironment. The effect of sparging additional CO2 before, and after the precipitation of CaCO3 was evaluated while utilizing both a mild pH swing (from, ∼8.3 to ∼9.5), and a larger pH swing (from, ∼8.3 to ∼10.2). A thermodynamic model is presented defining the energy consumptionrequired to increase the pH, and the influence of Mg thereon is explicated. Furthermore, we detail theoretical aquatic chemistry simulations via PHREEQC to rationalize the observed intricate dynamics of the carbonate system in seawater. We end with a discussion of the implications of total alkalinity, pH, salt complexation, and carbon uptake capacity relevant to of all ocean alkalinity enhancement and marine-based CO2 removal systems, concluding that the carbon uptake capacity of water returned to the ocean must be verified in such technologies.

Preparation of large specific surface rare earth oxides from calcium-containing rare earth solution by carbon dioxide carbonization method☆

The calcium-containing rare earth solution is generated during the recovery processes of NdFeB waste, which is treated as wastewater by enterprises. In this paper, the carbon dioxide carbonization method was applied to the separation of rare earths and calcium in the solution, as well as the preparation of rare earth oxides with a large specific surface. It is shown that the process of CO2 carbonization of solution includes reactions such as the dissolution, diffusion and ionization of CO2, the carbonate precipitation of rare earth ions, and the neutralization of hydrogen ions. At a pH of 4.5, the carbonization precipitation rate is effectively controlled, enabling homogeneous precipitation and ensuring both high precipitation yield and rare earth oxides purity. In this way, the crystallization of carbonization products is a process dominated by the oriented attachment theory and coexisting with the Ostwald ripening theory, resulting in abundant pores formed by multiple layers of stacking in the products. With the optimal carbonization conditions, the rare earth precipitation yield solution reaches 99.32%. The obtained carbonization products are crystalline (LaCe)(CO3)3·8H2O, and the purity of the rare earth oxides is as high as 99.22 wt%. The specific surface area of the rare earth oxides reaches 94.7 m2/g, and its adsorption efficiency for tetracycline hydrochloride in solution can reach 92.6% in a short time. The rare earth oxides are expected to be used as an adsorption material for wastewater treatment and other adsorption environments.

Research on Wellbore Blockage Mechanism and Blockage Removal Technology of Shale Gas Wells

Abstract With the continuous extension of development time, the production decline of single well is accelerated, and the problem of wellbore blockage in shale gas wells is prominent. The problem of wellbore blockage seriously restricts the stable production and efficient development of gas fields. In this paper, the ‘micro + macro’ analysis method is used to study the blockage. It is found that the wellbore blockage mainly includes corrosion, scaling products and a small amount of clay minerals brought by the reservoir during gas production. In the process of production, corrosion and scaling mechanism work together. Acidic gas such as CO2 in shale gas are dissolved in high-salinity formation water, causing electrochemical corrosion of the string. The formation of corrosion products will promote the deposition and adsorption of inorganic scales. The uneven accumulation of corrosion product films will enhance the surface roughness of the substrate and accelerate the deposition of scale samples around the crystal nucleus. At the same time, scaling will cause corrosion under the scale of the pipe string. Cl− can penetrate into the film through the micropores covering the product film on the metal surface, and pitting corrosion occurs to corrode the pipe string. Finally, the corrosion and scaling products together cause the pipe string to be blocked. Based on the analysis results of blockages and water samples, a blockage removal liquid system was developed according to the blockage mechanism. It has a high dissolution ability and the corrosion of 125SG, 155V and N80 steel sheets at 60°C for 4h is less than 1 g/(m2·h), which meets the requirements of industry standards. This system can inhibit the secondary precipitation of metal ions, has low corrosion damage to oil and casing, can remove wellbore blockage, does not need to flow back, will not cause secondary damage to the reservoir. It can provide guiding significance for similar shale gas well wellbore blockage removal.

β-Lactoglobulin separation from whey protein: A comprehensive review of isolation and purification techniques and future perspectives

Cow milk, although rich in essential nutrients, is a well-known allergic food that can cause allergic reactions in infants and young children. β-Lactoglobulin accounts for 10% of the total protein in milk and 50% of the whey protein, which has high nutritional value and excellent functional properties but is also the main allergen leading to milk protein allergy. Exploring the mechanism of milk allergy and selecting suitable separation and purification methods to obtain high-purity β-Lactoglobulin is the premise of research on reducing allergenicity. In this review, the research progress in membrane technology, gel filtration chromatography, ion exchange chromatography, affinity chromatography, precipitation and aqueous 2-phase system separation for the separation and purification of milk β-Lactoglobulin is reviewed in detail to promote the further development of milk β-Lactoglobulin separation and purification methods and provide a new method for the development of hypoallergenic dairy products in the future. Among these methods, ion exchange chromatography and gel chromatography are widely used, precipitation is generally used as a crude purification step, and high-performance liquid chromatography and membrane technology are used for further purification to improve the purity of allergens.

A Comprehensive Flow–Mass–Thermal–Electrochemical Coupling Model for a VRFB Stack and Its Application in a Stack Temperature Control Strategy

In this work, a comprehensive multi-physics electrochemical hybrid stack model is developed for a vanadium redox flow battery (VRFB) stack considering electrolyte flow, mass transport, electrochemical reactions, shunt currents, and as heat generation and transfer simultaneously. Compared with other VRFB stack models, this model is more comprehensive in considering the influence of multiple factors. Based on the established model, the electrolyte flow rate distribution across cells in the stack is investigated. The distribution and variation in shunt currents, single-cell current and single-cell voltage are analyzed. The distribution and variation in temperature and heat generation and heat transfer are also researched. It can be found that the VRFB stack temperature will exceed 40 °C when operating at 60 A and 100 mA cm−2 at an ambient temperature of 30 °C, which will lead to electrolyte ion precipitation, affecting the performance and safety of the battery. To control the stack temperature below 40 °C, a new tank cooling control strategy is proposed, and the suitable starting cooling point and the controlled temperature are specified. Compared with the common room cooling strategy, the new tank cooling strategy reduces energy consumption by 27.18% during 20 charge–discharge cycles.

Effect of Curing Light with Different Intensities on the Penetration of Silver and Fluoride Ions and Dentin Hardness in Primary Carious Molars Following Silver Diamine Fluoride Application: A Comparative Microscopic Ex Vivo Study.

A paradigm shift from surgical to medical approach for caries management has popularized silver diamine fluoride (SDF) as a preventive and interim caries arrest medicament. Few studies conducted have explored the effect of curing light on SDF's microbial property, its penetration, and effect on dentin. However, there is a research gap regarding the effect of different intensities of curing light on SDF performance. To determine the effect of different curing light intensities on SDF penetration depth and dentin hardness in carious lesions of primary molars. Silver diamine fluoride was applied on 30 extracted carious primary molars. Teeth were randomly allocated into three groups-(1) control group, no light curing after application of SDF; (2) light curing of SDF with low intensity (1000 mW/cm2); and (3) light curing of SDF with high intensity (2500 mW/cm2). A scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) analysis was performed to check ion penetration after 1 week, and a Vickers hardness test was used to assess dentin hardness of both infected and affected dentin layers at 1-week and 1-month intervals. Based on the distribution of data, parametric and nonparametric tests were applied. Statistical Package for the Social Sciences (SPSS) version 26 was used for statistical analysis. The level of significance was set at 5%. Silver diamine fluoride penetrated beyond the carious lesion in all three groups. The mean silver ion precipitation in infected dentin in group III (16.90 ± 0.68) was maximum, whereas it was found to be minimum in group II (7.31 ± 0.63). The mean fluoride ion precipitation in affected dentin in group III (4.06 ± 0.41) was highest and least in group II (3.09 ± 0.58). A considerable increase in mean dentin hardness of infected dentin was observed in all three groups (214.00 ± 89.06, 218.00 ± 75.17, 231.00 ± 98.86, respectively; p < 0.001) after 1 month. Applying SDF to carious lesions using a high-intensity dental curing light induced more silver ion precipitation in infected dentin and increased its hardness. Bhatt R, Patel M, Thakkar A, et al. Effect of Curing Light with Different Intensities on the Penetration of Silver and Fluoride Ions and Dentin Hardness in Primary Carious Molars Following Silver Diamine Fluoride Application: A Comparative Microscopic Ex Vivo Study. Int J Clin Pediatr Dent 2024;17(7):766-772.

Novel utilization exploration for the dephosphorization waste of Ca–modified biochar: enhanced removal of heavy metal ions from water

Phosphorus-modified biochar has been proven to enhance the precipitation and complexation of heavy metal ions from wastewater. However, the current modification methods require large amounts of exogenous P and have high energy consumption. Hence, this study proposes and analyzes a strategy integrating biochar production, phosphorus wastewater treatment, dephosphorization waste recovery, and heavy metal removal. “BC-Ca-P” was derived from Ca-modified biochar after phosphorus wastewater treatment. The adsorption of Pb(II) by BC-Ca-P followed the Langmuir isotherm and pseudo–second–order kinetic models. The maximum adsorption capability of 361.20 mg·g−1 at pH 5.0 for 2 h was markedly greater than that of external phosphorous-modified biochar. The adsorption mechanisms were dominated by chemical precipitation and complexation. Furthermore, density functional theory calculations indicated that oxygen-containing functional groups (P-O and C-O) contributed the most to the efficient adsorption of Pb(II) onto BC-Ca-P. To explore its practical feasibility, the adsorption performance of BC-Ca-P recovered from an actual environment was evaluated. The continuous-flow adsorption behavior was investigated and well-fitted utilizing the Thomas and Yoon–Nelson models. There was a negligible P leakage risk of BC-Ca-P during heavy metal treatment. This study describes a novel and sustainable method to utilize dephosphorization waste for heavy metal removal.Graphical