Ppm Mg2 Research Articles

Bipolar Membrane Capacitive Deionization for the Selective Capture of Lithium Ions from Brines and Conversion to Lithium Hydroxide

Meeting the increasing demand for lithium in vehicle electrification and renewable energy storage requires innovations in lithium-ion (Li+) separations. Traditional solar evaporation methods for lithium recovery are slow and consume tremendous volumes of water and secondary chemicals (acids and bases). This study introduces a bipolar membrane capacitive deionization (BPM-CDI) unit for direct lithium extraction and LiOH production without the external addition of acids and bases. Utilizing de-lithiated lithium-iron-phosphate (LFP) coated carbon cloth electrodes, the BPM-CDI unit demonstrates selective Li+ capture over competing ions. Molecular dynamics simulations and H-cell experiments elucidate pH inversion mechanisms during Li+ release, yielding LiOH. The BPM-CDI platform efficiently removes Li+ from synthetic brines featuring 8x higher Mg2+ concentrations (200 ppm Mg2+) and 26x higher Na+ concentrations (682 ppm Na+), achieving a LiOH concentration of 124 ppm (36 ppm Li+) after 8 cycles of recirculation. Post-mortem analysis confirms electrode integrity and stability. BPM-CDI integrated with selective electrodes is a promising electrochemical separation-reactor platform for lithium recovery while producing LiOH.

The characterization study of inhibited silica/silicate scale using vinyl sulfonated copolymer (VS-Co)

Silica/silicate scale is a significant problem, especially in oilfield production during Alkaline Surfactant Polymer (ASP) flooding, where chemical inhibitors are the preferred method to prevent them. In this study, the effect of inhibitor vinyl sulfonated copolymer (VS-Co) on silica/silicate scale formation was analysed using X-Ray Diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR).The functional group type of VS-Co are sulfonate ions, SO3-, and these interact in the scaling process. Bulk-inhibited scaling brine tests were conducted at 60C and pH 8.5. During these tests, the silicon brine (with VS-Co) representing the inhibited ASP leachate was mixed with a magnesium brine representing the connate water to replicate reservoir conditions during ASP flooding. The samples tested in this study were non-inhibited Si/Mg mixed brine of 60 ppm Mg2+ and 940 ppm Si4+ (60Mg:940Si) as a blank, and inhibited 60Mg:940Si mixture with various VS-Co concentrations of 20 ppm, 50 ppm, and 100 ppm. The inhibition efficiency of the VS-Co was determined, followed by the characterisation study of the silica/silicate scale deposited from both test conditions.The IR spectra of all 60Mg:940Si samples show a similar peak at 1050 cm-1 to 1080 cm-1, attributed to a Si-O covalent bond and a band at 790 cm-1 to 800 cm-1 showing the presence of Si-O-Si stretching. XRD patterns produced a broad scattering peak for all samples at 2 of 24 showing that the samples are amorphous silica. For tests of high Mg2+ in the brine mix, 900Mg:940Si, a mix of crystalline silica and crystalline magnesium silicate was produced. Based on these results, it can be concluded that the scale formed even with 100 ppm of VS-Co present. Further studies are required to address how to mitigate scale formation effectively in the future.Based on the research conducted, we can conclude that the VS-Co alone could not significantly inhibit the formation of silica/silicate scale even at the highest concentration (100 ppm) of VS-Co. However, having VS-Co present caused an alteration in IR spectra frequency which requires further investigation to assess how best to develop the inhibiting properties of the VS-Co product. The application of nanoparticles and their successful stories spark the interest of authors in searching for an efficient method of managing the silica/silicate scale where the modification of potential scale inhibitor (SI) with nanoparticles may be able to improve the inhibition efficiency towards the silicate/silicate scale.The presence of VS-Co in the scaling brine only slightly inhibits the Mg2+ ion (initially comes from connate water) from reacting. It is worth further investigation on how this VS-Co can make it happen. Hence, the functional groups responsible for this may be altered by adding other functional groups to provide a synergistic effect in preventing this silica/silicate scale; or by modifying the VS-Co with nanoparticles to improve their adsorption/desorption capacity.The newly developed technique in analysing the inhibition mechanism of a chemical inhibitor using various spectroscopic analysis is promising where an alteration in the spectra may provide proof of the chemicals inhibition efficiency.

Strategy to Enhance Geological CO2 Storage Capacity in Saline Aquifer

AbstractGeological CO2 storage is an emerging topic in energy and environmental community, which is, as a commonly accepted sense, considered as the most promising and powerful approach to mitigate the global carbon emissions during the transition to net‐zero. Of the geological media which initially considered cover the saline aquifers, oil and gas reservoirs, coal beds, and potentially basalts, up to now only the first two choices have been proven to be the most capable storage sites and successfully implemented at pilot/commercial scales. Here, two tandem papers propose novel strategies for the first time, by synthesizing and utilizing new high‐dryness CO2 foam, to enhance geological CO2 storage capacity in saline aquifer and oil and gas reservoirs. In this paper, a new high‐dryness CO2 foam is synthesized and injected into the saline aquifers to explore the storage capacity enhancement, with the unique foam‐induced advantages of sweep area expansion and storage efficiency improvement. Such a new idea is specifically evaluated and validated through a series of static analytical and dynamic performance experiments. With the optimum surfactant concentration of 0.5 wt%, the foaming volume and quality are determined to be 521 mL and 80.81%, respectively, which also shows excellent salt tolerance with 45,000 ppm Na+, 25,000 ppm Ca2+, and 25,000 ppm Mg2+. Moreover, the water consumption for CO2 storage decreases from 464.31 g/mol at 25% foam quality to 67.38 g/mol at 85% foam quality by using the new CO2 foam. Overall, the newly synthesized CO2 foam could effectively enhance geological CO2 storage capacity and concurrently diminish water consumption, therefore realizing the win‐win environment and economic benefits.

Investigation of mechanical properties and transparency of spark plasma sintered Mg2+ and Y3+ codoped α-Al2O3 nanoparticles synthesized via coprecipitation

This research aims to investigate the effect of different amounts of doping elements (magnesium and yttrium ions) on the hardness, elastic modulus, flexural strength, and transparency of alumina ceramics. For this purpose, different amounts of Mg2+ and Y3+ doped α-Al2O3 nanoparticles were synthesized via the co-precipitation method. The results revealed that the majority of Mg2+ and Y3+ doped α-Al2O3 nanoparticles have a particle size of 300–400 nm. Furthermore, the density and transparency (60% in-line transmittance at a wavelength of 5 μm, with a sample thickness of 2.4 mm) of the bulk materials prepared with doping of 100 ppm Mg2+and 400 ppm Y3+ (100M400Y) presented the best performance compared with other samples. Furthermore, the hardness and Young modulus of this sample were 28 GPa and 349 GPa, respectively. The flexural strength of the 100M400Y sample reached the highest value, 193 MPa, due to the smaller grain size and minimal porosity.

The Effect of NaHCO3 and Mg2+ Addition in Haematococcus pluvialis Cultivation by Carbon Injection Method

The emission of carbon dioxide has been continuously rising year by year. Many efforts that have been used with aim of climate recovery, such as capturing CO2 with the Carbon Capture Storage (CCS) method, which is the CCS technology is one of the effective tactics for reducing carbon emissions by utilizing energy from biomass of microalgae. This research will discuss about carbon capture using microalgae Haematococcus pluvialis in a lab scale photobioreactor (PBR), and resulting the optimum biomass productivity for Haematococcus pluvialis has occurred in the H2 variable (50 ppm Mg2+). This happens because of addition of Mg ions above 50 ppm can decrease the yield of biomass productivity, since Haematococcus pluvialis cannot live in high salinity concentrations. Further research should make a calculation of optimal cost incurred at the optimal carbon concentration that can be captured by microalgae, also the results of increasing value of the microalgae biomass produced for the comprehensive use of the microalgae.

High performance Mg2+/Li+ separation membranes modified by a bis-quaternary ammonium salt

The separation of lithium (Li+, 3.8 Å) and magnesium (Mg2+, 4.3 Å) ions represents the main challenge for lithium extraction from salt lakes with high magnesium-to‑lithium (Mg2+/Li+) ratio. A bis-quaternary ammonium salt (abbreviated as QEDTP) was designed to modify Polyethyleneimine (PEI) polyamide nanofiltration membrane. Water flux of the modified PEI membrane is 126.9 ± 1.6 L·m−2·h−1 (LMH) under 6 bar hydraulic pressure, which is 4.4 times as high as the pristine PEI membrane (25.8 ± 0.3 LMH). Meanwhile, the MgCl2 rejections of both membranes are maintained >95%. Nanofiltration performance of the QEDTP membrane is stable in 180 h continuous nanofiltration test at 6 bar pressure. The water flux and Mg2+/Li+ selectivity (SMg2+/Li+) of the QEDTP modified membrane in filtrating 2000 ppm Mg2+/Li+ mixture (Mg2+/Li+ ratio: 120:1, 6 bar) are 112.9 ± 1.6 LMH and 15.6 ± 0.3, which is one of the best Mg2+/Li+ separation performance considering both the flux and selectivity.

Selective Flocculation Study of Hematite in HematiteQuartz-Kaolinite System in Presence of Ca2+, Mg2+ and Fe3+ Ions. Part1: Optimization of Ligand

Separation of ultrafine hematite from quartz and kaolinite gangue minerals using selective flocculation technique is markedly affected by the state of inter mineral interaction which is governed by type and content of polyvalent metal ions. Because of the presence of polyvalent metal ions hetracoagulation of gangue minerals is widely acknowledged, thus selective flocculation of ultrafine hematite from associated gangue minerals is challenging task when their concentration is above 10 ppm. This study has shown that state of strong interaction of gangue minerals with hematite due to presence of 15 ppm Ca2+, 3 ppm Mg2+ and 3 ppm Fe3+ ions can be weakened by addition of optimal dose of Sodium Hexametaphosphate (SHMP) ligand. The optimization of ligand dose is achieved through analysis of Zeta Potential (ZP) as a function of slurry pH. It is noted that 50 ppm of SHMP is sufficient to restore the ZP of hematite, where selective dispersion of the slurry constituents are possible. Our results further showed that conventional strategy of obtaining minimum difference of ±30 mV in the ZP of hematite and gangue minerals quartz and kaolinite would not work especially in the presence of 15 ppm Ca2+, 3 ppm Mg2+ and 3 ppm Fe3+ ions. Attempts to achieve the minimum threshold difference in the ZP of the minerals will cause over dispersion.

A highly permeable UiO-66-NH2/polyethyleneimine thin-film nanocomposite membrane for recovery of valuable metal ions from brackish water

A positively charged thin film nanocomposite (TFN) membrane was synthetized based on the nano-gel UiO-66-NH2 for fractionation of monovalent and multivalent ions from saline water. The addition of nano-gel UiO-66-NH2 in the aqueous phase containing polyethyleneimine (PEI) led to the fabrication of a nanofiltration (NF) membrane with a looser structure, which can enhance the water permeability. The resulting TFN/PEI membranes were found to have a high rejection of 97.4 % and 88.1 % to MgCl2 and MgSO4 and a very low rejection of 4.1 % and 6.1 % for LiCl and NaCl with a permeability above 38 L/m2.h.bar. The TFN/PEI-3 membrane with 1 wt% nano-gel UiO-66-NH2 in PA layer had an optimal selectivity and permeability for fractionation of Mg2+/Li+ in MgCl2/ LiCl solution and Mg2+/Na+ in MgSO4/ NaCl solution. An efficient separation of Mg2+/Li+ with separation factor of 33, accompanied by a permeability as high as 30.6 L/m2.h.bar, was obtained. Moreover, the high hydrophilicity of the UiO-66-NH2-based TFN/PEI membrane led to a reasonable value of 82.6 % flux recovery after three cycles of filtration of a 2000 ppm Mg2+/Li+ mixed solution. These results demonstrate that this UiO-66-NH2-based TFN/PEI membrane with high permeability and selectivity can be an appropriate candidate for lithium extraction in practice.

Characterization of Hydrochloric Acid Activated Natural Kaolin and its application as adsorbent for Mg2+

Hard water can form deposits (scale) on pipe walls and operating units in industrial machines. One way to soften hard water is by using adsorbents to reduce the number of ions causing hardness, one of which is Mg2+. Kaolin is a natural mineral which has potential as an adsorbent. The ability of kaolin as an adsorbent can be enhanced utilizing activation. In this study, kaolin was chemically activated using HCl solution with varying concentrations, namely 4, 5, and 6 M. The activation was carried out by stirring kaolin with the activator solution for 24 hours. The adsorbent characterization was performed by the infrared spectrophotometer (FTIR) and the gravimetric method. The adsorption test for Mg2+ by activated kaolin was determined by adding 1g of adsorbent to 25 mL of 10 ppm Mg2+ solution with stirring rate 150 rpm. Furthermore, the adsorption contact time was varied, namely 30, 90, 150, and 180 minutes. The concentration of Mg2+was determined by a titration method using ethylenediaminetetraacetate (EDTA). The percentage of Mg2+ adsorbed was calculated as the concentration of Mg2+ adsorbed against the initial concentration. The results showed that kaolin activated by 6 M HCl could adsorb 68.9% of Mg2+ at the optimum contact time of 150 minutes. Activation of kaolin with HCl 6M can release organic impurities present in natural kaolin, which is thought to affect increasing its adsorption capacity for Mg2+.

Study of engineered low-modulus Mg/PLLA composites as potential orthopaedic implants: An in vitro and in vivo study.

Low molecular weight poly-lactic acid (PLLA) is a polymer matrix of orthopaedic implants. The PLLA matrix incorporating bioactive magnesium ion (Mg2+) enhances bone regeneration. But the optimal ratio of Mg2+ to PLLA matrix has not been well reported and is worthy of study. We synthesized silane-coated Mg/PLLA composites containing 1%, 2%, 3%, 4% and 5% Mg micro-particles. The mechanical properties, in vitro cytocompatibility, cell viability and osteogenesis differentiation and in vivo performance of silane-coated Mg/PLLA composites were evaluated. These results showed that the bending and tensile strength of PLLA matrix was reduced by incorporation of Mg micro-particles. Mg/PLLA composites with higher Mg micro-particles ratio showed higher Mg2+ leaching rate and pH value in immersion solutions. MC3T3-E1 pre-osteoblasts incubated with Mg/PLLA composites containing higher ratio of Mg micro-particles showed higher cytocompatibility, cell viability, osteogenesis differentiation and migration. In vitro cellular responses showed that MC3T3-E1 pre-osteoblasts had the highest cell viability at 50 ppm Mg2+. In vivo animal studies showed there was no change in serum Mg2+ concentration after implanting Mg/PLLA composites comparing with control and the implants of silane-coated Mg/PLLA composites accelerated bone formation. In summary, our study revealed the feasibility of silane-coated Mg/PLLA composites as orthopaedic implants. Silane-coated Mg/PLLA composites with Mg micro-particles ratio of 3% ∼ 5% were optimal substitutes for bone regeneration.

Selective detection of Mg2+ ions via enhanced fluorescence emission using Au-DNA nanocomposites.

The biophysical properties of DNA-modified Au nanoparticles (AuNPs) have attracted a great deal of research interest for various applications in biosensing. AuNPs have strong binding capability to the phosphate and sugar groups in DNA, rendering unique physicochemical properties for detection of metal ions. The formation of Au–DNA nanocomposites is evident from the observed changes in the optical absorption, plasmon band, zeta potential, DLS particle size distribution, as well as TEM and AFM surface morphology analysis. Circular dichroism studies also revealed that DNA-functionalized AuNP binding caused a conformational change in the DNA structure. Due to the size and shape dependent plasmonic interactions of AuNPs (33–78 nm) with DNA, the resultant Au–DNA nanocomposites (NCs) exhibit superior fluorescence emission due to chemical binding with Ca2+, Fe2+ and Mg2+ ions. A significant increase in fluorescence emission (λex = 260 nm) of Au–DNA NCs was observed after selectively binding with Mg2+ ions (20–800 ppm) in an aqueous solution where a minimum of 100 ppm Mg2+ ions was detected based on the linearity of concentration versus fluorescence intensity curve (λem = 400 nm). The effectiveness of Au–DNA nanocomposites was further verified by comparing the known concentration (50–120 ppm) of Mg2+ ions in synthetic tap water and a real life sample of Gelusil (300–360 ppm Mg2+), a widely used antacid medicine. Therefore, this method could be a sensitive tool for the estimation of water hardness after careful preparation of a suitably designed Au–DNA nanostructure.

Dual polymer flocculation approach to overcome activation of gangue minerals during beneficiation of complex iron ore

Abstract This paper reports potato and corn starch based dual polymer flocculation of partially liberated complex ooidic iron ore. Corn starch selectivity for hematite, lost due to incomplete liberation of hematite and the presence of 16 ppm Ca2 +, 3 ppm Fe3 +, and 1 ppm Mg2 + polyvalent metal ions, was improved by dual polymer flocculation when the induction order of potato starch followed by corn starch was used. The initial feed grade of 41% Fe was improved to 46.2% with a recovery of 49.3% Fe after the addition of 40 ppm potato starch and 30 ppm corn starch to the iron ore slurry. In our case, potato starch has been found to behave mainly as a selective polymeric dispersant rather than as a flocculant. The paper also discusses the possible occurrence of all the adsorption mechanisms involved in the flocculation of quartz and gangue minerals in the presence of polyvalent metal ions.

The effect of microdosimetric 12C6+ heavy ion irradiation and Mg2+ on canthaxanthin production in a novel strain of Dietzia natronolimnaea

BackgroundDietzia natronolimnaea is one of the most important bacterial bioresources for high efficiency canthaxanthin production. It produces the robust and stable pigment canthaxanthin, which is of special interest for the development of integrated biorefineries. Mutagenesis employing 12C6+ irradiation is a novel technique commonly used to improve microorganism productivity. This study presents a promising route to obtaining the highest feasible levels of biomass dry weight (BDW), and total canthaxanthin by using a microdosimetric model of 12C6+ irradiation mutation in combination with the optimization of nutrient medium components.ResultsThis work characterized the rate of both lethal and non-lethal dose mutations for 12C6+ irradiation and the microdosimetric kinetic model using the model organism, D. natronolimnaea svgcc1.2736. Irradiation with 12C6+ ions resulted in enhanced production of canthaxanthin, and is therefore an effective method for strain improvement of D. natronolimnaea svgcc1.2736. Based on these results an optimal dose of 0.5–4.5 Gy, Linear energy transfer (LET) of 80 keV μm-1and energy of 60 MeV u-1 for 12C6+ irradiation are ideal for optimum and specific production of canthaxanthin in the bacterium. Second-order empirical calculations displaying high R-squared (0.996) values between the responses and independent variables were derived from validation experiments using response surface methodology. The highest canthaxanthin yield (8.14 mg) was obtained with an optimized growth medium containing 21.5 g L-1 D-glucose, 23.5 g L-1 mannose and 25 ppm Mg2+ in 1 L with an irradiation dose of 4.5 Gy.ConclusionsThe microdosimetric 12C6+ irradiation model was an effective mutagenic technique for the strain improvement of D. natronolimnaea svgcc1.2736 specifically for enhanced canthaxanthin production. At the very least, random mutagenesis methods using 12C6+ions can be used as a first step in a combined approach with long-term continuous fermentation processes. Central composite design-response surface methodologies (CCD-RSM) were carried out to optimize the conditions for canthaxanthin yield. It was discovered D-glucose, Mg2+ and mannose have significant influence on canthaxanthin biosynthesis and growth of the mutant strain.

Protective effect of Crassostrea gigas extract on audiogenic seizures in magnesium deficient mice

Audiogenic seizures associated with loss of weight, prostration, piloerection, palpebral ptosis and motor deficiency were induced after sound stimulation of determined frequency and amplitude in magnesium-deficient DBA/2 mice. These symptoms were maintained when standard diet conditions (1700 ppm Mg2+) were restored. In contrast, mice were protected from audiogenic seizure in a dose related manner when Crassostrea gigas extract (JCOE) were added to the diet for 10 consecutive days. Although a rational explanation for this protective effect has not yet been determined, it is assumed that it might be due to a chelating complex formed between Mg2+ and taurine, which enhance the uptake of Mg2+.

Geochemical and Mineralogical Analyses, Pennsylvanian Kendrick Fauna, Eastern Kentucky: ABSTRACT

The Kendrick brachiopods of Pennsylvanian age secreted low-Mg calcite shells with average SR2+ content of 1,140 ppm. The crinoids and rugose corals secreted intermediate-Mg calcite skeletons with average Sr2+ contents of 2,140 ppm and 1,770 ppm, respectively. Conversely, the Kendrick mollusks secreted aragonite shells which contain less than 1,000 ppm Mg2+. However, the average Sr2+ content (4,040 ppm for the cephalopods, 5,210 ppm for the gastropods, and 4,840 ppm for the pelecypods) is higher by a factor of about 2 over the average Sr2+ content of their Holocene counterparts. The brachiopods, gastropods, and pelecypods precipitated calcium carbonate in oxygen (average -4.5 ppt, ^dgr18O, PDB) and carbon (average +1.7 ppt, ^dgr13C, PDB) isotopic equilibrium with ambient Pennsylvanian seawater. The crinoids and rugose corals are light in both ^dgr13C and ^dgr18O by about 5 ppt, relative to isotopic equilibrium values. This isotopic depletion, as in the crinoids' modern counterparts, probably relates to the incorporation of isotopically light metabolic oxygen and carbon at the site of calcification. In contrast, the Kendrick cephalopods apparently precipitated shell aragonite in oxygen isotopic (-4.5 ppt) equilibrium with ambient seawater, whereas their carbon isotopic composition (+0.5 to -5.4 ppt) is controlled pos ibly by kinetic effects. The Fe2+ and Mn2+ contents of the fossil allochems and shale suggest that Kendrick seawater was slightly euxinic. In addition, the Na2+ content and oxygen isotopic composition indicate a slightly higher water temperature and hyposalinity for Kendrick seawater. Diagenetic alteration is limited to occlusion of pore spaces in the fossils and to compaction and cementation of the shale. This process probably occurred in the marine and/or submarine environment. End_of_Article - Last_Page 552------------

Trace-Element Geochemistry and Diagenesis in Capitan Reef (Permian), West Texas: ABSTRACT

The lattice substitution of doubly charged cations into calcite during aqueous precipitation depends on solution composition and the appropriate partition coefficients. Thus, the trace-element geochemistry of a limestone encodes the chemical composition of the solution in which mineralogic stabilization occurred. Because different environments are characterized by specific solution chemistries, we can use the trace-element composition of a limestone to infer the diagenetic environment in which it stabilized. A suite of calcite samples was collected in the reef core (massive) and upper fore-reef facies of the Permian reef complex (Guadalupian), from the cliffs above the entrance to McKittrick Canyon. These rocks averaged 375 ppm Sr2+, 13,900 ppm Mg2+, 9.4 ppm Zn2+, and 40.1 ppm Mn2+ (AA analyses). Petrographic examination of these wackestones and packstones provided no conclusive evidence of the environment in which mineralogic stabilization occurred. However, the trace-element values, when compared to probable starting (sedimentary) compositions, indicate equilibration in an open chemical system with insignificant introduction of cations from an external source. Autodepletion of strontium and magnesium (kSrcal = 0.14; kcal = 0.02) accompanied autoenrichment of zinc and manganese (kZncal = 5; kMncal = 15). The degree of autoenrichment and autodepletion of these chemical species is characteristic of an open chemical system, that is, one in which fresh waters flush rapidly through the diagenetic site. This combination of fresh water and open system is diagnostic of a freshwater phreatic zone. We infer, then, that this part of the reef stabilized in a End_Page 509------------------------------ freshwater phreatic environment. This interpretation is consistent with the vadose origin ascribed to features observed within other parts of the complex. End_of_Article - Last_Page 510------------