Removal Of Calcium Research Articles

Analysis of the effectiveness of organic compounds from the amine group in precipitating ions from soda production wastewater

Treating wastewater from the soda industry is a complicated and lengthy process, requiring a great deal of labor and financial resources. No method has yet been developed to eliminate the environmental damage caused by the soda industry entirely. The work focused on the removal of chloride, sulfate, calcium, and magnesium from soda production wastewater by precipitation using organic solvents such as isopropylamine (IPA), diisopropylamine (DIIPA), propylamine (PA) and ethylamine (EA) in various proportions. Statistical modeling through Bayesian beta regression was used to select the amine most effectively removing the tested ions in precipitate form. The effect of precipitating agent dosage on the pH and conductivity of the solution was also investigated. Samples of wastewater obtained from the soda industry were characterized by high values of pH (up to 11.9), specific electrolytic conductivity (up to 128 mS cm-1), and high concentrations of sodium (up to 13 g L-1), chloride (up to 60 g L-1) and calcium (up to 24 g L-1) ions. Solvent-based precipitation showed that organic solvents are effective in precipitating salts from wastewater from the soda industry. Sulfate and chloride removal efficiencies of 85.1 and 34%, respectively, were observed. Statistical analysis showed that isopropylamine was the most effective amine for removal.

Simultaneous removal of nitrate, copper, carbamazepine, and calcium from micropolluted water by fulvic acid through promotion of denitrification and microbial-induced calcium precipitation: Performance and mechanism

In this paper, a study of the denitrification strain Cupriavidus sp. W12 was conducted to remove copper (Cu2+), carbamazepine (CBZ), and calcium (Ca2+) by microbial-induced calcium precipitation (MICP) after adding fulvic acid (FA). After the addition of 20 mg/L FA, the removal efficiencies of nitrate (NO3–-N), Cu2+, CBZ, and Ca2+ reached 100.0 %, 98.7 %, 96.6 %, and 73.6 %, correspondingly and there was no accumulation of nitrite (NO2–-N). FA stimulated the growth of strain W12, improved electron transfer activity, and facilitated the conversion of gaseous nitrogen. The research revealed that FA might enhance microbial activity and result in a more dense and porous structure of the biological precipitate. Cu2+ and CBZ were removed by co-precipitation and adsorption. As the initial report of FA promoting MICP to remove complex pollutants, this paper offers a theoretical foundation for NO3–-N, Cu2+, CBZ, and Ca2+ remediation in micropolluted water.

Impact of postharvest dips with abscisic acid, prohexadione, calcium, or water on bitter pit incidence and apple physiology

Bitter pit causes significant losses to apple producers, packers, and retailers each year. While bitter pit is often associated with calcium deficiency, this postharvest disorder is still not fully understood. Some studies have demonstrated positive effects of preharvest sprays with prohexadione and abscisic acid. To evaluate the effects of these phytohormones as postharvest dips, ‘Granny Smith’ apples were dipped after harvest in prohexadione-Ca, abscisic acid, or CaCl2. Undipped and water dipped fruit were included as controls. Bitter pit incidence and severity were evaluated on fruit stored at 0 °C and >90 % RH for 68–75 d. Postharvest prohexadione-Ca and abscisic acid treatments did not reduce bitter pit incidence over two years of testing. However, there was an increase in bitter pit incidence in control fruit dipped in water and surfactant compared to undipped control fruit in the first year of testing. This increase (7.5–14 %) was observed again in water dipped control fruit in each of the following 2 years of experimentation. Inclusion of 1 % calcium chloride in the dip solution eliminated this increase in bitter pit incidence. Applying calcium with a surfactant increased the apoplastic calcium concentration and reduced bitter pit development compared to water dipped fruit. Results indicate that the increase in bitter pit induced by water dips may be due to removal of residual calcium on the fruit’s surface from preharvest calcium treatments. Ethylene production was higher in bitter pit fruit compared to healthy fruit. Reduced and total ascorbate were decreased in pitted fruit compared to healthy calcium dipped fruit. Dichlorofluoresceine diacetate fluorescence was higher in tissue adjacent to pits compared to healthy tissue from healthy fruit, indicating accumulation of reactive oxygen species. However, no consistent trend was observed in antioxidant enzyme activity. These results indicate that bitter pit shares some, but not all, of the oxidative metabolic trends observed in other fruit calcium deficiency disorders.

Acid mine drainage activation mechanism on lime-depressed pyrite flotation from copper sulfide ore

The lime-depressed pyrite from Cu differential flotation tailings with acid mine drainage (AMD) as a natural activator was recovered. The effect of AMD on lime-depressed pyrite flotation was investigated by a series of laboratory flotation tests and surface analytical techniques. Flotation test results indicated that AMD could effectively activate the pyrite flotation with a sodium butyl xanthate (SBX) collector, and a high-quality sulfur concentrate was obtained. Pulp ion concentration analysis results indicated that AMD facilitated desorption of Ca2+ and adsorption of Cu2+ on the depressed-pyrite surface. Adsorption measurements and contact angle analysis results confirmed that adding AMD improved the adsorption amount of SBX collector on the pyrite surface and increased the contact angle by 31°. Results of Raman spectroscopy and X-ray photoelectron spectroscopy analysis indicated that AMD treatment promoted the formation of hydrophobic species (S0 hydrophobic entity and copper sulfides) and the removal of hydrophilic calcium and iron species on the pyrite surface, which reinforced the adsorption of collector. The findings of the present research provide important theoretical basis and technical support for a cleaner production of copper sulfide ores.

Magnesium recovery from brackish water desalination brine and valorization in fertilizer production

The generated brine from the desalination unit hurts the environment. In this work, we try to valorize the nanofiltration and reverse osmosis brine generated from a hybrid desalination unit of treated wastewater located in Tunisia by magnesium recovery and reuse it as a cheap resource for fertilizer production. The brine was first purified by calcium removal. The pH of calcite precipitation was 11.32 and 9.78 using brine NF and brine RO respectively. After that, the filtrate was used to produce brucite. The pH of brucite precipitation was 11.3 and 9.74 for NF and RO brine respectively. 55 % of magnesium was recovered from NF brine and 65.5 % from RO respectively. To obtain a 100 % recovery rate of magnesium for brucite precipitation, the optimal molar alkaline reagent/Mg ratio was 5.5 and the pH was 11.9. The brucite was dissolved in sulfuric acid, then the Epsomite fertilizer was extracted with pure ethanol. The highest weight of epsomite was obtained for a volume ratio of acid/ ethanol of 0.8:3.5. The second fertilizer produced using brine magnesium was struvite. It was obtained for pH 9 and 11 using H2NH4PO4 acid and wastewater as a source of ammonia and phosphate respectively. 90 % and 50 % of magnesium recovery were obtained for the first and the second cases respectively. The infrared spectrum and X-ray diffractogram confirmed the brucite, epsomite, and struvite production using brine magnesium.

The Efficiency of Phosphate Removal via Shallow Wastewater Injection into a Saline Carbonate Aquifer.

Wastewater-derived phosphate contributes to eutrophication if the phosphate is not efficiently removed before it is discharged to surface waters. In the Florida Keys (USA), shallow injection of treated wastewater into saline limestone aquifers is a common mode of wastewater disposal. We assessed the possibility of efficient and permanent phosphate removal following injection at a wastewater treatment facility in Marathon, Florida. The concentrations of nutrients, dissolved ions, and anthropogenic compounds in groundwater and nearshore waters were monitored over two years, as was the progression of a patch of fluorescent dye emplaced by the wastewater injection well. The density contrast between the wastewater effluent and saline groundwater caused the effluent plume to buoy to the shallow subsurface near the injection well. Soluble reactive phosphorus (SRP) and sucralose were both detected in nearshore waters, indicating incomplete removal of contaminants. However, ∼75% of the SRP is removed from the plume in the first 10 days of transit by adsorption followed by a slower removal mechanism, bringing the P removal efficiency above 90%. A positive relationship between excess calcium and phosphate removal efficiency, together with high levels of calcium phosphate mineral supersaturation, supports calcite dissolution followed by calcium phosphate mineralization as this slower removal process.

Green synthesis of zinc oxide nanoparticles using Eucalyptus leaf extract for effective calcium removal from groundwater

Green synthesis of zinc oxide nanoparticles using Eucalyptus leaf extract for effective calcium removal from groundwater

Reversal of heavy arterial calcification in a rat model of chronic kidney disease using targeted ethylene diamine tetraacetic acid-loaded albumin nanoparticles.

Elastin degradation and severe calcification in the medial layer of the vessel wall, known as medial arterial calcification (MAC), is typical in the aging population and patients with metabolic disorders, such as diabetes and chronic kidney disease (CKD). We have previously reported that ethylene diamine tetraacetic acid (EDTA) delivery to the site of calcification can be achieved by tagging nanoparticles with an elastin antibody that recognizes explicitly damaged elastin, and such systemic therapy can remove focal calcium deposits from the calcified arteries in CKD rodent model. The current study aims to test whether heavy calcification seen throughout arterial tree and kidneys in CKD can be reversed with nanoparticle therapy. Thirty healthy male Sprague-Dawley rats weighing approximately 300 g, were placed on an adenine diet for 21 non-consecutive days to induce kidney failure, followed by daily vitamin D3 (VitD3) injections for 4 sequential days to cause severe calcification throughout the cardiovascular system and kidneys. DiR-dye loaded and elastin antibody conjugated albumin nanoparticles were used to confirm the targeting of nanoparticles to the calcification area. The rats were divided into two groups for targeted removal of calcification starting at day 7 of the last doses of VitD3. The experimental group received biweekly IV injections of anti-elastin antibody conjugated EDTA loaded human serum albumin nanoparticles (EDTA-HSA-El-Ab NPs), while the sham controls received blank nanoparticles (Blank-HSA-El-Ab NPs) (5 injections in total). Micro-computed tomography (microCT) was used to analyze the extent of calcification. Reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemistry studies were performed for osteogenic markers, including bone morphogenic protein 2 (BMP2), runt-related transcription factor 2 (RUNX2), and tissue non-specific alkaline phosphatase (TNAP). For comparison, aortic ring organ cultures from healthy rats were treated with high phosphate to induce calcification in vitro, and then they were treated with EDTA. Human calcified femoral arteries were also treated ex vivo with EDTA-HSA-EL-Ab NPs to test if nanoparticles remove heavy calcification. EDTA-loaded nanoparticles that specifically target degraded elastin reversed existing heavy mineral deposits in arteries, as per elemental calcium analysis (124.161±34.410 µg Ca per mg of the dry aorta in Blank-HSA-El-Ab NPs vs. 100.520±19.131 µg in EDTA-HSA-El-Ab NPs group, P=0.04) and microCT (object volume, 129.001±37.785 vs. 29.815±24.169 mm3, P=0.0005). The reversal of aortic calcification was accompanied by a significant reduction of bone-associated mRNA expression of BMP2 and RUNX2 (P=0.01). Immunohistochemistry studies corroborated RT-PCR results, showing a reduction of BMP2 and RUNX2 stains in the vessel wall. The rat aortic ring culture study also showed similar results, where osteogenic genes (BMP2, RUNX2) and proteins (BMP2, RUNX2, TNAP) were suppressed upon reversal of calcification with EDTA (P=0.001). We also show ex vivo reversal of human femoral artery calcification by microCT (calcium intensity: untreated, 57.721±28.551 vs. day 6 of treatment, 5.441±3.615, P=0.01) by EDTA nanoparticle therapy. This is the first study showing the removal of calcium from heavily calcified arteries by using intravenous targeted EDTA therapy. Such therapy also reversed vascular smooth muscle cell osteoblastic transition and apoptosis in the arterial tissue, thereby potentially creating an environment for suitable tissue repair.

Removal of calcium from phosphoric acid produced by the nitric acid process using solvent extraction with TCHDGA and stripping with water

The phosphoric acid produced by the nitric acid method cannot be used as an industrial-grade product as a result of the high calcium nitrate content. It can only be used for fertilizer production due to difficulty of complete removal of calcium nitrate. Herein, an efficient approach for the removal of calcium nitrate from the phosphoric acid produced by the nitric acid process was studied. The proposed process is based on solvent extraction with N, N, N′, N′-tetracyclohexyl-3-oxyglutaramide (TCHDGA). The effects of time, diluent, temperature, impurity ions, and the concentrations of extractant and nitric acid on the extraction of Ca2+ were considered. A series of characterization tests involving FT-IR spectroscopy, XPS analysis, slope analysis and X-ray single crystal diffracted analysis revealed that the stoichiometry of the complex is (Ca(NO3)2)(TCHDGA)3. The concentration of Ca2+ in phosphoric acid drops below 5 mg/L a three-stage cross-current extraction process. The stripping efficiency of calcium nitrate in the organic phase by water is above 99.9%. The extraction efficiency of Ca2+ by TCHDGA remained above 96.8% after ten extraction-stripping cycles, realizing the efficient removal of calcium nitrate in the phosphoric acid produced by nitric acid process without changing the traditional production conditions.

Unlocking the potential of Spirulina microalgae: Cultivating in wastewater treatment for sustainable biofuel production

Municipal wastewater, known for its high nitrogen and phosphorus levels, disrupts natural biogeochemical cycles. However, these nutrients are vital for cultivating green algae, which show potential as a sustainable energy source. In this study, Spirulina microalgae biomass was cultivated from diluted municipal wastewater and converted into biofuel to assess its compatibility with conventional diesel applications. Algae growth rate, nutrient removal from wastewater, and proximate and ultimate analyses of the biomass were conducted. Elemental, functional group, and chemical analyses of the biodiesel were also performed using an elemental analyzer, Fourier-transform infrared (FTIR) spectroscopy, and Gas Chromatography-Mass Spectrometry (GC-MS), respectively. Results showed effective removal of calcium, magnesium, potassium, and nitrogen nutrients by 44.7%, 71.7%, 50%, and 55.6%, respectively, through algae cultivation. Proximate and ultimate analyses confirmed the biomass's energy content and efficiency for energy production. Elemental analysis of biodiesel revealed significant contributions of carbon, hydrogen, and oxygen, while FTIR and GC-MS analyses identified carbon-based components and methyl esters as major constituents, respectively. Physicochemical properties of algae biodiesel met ASTM D6751 limits. This comprehensive assessment suggests that Spirulina algae from wastewater treatment holds promise as a viable energy source for diesel applications.

Removal of calcium and magnesium ions from reverse osmosis concentrate using a two-stage precipitation with carbonation process.

The reverse osmosis (RO) technique has been extensively employed in the advanced treatment of industrial water and wastewater. However, this process results in the production of a significant quantity of reverse osmosis concentrate (ROC), which contains high levels of salinity and organic contaminants, thereby posing serious environmental problems. This study reported a two-stage precipitation process utilizing quicklime (CaO) and caustic soda (NaOH) in conjunction with air blowing (carbonation) for the removal of Ca2+ and Mg2+ from real brackish water ROC of factory. In stage I, the CaO precipitation-carbonation process was employed to eliminate the majority of Ca2+ from the ROC, while leaving Mg2+ virtually unaffected, yielding high-purity CaCO3 precipitates. In stage II, the NaOH precipitation method was utilized to eliminate the remaining Ca2+ and Mg2+ from the ROC. It was demonstrated that under optimal conditions, the removal rates of Ca2+ and Mg2+ exceeded 97%. Finally, the characterization of precipitates demonstrated the generation of high-purity CaCO3 precipitates in stage I, as well as the formation of CaCO3 and Mg(OH)2 precipitates in stage II. The results confirmed the feasibility of employing the two-stage precipitation with carbonation process to economically treat ROC and enable its reuse, offering valuable insights for the treatment of industrial wastewater.

Research on Carbon Dioxide-Assisted Electrocoagulation Technology for Treatment of Divalent Cations in Water

In the external drainage water of Xinjiang Karamay Petrochemical Company, the calcium and magnesium ion contents are as high as 630 mg/L and 1170 mg/L, respectively. These ions are subsequently scaled at large quantities in water treatment equipment, which greatly reduces the efficiency of the process. This study used a coupled chemical precipitation (CP) and electrocoagulation (EC) method to deal with external drainage water. The results show that the removal rates of calcium and magnesium were 94.71% and 96.33%, respectively, when the pH was adjusted with sodium silicate and EC was introduced after saturating the water samples with CO2. In this study, a quadratic polynomial equation was developed for predicting the removal of calcium and magnesium ions using this coupled technique under three factors of current density (CD) (15, 20 and 25 mA/cm2), reaction time (RT) (30, 40 and 50 min) and pH (10.0, 10.5 and 11.0). It was found that these three variables have a significant effect on the removal of both the abovementioned ions. The response surface method based on a Box–Behnken design showed that the average removal rates of calcium and magnesium ions could be 96.57% and 98.66% at a CD of 22 mA/cm2, RT of 46 min and pH of 11. This study confirmed the presence of calcium carbonate in the solid product through XRD and SEM analysis. The results indicate that this study is promising, and the developed technique can also be used to remove the high concentrations of calcium and magnesium ions from different wastewaters.

Perimenopause Decreases SERCA2a Activity in the Hearts of a Mouse Model of Ovarian Failure.

Risk of cardiovascular disease mortality rises in women after menopause. While increased cardiovascular risk is largely attributed to postmenopausal declines in estrogens, the molecular changes in the heart that contribute to risk are poorly understood. Disruptions in intracellular calcium handling develop in ovariectomized mice and have been implicated in cardiac dysfunction. Using a mouse model of menopause in which ovarian failure occurs over 120 days, we sought to determine if perimenopause impacted calcium removal mechanisms in the heart and identify the molecular mechanisms. Mice were injected with 4-vinylcyclohexene diepoxide (VCD) to induce ovarian failure over 120 days, mimicking perimenopause. Hearts were removed at 60 and 120 days after VCD injections, representing the middle and end of perimenopause. SERCA2a function was significantly diminished at the end of perimenopause. Neither SERCA2a nor phospholamban expression changed at either time point, but phospholamban phosphorylation at S16 and T17 was dynamically altered. Intrinsic SERCA inhibitors sarcolipin and myoregulin increased >4-fold at day 60, as did the native activator DWORF. At the end of perimenopause, sarcolipin and myoregulin returned to baseline levels while DWORF was significantly reduced below controls. Sodium-calcium exchanger expression was significantly increased at the end of perimenopause. These results show that the foundation for increased cardiovascular disease mortality develops in the heart during perimenopause and that regulators of calcium handling exhibit significant fluctuations over time. Understanding the temporal development of cardiovascular risk associated with menopause and the underlying mechanisms is critical to developing interventions that mitigate the rise in cardiovascular mortality that arises after menopause.

Same therapy, same calcium mobilization? Exploring calcium exchange across body compartments using a patient-specific predictive model.

Comprehensive, patient-specific models are essential to study calcium deposition and mobilization during dialysis. We aim to develop tools to support clinical prescriptions with a more accurate approach for the prediction of calcium mobilization while also considering major electrolytes and catabolites. We modified a multi-solute model predicting patient-specific dialysis response by incorporating a calcium buffer to represent bone exchanges. Data from four centers, involving 127 patients with six sessions each, were utilized. For each patient, three sessions were allocated for model training (ID123), while the remaining sessions were for validation (PRED456). The normalized root mean square error (nRMSE%) was used to evaluate both descriptive and predictive accuracy. Correlations between initial data and calcium exchanges were also assessed. The overall nRMSE% for ID123 was 3.92%. For PRED456, it was 3.46% (ranging from a minimum of 1.17% for [Na+] to a maximum of 6.62% for [urea]). The median nRMSE% for plasma calcium varied between 1.13 and 8.32 for SHD sessions, depending on whether Ca_dialysis fluid (Cad) was ≥ or <1.50 mmol/L, respectively. For HDF sessions, the range was between 2.90 and 5.89. A significant and moderate correlation was found between overall calcium removal and the buffer balance. The most robust correlation observed was between the amount of calcium administered via post-dilution fluid and the overall calcium removal in the dialysis filter. Identical therapy settings do not uniformly affect calcium mobilization, and our approach offers insight into calcium distribution across body compartments. This understanding will enhance clinical prescription practices.

Simultaneous removal of calcium, phosphorus, and bisphenol A from industrial wastewater by Stutzerimonas sp. ZW5 via microbially induced calcium precipitation (MICP): Kinetics, mechanism, and stress response

The biological treatment of complex industrial wastewater has always been a research hotspot. In this experiment, a salt-tolerant strain Stutzerimonas sp. ZW5 with aerobic denitrification and biomineralization ability was screened, and the optimum conditions of ZW5 were explored by kinetics. The removal efficiencies of nitrate (NO3--N), bisphenol A (BPA), phosphorus (PO43--P), and calcium (Ca2+) were 94.47 %, 100 %, 98.87 %, and 83.04 %, respectively. The removal mechanism of BPA was the adsorption of microbial induced calcium precipitation (MICP) and extracellular polymeric substances (EPS). Moreover, BPA could weaken the electron transfer ability and growth metabolism of microorganisms and affect the structure of biominerals. At the same time, the stress response of microorganisms would increase the secretion of EPS to promote the process of biomineralization. Through nitrogen balance experiments, it was found that the addition of BPA would lead to a decrease in the proportion of gaseous nitrogen. This experiment offers novel perspectives on the treatment of industrial effluents and microbial stress response.

Simultaneous removal of ammonia nitrogen, calcium and cadmium in a biofilm reactor based on microbial-induced calcium precipitation: Optimization of conditions, mechanism and community biological response

With the enhancement of environmental governance regulations, the discharge requirements for reverse osmosis wastewater have become increasingly stringent. This study proposes an innovative approach utilizing heterotrophic nitrification and aerobic denitrification (HNAD)-based biomineralization technology, combined with coconut palm silk loaded biochar, to offer a novel solution for resource-efficient and eco-friendly treatment of reverse osmosis wastewater. Zobellella denitrificans sp. LX16 were loaded onto modified coir silk and showed removal efficiencies of up to 97.38, 94.58, 86.24, and 100% for NH4+-N (65 mg L−1), COD (900 mg L−1), Ca2+ (180 mg L−1), and Cd2+ (25 mg L−1). Analysis of the metabolites of microorganisms reveals that coconut palm silk loaded with deciduous biochar (BCPS) not only exerts a protective effect on microorganisms, but also enhances their growth, metabolism, and electron transfer capabilities. Characterization of precipitation phenomena elucidated the mechanism of Cd2+ removal via ion exchange, precipitation, and adsorption. Employing high-throughput and KEGG functional analyses has confirmed the biota environmental response strategies and the identification of key genes like HNAD.

Study on Optimization of Deep Purification Process Design of Zinc Oxygen Pressure Acid Leaching Solution

According to the characteristics of high impurity content and complex composition of oxygen pressure leaching (OPL) solution of zinc sulfide concentrate, combined with the quality requirements of large plate electrowinning and automatic plate stripping, the advanced purification process of solution was designed. Through the deep purification process consisting of neutralization indium precipitation and low iron purification, high temperature antimony salt nickel and cobalt removal, copper slag chlorine removal, low temperature zinc powder replacement copper and cadmium removal, fine purification, calcium and magnesium removal, the contents of harmful impurities such as iron, indium, copper, cadmium, nickel, cobalt, fluorine and chlorine in the solution are strictly controlled to ensure that the quality of the deeply purified zinc sulfate solution is qualified and can meet the needs of continuous and stable production. The energy-saving effect of advanced purification process is obvious, and the average DC power consumption per ton of electric zinc is 2880kWh, reaching the advanced level of the same industry in China. The good effect of advanced purification process ensures the successful application of OPL and large plate zinc electrowinning, and improves the technology and equipment level of zinc smelting industry, which has important popularization and application value.

Recognition of granulocyte-macrophage colony-stimulating factor by specific S100 proteins

Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a pleiotropic myelopoietic growth factor and proinflammatory cytokine, clinically used for multiple indications and serving as a promising target for treatment of many disorders, including cancer, multiple sclerosis, rheumatoid arthritis, psoriasis, asthma, COVID-19. We have previously shown that dimeric Ca2+-bound forms of S100A6 and S100P proteins, members of the multifunctional S100 protein family, are specific to GM-CSF. To probe selectivity of these interactions, the affinity of recombinant human GM-CSF to dimeric Ca2+-loaded forms of 18 recombinant human S100 proteins was studied by surface plasmon resonance spectroscopy. Of them, only S100A4 protein specifically binds to GM-CSF with equilibrium dissociation constant, Kd, values of 0.3–2 μM, as confirmed by intrinsic fluorescence and chemical crosslinking data. Calcium removal prevents S100A4 binding to GM-CSF, whereas monomerization of S100A4/A6/P proteins disrupts S100A4/A6 interaction with GM-CSF and induces a slight decrease in S100P affinity for GM-CSF. Structural modelling indicates the presence in the GM-CSF molecule of a conserved S100A4/A6/P-binding site, consisting of the residues from its termini, helices I and III, some of which are involved in the interaction with GM-CSF receptors. The predicted involvement of the ‘hinge’ region and F89 residue of S100P in GM-CSF recognition was confirmed by mutagenesis. Examination of S100A4/A6/P ability to affect GM-CSF signaling showed that S100A4/A6 inhibit GM-CSF-induced suppression of viability of monocytic THP-1 cells. The ability of the S100 proteins to modulate GM-CSF activity is relevant to progression of various neoplasms and other diseases, according to bioinformatics analysis. The direct regulation of GM-CSF signaling by extracellular forms of the S100 proteins should be taken into account in the clinical use of GM-CSF and development of the therapeutic interventions targeting GM-CSF or its receptors.

Selective Calcium Removal at Near-Ambient Temperature in a Multimineral Recovery Process from Seawater Reverse Osmosis Synthetic Brine and Ex Ante Life Cycle Assessment

Potable water production from seawater generates brines that can produce stress in ecosystems, but they are also a potential source of metal and minerals. In our multi-mineral modular seawater brine mining process under development, calcium removal with minimal magnesium removal was the first stage. Even though calcium removal from reverse osmosis brine has been widely studied, there is no relevant research on its precipitation by carbonates at a near-ambient temperature (a range of 15–35 °C) and its selectivity over other minerals, as well as studies on operating conditions for selective precipitation considering the presence of antiscalants. We studied its reaction kinetics and equilibrium and conducted an ex ante life cycle assessment (LCA). The control of pH levels together with the Ostwald ripening process were very important factors to obtain a selective CaCO3 precipitation. The first-order average kinetic constant of the precipitation at 35 °C was 0.582 ± 0.141 h−1. The presence of minor ions and an antiscalant did not influence the precipitation, obtaining 85–90% on average for the %Ca2+ precipitation while the Mg2+ co-precipitation was lower than 5–7%. A lab-scale plant, tested in continuous (5 L/h synthetic brine) and in batch (15 L) modes, showed that the latter performs better and could be of interest at a larger scale. The ex ante LCA for the batch (100 L) showed that the main environmentally impactful factors were the thermostatic heating and the addition of a precipitant (Na2CO3), but these could be mitigated at the industrial level.

Nano-zerovalent copper biochar composite for treating selenium oxyanions in water: synthesis, evaluation, removal mechanism, density functional theory, and molecular dynamics simulations

This study focused on the synthesis and applicability of nano-zerovalent copper biochar composite (nCu0-BC) for treating selenium oxyanions in water. In batch experiments, 2 g/L of nCu0-BC efficiently removed 98.96 % of selenite [Se(IV)] and 98.78 % of selenate [Se(VI)] in 10 mL of water (10 mg/L for each Se oxyanion) in 12 h. Both Se(IV) and Se(VI) removal followed the pseudo-second-order kinetic model, and their removal rates increased by 3.02 and 7.44-folds, respectively, by increasing the nCu0-BC dose from 2 to 3 g/L. Co-existing ions had minimal effect on Se(VI) removal except PO43- which significantly reduced the Se(VI) removal; while the presence of calcium, sodium, nitrate, and bicarbonate lowered Se(IV) removal by 7–10 %. Spectroscopic analyses were employed to characterize virgin and spent nCu0-BC. XRD analysis revealed that nCu0-BC contains copper in two crystalline phases, i.e., zerovalent copper (Cu0) and cuprous oxide. XPS analysis showed that Cu0 was the main source of electrons for the reduction of Se oxyanions; Se(IV) was reduced to Se(0) while Se(VI) was reduced to Se(IV) and Se(0). The density functional theory simulation indicated that both Se(VI) and Se(IV) form stable complexes with nCu0-BC with the calculated adsorption energies of −3,657 kcal/mol and −3,669 kcal/mol, respectively. The molecular dynamic simulation revealed a high adsorption affinity of Se oxyanions towards nCu0-BC owing to the presence of Cu0 on its surface, resulting in stable bidentate binuclear complexes formation between Se oxyanions and Cu0.