Research progress of CO_(2) capture and mineralization based on natural minerals

Natural minerals,such as kaolinite,halloysite,montmorillonite,attapulgite,bentonite,sepiolite,forsterite,and wollastonite,have considerable potential for use in CO_(2) capture and mineralization due to their abundant reserves,low cost,excellent mechanical prop-erties,and chemical stability.Over the past decades,various methods,such as those involving heat,acid,alkali,organic amine,amino sil-ane,and ionic liquid,have been employed to enhance the CO_(2) capture performance of natural minerals to attain high specific surface area,a large number of pore structures,and rich active sites.Future research on CO_(2) capture by natural minerals will focus on the full utiliza-tion of the properties of natural minerals,adoption of suitable modification methods,and preparation of composite materials with high specific surface area and rich active sites.In addition,we provide a summary of the principle and technical route of direct and indirect mineralization of CO_(2) by natural minerals.This process uses minerals with high calcium and magnesium contents,such as forsterite(Mg_(2)SiO_(4)),serpentine[Mg_(3)Si_(2)O(OH)_(4)],and wollastonite(CaSiO_(3)).The research status of indirect mineralization of CO_(2) using hydro-chloric acid,acetic acid,molten salt,and ammonium salt as media is also introduced in detail.The recovery of additives and high-value-added products during the mineralization process to increase economic benefits is another focus of future research on CO_(2) mineralization by natural minerals.

OSDA-free synthesis of FeZSM-22 zeolite from natural minerals for n-octane hydroisomerization

A seed-directed approach to synthesizing Fe ZSM-22 zeolite without organic structure directing agent(OSDA)was developed by using Fe-rich diatomite as all aluminum and iron sources.The Fe ZSM-22zeolite with optimal crystallinity and purity can be obtained by systematically adjusting feed composition and synthesis conditions.Characterizations show that Fe ZSM-22 zeolite synthesized with OSDA-free owns high crystallinity,obvious thin needle-shaped morphology and high Bronsted/Lewis acid ratio.Significantly,when used for n-octane hydroisomerization reaction,its derived catalyst exhibits the best catalytic performance reflected by the highest selectivity to C_(8)isomers compared to the two reference catalysts prepared based on a Fe-containing and a Fe-free ZSM-22 synthesized through an OSDA-directed route from natural diatomite and conventional chemicals,respectively.This work provides an alternative route to sustainably synthesizing heteroatomic zeolites with high performance.

High-Precision Direct Determination of the ^(87)Sr/^(86)Sr Isotope Ratio of Bottled Sr-Rich Natural Mineral Drinking Water Using MC-ICP-MS

Strontium has four naturally occurring stable isotopes,84Sr,86Sr,87Sr,and 88Sr,with abundances of 0.56,9.87,approximately 7.04,and 82.53 atomic %,respectively.The 87Sr/86Sr isotope ratio is variable due to the addition of radiogenic 87Sr produced by the beta decay of 87Rb with a half-life of 4.88 ± 0.05 Ga.Thus,

Pilot Trial on the Efficacy and Safety of a Natural Mineral Water Rich in Hydrogen Carbonate on Functional Dyspepsia and Heartburn

Background: Dyspepsia and heartburn are among the most frequent complaints of the upper gastrointestinal tract impacting quality of life. The present study aimed to investigate the impact of drinking a natural mineral water (medicinal product category “Heilwasser” in Germany) high in hydrogen carbonate (Staatl. Fachingen STILL) on functional dyspeptic complaints and heartburn. Methods: 56 men and women with self-reported heartburn were enrolled to this one-arm pilot study. They had to drink 1.5 L of a hydrogen carbonate rich mineral water each day over a course of six weeks. Participants reported the number and duration of heartburn episodes in a daily dairy. The Reflux Disease Questionnaire (RDQ), Quality of Life in Reflux and Dyspepsia questionnaire (QOLRAD) and the Gastrointestinal Quality of Life Index (GILQI) were used to assess the therapeutic course of the treatment and the Short Form Health Survey (SF-12) to assess general quality of life. Mean ± standard deviation were calculated and pre- and post-treatment changes were compared using the Wilcoxon test. Results: The consumption of a hydrogen carbonate rich mineral water decreased the number of heartburn episodes per week significantly by 4.8 ± 8.2 at the end of the study (p < 0.001). The duration of episodes was also significantly reduced by 25.7 minutes after six weeks of intervention (p < 0.001). Accordingly, the subjectively perceived severity of heartburn, regurgitation and dyspeptic complaints as well as the GERD dimension as assessed by Reflux Disease Questionnaire improved significantly. There was a significant improvement in the disease-specific quality of life as measured by the Gastrointestinal Quality of Life Index (p < 0.001) and by the Quality Of Life in Reflux and Dyspepsia (p < 0.001) questionnaires and the general health-related quality of life as assessed by SF-12 (p < 0.007). Conclusions: The present pilot study provides evidence that supplementation with natural mineral water rich in hydrogen carbonate may improve heartburn and dyspeptic symptoms, which finally resulted in an improvement of the subjectively perceived quality of life. Drinking mineral water rich in hydrogen carbonate may be an alternative remedy for the treatment of dyspeptic symptoms and heartburn. Trial Registration: Eudra CT No 2013-001256-36.

Effects of natural mineral-rich water consumption on the expression of sirtuin 1 and angiogenic factors in the erectile tissue of rats with fructose-induced metabolic syndrome

Consuming a high-fructose diet induces metabolic syndrome （MS）-Iike features, including endothelial dysfunction. Erectile dysfunction is an early manifestation of endothelial dysfunction and systemic vascular disease. Because mineral deficiency intensifies the deleterious effects of fructose consumption and mineral ingestion is protective against MS, we aimed to characterize the effects of 8weeks of natural mineral-rich water consumption on the structural organization and expression of vascular growth factors and receptors on the corpus cavernosum （CC） in 10% fructose-fed Sprague-Dawley rats （FRUCT）. Differences were not observed in the organization of the CC either on the expression of vascular endothelial growth factor （VEGF） or the components of the angiopoietins/Tie2 system. However, opposing expression patterns were observed for VEGF receptors （an increase and a decrease for VEGFR1 and VEGFR2, respectively） in FRUCT animals, with these patterns being strengthened by mineral-rich water ingestion. Mineral-rich water ingestion （FRUCTMIN） increased the proportion of smooth muscle cells compared with FRUCT rats and induced an upregulatory tendency of sirtuin I expression compared with the control and FRUCT groups. Western blot results were consistent with the dual immunofluorescence evaluation. Plasma oxidized low-density lipoprotein and plasma testosterone levels were similar among the experimental groups, although a tendency for an increase in the former was observed in the FRUCTMIN group. The mineral-rich water-treated rats presented changes similar to those observed in rats treated with MS-protective polyphenol-rich beverages or subjected to energy restriction, which led us to hypothesize that the effects of mineral-rich water consumption may be more vast than those directly observed in this study.

Highly enhanced thermoelectric and mechanical performance of copper sulfides via natural mineral in-situ phase separation

In situ phase separation precipitates play an important role in enhancing the thermoelectric properties of copper sulfides by suppressing phonon transmission.In this study,Cu1.8S composites were fabricated by melting reactions and spark plasma sintering.The complex structures,namely,micron-PbS,Sb_(2)S_(3),nano-FeS,and multiscale pores,originate from the introduction of FePb_(4)Sb_(6)S_(14)into the Cu1.8S matrix.Using effective element(Fe)doping and multiscale precipitates,the Cu_(1.8)S+0.5 wt%FePb_(4)Sb_(6)S_(14)bulk composite reached a high dimensionless figure of merit(ZT)value of 1.1 at 773 K.Furthermore,the modulus obtained for this sample was approximately 40.27 GPa,which was higher than that of the pristine sample.This study provides a novel strategy for realizing heterovalent doping while forming various precipitates via in situ phase separation by natural minerals,which has been proven to be effective in improving the thermoelectric and mechanical performance of copper sulfides and is worth promoting in other thermoelectric systems.

Natural marmatite photocatalyst for treatment of mineral processing wastewater to help zero wastewater discharge

Mineral processing wastewater(MPW)with large discharge and high toxicity affects environmental safety,and the realizing zero discharge of MPW is of great significance for reducing environmental pollution,saving water resources,and promoting the sustainable development of the mining industry.In this study,we reported natural marmatite(NM)as a low-cost and efficient photocatalyst for the treatment of MPW to help zero wastewater discharge.The photocatalytic activity of NM was evaluated by the removal of total organic carbon(TOC)from MPW under visible-light illumination,and the optimal degradation conditions were discussed.Results showed that superoxide free radicals(^(·)O_(2)^(-))were the dominant active species responsible for organic pollutants degradation,and 74.25%TOC removal was obtained after 120 min reaction under the optimum treatment conditions.Meanwhile,the wastewater treated by NM photocatalysis can be reused in the flotation system without adverse impact on the product index.Based on these findings,a model of zero wastewater discharge for flotation with the help of photocatalytic treatment was established,it indicated that the water of the whole system can be balanced without affecting the ore dressing index,which showed that visible light-driven photocatalyst has a promising application prospect in the treatment and recycling of industrial wastewater.

Thermoelectric characteristics of semiconductor minerals in earth's deep crust and their seismogenic significance

Geo-electric anomalies are generated during the process of stress accumulation and release associated with earthquakes.However,the mechanism of these anomalies remains equivocal.Based on the analysis of thermoelectric characteristics of semiconductor minerals of the earth’s deep crust such as graphite,ferrosilicon alloy,magnetite etc.,we perform finite element analysis to evaluate the principles governing the thermoelectric power generated by minerals and rocks.The results show that graphite,ferrosilicon alloy and magnetite all exhibit Seebeck effect and can be superimposed.And the thermo-electric field can be enhanced with the activation temperature increases,the content of thermoelectric minerals increases,the size of aggregates increases,and the spacing of thermoelectric minerals grains decreases.Seismogenic processes would generate a similar thermal gradient.The natural semiconductor minerals in this thermal field show a thermoelectric effect,forming a thermoelectric field that interferes with the background electric field.This study indicates that thermoelectric effect may have an important influence on the formation of geoelectric field.

Interactions of organic phosphorus with soil minerals and the associated environmental impacts: A review

As an important part of the soil phosphorus(P)pool,organic P(OP)is widely found in terrestrial and aquatic environments(e.g.,soils and sediments).The interfacial behavior of OP on natural minerals affects the transport,transformation,and bioavailability of P in the environment.This paper reviews the processes involving adsorption-desorption,dissolution-precipitation,and enzymatic/mineral-mediated hydrolysis of OP at the mineral-water interface,and their subsequent effects on OP speciation and mineral colloidal stability/reactivity.The sorption mechanisms of OP on natural minerals mainly include surface complexation and precipitation,which are controlled by factors such as mineral identity and crystallinity,the relative molecular weight of OP,reaction pH,ionic strength,temperature,and co-existing ligands or ions.The desorption amount and rate of OP from minerals are determined by the mineral identity,desorbent type,pre-sorption time,OP species,reaction pH,number of desorption cycles,and redox status.The interactions between OP and minerals affect the sorption of co-existing metal ions and the stability of the minerals.The effect of minerals on the enzymatic hydrolysis of OP sorbed on mineral surfaces depends on the mineral identity and OP species.Some minerals also exhibit catalytic activity to promote the cleavage of C–O–P bonds and OP hydrolysis.We provide an overview of state-of-the-art techniques currently applied in environmental OP research.The main challenges and future research directions are also summarized to further explore OP interactions with natural minerals in complex environmental settings.

Development of a high-performance green Fe-Al_(2)O_(3)composites using Bayan Obo minerals:Enhancement effects of CeO_(2)

With the deepening understanding for the concept of sustainable development,the utilization of minerals is no longer limited to the traditional way.In this study,an environment friendly method for preparing Fe-Al_(2)O_(3)composites by using natural minerals was investigated.Additionally,the effects of CeO_(2)on the properties of composites were studied.The mechanical properties of Fe-Al_(2)O_(3)composites prepared by natural minerals are affected by the brittleness of glass phase.The strength and toughness of the glass phase in the composite are improved successfully by using rare earth oxides,indicating that the natural rare earths in Bayan Obo minerals have an enhanced influence on the properties of composite materials.The results show that the properties of glass phase can be significantly improved by addition of CeO_(2).At the optimal addition of 3 wt%CeO_(2),the composite achieves the density of 4.21 g/cm^(3),flexural strength of 401 MPa,Vickers hardness of 13.07 GPa and fracture toughness of 6.58 MPa·m^(1/2).The composite has excellent mechanical properties,which can be used in engineering as a cheap structural material.This study aims at reducing waste emissions,improving energy efficiencies and avoiding waste of rare earth resources during the preparation of composite materials.

MODIFICATION THE CEMENTIOUS MATERIAL OF ULTRA-HIGH-STRENGTH SLEEPER CONCRETE

This paper presents investigation results on the natural ultra-fine mineral flour of crystalline silica fume (CSF) and porous quartz sand stone (PQSS) which can modify cement mortar strength under hydrothermal synthesis reaction (HSR) in the autoclave-cured condition. The replacement of cement by CSF and PQSS can signifi cantly increase the Jflerural and compressive strength which reach 22MPa and 150MPa respectively and de-crease the porosity oj the cement mortar. The ratio oj fine aggregation, standard sand to cementions material has sig nificant influence on the mortar strength. The mechanisms involved in cement and natural mineral flour and the HSR are presented. CaO/SiO2 ratio ranges from 3. 20 to 1. 11. the main hydrate phase is C2SH and there is not Tober-morite through X-Ray diffraction qualitative analysis. The new and ultra-high strength cementious material as basic material of sleeper concrete can he used in prestressed reinforcement sleeper concrete.

Sorption of four s-triazine herbicides on natural zeolite and clay mineral materials with microporosity

Sorption is an important process that controls the fate and transport of herbicides in the soil and aquifer environment.However,sorption of these pollutants on natural microporous mineral materials has received little attention.This study investigated the sorption of four model s-triazine herbicides,namely,atrazine,metribuzin,ametryn,and prometryn,on two common natural zeolites(i.e.,clinoptilite and Fe-mordenite)and two common clays(i.e.,kaolin and attapulgite)with microporosity in batch experiments.The results showed that the sorption of s-triazines on the natural zeolites increased in the order of metribuzin<atrazine<ametryn<prometryn,which corresponded approximately to the order of increasing sorbate hydrophobicity and indicated the significant contribution of the hydrophobic effect.In contrast,the sorption of s-triazines on the natural clays increased in the order of metribuzin<atrazine<prometryn<ametryn,which corresponded to the order of increasing sorbate basicity and indicated the significant contribution of cation exchange and electrostatic interactions.The sorption of these s-triazines on the mineral materials was strongly pH-dependent,resulting from the pH dependence of the mineral surface charge and protonation/deprotonation of the s-triazines.Common alkali and alkaline earth cations at low concentrations had no significant impact on the sorption of s-triazines on the natural microporous mineral materials.Meanwhile,the presence of Fe^(3+)(at 0.05 mmol/L)significantly enhanced the sorption of atrazine,ametryn,and prometryn by increasing the protonation of s-triazine molecules in the interfacial region between the mineral surface and bulk solution(due to hydrolysis of Fe^(3+)).Co-sorption of s-triazines on the natural microporous mineral materials exhibited significant competitive effects when these herbicides are sorbed through similar mechanisms.The findings of this study provide insights on the interactions of s-triazine herbicides with natural microporous mineral materials,which help better understand and predict their occurrence and behavior in the subsurface.

Remediation of preservative ethylparaben in water using natural sphalerite:Kinetics and mechanisms

As a typical class of emerging organic contaminants(EOCs), the environmental transformation and abatement of preservative parabens have raised certain environmental concerns. However, the remediation of parabens-contaminated water using natural matrixes(such as, naturally abundant minerals) is not reported extensively in literature. In this study, the transformation kinetics and the mechanism of ethylparaben using natural sphalerite(NS) were investigated. The results show that around 63% of ethylparaben could be absorbed onto NS within 38 hr, whereas the maximum adsorption capacity was 0.45 mg/g under room temperature. High temperature could improve the adsorption performance of ethylparaben using NS. In particular, for the temperature of 313 K, the adsorption turned spontaneous. The well-fitted adsorption kinetics indicated that both the surface adsorption and intra-particle diffusion contribute to the overall adsorption process. The monolayer adsorption on the surface of NS was primarily responsible for the elimination of ethylparaben. The adsorption mechanism showed that hydrophobic partitioning into organic matter could largely govern the adsorption process, rather than the Zn S that was the main component of NS. Furthermore, the ethylparaben adsorbed on the surface of NS was stable, as only less than 2% was desorbed and photochemically degraded under irradiation of simulated sunlight for 5 days. This study revealed that NS might serve as a potential natural remediation agent for some hydrophobic EOCs including parabens, and emphasized the significant role of naturally abundant minerals on the remediation of EOCs-contaminated water bodies.

Mesoporogen-free synthesis of hierarchical sodalite as a solid base catalyst from sub-molten salt-activated aluminosilicate

A rapid and environmentally friendly approach to synthesize hierarchical sodalite from natural aluminosilicate mineral without the involvement of any mesoporogen or post-synthesis treatment was developed.This strategy involves three important steps:the first is the depolymerization of an aluminosilicate mineral into highly reactive silicon and aluminum species with ideal meso-scale structures through activation of a sub-molten salt.The second step is the hydrolysis and condensation of the activated aluminosilicate mineral into zeolitic precursors that also have a meso-scale structure.The third is the rapid zeolitization of the zeolitic precursors through the reversed crystal growth route at room temperature and ambient pressure to form hierarchical sodalite.The physicochemical properties of the as-synthesized sodalite were systematically characterized,and the formation mechanism of the hierarchical pore structure was discussed.When used as a solid base catalyst for Knoevenagel condensation,the as-synthesized sodalite and its potassium ion-exchanged product with hierarchical micro-meso-macroporous structure both exhibited high catalytic activity and product selectivity.

Challenges of a feasible route towards sustainability in environmental protection

Anaerobic processes for treatment of low and high strength wastewaters and solid wastes constitute the core method in the natural biological mineralization(NBM)treatment concept.When adequately combined with the complementary NBM-systems and modern clean water saving practices in wastewater collection and transport,they represent a feasible route to sustainable environmental protection(EPsus),in essence even towards a more sustainable society.Despite the development and implementation of modern high rate Anaerobic Wastewater Treatment(AnWT-)systems and complementary innovative NBM-processes,the considerable progress made since the seventies in fundamental insights in microbiology,biochemistry and process technology,still numerous challenging improvements in the NBM-field can be realized.This contribution is mainly based on the insights attained from wide ranging literature evaluations and the results of experimental research conducted by numerous PhD students who participated in our group over the last four decades.An attempt is made here to identify major facets on which an improved insight can,and consequently should,be obtained in order to accomplish more optimal operation and design of various types of Anaerobic Degradation(AnDeg-)processes.