Waterborne acrylic coatings are widely utilized due to their cost-effectiveness,high transparency,strong resistance to weather and chemicals,impressive mechanical properties,and excellent adhesion to various substrate...Waterborne acrylic coatings are widely utilized due to their cost-effectiveness,high transparency,strong resistance to weather and chemicals,impressive mechanical properties,and excellent adhesion to various substrates.In these coatings,a reactive emulsifier containing phosphate groups can be integrated into the molecular chain during polymerization,which enhances the coating's compactness and corrosion resistance.This work focuses on the synthesis of styrene-butyl acrylate(St-BA)latex and methyl methacrylate-butyl acrylate(MMA-BA)latex using the reactive phosphate emulsifier ANPEO_(10)-P_(1) through seed emulsion polymerization,achieving a conversion rate of approximately 99%and a solid content close to 50%.The resulting coatings from St-BA and MMA-BA latexes demonstrated long-term corrosion protection for carbon steel and aluminum alloy due to in-situ phosphatization,effectively preventing flash rust.Notably,the MMA-BA coating exhibited remarkable durability,enduring immersion for up to 1224 h(51 d)on Q 235 carbon steel before reaching the failure threshold(|Z|0.01 Hz£106Ω·cm^(2))on Q 235 carbon steel.On 5052 aluminum alloy,the St-BA coating maintained|Z|0.01 Hz>10^(8)Ω·cm^(2) for 480 h(20 d).Furthermore,the corrosion resistance of St-BA and MMA BA coatings on Q 235 steel sheet and 5052 aluminum alloy surpassed that of commercially available MMA-BA and St BA coatings after immersion in a 3.5 wt%NaCl aqueous solution.This work also delves into the anticorrosion mechanism of MMA-BA and St-BA coatings.展开更多
A detailed study on a small scale of the effect of phosphatization on the chemistry of marine cobalt-rich ferromanganese crusts supplies useful information for the evaluation and comprehensive utilization of crust min...A detailed study on a small scale of the effect of phosphatization on the chemistry of marine cobalt-rich ferromanganese crusts supplies useful information for the evaluation and comprehensive utilization of crust mineral resources. Sub-samples from top to bottom of a 10-cm thick sample from the NW Pacific Magellan seamount were taken at 5 mm intervals. The concentration profiles of ore-forming and rare earth elements show that obvious differences exist between young unphosphatized crusts and old phosphatized crusts. In the old crusts Fe, Mn, Si, Al, Zn, Mg, Co, Ni and Cu elements are depleted and Ca, P, Sr, Ba and Pb elements are enriched. The order of depletion is Co > Ni > Mg > Al > Mn > Si> Cu > Zn > Fe, while the order of enrichment is P > Ca > Ba > Pb > Sr. The phosphate mineral controls the concentration variation of the ore-forming elements in crusts and causes loss of the main ore-forming elements such as Co and Ni. The phosphatization also affects the abundance of REEs in the crusts. REEs are more abundant and the content of Ce in old crusts is higher than that in young crusts, however, the pattern of REEs and their fractionation characteristics in new and old crusts are not fundamentally changed. A Y-positive anomaly in old crusts has no relationship to the phosphatization.展开更多
In the present paper, iodine （I）, iron （Fe）, manganese （Mn）, cobalt （Co）, phosphorus （P） and calcium （Ca） contents in three ferromanganese crusts from the Pacific Ocean are measured by spectrophotometric m...In the present paper, iodine （I）, iron （Fe）, manganese （Mn）, cobalt （Co）, phosphorus （P） and calcium （Ca） contents in three ferromanganese crusts from the Pacific Ocean are measured by spectrophotometric method and inductively coupled plasma atomic emission spectrometers （ICP-AES） to investigate the contents and distribution of iodine in ferromanganese crusts. The results show that iodine contents in three crusts vary between 27.1 and 836 mg/kg, with an average of 172 mg/kg, and the profile of iodine in the three crusts all exhibits a two-stage distribution zone： a young non-phosphatized zone and an old phosphatized zone that is rich in I, P and Ca. The iodine content ratios of old to young zone in MP5D44, CXD62-1 and CXD08-1 are 2.3, 3.4 and 13.7, respectively. The boundary depths of two-stage zone in MP5D44, CXD62-1 and CXD08-1 locate at 4.0 cm, 2.5 cm and 3.75 cm, respectively, and the time of iodine mutation in three crusts ranges from 17-37 Ma derived from 129I dating and Co empirical formula, which is consistent with the times of Cenozoic phosphatization events. The present study shows that the intensity of phosphatization is the main responsible for the distribution pattern of iodine in the crusts on the basis of the correlation analysis. Consequently, iodine is a sensitive indicator for phosphatization.展开更多
Biomineralization may have an extremely long evolutionary history since the Paleoarchean, while the widespread biomineralization among metazoan lineages started at the earliest Cambrian. However, the primary mineralog...Biomineralization may have an extremely long evolutionary history since the Paleoarchean, while the widespread biomineralization among metazoan lineages started at the earliest Cambrian. However, the primary mineralogy of Anabarites shell remains controversial. Optical microscopic observations combined with the Back-Scattered Electron（BSE） and Energy-Dispersive X-ray Spectroscopy（EDS） analyses are used to study the shell of the fossil Anabarites from the Kuanchuanpu fauna in southern Shaanxi Province in China, which is correlated to the Cambrian Fortunian Stage. The EDS analysis shows that the phosphorus-rich layer closely adjacent to the calcified layer exhibits a Ca： P： C ratio compositionally similar to the mineral fluorapatite（Ca_5（PO_4,CO_3）_3（F,CO_3）. The result that the calcified layer and the phosphorus-rich layer have different chemical compositions is consistent with the optical observation that there is an obvious gap between these two layers and the phosphorus-rich layer can extend to the phosphatic material inside of the tube, suggesting the phosphorus-rich layer doesn＇t belong to the original shell. We suggest that the phosphorous-rich layer is diagenetic in origin, precipitated as a result of phosphorus release during the decay of organic matter by microbes. Considering the outermost shell layer（OMS, biologically controlled carbonate shell layer） should display different isotopic information from the carbonate matrix（i.e., OMS is ^（12）C concentrated due to the biogenic organic matter template is readily rich in ^（12）C）, Nano SIMS was used to map ion distributions of C and N in the shell of Anabarites and matrix. However, ion images show that the concentration differences of ^（12）C, ^（13）C and ^（26）CN among the OMS and the matrix are unclear, while ^（12）C and ^（26）CN are supposed to be enriched in the OMS. Therefore, the minor isotopic differences between the shell and the matrix is hard to be detected by Nano SIMS, at least in our sample, probably due to alteration of the ^（12）C-rich characteristic of the Anabarites OMS during the late diagenesis.展开更多
It was ascertained that when a RE element was added in bath,the sample was improved on the anti-corrosion power of the coating because of the increasing of covering rate of formless crystal Zn2Fe(PO4) 2·4H2O(mark...It was ascertained that when a RE element was added in bath,the sample was improved on the anti-corrosion power of the coating because of the increasing of covering rate of formless crystal Zn2Fe(PO4) 2·4H2O(marked P) crystals and the ratio of P/(P+H) (H was the mark of Zn3(PO4) 2 crystal) in the coating,combination of which with components parsing by EDS indicated that the sequence of contribution elements P and Zn to erosion resistance of coatings was P】Zn. And the correlative mechanism was discussed,which made it clear that owing to the particularity of the outer-shell electron structure and larger ionic radius,RE was so easy to be polarized and metamorphosed itself that it adsorbed lightly on the basic body to pose gels. They efficiently reduced the activation energy which was required for formation of a new solid phase of phosphates and made it also possible to engender effectively active nucleation regions of cathode and anode under low temperature phosphating condition,which was propitious to formation,densification and uniformization of the phosphate crystal nucleus and growth of the crystallite and coating buildup. Thus it could be seen that REN played the role of surface regulator and accelerant,which speeded up the phosphating,as well as bids amount of porosity of the coating fall to improve the corrosion resistance of the coating.展开更多
Oceanic phosphatization events episodically precipitate carbonate fluorapatite(CFA),inducing phosphatization of ferromanganese crusts and significantly influencing rare earth elements plus yttrium(REY)and associated m...Oceanic phosphatization events episodically precipitate carbonate fluorapatite(CFA),inducing phosphatization of ferromanganese crusts and significantly influencing rare earth elements plus yttrium(REY)and associated metal concentrations.Western Pacific ferromanganese crusts archive multiple phosphatization events,yet the absence of accurate chronological constraints hindered detailed investigations into the mechanisms of REY redistribution during distinct phosphatization episodes.Building upon previously established phosphatization events through CFA U-Pb geochronology,this study investigates three ferromanganese crusts from different water depths on Ita Mai Tai Guyot(Western Pacific)to evaluate the impacts of phosphatization on REYenrichment.Results show that all three hydrogenetic crusts experienced phosphatization,with phosphatized layers exhibiting higher average REY concentrations(2090,1885,and 1854 ppm)than non-phosphatized layers(1413,1174,and 1519 ppm),indicating that phosphatization enhances REYenrichment.However,when the crusts are precisely divided based on phosphatization episodes,one phosphatized layer(1293 ppm)exhibits lower REY concentrations than the unphosphatized layer(1413 ppm).This is attributed to a dilution effect from the precipitation of REY-poor authigenic CFA;the apatite within this specific layer contains only 602 ppm REY,a value lower than that of the unphosphatized crust.Concurrently,“REY-rich”veinlike CFA(2703 ppm)is associated with slow depositional processes,indicating its potential to increase the REY content of crusts.Therefore,this study reveals the dual role of phosphatization on REY enrichment.It can either promote enrichment by enhancing REY adsorption onto iron-manganese oxides and by forming REY-rich CFA,or cause dilution through the precipitation of REY-poor CFA.The net effect is ultimately controlled by a combination of environmental factors,including sedimentation rate and water depth,revealing the complex mechanisms of REY in phosphatized ferromanganese crusts.展开更多
Drought stress and abscisic acid(ABA)have been known to play a critical role in modulating sugar accumulation in fruit,and yet,the underlying molecular mechanisms remain elusive.In this study,we have demonstrated that...Drought stress and abscisic acid(ABA)have been known to play a critical role in modulating sugar accumulation in fruit,and yet,the underlying molecular mechanisms remain elusive.In this study,we have demonstrated that drought-mimicking film mulching increased sucrose levels in Satsuma mandarin(Citrus unshiu)fruit,coinciding with upregulation of CuSPS4,which encodes the sucrose phosphate synthase(SPS),in the transcriptome profiling.CuSPS4 was further shown to be drought-and ABA-inducible and functionally essential for sucrose synthesis.Mechanistically,two transcription factors,CuWRKY41 and CuWRKY23,directly bound to and activated the CuSPS4 promoter via the W-box element,with CuWRKY41 additionally regulating CuWRKY23 expression.Consistently,both Cu WRKY41 and Cu WRKY23 positively regulated sucrose synthesis by upregulating Cu SPS4.Meanwhile,the ubstrateinteracting subunit(Cu Sn RK1β1)and catalytic subunit(Cu Sn RK1α)of SUCROSE NON-FERMENTING RELATED KINASE 1(Sn RK1)interacted with Cu WRKY41,triggering Cu Sn RK1α-mediated phosphorylation and subsequent degradation of Cu WRKY41,thereby suppressing its activation.However,ABA promoted cytoplasmic translocation of Cu Sn RK1αand Cu Sn RK1β1 and reduced nuclear interaction with Cu WRKY41,leading to its phosphorylation alleviation and protein stabilization,concurrent with enhanced transcription activation of Cu WRKY23 and Cu SPS4.Taken together,these findings reveal a sophisticated regulatory mechanism whereby drought promotes sucrose accumulation by suppressing Cu Sn RK1α-mediated phosphorylation and degradation of Cu WRKY41,enabling its transcriptional activation of Cu SPS4 directly or via Cu WRKY23.Our study provides significant insights into the molecular basis of drought-induced sucrose accumulation and presents valuable regulatory components that could be targeted for fruit quality improvement.展开更多
Small shelly fossils(SSFs)have long been recognized as important to the studies of both metazoan evolution and the onset of biomineralization during the Cambrian radiation.The marked decline in the occurrence,diversit...Small shelly fossils(SSFs)have long been recognized as important to the studies of both metazoan evolution and the onset of biomineralization during the Cambrian radiation.The marked decline in the occurrence,diversity and abundance of SSFs in the middle to late Cambrian,when compared with the early Cambrian,has often been regarded as a result of the closure of a phosphatization window.Despite this,there have been numerous and consistent reports of SSFs from the middle Cambrian and younger deposits.To identify possible factors influencing SSF preservation,five microfacies including bioclastic limestone,flat-pebble conglomerates with bioclasts,hummocky cross-stratified grainstone with bioclasts,bioclastic grainstone in hardgrounds and glauconite bioclastic wackstone-packstone,from Cambrian Series 2 to Miaolingian in North China are compared to assess how differences in lithology impact the preservation potential of SSFs.Our results,based on 35,161 SSF specimens from deposits across six sections,suggest that there are still abundant and diverse SSFs in the middle Cambrian of North China preserved in ways not exclusively reliant on the presence of phosphate and that SSF preservation can be linked to the differences in microfacies in the early to middle Cambrian of North China.展开更多
The soaring demand for smart portable electronics and electric vehicles is propelling the advancements in high-energy–density lithium-ion batteries.Lithium manganese iron phosphate(LiMn_(x)Fe_(1-x)PO_(4))has garnered...The soaring demand for smart portable electronics and electric vehicles is propelling the advancements in high-energy–density lithium-ion batteries.Lithium manganese iron phosphate(LiMn_(x)Fe_(1-x)PO_(4))has garnered significant attention as a promising positive electrode material for lithium-ion batteries due to its advantages of low cost,high safety,long cycle life,high voltage,good high-temperature performance,and high energy density.Although LiMn_(x)Fe_(1-x)PO_(4)has made significant breakthroughs in the past few decades,there are still facing great challenges in poor electronic conductivity and Li-ion diffusion,manganese dissolution affecting battery cycling performance,as well as low tap density.This review systematically summarizes the reaction mechanisms,various synthesis methods,and electrochemical properties of LiMn_(x)Fe_(1-x)PO_(4)to analyze reaction processes accurately and guide material preparation.Later,the main challenges currently faced are concluded,and the corresponding various modification strategies are discussed to enhance the reaction kinetics and electrochemical performance of LiMn_(x)Fe_(1-x)PO_(4),including multi-scale particle regulation,heteroatom doping,surface coating,as well as microscopic morphology design.Finally,in view of the current research challenges faced by intrinsic reaction processes,kinetics,and energy storage applications,the promising research directions are anticipated.More importantly,it is expected to provide key insights into the development of high-performance and stable LiMn_(x)Fe_(1-x)PO_(4)materials,to achieve practical energy storage requirements.展开更多
Guided bone regeneration in the alveolar bone relies on the colonization and differentiation of immune cells within the defect area.The absence of osteoinductive and osteoimmune properties of currently available scaff...Guided bone regeneration in the alveolar bone relies on the colonization and differentiation of immune cells within the defect area.The absence of osteoinductive and osteoimmune properties of currently available scaffolds hinders to achieve optimal repair outcomes in clinical settings.Thus,we aimed to enhance the bone repair ability of polycaprolactone(PCL)scaffolds by incorporating osteoinductive amorphous calcium phosphate(ACP)with immune-regulating zinc ions(ACP(Zn),ACZP),to create a favorable immunomodulatory microenvironment.After one day of co-culture with PCL-ACZP,the spreading area of macrophage cells was significantly higher than that from the original PCL scaffold.Additionally,over 32.1%of macrophages exhibited M2 polarization within three days of co-culture.The PCLACZP/macrophage-conditioned medium significantly boosted osteogenic gene expression in MC3T3-E1 cells.After eight weeks of implantation in a rat femoral condyle defect,the BV/TV from the PCL-ACZP group reached 32.9%,1.4 times of that from the PCL group.Furthermore,the PCL-ACZP-GelMA biphasic module as prepared successfully achieved complete regeneration of three-walled alveolar bone defects in rabbits,resulting in arch-shaped alveolar bone repair and providing greater convenience in the clinical settings.This study showcased the effectiveness of PCL-ACZP-GelMA biphasic module as bioactive scaffolds in the morphological restoration of alveolar bone.展开更多
In this study,a phosphate-based conversion coating(PCC)was applied as a precursor before forming silicate-fluoride(SiF)and silicate-phosphate-fluoride(SiPF)based flash-plasma electrolytic oxidation(Flash-PEO)coatings ...In this study,a phosphate-based conversion coating(PCC)was applied as a precursor before forming silicate-fluoride(SiF)and silicate-phosphate-fluoride(SiPF)based flash-plasma electrolytic oxidation(Flash-PEO)coatings on AZ31B magnesium alloy.The main novelty is the successful incorporation of calcium,zinc,manganese and phosphate species into the Flash-PEO coatings via a precursor layer rather than using the electrolyte.The precursor also led to longer lasting and more intense discharges during the PEO process,resulting in increased pore size.Corrosion studies revealed similar short-term performance for all coatings,with impedance modulus at low frequencies above 10^(7)Ωcm^(2),and slightly better performance for the SiPF-based coating.Nonetheless,the enlarged pores in the PEO coatings functionalized with the PCC precursor compromised the effectiveness of self-healing mechanisms by creating diffusion pathways for corrosive species,leading to earlier failure.These phenomena were effectively monitored by recording the open circuit potential during immersion in 0.5 wt.%NaCl solution.In summary,this study demonstrates that conversion coatings are a viable option for the functionalization of PEO coatings on magnesium alloys,as they allow for the incorporation of cationic and other species.However,it is crucial to maintain a small pore size to facilitate effective blockage through self-healing mechanisms.展开更多
In this study,synthetic wastewater containing 110μg/L arsenate(As(V)),0-20 mg/L fulvic acid(FA),and 0-12.3 mg/L phosphate was treated with 3 mg/L Fe3+.The mechanisms of FA and phosphate effects on As(V)removal by fer...In this study,synthetic wastewater containing 110μg/L arsenate(As(V)),0-20 mg/L fulvic acid(FA),and 0-12.3 mg/L phosphate was treated with 3 mg/L Fe3+.The mechanisms of FA and phosphate effects on As(V)removal by ferric chloride were determined using 0.22-10μm pore-size filtration,Zetasizer analysis,and in situ flow through cell ATR-FTIR.The results showed that up to 20mg/L FA had almost no effect on the solubility of ferric hydroxide precipitates and adsorption of As(V)by the precipitates.When FA concentration increased from 0 to 20 mg/L,the adsorption of FA led to higher negative zeta potential of the precipitates and the strong electrostatic repulsion between the precipitates decreased the particle size of ferric hydroxide flocs fromlarger than 10μmto smaller than 1μm.In the presence of 5-20 mg/L FA,46%-63%As(V)was adsorbed onto the flocs with particle size in the range of 0.45-1μm.On the other hand,phosphate did not affect the size of ferric hydroxide flocs and significantly increased the dissolved As(V)concentration because it competed with As(V)for adsorption sites on ferric hydroxide precipitates.The addition of 5mg/L cationic organic flocculant significantly reduced the effect of FA on As(V)removal,but did not reduce the effect of phosphate on As(V)removal.The findings of this study will help develop effective arsenic treatment techniques and predict the mobility of arsenic in the environment.展开更多
The green energy transition relies heavily on critical metals,such as rare earth elements(REEs).However,their reserves are primarily focused in a few countries,such as China,which accounts for approximately 70%of glob...The green energy transition relies heavily on critical metals,such as rare earth elements(REEs).However,their reserves are primarily focused in a few countries,such as China,which accounts for approximately 70%of global production.Hence,several countries are currently looking for alternative resources for REEs.Alternative REE resources in the supply chain include recycling of e-waste,industrial waste like red mud and phosphogypsum,coal ash,mine tailings,ocean floor sediments,and even certain types of sedimentary deposits like phosphorites where REEs are present in lower concentrations but at larger volumes compared to primary ore deposits which are becoming targets by REEs industry.Currently,several studies are going on the development of eco-friendly REEs extraction technologies from phosphorite deposits.Consequently,advanced data analysis tools,such as Machine Learning(ML),are becoming increasingly important in mineral prospectivity and are rapidly gaining traction in the earth sciences.Phosphorite deposits are mainly used to manufacture fertilizers as these rocks are known for their significant phosphorus content.Moreover,these formations are considered a prospective resource of REEs.The different types of phosphorite deposits such as continental,seamount,and ore deposits worldwide reported concentrations of∑REE upto 18,000µg/g.Due to the augmented claim of REEs for various ultra-modern,and green technology applications that are required to switch over to a carbon-neutral environment,these phosphorite deposits have become an important target mostly because of their relatively higher content of REEs especially heavy rare earth elements(HREE).For example,Mississippian phosphorites reported ∑ HREE 7,000µg/g.To have a comprehensive understanding of the REEs potential of these phosphorite deposits which also include several Chinese phosphorite deposits,this study is undertaken to review the phosphorite deposits in the world and their REEs potential,in addition to some of the associated aspects such as applications and formation mechanisms for different types of phosphorite deposits such as igneous phosphate deposits,sedimentary phosphorite deposits,marine phosphorite deposits,cave phosphate deposits,and insular guano deposits.Other important aspects include their occurrences,types,geochemical characteristics,the REEs enrichment mechanisms,and various recovery methods adopted to recover REEs from different phosphorite deposits.The present review paper concludes that the recent studies highlight the global potential of phosphorite deposits to satisfy the increasing demand for REEs.Extracting REEs from phosphorite presents no significant technological or environmental difficulties,as long as radioactive elements are eliminated.In India,more comprehensive geological surveys,along with the advancement of new methods and evaluations,are required to locate phosphorite deposits with high concentrations of REEs.展开更多
Whilst phosphorus(P)in soil is considered to be abundant,the portion available for plant uptake constitutes less than 1%of the overall P present.To enhance crop productivity,the utilization of mineral P fertilizers ha...Whilst phosphorus(P)in soil is considered to be abundant,the portion available for plant uptake constitutes less than 1%of the overall P present.To enhance crop productivity,the utilization of mineral P fertilizers has become pervasive in agriculture.Nonetheless,the escalating prices of chemical fertilizers,coupled with new European regulations prohibiting the use of P fertilizers containing cadmium,have highlighted the urgency to identify environmentally friendly products and practices for P fertilization in agricultural soils.This comprehensive review delves into the current landscape of P fertilization from agricultural,political,and economic standpoints.We recognize the potential of microbes in mobilizing P,but emphasize the necessity for more robust research to establish their effectiveness in promoting plant P uptake under real-world conditions.Additionally,we explore the role of agricultural conservation practices,such as optimal tillage,diversified cropping systems,and increased organic carbon input,in conserving P.Furthermore,this review contemplates forthcoming innovations in research.These innovations encompass the development of enhanced formulations for biofertilizers and the undertaking of more comprehensive studies within the realm of conservation agriculture.All these endeavors collectively hold the potential to augment P accessibility to plants in a sustainable manner,thereby advancing agricultural sustainability and productivity.展开更多
The interaction mechanism between eggshell calcium and endogenous silica in biomass during biochar modification,and its impact on phosphate adsorption performance and slow-release fertilizer characteristics,remains un...The interaction mechanism between eggshell calcium and endogenous silica in biomass during biochar modification,and its impact on phosphate adsorption performance and slow-release fertilizer characteristics,remains unexplored.This study investigates that high silica content in biomass(>6%)inhibits the decomposition of CaCO_(3)in eggshells during pyrolysis,reducing the formation of active calcium species(CaO and Ca(OH)_(2)),while moderate silica levels(4%-5%)promote the formation of CaSiO_(3),enhancing phosphorus adsorption without hindering Ca^(2+)activation.Adsorption studies reveal that the precipitation of Ca_(5)(PO_(4))_(3)(OH)resulting from the combination of CaO and Ca(OH)_(2)with phosphate is the primary and effective form for phosphorus removal in calcium-modified adsorbents,accompanied by Ca_(3)(PO_(4))_(2)·2H_(2)O precipitation formed by CaSi O_(3).Eggshell calcium-modified corn straw biochar(ECS)exhibited the highest adsorption capacity,reaching 123.3 mg/g,outperforming materials in previous studies.ECS also demonstrated excellent pH adaptability and selective phosphate removal.As a biochar-based phosphorus fertilizer,ECS-P exhibits high phosphorus extractability in formic acid(93.92%)but low water solubility(0.62%),with phosphorus release during the seven-day intermittent leaching experiment remaining between 0.53 to 0.875 mg/L.These results confirm its potential as a phosphorus cycling fertilizer.This study provides fundamental insights into optimizing biomass selection based on silica content for calcium modification,offering an efficient strategy for both phosphate recovery and slow-release fertilizer development.展开更多
The efficient recycling of spent lithium iron phosphate(LiFePO_(4),also referred to as LFP)should convert Fe(Ⅱ)to Fe(Ⅲ),which is key to the extraction of Li and separation of Fe and is not well understood.Herein,we ...The efficient recycling of spent lithium iron phosphate(LiFePO_(4),also referred to as LFP)should convert Fe(Ⅱ)to Fe(Ⅲ),which is key to the extraction of Li and separation of Fe and is not well understood.Herein,we systematically study the oxidation of LiFePO_(4)in the air and in the solution containing oxidants such as H_(2)O_(2)and the effect of oxidation on the leaching behaviors of LFP.In the air,O_(2)breaks down the LFP olivine structure at 550℃for 1 h by oxidizing Fe(Ⅱ)to Fe(Ⅲ)in terms of converting LFP to Li_(3)Fe_(2)(PO_(4))_(3)and Fe_(2)O_(3).After that,Li is leached in 0.5 M sulfuric acid solution and is further recycled as Li_(3)PO_(4)with a Li recovery efficiency of 97.48%.Meanwhile,Fe is recovered as FePO_(4)and Fe_(2)O_(3).Compared with H_(2)SO_(4)-H_(2)O_(2),the air oxidation saves H_(2)O_(2)but increases the leaching efficiency of Fe and H_(2)SO_(4)consumption.The discrepancy of Fe leaching efficiency can be attributed to the different leaching mechanisms involving the solid-to-solid and solid-to-liquid-to-solid conversions.Furthermore,the results of the Everbatt model analysis show that the air roasting-H_(2)SO_(4)leaching method has low emission and potentially high income,which is simple and safe.Overall,this work will deepen the understanding of acid leaching of LFP and favorably stimulate the maturation of the LFP recycling technique.展开更多
Pure Mg boasting a relatively small corrosion rate is a potential biodegradable metal material for implants.However,its degradation behavior in the complex physiological environment is still a lack of understanding.In...Pure Mg boasting a relatively small corrosion rate is a potential biodegradable metal material for implants.However,its degradation behavior in the complex physiological environment is still a lack of understanding.In this work,we investigated the effect of corrosion product film layers on the degradation behavior of pure Mg in physiological environments.Pure Mg shows a faster corrosion rate in simulated body fluid(SBF)compared to NaCl solution.Hydrogen evolution experiments indicate that the degradation rate of pure Mg in SBF decreases rapidly within the first 12 h but stabilizes afterward.The rapid deposition of low-solubility calcium phosphate on the pure Mg in SBF provides protection to the substrate,resulting in a gradual decrease in the degradation rates.Consequently,the corrosion product film of pure Mg formed in SBF exhibits a layered structure,with the upper layer consisting of dense Ca_(3)(PO_(4))_(2)/Mg_(3)(PO_(4))_(2) and the lower layer consisting of Mg(OH)_(2)/MgO.Electrochemical impedance spectroscopy(EIS)shows that the resistance of the corrosion product film increases over time,indicating gradual strengthening of the corrosion resistance.The 4-week degradation results in the femoral marrow cavity of mice are consistent with the result in SBF in vitro.展开更多
Developing high-efficient and low-loading Pt based catalyst is significant for the electrocatalytic p Huniversal hydrogen evolution reaction(HER). Herein, the molybdenum carbide nanoparticles supported on the polyhedr...Developing high-efficient and low-loading Pt based catalyst is significant for the electrocatalytic p Huniversal hydrogen evolution reaction(HER). Herein, the molybdenum carbide nanoparticles supported on the polyhedral N-doped carbon nanotube skeleton(Mo C/NCT) composite has been synthesized by a pyrolysis of polyacid organo-metallic phosphate framework precursor. Then, only 2.15 wt% Pt are loaded on the Mo C/NCT to form Pt-Mo C/NCT catalyst, which performs superior HER activity and stability in entire p H range. Specially, the overpotentials of 22 and 74 m V are respectively attained at 10 m A/cm^(2) in1.0 mol/L KOH and 0.5 mol/L H_(2)SO_(4) electrolytes, approaching or even exceeding commercial Pt/C. More importantly, it can be used as excellent catalyst for efficient hydrogen production at 0–14 p H range. Density functional theory(DFT) calculations demonstrate that the interaction between Mo C and Pt leads to the electron redistribution at the corresponding interfaces and the downward shift of the d-band centers, thus optimizing H*adsorption and desorption for promoting the HER activity. Besides, the unique three-dimensional network structure is conductive to the transmission of mass and electrons. In the application of both alkaline and acidic electrolysers, only 1.52 V voltage of solar panel can drive a hydrogen production current density of 10 m A/cm^(2).展开更多
Potassium hydroxide(KOH)was introduced into the molybdenite roasting process to convert molybdenum(Mo)and sulfur(S)into water-soluble potassium molybdate(K_(2)MoO_(4))and potassium sulfate(K_(2)SO_(4)).Roasting with a...Potassium hydroxide(KOH)was introduced into the molybdenite roasting process to convert molybdenum(Mo)and sulfur(S)into water-soluble potassium molybdate(K_(2)MoO_(4))and potassium sulfate(K_(2)SO_(4)).Roasting with a 1.8-fold excess of KOH at 400℃ for 3 h enabled the leaching of over 99%of Mo from the molybdenum calcine using water.A precipitation method involving potassium–magnesium(K-Mg)salts was proposed for impurity removal.Under the conditions of pH 11,30℃,excess coefficient of 1.7 for Mg salts,and a duration of 1 h,98.37%of phosphorus(P)was removed from the K_(2)MoO_(4) solution.With post-purification,over 99%of Mo crystallized upon adjustment of pH to 1.Subsequently,S and K were recovered as K_(2)SO_(4) fertilizer from the crystalline mother liquor.An environmentally sustainable approach was proposed to conduct molybdenite production and ensure the efficient recovery of both Mo and S.展开更多
Magnesium phosphate cements(MPC)have shown promising applications in many fields,but high raw material prices hinder their development.The production of salt lake MPC(SLMPC)from magnesium slag(MS),a byproduct of lithi...Magnesium phosphate cements(MPC)have shown promising applications in many fields,but high raw material prices hinder their development.The production of salt lake MPC(SLMPC)from magnesium slag(MS),a byproduct of lithium extraction from salt lakes,offers significant environmental and economic advantages.In this study,a low-cost magnesia raw material was obtained through the calcination of MS,which was subsequently utilized in conjunction with KH_(2)PO_(4) to prepare SLMPC.The changes in hydration products,microscopic morphology,solution pH value,and TG content during the SLMPC curing process,and the hydration kinetics equation and model were used to study the hydration processes of SLMPC.The results show that the outcome indicates that the SLMPC system entered the accelerated reaction stage within 6 min after mixing,where the highest heat release rate was 6.29 J·g^(-1)·min^(-1),the maximum heat release was 205.3 J·g^(-1),and the main hydration product appeared at 50-60 min.The hydration behavior of SLMPC exhibits similarities to that of traditional MPC.Specifically,the acceleration phase is governed by an autocatalytic reaction,the deceleration phase is influenced by both autocatalytic reactions and diffusion processes,and the stabilization phase is predominantly controlled by diffusion mechanisms.This paper aims to establish the theoretical foundation for the industrial application of MS and the cost-effective production of MPC.展开更多
基金Project(52373065)supported by the National Natural Science Foundation of ChinaProject(2220004002898)supported by the Zhuhai Industry University Research Cooperation and Basic and Applied Research Projects,China。
文摘Waterborne acrylic coatings are widely utilized due to their cost-effectiveness,high transparency,strong resistance to weather and chemicals,impressive mechanical properties,and excellent adhesion to various substrates.In these coatings,a reactive emulsifier containing phosphate groups can be integrated into the molecular chain during polymerization,which enhances the coating's compactness and corrosion resistance.This work focuses on the synthesis of styrene-butyl acrylate(St-BA)latex and methyl methacrylate-butyl acrylate(MMA-BA)latex using the reactive phosphate emulsifier ANPEO_(10)-P_(1) through seed emulsion polymerization,achieving a conversion rate of approximately 99%and a solid content close to 50%.The resulting coatings from St-BA and MMA-BA latexes demonstrated long-term corrosion protection for carbon steel and aluminum alloy due to in-situ phosphatization,effectively preventing flash rust.Notably,the MMA-BA coating exhibited remarkable durability,enduring immersion for up to 1224 h(51 d)on Q 235 carbon steel before reaching the failure threshold(|Z|0.01 Hz£106Ω·cm^(2))on Q 235 carbon steel.On 5052 aluminum alloy,the St-BA coating maintained|Z|0.01 Hz>10^(8)Ω·cm^(2) for 480 h(20 d).Furthermore,the corrosion resistance of St-BA and MMA BA coatings on Q 235 steel sheet and 5052 aluminum alloy surpassed that of commercially available MMA-BA and St BA coatings after immersion in a 3.5 wt%NaCl aqueous solution.This work also delves into the anticorrosion mechanism of MMA-BA and St-BA coatings.
基金supported by grant DY95-08-05 from the China Ocean Mineral Resources R&D Associationthe National Natural Science Foundation of China(Grant 40373002).
文摘A detailed study on a small scale of the effect of phosphatization on the chemistry of marine cobalt-rich ferromanganese crusts supplies useful information for the evaluation and comprehensive utilization of crust mineral resources. Sub-samples from top to bottom of a 10-cm thick sample from the NW Pacific Magellan seamount were taken at 5 mm intervals. The concentration profiles of ore-forming and rare earth elements show that obvious differences exist between young unphosphatized crusts and old phosphatized crusts. In the old crusts Fe, Mn, Si, Al, Zn, Mg, Co, Ni and Cu elements are depleted and Ca, P, Sr, Ba and Pb elements are enriched. The order of depletion is Co > Ni > Mg > Al > Mn > Si> Cu > Zn > Fe, while the order of enrichment is P > Ca > Ba > Pb > Sr. The phosphate mineral controls the concentration variation of the ore-forming elements in crusts and causes loss of the main ore-forming elements such as Co and Ni. The phosphatization also affects the abundance of REEs in the crusts. REEs are more abundant and the content of Ce in old crusts is higher than that in young crusts, however, the pattern of REEs and their fractionation characteristics in new and old crusts are not fundamentally changed. A Y-positive anomaly in old crusts has no relationship to the phosphatization.
文摘In the present paper, iodine （I）, iron （Fe）, manganese （Mn）, cobalt （Co）, phosphorus （P） and calcium （Ca） contents in three ferromanganese crusts from the Pacific Ocean are measured by spectrophotometric method and inductively coupled plasma atomic emission spectrometers （ICP-AES） to investigate the contents and distribution of iodine in ferromanganese crusts. The results show that iodine contents in three crusts vary between 27.1 and 836 mg/kg, with an average of 172 mg/kg, and the profile of iodine in the three crusts all exhibits a two-stage distribution zone： a young non-phosphatized zone and an old phosphatized zone that is rich in I, P and Ca. The iodine content ratios of old to young zone in MP5D44, CXD62-1 and CXD08-1 are 2.3, 3.4 and 13.7, respectively. The boundary depths of two-stage zone in MP5D44, CXD62-1 and CXD08-1 locate at 4.0 cm, 2.5 cm and 3.75 cm, respectively, and the time of iodine mutation in three crusts ranges from 17-37 Ma derived from 129I dating and Co empirical formula, which is consistent with the times of Cenozoic phosphatization events. The present study shows that the intensity of phosphatization is the main responsible for the distribution pattern of iodine in the crusts on the basis of the correlation analysis. Consequently, iodine is a sensitive indicator for phosphatization.
基金funded by MOST Special Fund from the State Key Laboratory of Continental Dynamics, Northwest University, MOST (No. 2011CB808805)NSFC (No. 41172029)
文摘Biomineralization may have an extremely long evolutionary history since the Paleoarchean, while the widespread biomineralization among metazoan lineages started at the earliest Cambrian. However, the primary mineralogy of Anabarites shell remains controversial. Optical microscopic observations combined with the Back-Scattered Electron（BSE） and Energy-Dispersive X-ray Spectroscopy（EDS） analyses are used to study the shell of the fossil Anabarites from the Kuanchuanpu fauna in southern Shaanxi Province in China, which is correlated to the Cambrian Fortunian Stage. The EDS analysis shows that the phosphorus-rich layer closely adjacent to the calcified layer exhibits a Ca： P： C ratio compositionally similar to the mineral fluorapatite（Ca_5（PO_4,CO_3）_3（F,CO_3）. The result that the calcified layer and the phosphorus-rich layer have different chemical compositions is consistent with the optical observation that there is an obvious gap between these two layers and the phosphorus-rich layer can extend to the phosphatic material inside of the tube, suggesting the phosphorus-rich layer doesn＇t belong to the original shell. We suggest that the phosphorous-rich layer is diagenetic in origin, precipitated as a result of phosphorus release during the decay of organic matter by microbes. Considering the outermost shell layer（OMS, biologically controlled carbonate shell layer） should display different isotopic information from the carbonate matrix（i.e., OMS is ^（12）C concentrated due to the biogenic organic matter template is readily rich in ^（12）C）, Nano SIMS was used to map ion distributions of C and N in the shell of Anabarites and matrix. However, ion images show that the concentration differences of ^（12）C, ^（13）C and ^（26）CN among the OMS and the matrix are unclear, while ^（12）C and ^（26）CN are supposed to be enriched in the OMS. Therefore, the minor isotopic differences between the shell and the matrix is hard to be detected by Nano SIMS, at least in our sample, probably due to alteration of the ^（12）C-rich characteristic of the Anabarites OMS during the late diagenesis.
文摘It was ascertained that when a RE element was added in bath,the sample was improved on the anti-corrosion power of the coating because of the increasing of covering rate of formless crystal Zn2Fe(PO4) 2·4H2O(marked P) crystals and the ratio of P/(P+H) (H was the mark of Zn3(PO4) 2 crystal) in the coating,combination of which with components parsing by EDS indicated that the sequence of contribution elements P and Zn to erosion resistance of coatings was P】Zn. And the correlative mechanism was discussed,which made it clear that owing to the particularity of the outer-shell electron structure and larger ionic radius,RE was so easy to be polarized and metamorphosed itself that it adsorbed lightly on the basic body to pose gels. They efficiently reduced the activation energy which was required for formation of a new solid phase of phosphates and made it also possible to engender effectively active nucleation regions of cathode and anode under low temperature phosphating condition,which was propitious to formation,densification and uniformization of the phosphate crystal nucleus and growth of the crystallite and coating buildup. Thus it could be seen that REN played the role of surface regulator and accelerant,which speeded up the phosphating,as well as bids amount of porosity of the coating fall to improve the corrosion resistance of the coating.
基金supported by the National Natural Science Foundation of China(Grant Nos.92262304,40473024,40343019)the National Key R&D Program of China during the 13th Five-year Plan Period(Grant No.DY135-R2-1-01)。
文摘Oceanic phosphatization events episodically precipitate carbonate fluorapatite(CFA),inducing phosphatization of ferromanganese crusts and significantly influencing rare earth elements plus yttrium(REY)and associated metal concentrations.Western Pacific ferromanganese crusts archive multiple phosphatization events,yet the absence of accurate chronological constraints hindered detailed investigations into the mechanisms of REY redistribution during distinct phosphatization episodes.Building upon previously established phosphatization events through CFA U-Pb geochronology,this study investigates three ferromanganese crusts from different water depths on Ita Mai Tai Guyot(Western Pacific)to evaluate the impacts of phosphatization on REYenrichment.Results show that all three hydrogenetic crusts experienced phosphatization,with phosphatized layers exhibiting higher average REY concentrations(2090,1885,and 1854 ppm)than non-phosphatized layers(1413,1174,and 1519 ppm),indicating that phosphatization enhances REYenrichment.However,when the crusts are precisely divided based on phosphatization episodes,one phosphatized layer(1293 ppm)exhibits lower REY concentrations than the unphosphatized layer(1413 ppm).This is attributed to a dilution effect from the precipitation of REY-poor authigenic CFA;the apatite within this specific layer contains only 602 ppm REY,a value lower than that of the unphosphatized crust.Concurrently,“REY-rich”veinlike CFA(2703 ppm)is associated with slow depositional processes,indicating its potential to increase the REY content of crusts.Therefore,this study reveals the dual role of phosphatization on REY enrichment.It can either promote enrichment by enhancing REY adsorption onto iron-manganese oxides and by forming REY-rich CFA,or cause dilution through the precipitation of REY-poor CFA.The net effect is ultimately controlled by a combination of environmental factors,including sedimentation rate and water depth,revealing the complex mechanisms of REY in phosphatized ferromanganese crusts.
基金supported by the National Natural Science Foundation of China(32330095)the Hubei Hongshan Laboratory project(2021hszd009)。
文摘Drought stress and abscisic acid(ABA)have been known to play a critical role in modulating sugar accumulation in fruit,and yet,the underlying molecular mechanisms remain elusive.In this study,we have demonstrated that drought-mimicking film mulching increased sucrose levels in Satsuma mandarin(Citrus unshiu)fruit,coinciding with upregulation of CuSPS4,which encodes the sucrose phosphate synthase(SPS),in the transcriptome profiling.CuSPS4 was further shown to be drought-and ABA-inducible and functionally essential for sucrose synthesis.Mechanistically,two transcription factors,CuWRKY41 and CuWRKY23,directly bound to and activated the CuSPS4 promoter via the W-box element,with CuWRKY41 additionally regulating CuWRKY23 expression.Consistently,both Cu WRKY41 and Cu WRKY23 positively regulated sucrose synthesis by upregulating Cu SPS4.Meanwhile,the ubstrateinteracting subunit(Cu Sn RK1β1)and catalytic subunit(Cu Sn RK1α)of SUCROSE NON-FERMENTING RELATED KINASE 1(Sn RK1)interacted with Cu WRKY41,triggering Cu Sn RK1α-mediated phosphorylation and subsequent degradation of Cu WRKY41,thereby suppressing its activation.However,ABA promoted cytoplasmic translocation of Cu Sn RK1αand Cu Sn RK1β1 and reduced nuclear interaction with Cu WRKY41,leading to its phosphorylation alleviation and protein stabilization,concurrent with enhanced transcription activation of Cu WRKY23 and Cu SPS4.Taken together,these findings reveal a sophisticated regulatory mechanism whereby drought promotes sucrose accumulation by suppressing Cu Sn RK1α-mediated phosphorylation and degradation of Cu WRKY41,enabling its transcriptional activation of Cu SPS4 directly or via Cu WRKY23.Our study provides significant insights into the molecular basis of drought-induced sucrose accumulation and presents valuable regulatory components that could be targeted for fruit quality improvement.
基金supported by the National Key Research and Development Program of China(Grant No.2023YFF0803600)National Natural Science Foundation of China(Grant Nos.42302009,42072003,and W2441016)+3 种基金HYZ thanks the Shaanxi Province postdoctoral research project and China Scholarship Council(202306970031)We also thank the Department of Science and Technology of Shaanxi Province(2022TD-11)TPT also acknowledges the Swedish Research Council(VR2017-05183 and VR2021-04295)This is also a contribution to the project of Theory of Hydrocarbon Enrichment under MultiSpheric Interactions of the Earth(THEMSIE04010106).
文摘Small shelly fossils(SSFs)have long been recognized as important to the studies of both metazoan evolution and the onset of biomineralization during the Cambrian radiation.The marked decline in the occurrence,diversity and abundance of SSFs in the middle to late Cambrian,when compared with the early Cambrian,has often been regarded as a result of the closure of a phosphatization window.Despite this,there have been numerous and consistent reports of SSFs from the middle Cambrian and younger deposits.To identify possible factors influencing SSF preservation,five microfacies including bioclastic limestone,flat-pebble conglomerates with bioclasts,hummocky cross-stratified grainstone with bioclasts,bioclastic grainstone in hardgrounds and glauconite bioclastic wackstone-packstone,from Cambrian Series 2 to Miaolingian in North China are compared to assess how differences in lithology impact the preservation potential of SSFs.Our results,based on 35,161 SSF specimens from deposits across six sections,suggest that there are still abundant and diverse SSFs in the middle Cambrian of North China preserved in ways not exclusively reliant on the presence of phosphate and that SSF preservation can be linked to the differences in microfacies in the early to middle Cambrian of North China.
基金National Natural Science Foundation of China(52104294)Fundamental Research Funds for the Central Universities(FRF-TP-19-079A1)。
文摘The soaring demand for smart portable electronics and electric vehicles is propelling the advancements in high-energy–density lithium-ion batteries.Lithium manganese iron phosphate(LiMn_(x)Fe_(1-x)PO_(4))has garnered significant attention as a promising positive electrode material for lithium-ion batteries due to its advantages of low cost,high safety,long cycle life,high voltage,good high-temperature performance,and high energy density.Although LiMn_(x)Fe_(1-x)PO_(4)has made significant breakthroughs in the past few decades,there are still facing great challenges in poor electronic conductivity and Li-ion diffusion,manganese dissolution affecting battery cycling performance,as well as low tap density.This review systematically summarizes the reaction mechanisms,various synthesis methods,and electrochemical properties of LiMn_(x)Fe_(1-x)PO_(4)to analyze reaction processes accurately and guide material preparation.Later,the main challenges currently faced are concluded,and the corresponding various modification strategies are discussed to enhance the reaction kinetics and electrochemical performance of LiMn_(x)Fe_(1-x)PO_(4),including multi-scale particle regulation,heteroatom doping,surface coating,as well as microscopic morphology design.Finally,in view of the current research challenges faced by intrinsic reaction processes,kinetics,and energy storage applications,the promising research directions are anticipated.More importantly,it is expected to provide key insights into the development of high-performance and stable LiMn_(x)Fe_(1-x)PO_(4)materials,to achieve practical energy storage requirements.
基金financially supported by the National Natural Science Foundation of China(Nos.82203680 and 52273278)the Natural Scientific Foundation of Liaoning Province(No.2021-MS-176)+1 种基金Shenyang Bureau of Science and Technology(No.RC230527)the Central Guidance Funding for Local Scientific and Techno-logical Development in Liaoning(No.2023JH6/100100029).
文摘Guided bone regeneration in the alveolar bone relies on the colonization and differentiation of immune cells within the defect area.The absence of osteoinductive and osteoimmune properties of currently available scaffolds hinders to achieve optimal repair outcomes in clinical settings.Thus,we aimed to enhance the bone repair ability of polycaprolactone(PCL)scaffolds by incorporating osteoinductive amorphous calcium phosphate(ACP)with immune-regulating zinc ions(ACP(Zn),ACZP),to create a favorable immunomodulatory microenvironment.After one day of co-culture with PCL-ACZP,the spreading area of macrophage cells was significantly higher than that from the original PCL scaffold.Additionally,over 32.1%of macrophages exhibited M2 polarization within three days of co-culture.The PCLACZP/macrophage-conditioned medium significantly boosted osteogenic gene expression in MC3T3-E1 cells.After eight weeks of implantation in a rat femoral condyle defect,the BV/TV from the PCL-ACZP group reached 32.9%,1.4 times of that from the PCL group.Furthermore,the PCL-ACZP-GelMA biphasic module as prepared successfully achieved complete regeneration of three-walled alveolar bone defects in rabbits,resulting in arch-shaped alveolar bone repair and providing greater convenience in the clinical settings.This study showcased the effectiveness of PCL-ACZP-GelMA biphasic module as bioactive scaffolds in the morphological restoration of alveolar bone.
基金support of the PID2021-124341OB-C22/AEI/10.13039/501100011033/FEDER,UE(MICIU)J.M.Vega also acknowledges the Grant RYC2021-034384-I funded by MICIU/AEI/10.13039/501100011033 and by“European Union Next Generation EU/PRTR”.
文摘In this study,a phosphate-based conversion coating(PCC)was applied as a precursor before forming silicate-fluoride(SiF)and silicate-phosphate-fluoride(SiPF)based flash-plasma electrolytic oxidation(Flash-PEO)coatings on AZ31B magnesium alloy.The main novelty is the successful incorporation of calcium,zinc,manganese and phosphate species into the Flash-PEO coatings via a precursor layer rather than using the electrolyte.The precursor also led to longer lasting and more intense discharges during the PEO process,resulting in increased pore size.Corrosion studies revealed similar short-term performance for all coatings,with impedance modulus at low frequencies above 10^(7)Ωcm^(2),and slightly better performance for the SiPF-based coating.Nonetheless,the enlarged pores in the PEO coatings functionalized with the PCC precursor compromised the effectiveness of self-healing mechanisms by creating diffusion pathways for corrosive species,leading to earlier failure.These phenomena were effectively monitored by recording the open circuit potential during immersion in 0.5 wt.%NaCl solution.In summary,this study demonstrates that conversion coatings are a viable option for the functionalization of PEO coatings on magnesium alloys,as they allow for the incorporation of cationic and other species.However,it is crucial to maintain a small pore size to facilitate effective blockage through self-healing mechanisms.
基金financially supported by the New Jersey Department of Environmental ProtectionUS EPA。
文摘In this study,synthetic wastewater containing 110μg/L arsenate(As(V)),0-20 mg/L fulvic acid(FA),and 0-12.3 mg/L phosphate was treated with 3 mg/L Fe3+.The mechanisms of FA and phosphate effects on As(V)removal by ferric chloride were determined using 0.22-10μm pore-size filtration,Zetasizer analysis,and in situ flow through cell ATR-FTIR.The results showed that up to 20mg/L FA had almost no effect on the solubility of ferric hydroxide precipitates and adsorption of As(V)by the precipitates.When FA concentration increased from 0 to 20 mg/L,the adsorption of FA led to higher negative zeta potential of the precipitates and the strong electrostatic repulsion between the precipitates decreased the particle size of ferric hydroxide flocs fromlarger than 10μmto smaller than 1μm.In the presence of 5-20 mg/L FA,46%-63%As(V)was adsorbed onto the flocs with particle size in the range of 0.45-1μm.On the other hand,phosphate did not affect the size of ferric hydroxide flocs and significantly increased the dissolved As(V)concentration because it competed with As(V)for adsorption sites on ferric hydroxide precipitates.The addition of 5mg/L cationic organic flocculant significantly reduced the effect of FA on As(V)removal,but did not reduce the effect of phosphate on As(V)removal.The findings of this study will help develop effective arsenic treatment techniques and predict the mobility of arsenic in the environment.
基金the Anusandhan National Research Foundation(ANRF),Science and Engineering Research Board(SERB),Department of Science&Technology,Government of India for a start-up research grant(M-14/0599,Sanction order no.SRG/2022/001478)Seed Grant under Institutions of Eminence(IoE),Banaras Hindu University(BHU)(Dev.Scheme No.6031)for financial assistance.
文摘The green energy transition relies heavily on critical metals,such as rare earth elements(REEs).However,their reserves are primarily focused in a few countries,such as China,which accounts for approximately 70%of global production.Hence,several countries are currently looking for alternative resources for REEs.Alternative REE resources in the supply chain include recycling of e-waste,industrial waste like red mud and phosphogypsum,coal ash,mine tailings,ocean floor sediments,and even certain types of sedimentary deposits like phosphorites where REEs are present in lower concentrations but at larger volumes compared to primary ore deposits which are becoming targets by REEs industry.Currently,several studies are going on the development of eco-friendly REEs extraction technologies from phosphorite deposits.Consequently,advanced data analysis tools,such as Machine Learning(ML),are becoming increasingly important in mineral prospectivity and are rapidly gaining traction in the earth sciences.Phosphorite deposits are mainly used to manufacture fertilizers as these rocks are known for their significant phosphorus content.Moreover,these formations are considered a prospective resource of REEs.The different types of phosphorite deposits such as continental,seamount,and ore deposits worldwide reported concentrations of∑REE upto 18,000µg/g.Due to the augmented claim of REEs for various ultra-modern,and green technology applications that are required to switch over to a carbon-neutral environment,these phosphorite deposits have become an important target mostly because of their relatively higher content of REEs especially heavy rare earth elements(HREE).For example,Mississippian phosphorites reported ∑ HREE 7,000µg/g.To have a comprehensive understanding of the REEs potential of these phosphorite deposits which also include several Chinese phosphorite deposits,this study is undertaken to review the phosphorite deposits in the world and their REEs potential,in addition to some of the associated aspects such as applications and formation mechanisms for different types of phosphorite deposits such as igneous phosphate deposits,sedimentary phosphorite deposits,marine phosphorite deposits,cave phosphate deposits,and insular guano deposits.Other important aspects include their occurrences,types,geochemical characteristics,the REEs enrichment mechanisms,and various recovery methods adopted to recover REEs from different phosphorite deposits.The present review paper concludes that the recent studies highlight the global potential of phosphorite deposits to satisfy the increasing demand for REEs.Extracting REEs from phosphorite presents no significant technological or environmental difficulties,as long as radioactive elements are eliminated.In India,more comprehensive geological surveys,along with the advancement of new methods and evaluations,are required to locate phosphorite deposits with high concentrations of REEs.
基金financed by the Spanish Ministry of Science and Innovation and the European Regional Development Fund(ERDF)(No.PID20211234690BI00)the European Joint Program EJP_Soil(TRACE-Soils)(No.862695)+1 种基金the Spanish Ministry of Science and Innovation(RED2018-102624TMCIN/AEI/10.13039/501100011033)the Project PREPSOIL European Union(No.101070045,HORIZON CSA)。
文摘Whilst phosphorus(P)in soil is considered to be abundant,the portion available for plant uptake constitutes less than 1%of the overall P present.To enhance crop productivity,the utilization of mineral P fertilizers has become pervasive in agriculture.Nonetheless,the escalating prices of chemical fertilizers,coupled with new European regulations prohibiting the use of P fertilizers containing cadmium,have highlighted the urgency to identify environmentally friendly products and practices for P fertilization in agricultural soils.This comprehensive review delves into the current landscape of P fertilization from agricultural,political,and economic standpoints.We recognize the potential of microbes in mobilizing P,but emphasize the necessity for more robust research to establish their effectiveness in promoting plant P uptake under real-world conditions.Additionally,we explore the role of agricultural conservation practices,such as optimal tillage,diversified cropping systems,and increased organic carbon input,in conserving P.Furthermore,this review contemplates forthcoming innovations in research.These innovations encompass the development of enhanced formulations for biofertilizers and the undertaking of more comprehensive studies within the realm of conservation agriculture.All these endeavors collectively hold the potential to augment P accessibility to plants in a sustainable manner,thereby advancing agricultural sustainability and productivity.
基金supported by Hebei Key Laboratory of Mineral Resources and Ecological Environment Monitoring(No.HBMREEM202302)Tianjin Key Research and Development Science and Technology Project(Nos.24YFXTHZ00170 and 24YFXTHZ00050)。
文摘The interaction mechanism between eggshell calcium and endogenous silica in biomass during biochar modification,and its impact on phosphate adsorption performance and slow-release fertilizer characteristics,remains unexplored.This study investigates that high silica content in biomass(>6%)inhibits the decomposition of CaCO_(3)in eggshells during pyrolysis,reducing the formation of active calcium species(CaO and Ca(OH)_(2)),while moderate silica levels(4%-5%)promote the formation of CaSiO_(3),enhancing phosphorus adsorption without hindering Ca^(2+)activation.Adsorption studies reveal that the precipitation of Ca_(5)(PO_(4))_(3)(OH)resulting from the combination of CaO and Ca(OH)_(2)with phosphate is the primary and effective form for phosphorus removal in calcium-modified adsorbents,accompanied by Ca_(3)(PO_(4))_(2)·2H_(2)O precipitation formed by CaSi O_(3).Eggshell calcium-modified corn straw biochar(ECS)exhibited the highest adsorption capacity,reaching 123.3 mg/g,outperforming materials in previous studies.ECS also demonstrated excellent pH adaptability and selective phosphate removal.As a biochar-based phosphorus fertilizer,ECS-P exhibits high phosphorus extractability in formic acid(93.92%)but low water solubility(0.62%),with phosphorus release during the seven-day intermittent leaching experiment remaining between 0.53 to 0.875 mg/L.These results confirm its potential as a phosphorus cycling fertilizer.This study provides fundamental insights into optimizing biomass selection based on silica content for calcium modification,offering an efficient strategy for both phosphate recovery and slow-release fertilizer development.
基金supported by the Chilwee Group(No.CWDY-ZH-YJY-202101-001)the Fundamental Research Funds for the Central Universities(No.2042023kf0214)the Starting Funding from Wuhan University.
文摘The efficient recycling of spent lithium iron phosphate(LiFePO_(4),also referred to as LFP)should convert Fe(Ⅱ)to Fe(Ⅲ),which is key to the extraction of Li and separation of Fe and is not well understood.Herein,we systematically study the oxidation of LiFePO_(4)in the air and in the solution containing oxidants such as H_(2)O_(2)and the effect of oxidation on the leaching behaviors of LFP.In the air,O_(2)breaks down the LFP olivine structure at 550℃for 1 h by oxidizing Fe(Ⅱ)to Fe(Ⅲ)in terms of converting LFP to Li_(3)Fe_(2)(PO_(4))_(3)and Fe_(2)O_(3).After that,Li is leached in 0.5 M sulfuric acid solution and is further recycled as Li_(3)PO_(4)with a Li recovery efficiency of 97.48%.Meanwhile,Fe is recovered as FePO_(4)and Fe_(2)O_(3).Compared with H_(2)SO_(4)-H_(2)O_(2),the air oxidation saves H_(2)O_(2)but increases the leaching efficiency of Fe and H_(2)SO_(4)consumption.The discrepancy of Fe leaching efficiency can be attributed to the different leaching mechanisms involving the solid-to-solid and solid-to-liquid-to-solid conversions.Furthermore,the results of the Everbatt model analysis show that the air roasting-H_(2)SO_(4)leaching method has low emission and potentially high income,which is simple and safe.Overall,this work will deepen the understanding of acid leaching of LFP and favorably stimulate the maturation of the LFP recycling technique.
基金supported by the National Natural Science Foundation of China(52127801)Postdoctoral Fellowship Program of CPSF under Grant Number GZC20231545,China Postdoctoral Science Foundation(2024T170557 and 2023M742224)+1 种基金Shanghai Post-doctoral Excellence Program(No.2023440)City University of Hong Kong Donation Grants(DON-RMG No.9229021 and 9220061).
文摘Pure Mg boasting a relatively small corrosion rate is a potential biodegradable metal material for implants.However,its degradation behavior in the complex physiological environment is still a lack of understanding.In this work,we investigated the effect of corrosion product film layers on the degradation behavior of pure Mg in physiological environments.Pure Mg shows a faster corrosion rate in simulated body fluid(SBF)compared to NaCl solution.Hydrogen evolution experiments indicate that the degradation rate of pure Mg in SBF decreases rapidly within the first 12 h but stabilizes afterward.The rapid deposition of low-solubility calcium phosphate on the pure Mg in SBF provides protection to the substrate,resulting in a gradual decrease in the degradation rates.Consequently,the corrosion product film of pure Mg formed in SBF exhibits a layered structure,with the upper layer consisting of dense Ca_(3)(PO_(4))_(2)/Mg_(3)(PO_(4))_(2) and the lower layer consisting of Mg(OH)_(2)/MgO.Electrochemical impedance spectroscopy(EIS)shows that the resistance of the corrosion product film increases over time,indicating gradual strengthening of the corrosion resistance.The 4-week degradation results in the femoral marrow cavity of mice are consistent with the result in SBF in vitro.
基金the support of this research by the National Natural Science Foundation of China (No. 22179034)the Natural Science Foundation of Heilongjiang Province (No. ZD2023B002)。
文摘Developing high-efficient and low-loading Pt based catalyst is significant for the electrocatalytic p Huniversal hydrogen evolution reaction(HER). Herein, the molybdenum carbide nanoparticles supported on the polyhedral N-doped carbon nanotube skeleton(Mo C/NCT) composite has been synthesized by a pyrolysis of polyacid organo-metallic phosphate framework precursor. Then, only 2.15 wt% Pt are loaded on the Mo C/NCT to form Pt-Mo C/NCT catalyst, which performs superior HER activity and stability in entire p H range. Specially, the overpotentials of 22 and 74 m V are respectively attained at 10 m A/cm^(2) in1.0 mol/L KOH and 0.5 mol/L H_(2)SO_(4) electrolytes, approaching or even exceeding commercial Pt/C. More importantly, it can be used as excellent catalyst for efficient hydrogen production at 0–14 p H range. Density functional theory(DFT) calculations demonstrate that the interaction between Mo C and Pt leads to the electron redistribution at the corresponding interfaces and the downward shift of the d-band centers, thus optimizing H*adsorption and desorption for promoting the HER activity. Besides, the unique three-dimensional network structure is conductive to the transmission of mass and electrons. In the application of both alkaline and acidic electrolysers, only 1.52 V voltage of solar panel can drive a hydrogen production current density of 10 m A/cm^(2).
基金financially supported by the National Natural Science Foundation of China(No.52174340)the National Key Research and Development Project of China(No.2022YFC2904505)the Hunan FURONG Scholars Project and the Basic Science Centre of the National Natural Science Foundation of China(No.72088101)。
文摘Potassium hydroxide(KOH)was introduced into the molybdenite roasting process to convert molybdenum(Mo)and sulfur(S)into water-soluble potassium molybdate(K_(2)MoO_(4))and potassium sulfate(K_(2)SO_(4)).Roasting with a 1.8-fold excess of KOH at 400℃ for 3 h enabled the leaching of over 99%of Mo from the molybdenum calcine using water.A precipitation method involving potassium–magnesium(K-Mg)salts was proposed for impurity removal.Under the conditions of pH 11,30℃,excess coefficient of 1.7 for Mg salts,and a duration of 1 h,98.37%of phosphorus(P)was removed from the K_(2)MoO_(4) solution.With post-purification,over 99%of Mo crystallized upon adjustment of pH to 1.Subsequently,S and K were recovered as K_(2)SO_(4) fertilizer from the crystalline mother liquor.An environmentally sustainable approach was proposed to conduct molybdenite production and ensure the efficient recovery of both Mo and S.
基金financially supported by the Natural Science and Engineering Technology in Qinghai Province(2023)the Qinghai Province"Kunlun Talents"High end Innovation and Entrepreneurship Talent Project(2023)+4 种基金the Western Young Scholars Program of Chinese Academy of Sciences(20242022000018)the National Natural Science Foundation of China(52404189)the Open Fund of Key Laboratory of Green and High-end Utilization of Salt Lake Resources(ISL2024-15)the Independent deployment project of the Qinghai Salt Lake Research Institute,CAS(E455HX3501)。
文摘Magnesium phosphate cements(MPC)have shown promising applications in many fields,but high raw material prices hinder their development.The production of salt lake MPC(SLMPC)from magnesium slag(MS),a byproduct of lithium extraction from salt lakes,offers significant environmental and economic advantages.In this study,a low-cost magnesia raw material was obtained through the calcination of MS,which was subsequently utilized in conjunction with KH_(2)PO_(4) to prepare SLMPC.The changes in hydration products,microscopic morphology,solution pH value,and TG content during the SLMPC curing process,and the hydration kinetics equation and model were used to study the hydration processes of SLMPC.The results show that the outcome indicates that the SLMPC system entered the accelerated reaction stage within 6 min after mixing,where the highest heat release rate was 6.29 J·g^(-1)·min^(-1),the maximum heat release was 205.3 J·g^(-1),and the main hydration product appeared at 50-60 min.The hydration behavior of SLMPC exhibits similarities to that of traditional MPC.Specifically,the acceleration phase is governed by an autocatalytic reaction,the deceleration phase is influenced by both autocatalytic reactions and diffusion processes,and the stabilization phase is predominantly controlled by diffusion mechanisms.This paper aims to establish the theoretical foundation for the industrial application of MS and the cost-effective production of MPC.
