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1.
Appl Microbiol Biotechnol ; 108(1): 278, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38558151

RESUMO

The production of succinic acid from corn stover is a promising and sustainable route; however, during the pretreatment stage, byproducts such as organic acids, furan-based compounds, and phenolic compounds generated from corn stover inhibit the microbial fermentation process. Selecting strains that are resistant to stress and utilizing nondetoxified corn stover hydrolysate as a feedstock for succinic acid production could be effective. In this study, A. succinogenes CICC11014 was selected as the original strain, and the stress-resistant strain A. succinogenes M4 was obtained by atmospheric and room temperature plasma (ARTP) mutagenesis and further screening. Compared to the original strain, A. succinogenes M4 exhibited a twofold increase in stress resistance and a 113% increase in succinic acid production when hydrolysate was used as the substrate. By conducting whole-genome resequencing of A. succinogenes M4 and comparing it with the original strain, four nonsynonymous gene mutations and two upstream regions with base losses were identified. KEY POINTS: • A high-stress-resistant strain A. succinogenes M4 was obtained by ARTP mutation •  The production of succinic acid increased by 113% • The mutated genes of A. succinogenes M4 were detected and analyzed.


Assuntos
Actinobacillus , Zea mays , Zea mays/química , Ácido Succínico , Melhoramento Vegetal , Fermentação , Mutação
2.
Environ Monit Assess ; 196(5): 430, 2024 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-38578570

RESUMO

Arsenic contamination in soils poses a critical global challenge, yet the influence of surfactants on arsenic adsorption behavior is often underestimated. This study aims to investigate the effects of three representative surfactants, namely cetyltrimethylammonium bromide (CTAB), sodium dodecyl sulfate (SDS), and polyethylene glycol anhydrous sugar alcohol monooleate (Tween 80), on arsenic adsorption behavior in soils. The adsorption isotherm shifts from a single Temkin model without surfactants to both the Langmuir and Temkin models in the presence of surfactants, indicating the simultaneous occurrence of monolayer and multilayer adsorption for arsenic in soils. Moreover, the surfactants can inhibit the adsorption and hasten the attainment of adsorption equilibrium. SDS displayed the most inhibitory effect on arsenic adsorption, followed by Tween 80 and CTAB, due to the competitive adsorption, electrostatic interaction, and hydrophobic interaction. Variations in zeta potential with different surfactants further elucidate this inhibitory phenomenon. Through orthogonal experiment analyses, pH emerges as a primary factor influencing arsenic adsorption in soils, with surfactant concentration and type identified as secondary factors. Temperature notably affects CTAB, with the adsorption inhibition rate plummeting to a mere 0.88% at 50 °C. Sequential extraction analysis revealed that surfactants enhanced the bioavailability of arsenic. The FTIR, XRD, SEM, and CA analyses further support the mechanism underlying the effect of surfactants on arsenic adsorption in soil. These analyses indicate that surfactants modify the composition and abundance of functional groups, hinder the formation of arsenic-containing substances, and improve soil compactness, smoothness, and hydrophilicity. This study provides valuable insights into the effect of surfactants in arsenic-contaminated soils, which is often ignored in previous work.


Assuntos
Arsênio , Tensoativos , Tensoativos/química , Solo/química , Polissorbatos , Cetrimônio , Adsorção , Arsênio/química , Monitoramento Ambiental
3.
Molecules ; 27(12)2022 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-35744917

RESUMO

Maoji Jiu (MJ) is a kind of medicinal wine that has been widely used by Chinese people for many years to nourish and promote blood circulation. The purpose of this study was to investigate the hematopoietic effect of MJ on the metabolism of blood deficient rats and to explore the underlying hematopoietic regulation mechanisms. Blood deficiency model rats were induced by subcutaneous injection of N-acetylphenylhydrazine (APH) and intraperitoneal injection of cyclophosphamide (CTX). The plasma metabolic fingerprints of blood deficiency model rats with and without MJ treatment were obtained by using metabonomics based on ultra-high-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (UHPLC-QTOF/MS). Orthogonal partial least squares-discriminant analysis (OPLS-DA) was used to evaluate the hematopoietic effect of MJ and identify potential biomarkers in the plasma of blood deficiency model rats. The levels of white blood cells (WBC), red blood cells (RBC) and hemoglobin (HGB) and the activity of antioxidant capacity showed a recovery trend to the control group after MJ treatment, while the dose of 10 mL/kg showed the best effect. In this study, thirteen potential biomarkers were identified, which were mainly related to seven metabolic pathways, including linoleic acid metabolism, d-glutamine and d-glutamate metabolism, alanine, aspartate and glutamate metabolism, tryptophan metabolism, pyrimidine metabolism, porphyrin and chlorophyll metabolism and arginine biosynthesis. Metabolomics was applied frequently to reflect the physiological and metabolic state of organisms comprehensively, indicating that the rapid plasma metabonomics may be a potentially powerful tool to reveal the efficacy and enriching blood mechanism of MJ.


Assuntos
Medicamentos de Ervas Chinesas , Vinho , Animais , Biomarcadores/metabolismo , Cromatografia Líquida de Alta Pressão/métodos , Medicamentos de Ervas Chinesas/química , Humanos , Espectrometria de Massas/métodos , Metabolômica/métodos , Ratos
4.
Nanotechnology ; 31(37): 375203, 2020 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-32434165

RESUMO

Improved performance in flexible organic light-emitting diodes (OLEDs) is demonstrated by using a hybrid nanostructured plasmonic electrode consisting of silver nanowires (AgNWs) decorated with silver nanoparticles (AgNPs) and covered by exfoliated graphene sheets. Such all-solution processed electrodes show high optical transparency and electrical conductivity. When integrated in an OLED with super yellow polyphenylene vinylene as the emissive layer, the plasmon coupling of the NW-NP hybrid plasmonic system is found to significantly enhance the fluorescence, demonstrated by both simulations and photoluminescence measurements, leading to a current efficiency of 11.61 cd A-1 and a maximum luminance of 20 008 cd m-2 in OLEDs. Stress studies reveal a superior mechanical flexibility to the commercial indium-tin-oxide (ITO) counterparts, due to the incorporation of exfoliated graphene sheets. Our results show that these hybrid nanostructured plasmonic electrodes can be applied as an effective alternative to ITO for use in high-performance flexible OLEDs.

5.
Luminescence ; 35(2): 250-259, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31749285

RESUMO

Four core-shell structured nanometre luminescent composites with different kernel sizes and different shell layer thicknesses (SiO2(500) @Eu (phen-Si)(50) , SiO2(500) @Eu (phen-Si)(15) , SiO2(250) @Eu (phen-Si)(5) and SiO2(250) @Eu (phen-Si)(10) ) were made by changing synthesis conditions. Here, initial subscript numbers in parentheses refer to the particle size of the SiO2 core, whereas the final subscript numbers in parentheses refer to shell layer thickness. In these composites, silica spheres of 500 nm or 250 nm were identified as the core. The shell layer was composited of silicon, 1,10-phenanthroline and europium perchlorate, abbreviated as Eu(phen-Si); the chemical formula of phen-Si was phen-N-(CONH (CH2 )Si(OCH2 CH3 )3 )2 . The composites were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and infrared spectroscopy. The monodispersed spherical SiO2 showed characteristics of a regular microstructure and a smooth surface, as well as the advantage of dispersity, shown by SEM. The Eu(phen-Si) complex was able to self-assemble into monodispersed SiO2 spheres, as seen using TEM. Fluorescence spectra indicated that the four composites had excellent luminescence properties. Furthermore, composites composed of a SiO2 core and a 250 nm kernel size exhibited stronger fluorescence than 500 nm kernel-sized composites. Fluorescence properties were affected by shell thickness: the thicker the shell, the greater the fluorescence intensity. For the four composites, quantum yield values and fluorescence lifetime corresponded to fluorescence emission intensity data as quantum yield values and fluorescence lifetime were higher, and luminescence properties increased.


Assuntos
Complexos de Coordenação/química , Európio/química , Substâncias Luminescentes/química , Nanosferas/química , Compostos de Organossilício/química , Dióxido de Silício/química , Complexos de Coordenação/síntese química , Substâncias Luminescentes/síntese química , Estrutura Molecular , Tamanho da Partícula , Propriedades de Superfície
6.
Water Sci Technol ; 77(3-4): 920-930, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29488955

RESUMO

Humic acids (HAs) were extracted and characterized from three kinds of uranium-enriched lignites from Yunnan province, China. Batch experiments were used to study the adsorption and desorption behavior of uranium (VI) onto these HAs and a commercial HA. The results showed that the optimum pH level at which all the HAs adsorbed uranium(VI) ranged from 5 to 8. The high uranium content of the HAs was released into the solution at the pH values between 1 and 3; when the HA dosage was 2.5 g L-1, the maximum concentration of uranium was 44.14 µg L-1. This shows that HAs derived from uranium-enriched lignites may present a potential environmental risk when used in acidic conditions. The experimental data were found to comply with the pseudo-second-order kinetic model, and the adsorption isotherms fit the Langmuir and Freundlich models well. The desorption experiments revealed that the sorption mechanism was controlled by the complex interactions between the organic ligands of the HAs and uranium(VI). The uranium present in the HAs may not affect the adsorption capacity of the uranium(VI), but the carboxylic and phenolic hydroxyl groups in the HAs play a significant role in controlling the adsorption capacity.


Assuntos
Carvão Mineral , Substâncias Húmicas , Urânio/química , Adsorção , China , Concentração de Íons de Hidrogênio , Cinética
7.
J Hazard Mater ; 469: 133883, 2024 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-38412648

RESUMO

The effect of several prevalent cations (including Na+, K+, Mg2+, Ca2+, Al3+, and Fe3+) on the adsorption of monochlorobenzene (MCB) onto bentonite was investigated at the coexistence of nonionic surfactant Tween 80 (T80) in surfactant-enhanced remediation (SER). They are all favorable for MCB and T80 adsorption, especially Mg2+ and Ca2+. Adsorption of MCB is strongly depended on T80 micelles. When its concentration exceeds the solubility, MCB is easier to bind with T80 micelles and be adsorbed by bentonite. Acidic environment can facilitate MCB and T80 adsorption, but the effect of cations on the adsorption is most significant under alkaline conditions. Adsorption capacity of MCB increases first followed by a slight decrease with increasing cations concentrations. The maximum adsorption rate of MCB determined is about 68.4% in a solution containing Mg2+ in the isothermal adsorption of MCB, while it is only 6.8% in a cation-free solution. Various characterizations showed that cations mainly changed the repulsion between bentonite particles and T80 micelles and the agglomeration and structure of bentonite, thus affecting the adsorption of MCB and T80 micelles. Our research demonstrated the nonnegligible promotion of MCB adsorption on bentonite by cations and acidic environment, which will adversely affect SER efficiency.

8.
J Hazard Mater ; 468: 133781, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38401220

RESUMO

Several studies conducted at industrial sites have documented the infiltration of dense non-aqueous phase liquids (DNAPLs) into clay layers, a phenomenon potentially influenced by the coexistence of chemicals like surfactants in some common pollutants. Bentonite (Ben), monochlorobenzene (MCB), and Tween 80 (T80) were selected as reference components to investigate the influences of nonionic surfactants on DNAPLs migration in clays. Results showed that T80 promotes MCB dissolution and encourages MCB adsorption on Ben. This process reduces the hydrophilicity of Ben, resulting in water loss and shrinkage, which creates cracks and facilitates the migration of MCB within the clay. Tw80 notably enhances MCB solubility, as indicated by a molar solubilization ratio of 7.80. The MCB adsorption on Ben (QMCB) displays a linear increase with raising the T80 adsorption on Ben (QT80), especially when QT80 are below the thresholds, e.g., 408.4 mg/g at pH 3 and 339.3 mg/g at pH 7; however, QMCB is decreased with increasing adsorbed T80 further. The average fracture ratio, crack length, and crack width of cracked samples in the cracking experiments were 0.794%, 11.29 mm, and 0.209 mm, respectively. The findings here contribute to understanding the role of surfactants in VOC transport in contaminated sites.

9.
Int J Pharm ; 659: 124295, 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38823469

RESUMO

Opioids are powerful analgesics; however, their significant systemic adverse effects and the need for frequent administration restrict their use. Nalbuphine (NA) is a κ-agonist narcotic with limited adverse effects, but needs to be frequently administrated due to its short elimination half-life. Whereas sebacoyl dinalbuphine ester (SDE) is a NA prodrug, which can effectively prolong the analgesic effect, but lacks immediate pain relief. Therefore, in this study, a rapid and sustained local delivery formulation to introduce NA and SDE directly into surgical sites was developed. An amphiphilic nanostructured lipid carrier (NLC) poloxamer 407 (P407) gel (NLC-Gel) was developed to permit concurrent delivery of hydrophobic SDE from the NLC core and hydrophilic NA from P407, offering a dual rapid and prolonged analgesic effect. Benefiting from the thermal-sensitive characteristic of P407, the formulation can be injected in liquid phase and instantly transit into gel at wound site. NLC-Gel properties, including particle size, drug release, rheology, and stability, were assessed. In vivo evaluation using a rat spinal surgery model highlighted the effect of the formulation through pain behavior test and hematology analysis. NLC-Gels demonstrated an analgesic effect comparable with that of commercial intramuscular injected SDE formulation (IM SDE), with only 15 % of the drug dosage. The inclusion of supplemental NA in the exterior gel (PA12-Gel + NA) provided rapid drug onset owing to swift NA dispersion, addressing acute pain within hours along with prolonged analgesic effects. Our findings suggest that this amphiphilic formulation significantly enhanced postoperative pain management in terms of safety and efficacy.


Assuntos
Analgésicos Opioides , Portadores de Fármacos , Liberação Controlada de Fármacos , Géis , Nalbufina , Dor Pós-Operatória , Poloxâmero , Ratos Sprague-Dawley , Nalbufina/administração & dosagem , Dor Pós-Operatória/tratamento farmacológico , Animais , Masculino , Poloxâmero/química , Analgésicos Opioides/administração & dosagem , Analgésicos Opioides/química , Portadores de Fármacos/química , Ratos , Lipídeos/química , Tamanho da Partícula , Nanoestruturas/administração & dosagem , Nanoestruturas/química , Ésteres/química
10.
Sci Rep ; 14(1): 3802, 2024 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-38360974

RESUMO

Myocardial perfusion imaging (MPI) is a clinical tool which can assess the heart's perfusion status, thereby revealing impairments in patients' cardiac function. Within the MPI modality, the acquired three-dimensional signals are typically represented as a sequence of two-dimensional grayscale tomographic images. Here, we proposed an end-to-end survival training approach for processing gray-scale MPI tomograms to generate a risk score which reflects subsequent time to cardiovascular incidents, including cardiovascular death, non-fatal myocardial infarction, and non-fatal ischemic stroke (collectively known as Major Adverse Cardiovascular Events; MACE) as well as Congestive Heart Failure (CHF). We recruited a total of 1928 patients who had undergone MPI followed by coronary interventions. Among them, 80% (n = 1540) were randomly reserved for the training and 5- fold cross-validation stage, while 20% (n = 388) were set aside for the testing stage. The end-to-end survival training can converge well in generating effective AI models via the fivefold cross-validation approach with 1540 patients. When a candidate model is evaluated using independent images, the model can stratify patients into below-median-risk (n = 194) and above-median-risk (n = 194) groups, the corresponding survival curves of the two groups have significant difference (P < 0.0001). We further stratify the above-median-risk group to the quartile 3 and 4 group (n = 97 each), and the three patient strata, referred to as the high, intermediate and low risk groups respectively, manifest statistically significant difference. Notably, the 5-year cardiovascular incident rate is less than 5% in the low-risk group (accounting for 50% of all patients), while the rate is nearly 40% in the high-risk group (accounting for 25% of all patients). Evaluation of patient subgroups revealed stronger effect size in patients with three blocked arteries (Hazard ratio [HR]: 18.377, 95% CI 3.719-90.801, p < 0.001), followed by those with two blocked vessels at HR 7.484 (95% CI 1.858-30.150; p = 0.005). Regarding stent placement, patients with a single stent displayed a HR of 4.410 (95% CI 1.399-13.904; p = 0.011). Patients with two stents show a HR of 10.699 (95% CI 2.262-50.601; p = 0.003), escalating notably to a HR of 57.446 (95% CI 1.922-1717.207; p = 0.019) for patients with three or more stents, indicating a substantial relationship between the disease severity and the predictive capability of the AI for subsequent cardiovascular inciidents. The success of the MPI AI model in stratifying patients into subgroups with distinct time-to-cardiovascular incidents demonstrated the feasibility of proposed end-to-end survival training approach.


Assuntos
Doença da Artéria Coronariana , Infarto do Miocárdio , Imagem de Perfusão do Miocárdio , Humanos , Imagem de Perfusão do Miocárdio/métodos , Fatores de Risco , Modelos de Riscos Proporcionais , Prognóstico , Tomografia Computadorizada de Emissão de Fóton Único/métodos
11.
Environ Sci Pollut Res Int ; 30(15): 43886-43900, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36670226

RESUMO

Due to the high-acidic arsenic-containing wastewater pollution greatly threatening human health and ecological safety, a simple and efficient method for reducing arsenic was proposed in this paper to solve this problem. By using potassium borohydride (KBH4) as a reducing agent, the soluble arsenic was converted into the gaseous arsine (AsH3) or solid arsenic (As0) to achieve the purpose of removing arsenic in wastewater. By exploring the reaction kinetics of the arsenic removal process, it was found that the fast reaction stage (0-2 min) conformed to pseudo-first-order kinetics. The removal rate of arsenic increased to over 73% in 0.5 min, and reaction equilibrium was reached after 30 min. Various influence factors including arsenic valence, aeration, addition method, concentrations of reducing agent, and hydrogen ion (H+) were investigated. The results showed that As(III) was easier to be removed by reduction than As(V), while adding KBH4 in multiples and aeration were both favorable to the removal of arsenic. Increased concentration of KBH4 also enhanced the removal of arsenic. Appropriate H+ concentration contributed to the arsenic removal, but excessive H+ concentration conversely has an inhibitory effect. The maximum removal rate of arsenic was 95.87%, with the maximum removal capacity of 45.50 mg/g. Based on the XRD and SEM-EDS analysis of residue, amorphous arsenic (As0) with a mass ratio of more than 94.52% was generated after the reduction of soluble arsenic. Our study demonstrated that the reaction mechanism of reductive degradation is soluble arsenic with hydrogen radicals (H•) to form arsenic (As0) and arsine (AsH3) (in the molar ratio of 6:1). Although the generated solid arsenic (As0) is convenient for the soluble arsenic removal from wastewater, attention must be paid to the formation of AsH3, and strategies for AsH3 treatment should be considered.


Assuntos
Arsênio , Arsenicais , Poluentes Químicos da Água , Humanos , Arsênio/análise , Águas Residuárias , Substâncias Redutoras , Concentração de Íons de Hidrogênio , Prótons , Poluentes Químicos da Água/análise , Adsorção , Cinética
12.
Environ Pollut ; 321: 121091, 2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36657511

RESUMO

Since incineration is a feasible method for stabilization/solidification of chromium (Cr)-enriched wastes, the species, distribution, and mobility of Cr in ashes deserve more studies, especially as the function of ash composition. Synthetic Cr-bearing ashes (SAs) were synthesized by SiO2-Al2O3-Fe2O3-CaO systems to investigate Cr mobility under 1100 °C. A study from simplicity to complexity. The Cr in SiO2-CaO is of high mobility with CrO42- formation, in contrary to the moderate mobility in SiO2-Al2O3 and poor mobility in SiO2-Fe2O3. However, species and mobility of Cr are affected by the values of CaO/SiO2, Al2O3/SiO2, and Fe2O3/SiO2 ratios. When other oxides are added to the two-phase systems above, the fate of Cr is affected more considerably. With the SiO2 content of 70%, adding a slight amount of CaO (<10%) strengthens the stabilization/solidification of Cr, due to the favorable solid integration under Ca2+ fusion. However, the Cr mobility is higher with increasing the CaO content further. The minimum content of CaO is ∼20% to sufficiently decrease the proportion of residual Cr (QCr-S5) in SiO2-Al2O3-CaO, much lower than in SiO2-Fe2O3-CaO, which confirms the easier release of Cr immobilized in Si-Al matrixes. Considering the opposite effects of Fe2O3 and CaO on Cr mobility, increasing Fe2O3/CaO ratios >3/2 can limit the effect of CaO, leading to the efficient stabilization/solidification of Cr waste. Additionally, the QCr-S5 is 83% with the Fe2O3 content of 15% in SiO2-Al2O3-Fe2O3, higher than in SiO2-Al2O3 and SiO2-Fe2O3. This suggests the intense stabilization/solidification of Cr, probably due to the formation of amorphous Fe-rich glass. Based on these above, an equation is developed to describe the relationship between ash compositions and QCr-S5 (QCr-S5 = -39.37X1 + 24.96X2 + 5.34X3 - 2.51X4 + 54.29).


Assuntos
Cromo , Dióxido de Silício , Óxidos , Incineração
13.
Environ Sci Pollut Res Int ; 30(52): 111748-111765, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37843707

RESUMO

The global industrial structure had undertaken significant changes since the twenty-first century, making a severe problem of chlorobenzene pollution in soil and groundwater (CBsPSG). CBsPSG receives increasing attention due to the high toxicity, persistence, and bioaccumulation of chlorobenzenes. To date, despite the gravity of this issue, no bibliometric analysis (BA) of CBsPSG does exist. This study fills up the gap by conducting a BA of 395 articles related to CBsPSG from the Web of Science Core Collection database using CiteSpace. Based on a comprehensive analysis of various aspects, including time-related, related disciplines, keywords, journal contribution, author productivity, and institute and country distribution, the status, development, and hotspots of research in the field were shown visually and statistically. Moreover, this study has also delved into the environmental behavior and remediation techniques of CBsPSG. In addition, four challenges (unequal research development, insufficient cooperation, deeply mechanism research, and developing new technologies) have been identified, and corresponding suggestions have been proposed for the future development of research in the field. Afterwards, the limitations of BA were discussed. This work provides a powerful insight into CBsPSG, enabling to quickly identify the hotspot and direction of future studies by relevant researchers.


Assuntos
Poluição Ambiental , Água Subterrânea , Bibliometria , Clorobenzenos , Solo
14.
Environ Sci Pollut Res Int ; 30(21): 60607-60617, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37036649

RESUMO

We used magnesium slag (MS) as a calcium source for modifying coal gasification coarse slag (CGCS) in the presence of NaOH to prepare a novel phosphate adsorbent (MS-CGCS). Ca2SiO4 in MS reacts with NaOH during the high-temperature synthesis process, with sodium displacing a part of the calcium content in Ca2SiO4 and entering the mineral lattice to form Na2CaSiO4. Hydroxide ions reacted with calcium in Ca2SiO4 to generate Ca(OH)2 and decomposed into CaO at a high temperature. The two newly formed species participated in the phosphate removal. The MS-CGCS adsorbent showed good phosphate removal performance over a wide pH range, with a maximum phosphate adsorption capacity of 50.14 mg/g, which was significantly higher than that of other reported adsorbents. The Langmuir and pseudo-second-order models described the adsorption process well, indicating it being a monolayer and chemisorption process. The main mechanisms of phosphate removal are as follows: electrostatic interaction between the positively charged MS-CGCS and negatively charged phosphate ions; the inner-sphere complexation of oxides of metal, such as magnesium, aluminum, and calcium, with phosphate ions; and the precipitation of phosphate ions with calcium ions. Precipitation contributes to ~ 32% of the phosphate removal. This study provides a new method for the development of phosphate adsorbents while recycling CGCS and MS.


Assuntos
Fosfatos , Poluentes Químicos da Água , Fosfatos/química , Magnésio , Carvão Mineral , Cálcio , Hidróxido de Sódio , Adsorção , Cinética , Concentração de Íons de Hidrogênio , Poluentes Químicos da Água/química
15.
Environ Sci Pollut Res Int ; 29(37): 56562-56578, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35347614

RESUMO

A series of sodium polysulfides (SPSs) with different sulfur indexes was prepared as stabilizers to amend elemental mercury-contaminated artisanal small-scale gold mine (ASGM) tailings in Hubei, China, by controlling the molar ratio of sulfur and sodium sulfides as 1:1, 2:1, 3:1, and 4:1 during the synthesis. XRD, XPS, and laser Raman spectroscopy all suggested that the synthesized SPSs were a mixture of multiple polysulfides, sulfur, sodium sulfides, and sodium thiosulfate. Based on toxicity characteristic leaching procedure test (TCLP), mercury stabilization efficiency of SPSs was evaluated and proved to be more superior than sulfur, sodium sulfide, and also calcium polysulfide, with an optimal stabilization efficiency of 97.16% at SPS/THg = 1:2, SPSs pH = initial pH, and liquid-to-solid ratio = 20:7. A pseudo-second-order kinetic model was able to interpret the stabilization kinetics and demonstrated that mercury stabilization rate increased with the sulfur index in the SPSs, but excess SPSs were potentially to inhibit the precipitation of mercury. Speciation analysis results determined with sequential extraction indicated that the unstable mercury, elemental mercury, and organic-bound mercury fractions decreased respectively by up to 88.6%, 53.5%, and 26.3%. Pearson correlation analysis showed that the mercury stabilization in the mine tailings amended with SPSs mainly occurs from the precipitation of the elemental mercury, and the organic mercury fraction reduction was correlated with the decrease of the unstable mercury.


Assuntos
Mercúrio , Monitoramento Ambiental/métodos , Ouro/análise , Mercúrio/análise , Mineração , Sódio/análise , Sulfetos/análise , Enxofre/análise
16.
Environ Sci Pollut Res Int ; 29(56): 85465-85481, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35799008

RESUMO

In this study, the CO2 carbonatization potential of the Deccan basalt formation in Eastern India is evaluated by establishing a hydro-chemical field-scale model based on the geological, hydrological, and geochemical parameter of the basalt in the Mandla lobe. The reliable initial mineral thermodynamic parameters are obtained by validating the laboratory scale experiment of CO2-water-basalt reaction with a numerical method. Over 50% of injected carbon mineralized within 140 days for the Deccan basalt in the Mandla lobe, and the majority of CO2 is sequestered as ankerite, siderite, and calcite, which occupy a percent of 65%, 28%, and 7%, respectively. Clay minerals, including smectite and chlorite, are important secondary minerals contributing to the process of CO2 storage in the basaltic reservoir. Clay precipitation can promote the dissolution of silica- and aluminum-rich plagioclase and release Ca2+ to enhance the carbonatization of CO2 to Ca carbonates but competes for Fe2+ and Mg2+ from siderite and magnesite. Clay precipitation also impacts the CO2 carbonatization efficiency by changing the basalt conductivity. CO2 carbonatization efficiency was found to increase with the reduction of injection rate. However, slow flow rate can increase the pore clogging risk and induce large pressure build-up. This is the first field-scale assessment of CO2 mineralization potential of the Deccan basalt, which is one of the largest terrestrial flood basalt formations in the world. The results can provide valuable information and scientific support for India and global carbon mitigation.


Assuntos
Dióxido de Carbono , Minerais , Argila , Carbono
17.
RSC Adv ; 12(27): 17147-17157, 2022 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-35755595

RESUMO

Zr-modified materials have an adsorption affinity for phosphate ions, but because of the cost of carrier materials, they are difficult to apply on a large scale. Herein, coal gasification coarse slag (CGCS) was used as a carrier material and modified with Zr, and its dephosphorization performance was studied. A series of adsorbents with different CGCS/ZrOCl2·8H2O mass ratios were prepared, from which the adsorbent with a CGCS/ZrOCl2·8H2O mass ratio of 5 : 4 (denoted as CGCS-Zr4) was identified as the most promising for phosphate adsorption. The specific surface area of CGCS-Zr4 was much greater than that of raw CGCS (100.12 vs. 12.43 m2 g-1). CGCS-Zr4 showed good adsorption selectivity towards phosphate when competitive anions co-existed, and exhibited good reusability; the adsorption capacity in the fourth adsorption-desorption cycle remained above 11.98 mg g-1. The adsorbent was also suitable for the continuous treatment of up to 830 and 743 bed volumes of synthesised and actual wastewater, respectively. The results of Fourier-transform infrared and X-ray photoelectron spectroscopy indicated that CGCS not only plays the role of a carrier, but also that Ca and Al in CGCS play an important role in phosphate adsorption. Compared with other carrier materials such as biochar and synthetic zeolite, CGCS has the advantages of a large stockpile, low cost, and easy availability. In addition, the preparation of CGCS-Zr4 is simpler and more energy-saving. Zr-modified CGCS is a promising dephosphorization material.

18.
Seizure ; 101: 205-210, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36084526

RESUMO

OBJECTIVE: It has been suggested that asymmetric hypsarrhythmia is associated with structural etiology. We devised the Hypsarrhythmic Asymmetric Scoring Scheme (HASS) to quantify the degree of hypsarrhythmic asymmetry in a retrospective series of patients who underwent surgical treatment at our center. The present study aimed to investigate the role of HASS in predicting the postsurgical seizure outcomes. METHODS: We retrospectively analyzed the records of 46 children with hypsarrhythmia who underwent resective epilepsy surgery between 2018 and 2020 and were followed up for at least 1 year after surgery. Hypsarrhythmia severity in each hemisphere was quantified and scored. The HASS score was calculated as the difference between the two hemispheres. Univariate results were submitted to logistic regression models to identify independent predictors for favorable surgical outcomes. RESULTS: Of the 46 patients who underwent resective surgery, Engel's class I-Ⅱ outcomes were achieved in 34 (73.9%). The Engel I-Ⅱ group had a significantly higher HASS score than the Engel Ⅲ-Ⅳ group (p<0.001). Multivariate analysis showed that the HASS score was the only significant predictor of good outcomes (p = 0.011). Further receiver operating characteristic analysis showed that a threshold of 7 yielded a better seizure outcome with a sensitivity of 97.06% and specificity of 83.33%. SIGNIFICANCE: As the first hypsarrhythmia scoring system specially designed for presurgical evaluation, the HASS score may contribute to predicting the postsurgical seizure outcome from the electroencephalography perspective.


Assuntos
Epilepsia , Espasmos Infantis , Criança , Eletroencefalografia/efeitos adversos , Epilepsia/diagnóstico , Epilepsia/etiologia , Epilepsia/cirurgia , Humanos , Estudos Retrospectivos , Convulsões/complicações , Convulsões/diagnóstico , Convulsões/cirurgia , Espasmos Infantis/complicações , Espasmos Infantis/diagnóstico , Espasmos Infantis/cirurgia , Resultado do Tratamento
19.
Chemosphere ; 271: 129520, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33445021

RESUMO

Monochlorobenzene (MCB), a solvent and synthetic intermediate, has been widely detected in groundwater at industrial contaminated sites. Cysteine (Cys) enhanced Fe2+/persulfate (Fe2+/Cys/PS) process with high degradation efficiency of organic pollutants has the potential for in-situ chemical oxidation of MCB. In this study, we systematically explored the impacts of common anions (CO32-, HCO3-, SO42-, NO3-, NO2-, PO43-, HPO42-, H2PO4-, Cl-, Br-), cations (NH4+, Mg2+, Al3+, Mn2+, Cu2+) and natural organic matter (NOM) on the degradation kinetics of MCB by the novel Fe2+/Cys/PS process and evaluated the ecotoxicity. The results showed that the removal of MCB in absence of matrices was enhanced by Cys due to its reduction and complexation ability. All of the anions inhibited the MCB degradation through the scavenging of SO4•- and HO•, though the inhibition degree of SO42-and NO3- was slight. Cations such as NH4+, Mg2+ and Al3+ hardly interfered with the reaction. Low concentrations of Cu2+ and NOM promoted the MCB oxidation, but the promotion strength weakened and turned into inhibition with the increased concentration of Cu2+ and NOM. The toxicity assessment of the transformation products (TPs) in the presence of Cl- and Br- based on the quantitative structure-activity relationships model showed the potentially higher toxicity of some TPs than their parent MCB. These results indicate that groundwater matrices may interfere with the MCB oxidation process. To accurately evaluate the effects of groundwater matrices on Fe2+/Cys/PS process for MCB oxidation and its potential toxicity, the field tests should be carried out in the future.


Assuntos
Água Subterrânea , Poluentes Químicos da Água , Clorobenzenos , Cisteína , Ferro , Cinética , Oxirredução , Sulfatos , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
20.
Chemosphere ; 257: 127112, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32474150

RESUMO

Given the millions of coal-fired power stations worldwide and the generalization of co-firing technologies in the near future, the aqueous extraction experiments were taken to study the effects of oxides on Cr mobility in ashes through SiO2-Al2O3-Fe2O3-CaO system. The results identify that both the component and the species of Cr in samples are vital factors to govern the fate of Cr during combustion. Although Cr-oxide hardly reacts with Al2O3, SiO2, and mixtures at 900 °C, the immobilization of Cr in Si-Al glass is ascribable to the heat-driven phase transformation of Cr-rich clay. The strong capture of Cr-oxide by CaO leads to the primary extraction of active Cr with the high toxicity and mobility; however, the opposite effect is found by Fe2O3. But the interactions of Al-/Si- oxides with others can trigger some changes in Cr mobility, wherein there is the lowest mobility of Cr in the case of Cr entering into the structures of Fe-rich SiO2/Si-Al glass during combustion. Thus, without regard to the sample source, it is effective to reduce the environmental risk of Cr in ashes through raising SiO2 and reducing MCaO/MFe2O3 < 5/4 prior to combustion.


Assuntos
Cromo/análise , Modelos Químicos , Cromo/química , Carvão Mineral/análise , Cinza de Carvão/química , Compostos Férricos , Óxidos/química , Dióxido de Silício
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