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1.
J Environ Manage ; 253: 109683, 2019 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-31666210

RESUMO

This study analyzed the seasonal variations and the spatial distributions of total mercury (THg), inorganic divalent mercury (IHg), and methylmercury (MeHg) in sediments of river mouth (RM), main channel (MC), and entrance (E) of the Port of Kaohsiung, Taiwan. The THg, IHg, and MeHg concentrations were, respectively, 198-9130, 2.6-3164, and <0.3-42.6 µg/kg in the wet season and 362-2264, 11.0-790, and 3.3-65.6 µg/kg in the dry season. As for seasonal variations, the concentrations of THg and IHg for RM sediment were higher in the wet season than in the dry season, whereas for MC and E was converse. Generally, MeHg in sediment was higher in the dry season than in the wet season. THg and IHg were mainly transported from the river, whereas MeHg was generated by onsite microbes transforming the local available IHg. Results indicated that the formation of MeHg in sediment may be mainly influenced by the concentration of IHg and seasonal variations.

2.
Bioresour Technol ; 293: 121929, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31476565

RESUMO

In the present study, was investigated an environmentally friendly method for pretreating lignocellulosic rice straw (RS) by using 1-butyl-3-methylimidazolium chloride ([Bmim]Cl) as an ionic liquid (IL) and 1-butyl-3-methylimidazolium hydrogen sulfate ([Bmim]HSO4) as an acidic-IL (Acidic-IL) under microwave irradiation (microwave-[Bmim]Cl and microwave-[Bmim]HSO4). The conversion of lignocellulosic biomass into simple sugars requires both efficient pretreatment and hydrolysis enzymes to produce biofuels and specialty chemicals. Therefore, the applied [Bmim]Cl, [Bmim]HSO4, microwave-[Bmim]Cl, and microwave-[Bmim]HSO4 to improve hydrolysis yields. Structural analyses of the pretreated solids were performed to understand the synergistic effects of [Bmim]Cl, and [Bmim]HSO4 pretreatment under microwave irradiation (microwave-[Bmim]Cl and microwave-[Bmim]HSO4) on the efficiencies of enzymatic hydrolyses. The results of a chemical composition analysis of untreated and all pretreated RS samples by using the difference pretreatment methods showed that significant lignin removal was achieved using microwave-[Bmim]Cl (57.02 ±â€¯1.24%), followed by [Bmim]Cl only (41.01 ±â€¯2.67%), microwave-[Bmim]HSO4 (20.77 ±â€¯1.79%), and [Bmim]HSO4-only (16.88 ±â€¯1.14%). The highest glucan yield and xylan conversion achieved through the enzymatic saccharification of microwave-[Bmim]Cl-regenerated cellulose was consistent with the observations obtained from a structural analysis, which indicated a more disrupted, amorphous structure, with lowered crystallinity index (CrI) and lateral order index (LOI) of cellulose polymers. Thus results demonstrated that the pretreatment of lignocellulosic biomass with [Bmim]Cl under microwave irradiation has potential as an alternative method for pretreating lignocellulosic materials.


Assuntos
Líquidos Iônicos , Oryza , Biomassa , Hidrólise , Lignina , Micro-Ondas
3.
J Hazard Mater ; 383: 121194, 2019 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-31541961

RESUMO

This study applied a circulation-enhanced electrokinetics (CEEK) technique to remove heavy metal lead from the agricultural land. Soil samples (lead concentration around 4000 mg/kg) were collected in a certain polluted agricultural site in Nantou, Taiwan. Operational parameters of CEEK such as the voltage gradient (1.0 V/cm), the concentration of working solution (EDTA), and pH buffer (0.01 M Na2CO3) were controlled. The CEEK with EDTA can maintain at relatively neutral pH to beneficially remove heavy metals due to appropriate EO flow, electromigration, and EDTA complexation. EDTA served as the chelating agent to react with lead in soils and its concentration plays the key factor for desorbing heavy metals from soils; the 0.1 M EDTA can achieve 79% of Pb depletion (from 3703 mg/kg to 781 mg/kg). The stoichiometric calculation can be roughly used to estimate the Pb removal efficiency based on the 1:1 M ratio of Pb to EDTA and ignores other reactions between EDTA and soil constituents. The CEEK technique with 0.1 M EDTA can remove 63% Pb (from 3430 mg/kg to 1260 mg/kg) within 6-day treatment.

4.
Sci Total Environ ; 696: 133973, 2019 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-31454601

RESUMO

This study investigated the degradation of phthalate esters (PAEs) in marine sediments by sodium persulfate (Na2S2O8, PS) activated by a series of iron-cerium (Fe-Ce) bimetallic catalysts (FCBCs). The surface structure and chemistry of the FCBCs were characterized by TEM, HRTEM, XRD, FTIR, BET and XPS. Results show successful synthesis of FCBC catalysts. Factors such as PS concentration, Fe to Ce molar ratio, catalyst dosage, and initial pH that might affect PAEs degradation were investigated. Results revealed that PAEs was degraded more effectively over FCBC with a Fe-Ce molar ratio of 1.5:1. Increase in Ce improved the catalytic activity of FCBC due to increase in oxygen storage capacity (OSC). Acidic conditions enhanced PAEs degradation with a maximum degradation of 86% at pH 2 and rate constant (kobs) of 1.5 × 10-1 h-1 when the PS and FCBC concentrations were to 1.0 × 10-5 M and 1.67 g/L, respectively. Di-(2-ethylhexyl) phthalate (DEHP) was a salient marker of PAE contamination in sediments. Dimethyl phthalate (DMP) and diethyl phthalate (DEP) were easier to degrade than DEHP, diisononyl phthalate (DINP), dioctyl phthalate (DnOP) and diisononyl phthalate (DIDP). The synergistic catalytic effect of Fe3+/Fe2+ and Ce4+/Ce3+ redox couples, in addition to electron transfer of oxygen vacancies, activated S2O82- to generate SO4- and HO radicals, which played the major role of PAEs degradation. 5,5-dimethyl-1-pyrroline N-oxide (DMPO) spin trapping EPR studies verified the crucial role of SO4- and HO in the oxidative degradation process. FCBC/PS oxidation exhibited high-performance for the remediation of PAEs-contaminated marine sediments.

5.
Bioresour Technol ; 292: 121954, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31404756

RESUMO

Cobalt-impregnated spent coffee ground biochar (Co-SCG) was synthesized and applied for tetracycline (TC) removal from water. The results showed that Co-SCG biochar exhibited marked adsorption capacity and catalyst activity. The maximum adsorption capacity of Co-SCG biochar toward TC was 370.37 mg g-1. TC was almost completely degraded in 25 min with a rate constant of 17.78 × 10-2 min-1 under the following optimal condition: TC concentration of 0.2 mM, PMS concentration of 0.6 mM, Co-SCG dosage of 100 mg L-1, and pH of 7.0. Co-SCG was characterized for surface properties by SEM, TEM, HRTEM, and BET. The concentration of 16 PAHs in Co-SCG biochar was studied also. Results demonstrated that Co-SCG was an effective eco-friendly material for the removal of tetracycline from water.


Assuntos
Poluentes Químicos da Água , Água , Carvão Vegetal , Cobalto , Peróxidos , Tetraciclina
6.
Bioresour Technol ; 290: 121786, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31306936

RESUMO

In this study, microalgal cultivation was applied as a feasible strategy for treating shrimp culture wastewater (SCW) from a shrimp farm in southern Tainan. Chlorella sorokiniana MB-1-M12 was first grown on BG-11 medium with 0.5% salinity, obtaining a biomass concentration and productivity of 4.35 g/L and 1.56 g/L/d, respectively. When 80% of BG-11 nutrients were added to 75% strength SCW, lutein content and productivity increased to 5.19 mg/g and 5.55 mg/L/d, respectively. A novel operation strategy involving periodic exchange of freshwater and SCW was designed for semi-continuous cultivation of MB-1-M12 strain for optimal biomass and lutein production. The average biomass concentration, productivity, lutein content, and productivity were 3.5 g/L, 1.3 g/L/d, 3.89 mg/g and 5.0 mg/L/d, respectively. Although microalgae have been considered as an alternative natural source of lutein, this work is among the earliest reports describing lutein production from microalgae cultivated with wastewater via a circular economy concept.


Assuntos
Chlorella , Microalgas , Aquicultura , Biomassa , Luteína , Águas Residuárias
7.
Artigo em Inglês | MEDLINE | ID: mdl-31336632

RESUMO

The qualitative and quantitative analysis of 16 polycyclic aromatic hydrocarbons (PAHs) in sludge samples from drinking water treatment plants (DWTP) and wastewater treatment plants (WWTP) were established using gas chromatography-mass spectrometry (GC-MS). The method was suitable to quantify PAHs in the sludge of DWTP and WWTP and it was confirmed by the relevant quality assurance/quality control (QA/QC) procedures. The recovery of individual PAHs in the spiked samples ranged from 74.3% to 108.7%. Detection limits of the analytical procedure were 0.0010-0.0046 mg/kg dw for individual PAHs. This method was used to determine the concentration of PAHs in the selected two DWTP and four WWTP sludge samples. The results showed that the total PAHs (∑PAHs) were in low levels which ranged from 0.0668 to 0.1357 mg/kg dw, and 0.5342-1.0666 mg/kg dw for DWTP and WWTP respectively. The 3- & 4-ring PAHs were predominant in DWTP sludge, ranging from 77.4% to 82.7%; the 4-ring PAHs were predominant in WWTP sludge, ranging from 40.7% to 47.6%. The PAHs of DWTP sludge are mainly composed of 3-ring phenanthrene and anthracene and 4-ring pyrene, and chrysene. The PAHs of WWTP sludge are dominated by 4-ring fluoranthene, pyrene, and chrysene. The detected PAHs concentration should be undoubtedly considered for agriculture in sludge applications based on the limits of the EU regulations. The results of this study can be used for regular monitoring to establish a reference for sludge management and application to agriculture.

8.
Bioresour Technol ; 289: 121718, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31296361

RESUMO

There is an exponential increase in swine farms around the world to meet the increasing demand for proteins, resulting in a significant amount of swine/piggery wastewater. The wastewater produced in swine farms are rich in ammonia with high eutrophication potential and negative environmental impacts. Safe methods for treatment and disposal of swine wastewater have attracted increased research attention in the recent decades. Conventional wastewater treatment methods are limited by the high ammonia content and chemical/biological oxygen demand of swine wastewater. Recently, microalgal cultivation is being proposed for the phytoremediation of swine wastewater. Microalgae are tolerant to high ammonia levels seen in swine wastewater and they also ensure phosphorus removal simultaneously. This review first gives a brief overview on the conventional methods used for swine wastewater treatment. Microalgae-based processes for the clean-up of swine wastewater are discussed in detail, with their potential advantages and limitations. Future research perspectives are also presented.


Assuntos
Microalgas/metabolismo , Águas Residuárias/química , Amônia/metabolismo , Animais , Análise da Demanda Biológica de Oxigênio , Fósforo/metabolismo , Suínos
9.
Sci Total Environ ; 691: 55-63, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31319258

RESUMO

Methylmercury (MeHg) presents high toxicity to humans and can be accumulated to organisms via the food chains. In aquatic environments, MeHg is mainly formed by microorganism using the bioavailable inorganic mercury in sediment. In this study, a total of 120 surface sediments from 20 sites in the Kaohsiung Harbor were collected quarterly in the period from July 2016 to October 2017 and analyzed for total mercury (THg), bioavailable inorganic mercury (BIHg), MeHg, and several geochemical parameters. The concentrations of THg, BIHg, and MeHg in sediment were 455-5108, 7.0-1021, and 0.84-24.1 µg/kg dw, respectively. Results indicated that the percentage of MeHg to THg (MeHg ratio) in most sediment (85%) is <1.2%. Correlation analysis showed that MeHg in sediment was mainly controlled by BIHg (r = 0.759, p < 0.01), while the concentration of BIHg in sediment was mainly related to TOC (r = 0. 480, p < 0.01) and THg (r = 0.435, p < 0.01). The relationship between total bioavailable inorganic mercury (containing BIHg and the bioavailable inorganic mercury used in the synthesis of MeHg) and MeHg concentration in the sediments that collected from the estuary, harbor channel, and the entrance was established by a Michaelis-Menten model to predict the maximum value of MeHg. The efficiency of Hg methylation in the sediments of Kaohsiung Harbor is significantly affected by the total bioavailable inorganic mercury and the related environmental factors. In addition, changes in environmental conditions caused by local seasonality should also be an important factor to consider when assessing the efficiency of Hg methylation.

10.
Acta Crystallogr C Struct Chem ; 75(Pt 6): 643-649, 2019 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-31166915

RESUMO

Compared with the monomorphic type of ligand, combining mixed ligands in one coordination polymer offers greater tunability of the structural framework. Employment of N-heterocyclic ligands and aromatic polycarboxylates is an effective approach for the construction of metal-organic frameworks (MOFs). Two new coordination polymers incorporating both 2-[(1H-imidazol-1-yl)methyl]-1H-benzimidazole (imb) and benzenedicarboxylic acid isomers, namely, catena-poly[[[di-µ-chlorido-bis[(2-carboxybenzoato-κ2O1,O1')cadmium(II)]]-bis{µ-2-[(1H-imidazol-1-yl)methyl]-1H-benzimidazole-κ2N:N'}] dihydrate], {[Cd(C8H5O4)Cl(C11H10N4)]·H2O}n, (I), and poly[[aqua(µ2-benzene-1,3-dicarboxylato-κ3O1,O1':O3){µ2-2-[(1H-imidazol-1-yl)methyl]-1H-benzimidazole-κ2N:N'}cadmium(II)] dihydrate], {[Cd(C8H4O4)(C11H10N4)(H2O)]·2H2O}n, (II), have been prepared and structurally characterized by single-crystal X-ray diffraction. In polymer (I), imb ligands bridge CdII ions, forming a one-dimensional chain, and 2-carboxybenzoate anions coordinate to the CdII ions in a terminal fashion. Polymer (II) exhibits a two-dimensional network structure in which imb ligands and the benzene-1,3-dicarboxylate anions join CdII ions co-operatively. This indicates that changing of the aromatic dicarboxylic acids can result in polymers with different compositions and architectures. Moreover, their IR spectra, PXRD (powder X-ray diffraction) patterns, thermogravimetric analyses and fluorescence properties were also investigated.

11.
Diabetes Care ; 42(8): 1539-1548, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31152120

RESUMO

OBJECTIVE: Uncertainty remains regarding the predictive value of various glycemic measures as they relate to the risk of diabetes and its complications. Using the cutoffs recommended by the American Diabetes Association's 2010 criteria, we determined the associations of fasting plasma glucose (FPG), 2-h postload glucose (2h-PG), and HbA1c with the outcomes. RESEARCH DESIGN AND METHODS: Baseline medical history, FPG, 2h-PG, and HbA1c were obtained from a population-based cohort of 193,846 adults aged ≥40 years in China during 2011-2012. A follow-up visit was conducted during 2014-2016 in order to assess incident diabetes, cardiovascular disease (CVD), cancer, and mortality. RESULTS: We documented 8,063 cases of diabetes, 3,014 CVD-related events, 1,624 cases of cancer, and 2,409 deaths during up to 5 years of follow-up. Multivariable-adjusted risk ratios (95% CIs) of diabetes associated with prediabetes based on FPG of 100-125 mg/dL, 2h-PG of 140-199 mg/dL, or HbA1c of 5.7-6.4% (39-47 mmol/mol) were 1.60 (1.43-1.79), 2.72 (2.43-3.04), and 1.49 (1.36-1.62), respectively. Restricted cubic spline analyses suggested J-shaped associations of FPG, 2h-PG, and HbA1c levels with CVD, cancer, and mortality. Multivariable-adjusted hazard ratios (95% CIs) associated with untreated diabetes based on FPG ≥126 mg/dL, 2h-PG ≥200 mg/dL, or HbA1c ≥6.5% (48 mmol/mol) were 1.18 (1.05-1.33), 1.31 (1.18-1.45), and 1.20 (1.07-1.34) for CVD; 1.10 (0.92-1.32), 1.44 (1.25-1.67), and 1.08 (0.92-1.28) for cancer; and 1.37 (1.20-1.57), 1.57 (1.41-1.76), and 1.33 (1.17-1.52) for mortality, respectively. 2h-PG remained significantly associated with outcomes in models including FPG and HbA1c as spline terms. Furthermore, 2h-PG significantly improved the ability of the C statistic to predict diabetes, CVD, and mortality. CONCLUSIONS: 2h-PG remains independently predictive of outcomes in models including FPG and HbA1c. Therefore, in addition to FPG and HbA1c, routine testing of 2h-PG should be considered in order to better assess the risks of outcomes.

12.
J Diabetes ; 11(11): 884-894, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30941862

RESUMO

BACKGROUND: This study examined whether resting heart rate (RHR) was associated with metabolic syndrome (MetS) and the 10-year predicted risk of cardiovascular disease in a Chinese population. METHODS: The associations of RHR with MetS and 10-year risk of atherosclerotic cardiovascular diseases (ASCVD) was examined in a cross-sectional study conducted in Shanghai, China (n = 9486). RESULTS: Compared with individuals in the lowest RHR quintile (≤71 b.p.m.), those in the highest quintile (≥91 b.p.m.) had a higher prevalence of MetS (21.2% vs 32.6%, respectively; P < 0.001). Logistic regression analyses showed that the multivariate-adjusted odds ratio (OR) and 95% confidence interval (CI) for MetS was 1.13 (1.08-1.18) for each 10-b.p.m. increment of RHR (P < 0.0001). Furthermore, RHR was strongly associated with the prevalence of hypertension, high blood glucose, and dyslipidemia, but not with central obesity. A stronger association of RHR with MetS was observed among individuals aged <65 years, male, with a body mass index <24 kg/m2 , without diabetes, hypertension, abnormal lipids, and insulin resistance than among their counterparts (P < 0.05 for all). A significantly higher 10-year risk for ASCVD was observed with each 10-b.p.m. increment in RHR in both men and women (ORs [95% CIs] 1.20 [1.07-1.33] and 1.28 [1.17-1.39], respectively; Ptrend = 0.002 and < 0.0001, respectively). CONCLUSIONS: In this study, RHR was associated with a higher prevalence of MetS and elevated 10-year predicted risk of ASCVD in both Chinese men and women. Whether RHR may serve as an indicator for MetS among relatively healthy individuals requires further investigation.

13.
Bioresour Technol ; 284: 197-203, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30939381

RESUMO

The main objective of this study was to evaluate the effect of different pyrolysis temperatures on the formation of polycyclicaromatichydrocarbons (PAHs) in biochar originated spent coffee ground (SCG) and the tetracycline (TC) adsorption behavior of biochar in water. The results showed that biochar synthesized at 500 °C (SCG 500) contained low PAHs (600 µg kg-1) and the highest TC adsorption efficiency. In addition, the characteristics, influencing factors on TC adsorption, and the related mechanisms of SCG 500 were comprehensively investigated. The results showed that the highest efficiency was observed at pH of 7 and the presence of ions in salinity solution reduced the adsorption capacity of SCG 500. The electrostatic interaction, hydrogen bonding, and π-EDA were the major adsorption mechanisms. Safety PAHs level, low-cost, widely material sources and high TC removal capacity suggested that SCG 500 was a promising environmentally friendly effective absorbent.


Assuntos
Carvão Vegetal/química , Café/química , Hidrocarbonetos Policíclicos Aromáticos/química , Tetraciclina/química , Água/química , Adsorção , Pirólise , Temperatura Ambiente
14.
Colloids Surf B Biointerfaces ; 179: 56-65, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-30947084

RESUMO

One hallmark of solid tumors, regardless of its type or stage, is the existence of an unsual acidic microenvironment, which has been considered a specific and ideal target for cancer imaging. Therefore, we developed a pH-activatable nanoprobe GNPs-CKL-FA for near-infrared fluorescence (NIR) and computed tomography (CT) imaging of tumors. This nanoprobe consists of a near-infrared fluorophore (Cy5.5), a pH-sensitive ketal linker, and gold nanoparticles (GNPs) decorated with folates that could bind to tumor cells' surface receptors to promote cellular internalization. This ability of folate to mediate tumor targeting and accelerate internalization has been confirmed by in vitro experiments with HeLa cells. The fluorescence of the nanoprobes successfully activated by low intracellular pH, especially in more acidic organelles. Furthermore, fluorescence signals increased to a greater extent when the pH in tumors was lowered by injection of acetate buffer and isoproterenol. The CT contrast of GNPs-CKL-FA was obtained after administering intravenously to HeLa subcutaneous tumor-bearing mice. These results suggest that GNPs-CKL-FA has the potential to be a pH-activatable fluorescent nanoprobe combined with CT contrast agent for tumor targeted imaging.

15.
Sci Total Environ ; 673: 296-305, 2019 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-30991319

RESUMO

An electrode made of loofah sponge derived activated carbon supported on nickel foam (AC/Ni) was successfully fabricated and used to remove ammonium ion (NH4+) from aqueous solution. A multilayer adsorption isotherm was used to describe ammonium electro-sorption on AC/Ni electrodes at different temperature, initial NH4+ concentration, and electrical field. The cyclic voltammetry (CV) results suggested that the electrical capacitance of AC/Ni electrodes, with the AC being prepared without preheating (OAC) or with low temperature heating (i.e., 300 AC), were higher than those prepared at high preheating temperature (i.e., 400 AC and 500 AC). Increasing the electro-sorption temperature from 10 to 50 °C decreased the monolayer NH4+ adsorption capacity from 5 to ca. 2-3 mg-N g-1, respectively. Background electrolyte, namely, sodium sulfate, exhibited significant competitive effect on the adsorption of ammonium ion at sodium ion concentration > 10-2 M. The activation energy and heat of adsorption were 9-23.2 kJ mol-1 and -3.7--10.7 kJ mol-1, respectively, indicating a physisorption and exothermic adsorption characteristics. Based on the kinetics and thermodynamics analysis, there was slight increase in the activation energy with elevating preheating temperature, which increased the quantity of micro-pores and surface heterogeneity of the AC materials. Overall, results clearly demonstrated that carbon pyrolysis played a role on the capacitive charging behaviors of electrodes and the efficiency of NH4+ electro-sorption on the AC/Ni electrodes.


Assuntos
Compostos de Amônio/química , Carvão Vegetal/química , Luffa/química , Níquel/química , Poluentes Químicos da Água/química , Adsorção , Compostos de Amônio/análise , Eletrodos , Concentração de Íons de Hidrogênio , Cinética , Modelos Químicos , Temperatura Ambiente , Termodinâmica , Poluentes Químicos da Água/análise
16.
Sci Total Environ ; 675: 31-40, 2019 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-31026641

RESUMO

MnO2 is a common material for the fabrication and design of capacitive deionization (CDI) devices but there is little information on the role of MnO2 crystal phase on CDI performance. A series of MnO2 (α, ß, γ, and δ phase) were synthesized and fabricated as cathodes for studying the CDI performance as affected by pH in simple batch mode experiments. Our results revealed that the deionization efficiency decreased with increased negative surface charge as a result of the deprotonated surface. Importantly, this correlation was pH independent and the surface heterogeneity due to different MnO2 phase was likely responsible for the different degree of surface ionization and consequently the CDI efficiency. Results of electrochemical impedance spectroscopy analyses further implicated that a highly ionized surface would result in a diffusion layer with a great resistance that conversely inhibited the access of co-ions in the CDI process. This indicated the applied potential was mainly responsible for driving ions transporting through the double layer resistance instead of accommodating them (electrosorption). Based on our results, the surface heterogeneity as a result of different spatially distributed MnO6 octahedral would be accounted for the varying degree of surface ionization and consequently the discrepancy in CDI efficiency among different MnO2 phases.

17.
Sci Total Environ ; 675: 531-541, 2019 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-31030159

RESUMO

A simple and facile synthesis method is developed for the fabrication of CoO loaded ordered mesoporous carbon nitride (CoO@meso-CN) composites, at various CoO loadings, and used, for the first time, to activate persulfate (PS) for methylene blue (MB) degradation. The interfacial interaction between the ultrafine CoO nanoparticles, immobilized by high surface area, regular mesopores, and graphitic nature of the meso-CN support can further enhance the catalytic activation of PS for methylene blue (MB) degradation. Among all catalysts studied, the 5-wt% CoO@meso-CN exhibits the best catalytic performance with a kobs of 0.264 min-1. High initial pH, especially at pH-11, is more beneficial for PS activation. Furthermore, the CoO@meso-CN nanocatalyst is highly stable with a consistently high degree of MB degradation and negligible cobalt leaching for at least 5 consecutive catalytic cycles. Both SO4- and OH are the major reactive species based on results of EPR and quenching experiments. The degradation intermediates of MB are also identified by HPLC/MS/MS and the possible degradation pathway is proposed. Results clearly demonstrate that CoO@meso-CN is a promising green catalyst with enormous potential for the remediation of hazardous chemicals using PS.

18.
J Chin Med Assoc ; 82(1): 55-59, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30839405

RESUMO

BACKGROUND: Hyperkalemia is a risky and potentially life-threatening condition in pre-term infants. Glucose-insulin infusion has been considered a major therapeutic way for non-oligouric hyperkalemia but affects the stability of blood sugar level. We aimed to evaluate the effectiveness of salbutamol nebulization compared to glucose-insulin infusion for the treatment of non-oliguric hyperkalemia in premature infants. METHODS: Forty premature infants (gestation age ≤36 weeks) with non-oliguric hyperkalemia (central serum potassium level greater than 6.0 mmol/L) within 72 h of birth were enrolled in this study. These infants were randomly assigned into two groups. One group received a regular insulin bolus with glucose infusion (Group A; n = 20), and the other received salbutamol (Ventolin) by nebulization (Group B; n = 20). Potassium level, blood sugar, heart rate, and blood pressure were recorded for each group before treatment and at 3, 12, 24, 48, and 72 h post-treatment. RESULTS: The serum potassium levels were reduced after treatment in both groups. No significant changes in heart rate or blood pressure were observed in either group. The fluctuation in glucose levels was gentler in the salbutamol-treated group than in the glucose-insulin infusion group. CONCLUSION: Salbutamol nebulization is not only as effective as glucose-insulin infusion for treating non-oliguric hyperkalemia in premature infants but can avoid potential side effects such as vigorous blood glucose fluctuations.


Assuntos
Albuterol/administração & dosagem , Glicemia/análise , Hiperpotassemia/tratamento farmacológico , Pressão Sanguínea/efeitos dos fármacos , Método Duplo-Cego , Frequência Cardíaca/efeitos dos fármacos , Humanos , Hiperpotassemia/sangue , Hiperpotassemia/fisiopatologia , Recém-Nascido , Recém-Nascido Prematuro , Nebulizadores e Vaporizadores , Estudos Prospectivos
19.
Bioresour Technol ; 281: 143-148, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30818265

RESUMO

In this study, an environmentally friendly and economically viable bamboo biochar (BB) was modified by Fe3O4 and was applied for the treatment of real river sediments containing the endocrine disruptor chemical (EDC) 4-nonylphenol (4-NP). The microporosity of Fe3O4-BB was clearly observed from the N2 adsorption isotherms. The catalytic performance of Fe3O4-BB is highly dependent on pH and the catalyst dosage. The degradation efficiency of 4-NP (85%) was achieved at pH 3.0 using an initial dosage of 3.33 g L-1 Fe3O4-BB and 2.3 × 10-5 M persulfate (PS) in a biochar-sediment system. The kinetic behavior of 4-NP degradation with catalysis can be accounted by using the Langmuir-Hinshelwood type kinetic model. The MTT assay results indicated that Fe3O4-BB has a low potent cytotoxic effect and is therefore suitable for application in remediation of contaminated sediment.


Assuntos
Carvão Vegetal/química , Sedimentos Geológicos/química , Fenóis/química , Adsorção , Catálise , Cinética
20.
Anal Chim Acta ; 1059: 86-93, 2019 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-30876636

RESUMO

A novel, simple, and label-free amplification electrochemical impedance method for quantitative detection of Human T-lymphotropic virus types II(HTLV-II) via click chemistry-mediated of hairpin DNA probes (hairpins) with polymers was developed. The hairpins were firstly attached to the gold electrode surface by an S-Au bond, the azido terminals of hairpins were close to the electrode surface, which make it difficult to be approached. After hybridizing with HTLV-II, the hairpins were unfolded and experienced a big configuration change, which made the azido terminals of the hairpins available to conjugate with alkynyl-containing polymer, called P(DEB-DSDA), formed by 1,4-diacetylenebenzene (DEB) and 4,4'-Diazido-2,2'-stilbenedisulfonic acid disodium salt tetrahydrate (DSDA) via Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC). With amount of P(DEB-DSDA) conjugated with the hairpin probes via click polymerization, its electrochemical signal can have a great amplification. Under optimized experimental conditions, this new probe showed a low detection limit of 0.171 pM with a good liner in the range of 1 pM-1 nM. Meanwhile, the biosensor also exhibited good selectivity and reliability in detection of real serum samples, indicating that it has great application potential in clinical DNA diagnosis and detection.


Assuntos
Técnicas Biossensoriais/métodos , Sondas de DNA/química , Técnicas Eletroquímicas/métodos , Vírus Linfotrópico T Tipo 2 Humano/isolamento & purificação , Carga Viral/métodos , Azidas/síntese química , Azidas/química , Sangue/virologia , Química Click , Reação de Cicloadição , Sondas de DNA/genética , DNA Viral/genética , Sequências Repetidas Invertidas , Limite de Detecção , Hibridização de Ácido Nucleico , Polímeros/síntese química , Polímeros/química , Estilbenos/síntese química , Estilbenos/química
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