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Two air-stable novel Lewis acids of triphenylantimony(V) pentafluorbezenesulfonates ( 2 ) and perfluorooctanesulfonates ( 3 ) were successfully synthesized and characterized. X-ray studies and thermo-gravimetric analysis found that these complexes showed high anti -hydrolyzability and thermal stability. The high catalytic activity and excellent recyclability of these complexes were achieved in the Michael addition reaction and the allylation reaction. On account of their stability, storability, as well as catalytic efficiency, these complexes should find a broad range of utility in organic synthesis. [ABSTRACT FROM AUTHOR]

Zirconocene bis(perfluorobutanesulfonate) is air- and water-stable and proved to be ionic on basis of conductivity measurements. It exhibits high catalytic efficiency for the synthesis of N-heterocyclic compounds under solvent-free condition, such as benzimidazoles, benzodiazepines, dihydropyrimidinones and dihydropyridines under mild condition. Furthermore, it can be reused without loss of activity in a test of five cycles. This catalytic system affords a simple and efficient approach for the synthesis of N-heterocyclic compounds. [ABSTRACT FROM AUTHOR]

In this study, a novel composite adsorbent (HBC–Fe 3 O 4 –MnO 2 ) was synthesized by combining honeycomb briquette cinders (HBC) with Fe 3 O 4 and MnO 2 through a co-precipitation process. The purpose was to make the best use of the oxidative property of MnO 2 and the adsorptive ability of magnetic Fe 3 O 4 for enhanced As(III) and As(V) removal from aqueous solutions. Experimental results showed that the adsorption capacity of As(III) was observed to be much higher than As(V). The maximum adsorption capacity (2.16 mg/g) was achieved for As(III) by using HBC–Fe 3 O 4 –MnO 2 (3:2) as compared to HBC–Fe 3 O 4 –MnO 2 (2:1) and HBC–Fe 3 O 4 –MnO 2 (1:1). The experimental data of As(V) adsorption fitted well with the Langmuir isotherm model, whereas As(III) data was described perfectly by Freundlich model. The pseudo-second-order kinetic model was fitted well for the entire adsorption process of As(III) and As(V) suggesting that the adsorption is a rate-controlling step. Aqueous solution pH was found to greatly affect the adsorption behavior. Furthermore, co-ions including HCO 3 − and PO 4 3− exhibited greater influence on arsenic removal efficiency, whereas Cl − , NO 3 − , SO 4 2− were found to have negligible effects on arsenic removal. Five consecutive adsorption-regeneration cycles confirmed that the adsorbent could be reusable for successive arsenic treatment and can be used in real treatment applications. [ABSTRACT FROM AUTHOR]

An air-stable uninuclear complex of bis(isopropylcyclopentadienyl) zirconium perfluorooctane sulfonate ( 1a · H 2 O · 3THF ) was successfully synthesized by the reaction of ( i -PrCp) 2 ZrCl 2 with C 17 SO 3 Ag. The compound 1a · H 2 O · 3THF was characterized by different techniques (such as X-ray single crystal diffraction, TG-DSC, conductivity measurement and acid strength) and found to have the similar nature of water tolerance, air-stability, thermally-stability and strong Lewis-acidity with that of our previously reported binuclear and uninuclear zirconocenes perfluorooctanesulfonate. This novel complex was confirmed to be an effective catalyst with good recyclability and reusability for the direct benzylation of 1,3-dicarbonyl derivatives using alcohols as alkylating agents. Various 1,3-dicarbonyl and alcohols derivatives can participate in the reaction, affording the corresponding monobenzylated products in competitive yields as compared to its counterparts, such as Cp 2 Zr(OSO 17 ) 2 ·3H 2 O·THF and the traditional Lewis-acid catalysts. [ABSTRACT FROM AUTHOR]

Wet flue gas desulfurization (WFGD) system has been increasingly recognized to be effective in Hg removal. But the generated secondary pollution due to Hg re-emission from desulfurization solutions or solid byproducts has received researchers’ attention. In this paper, the distribution of captured Hg 2+ (L) in the simulated WFGD slurry was studied as a function of various environmental factors. Experimental results indicated that the pH value had a strong effect on Hg 2+ reduction but had negligible influence on the Hg 2+ retention by the grained fraction of gypsum. Increasing in pH value resulted in higher Hg 2+ reduction and over 46% of Hg 2+ was found to be reduced into Hg 0 at pH 5.0. Besides, increased slurry temperature also promoted the Hg 2+ reduction and Hg 0 re-emission as well as the Hg 2+ retention efficiency by gypsum. Other factors including S (IV), Cl − and NO 3 − concentration was found to inhibit Hg 2+ transformation into Hg 0 but slightly promoted the Hg 2+ retained in gypsum. Moreover, the addition of sodium sulfide (Na 2 S), 2,4,6-trimercaptotiazine, trisodium salt nonahydrate (TMT), and sodium dithiocarbamate (DTCR) prevented the Hg 2+ reduction and precipitated out as insoluble HgS, Hg 3 (TMT) 2 and Hg(DTCR) 2 on gypsum. The findings presented in this study could provide theoretical basis for Hg removal in coal-fired power plants. [ABSTRACT FROM AUTHOR]

Microbial-driven biogeochemical cycles in wetlands impacted by global warming pose a potential downstream eutrophication risk. However, the consequences of ongoing warming on the functional and metabolic potential of sediment microbial communities are largely unknown. We incubated sediment samples under both ambient temperature conditions (control) and simulated warming conditions of 5°C above ambient temperature (warmed) using a novel field microcosm system. In warmed samples, we observed in situ a decreased thickness of the oxidized sediment layer and associated lower sediment redox potential. GeoChip 4.0, a comprehensive functional gene microarray, demonstrated that many functional genes that are involved in oxidation-reduction reactions and in phosphorus (P) degradation were preferentially enriched under warming conditions. The enriched genes included those genes encoding carbon monoxide dehydrogenase, acetyl-CoA carboxylase biotin carboxylase ( ppc), and ribulose-1,5-bisphosphate carboxylase (Rubisco) for carbon fixation; nitrate reductases ( narG) and nitrous oxide reductases ( nosZ) for denitrification; cytochrome c for metal reduction; and exopolyphosphatase ( ppx) for polyphosphate degradation. The redox potential was one of the most significant parameters linked to microbial functional gene structure. These results demonstrate that the enhanced hypoxia and anaerobic metabolic pathways accelerated sediment P mobilization in freshwater wetland subject to warming, raising the potential of water eutrophication. [ABSTRACT FROM AUTHOR]

Nitrite-dependent anaerobic methane oxidation (n-damo) is a newly discovered biological process that couples anaerobic oxidation of methane (AOM) to nitrite reduction. In this study, three different inocula, methanogenic sludge, paddy soil, and freshwater sediment were used to enrich n-damo bacteria in three sequencing batch reactors (SBRs), and three n-damo enrichment cultures, C1, C2 and C3, were obtained, respectively. After 500 days of incubation, Methylomirabilis oxyfera-like bacteria and n-damo activities were observed in cultures C1, C2, and C3, and the specific activities were 0.8 ± 0.1, 1.4 ± 0.1, and 1.0 ± 0.1 μmol CH h g VSS, respectively. The copy numbers of 16S rRNA genes from cultures C1, C2, and C3 were 5.0 ± 0.4 × 10, 6.1 ± 0.1 × 10, and 1.0 ± 0.2 × 10 copies g dry weight, respectively. The results indicated that paddy soil is an excellent inoculum for n-damo bacterial enrichment. This work expanded the alternative source of n-damo inoculum and benefited the further research of n-damo process. [ABSTRACT FROM AUTHOR]

Anaerobic oxidation of methane coupled to nitrite reduction (n-damo) plays an important role in global carbon and nitrogen cycles and also is a potential bioprocess in wastewater treatment. In this work, the effects of environmental conditions – temperature, pH and salinity – on the metabolic activity and growth rate of n-damo bacteria were investigated by short-term batch test and long-term bacterial incubation. Quantitative PCR and 16S rRNA and pmo A gene sequencing were applied to detect the microbial community in the long-term incubation. The results indicated that all the three environmental factors significantly affected the metabolic activity and growth rate of n-damo bacteria and the optimum temperature, pH and salinity were 35 °C, 7.6 and 0 g NaCl L −1 , respectively. Notably, salinity adaption of n-damo bacteria was first observed under salinity stress of 20 g NaCl L −1 . It's predicted that n-damo process might occur in saline environments and future work could focus on this. [ABSTRACT FROM AUTHOR]

Elevated concentration of arsenic in water supplies is detected worldwide and therefore becomes a global issue. Calcination process is known to increase the adsorbent hardness for its effective application in column-based treatment. In this study, magnetic honeycomb briquette cinders (MHBC) and its calcined products: MHBC(A) and MHBC(N) were employed for the adsorptive removal of As(III) in fixed-bed column. Characterizations revealed that the calcination at 1000 °C under nitrogen has significantly increased the adsorbent particles size; favored phase transformation and improved saturation magnetization (>20 emu g − 1 ). Additionally, the new iron silicate phase (Fe 2 SiO 4 ) in aqueous medium generated highly reactive iron oxide species (=FeOOH), which effectively bind As(III) from the influent water by ligand exchanges. In contrast, calcination under dynamic air drastically reduced the saturation magnetization (<1 emu g − 1 ) and assisted to form segregated magnetite, quartz and hematite, as revealed in XRD patterns. The breakthrough curve of each column was compared with Thomas model and found that the model could be applied to estimate As(III) adsorption in fixed-bed column. Thomas model suggested parameters follow the order: MHBC(N) > MHBC > MHBC(A) and the maximum solid phase concentration ( q T ) was found to be about 56.07 mg g − 1 for MHBC(N). The column beds could be successfully regenerated using 200 bed volume of 10% NaOH solution. This study suggests that the selective calcination process need to be integrated with the adsorbent development process for the efficient removal of As(III) from contaminated water using column-based treatment. [ABSTRACT FROM AUTHOR]

Magnetic biochar is increasingly known as a multi-functional material and the appropriate synthesis method further increase its efficient applications. In this study, the effects of synthesis methods on the fabrication of Kans grass straw/biochar (KGS/KGB) with Fe 3+ /Fe 2+ by chemical co-precipitation and subsequently pyrolyzing at 500 °C for 2 and 4 h were studied in details, and compared their As(III, V) adsorption potentials under different operating conditions. Magnetic biochars (MKGB3 and MKGB4) prepared from KGS revealed of superior Fe 3 O 4 loading, higher As(III, V) adsorption efficiency and saturation magnetization (45.7 Am 2 kg −1 ) than that of KGB (MKGB1 and MKGB2). Moreover, Thermogravimetric analysis (TGA) demonstrated three stages of decomposition and the MKGB3 and MKGB4 generated higher residual mass (>60%) at stage 3 (1000 °C) due to greater Fe 3 O 4 composite in biochar matrix and turned to be thermally more stable. As(III) and As(V) adsorption equilibrium data well fitted in Langmuir model and followed the order: MKGB4 > MKGB3 > MKGB2 > MKGB1. The maximum As(III) and As(V) adsorption capacities were about 2.0 mg g −1 and 3.1 mg g −1 , respectively. The data best fitted in pseudo-second-order ( R 2 > 0.99) rather than pseudo-first-order kinetics model indicating of more complex mechanism. The adsorption of As(III) and As(V) was found to decrease with increasing in ionic strength of competing ions and PO 4 3− was found to strongly inhibit arsenic adsorption. Highest desorption was achieved at pH 13.5 using NaOH. This study suggests that selective adsorbent synthesis method could be useful to prepare effective adsorbent for toxic metals immobilization. [ABSTRACT FROM AUTHOR]

Highlights: [•] Effective electrocatalytic dechlorination of 2,4-D was achieved. [•] Dechlorination efficiency was enhanced by nTiN doped in Pd layer on the electrode. [•] nTiN doping content and Pd loading influenced the dechlorination efficiency. [•] Hydrogen adsorption balance existed between two phases in Pd layer. [•] Active hydrogen atom [H] could be stored in Pd lattice for a period of time. [Copyright &y& Elsevier]

Nitrite-dependent anaerobic methane oxidation (n-damo) is mediated by bacteria that anaerobically oxidize methane coupled with nitrite reduction and is a potential bioprocess for wastewater treatment. In this work, the effect of reactor configuration on n-damo bacterial cultivation was investigated. A magnetically stirred gas lift reactor (MSGLR), a sequencing batch reactor (SBR), and a continuously stirred tank reactor (CSTR) were selected to cultivate the bacteria. Microbial community was monitored by using quantitative PCR, 16S rRNA gene sequencing, pmoA gene sequencing, and fluorescence in situ hybridization (FISH). The effects of substrate inhibition, methane mass transfer, and biomass washout in the three reactors were focused on. The results indicated that the MSGLR had the best performance among the three reactor systems, with the highest total and specific n-damo activities. Its maximum volumetric nitrogen removal rate was up to 76.9 mg N L day, which was higher than previously reported values (5.1-37.8 mg N L d). [ABSTRACT FROM AUTHOR]

Highlights: [•] Nano-Ni/Fe were synthesized in the presence of ultrasonic irradiation. [•] Ultrasonic irradiation can improve nano-Ni/Fe′ disparity and avoid agglomeration. [•] 2,4-DCP was first adsorbed by nano-Ni/Fe, then was quickly dechlorinated. [•] Factors of reductive dechlorination by nano-Ni/Fe were studied. [ABSTRACT FROM AUTHOR]

Abstract: Sn hollow nanospheres (HNSs) were prepared by galvanic replacement, employing Ni nanospheres (NSs) as templates. The formation process and electrochemical performance of Sn HNS were studied. The Sn HNS resulted in better stability and electrochemical performance when used as an anode material in lithium-ion batteries. The Sn HNS electrode retained a good reversible capacity of 516.1mAhg−1 after 50 cycles at a current density of 100mAhg−1, which was much higher than that of Sn NS (128mAhg−1). TEM images of the Sn HNSs after 50 cycles indicated that the volume expansion outside the spheres had been alleviated, and the aggregation between the active materials had been prevented. [Copyright &y& Elsevier]

In the presence of a catalytic amount cesium hydroxide, the corresponding aryltellurophosphates can be obtained by the reactions of dialkyl phosphites with diaryl ditellurides in excellent yield at room temperature, using dimethylsulfoxide as solvent. The possible reaction mechanism was discussed. The method could provide a new and expedient path for the preparation of aryltellurophosphates. [ABSTRACT FROM AUTHOR]

The catalytic dechlorination of2,4-dichlorophenol (2,4-DCP) by Ni/Fe bimetallic nanoparticles in the presence of humic acid (HA) was investigated in order to understand their applicability forin situremediation of groundwater.2,4-DCP was catalytically dechlorinated to form the final products – phenol (P) via two intermediates,o-chlorophenol (o-CP) andp-chlorophenol (p-CP). It was demonstrated that the carbon mass balances during the dechlorination were between 84% and 92%, and other carbons were adsorbed on the surface of Ni/Fe bimetallic nanoparticles. The experimental results suggest that HA competed for reaction sites on the Ni/Fe bimetallic nanoparticles with2,4-DCP, and thus reduced the efficiency and rate of the dechlorination of2,4-DCP. The catalytic degradation slowed down as the increase of HA in solution, and when HA's concentrations were 0, 10, 20 and 30 mg L−1, the maximum concentrations ofo-CP were 0.025, 0.041, 0.039 and 0.034 mM in 10, 30, 30 and 30 min, respectively. High Ni content, low initial pH value, high Ni/Fe nanoparticles’ dosage and high temperature favoured the catalytic dechlorination of2,4-DCP. The experimental results show that no other intermediates were generated besides Cl−,o-CP,p-CP and P during the catalytic dechlorination of2,4-DCP. [ABSTRACT FROM PUBLISHER]

The air-stable hafnocene Lewis acid catalyst is shown to be effective in Lewis acid-catalyzed C-C bond forming reactions. [ABSTRACT FROM AUTHOR]

The presence of elevated concentration of arsenic in water sources is considered to be health hazard globally. Calcination process is known to change the surface efficacy of the adsorbent. In current study, five adsorbent composites: uncalcined and calcined Fe3O4-HBC prepared at different temperatures (400°C and 1000°C) and environment (air and nitrogen) were investigated for the adsorptive removal of As(V) and As(III) from aqueous solutions determining the influence of solution's pH, contact time, temperature, arsenic concentration and phosphate anions. Characterizations from FTIR, XRD, HT-XRD, BET and SEM analyses revealed that the Fe3O4-HBC composite at higher calcination temperature under nitrogen formed a new product (fayalite, Fe2SiO4) via phase transformation. In aqueous medium, ligand exchange between arsenic and the effective sorbent site ( = FeOOH) was established from the release of hydroxyl group. Langmuir model suggested data of the five adsorbent composites follow the order: Fe3O4-HBC-1000°C(N2)>Fe3O4-HBC (uncalcined)>Fe3O4-HBC-400°C(N2)>Fe3O4-HBC-400°C(air)>Fe3O4-HBC-1000°C(air) and the maximum As(V) and As(III) adsorption capacities were found to be about 3.35 mg g−1 and 3.07 mg g−1, respectively. The adsorption of As(V) and As(III) remained stable in a wider pH range (4–10) using Fe3O4-HBC-1000°C(N2). Additionally, adsorption data fitted well in pseudo-second-order (R2>0.99) rather than pseudo-first-order kinetics model. The adsorption of As(V) and As(III) onto adsorbent composites increase with increase in temperatures indicating that it is an endothermic process. Phosphate concentration (0.0l mM or higher) strongly inhibited As(V) and As(III) removal through the mechanism of competitive adsorption. This study suggests that the selective calcination process could be useful to improve the adsorbent efficiency for enhanced arsenic removal from contaminated water. [ABSTRACT FROM AUTHOR]

Highlights: [•] Hg was mainly distributed in strong complex phase in FGD gypsum. [•] Chlorine content in coal might influence water soluble Hg in FGD gypsum. [•] Hg release ability from FGD gypsum was related to its speciation. [•] Water soluble Hg was easily to release, while residual Hg was relatively stable. [•] Hg emission from FGD gypsum during its disposal in Zhejiang province was estimated. [Copyright &y& Elsevier]

The inhibitory effect of barley straw ( Hordeum vulgare) on cyanobacteria has been observed in many field and laboratory studies for over 30 years, although the compounds responsible for this anti-cyanobacterial effect have remained unknown. In this study, a pair of chiral flavonolignans were isolated from barley straw extract using a bioassay-guided isolation procedure against Microcystis sp. The structures of the allelopathic compounds were elucidated by NMR (nuclear magnetic resonance) and HPLC-MS (high performance liquid chromatography-mass spectrometry), and turned out to be salcolin A and B. The enantiomers differ in their anti-cyanobacterial abilities. Both enantiomers exhibited inhibitory effects on Microcystis sp., and the EC50 (concentration for 50% of maximal effect) of salcolin A and B were 6.02 × 10−5 and 9.60 × 10−5 mol l−1, respectively. Furthermore, the modes of actions of the enantiomers were investigated and compared at a single cell level by flow cytometry. Salcolin A was found to induce an increase on cyanobacterial intracellular ROS (reactive oxygen species) levels and to inhibit esterase activity, whereas salcolin B caused leakages of cyanobacterial cytoplasms. Thus, salcolin A was more 'algistatic', and salcolin B was more 'algicidal'. This study suggests that salcolin is the key allelochemical in barley straw's inhibitory effect on cyanobacteria and could be used as an agent in the future control of cyanobacterial harmful algae blooms. [ABSTRACT FROM AUTHOR]

Nanostructured hollow Sn-Cu multi-phase composite nanoparticles anode that contains Sn and CuSn was synthesized via galvanic replacement reaction using Sn nanoparticles as a sacrificial template. The sacrificial oxidation of Sn and simultaneous reduction of Cu on the surface because of the redox potential difference is proposed to account for the formation of hollow Sn-Cu nanostructures. The structural evolution of the Sn-Cu hollow nanoparticle, in the process of galvanic replacement and structure, composition changes during charge/discharge processes were studied based on scanning electron microscope, X-ray powder diffraction, transmission electron microscopy, and energy dispersive X-ray spectroscopy investigations. The electrochemical properties of the samples were evaluated by galvanostatic discharge-charge cycling, cyclic voltammetry, and electrochemical impedance spectroscopy. Compared with solid Sn-Cu nanoparticles, hollow Sn-Cu nanoparticles showed better capacity retention. The improved electrochemical performance may be attributed to the stable hollow structure and the combination of CuSn. The facile solution-based process and excellent cycling stability show great potential of the multi-phase Sn-Cu hollow composite nanoparticles as an anode material for lithium-ion batteries. [ABSTRACT FROM AUTHOR]

Highlights: [•] nZVI assembled on magnetic Fe3O4/graphene nanocomposites is synthesized. [•] Better dispersion and stability of nZVI are achieved. [•] These nanocomposites exhibit high removal efficiency on Cr(VI). [•] Cr(VI) adsorption and reduction via nZVI-graphene/Fe3O4 battery work synergically. [ABSTRACT FROM AUTHOR]

Objective: This study investigated the feasibility, timing and indications for closure of large muscular ventricular septal defects (VSDs) in infants without use of a cardiopulmonary bypass. Methods: A total of 9 infants with large muscular VSDs ranging in size from 7 to 15 mm were treated by minimally invasive closure without cardiopulmonary bypass between April 2010 and February 2013. Results: All surgeries were successful without resulting in uncontrolled systemic infection, a pulmonary hypertensive crisis or a severely low cardiac output, and with an apparently shorter operation time and postoperative tracheal cannula. Conclusions: VSD closure without cardiopulmonary bypass can improve the efficacy and prognosis of infants with large muscular VSDs and concurrent pulmonary infections or respiratory failure. © 2014 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Abstract: Flue gas desulfurization system used for SO2 removal has co-beneficial removal of Hg, which has resulted in Hg-laden gypsums. With growing beneficial reuse applications of the FGD gypsum, it has been recognized as a potential source of Hg pollution. In this paper, the fate and mobility of Hg were investigated. The Hg content in four samples varied widely and it showed a significant correlation between Hg and sulfite contents in gypsum. In leachate, Hg concentration varied during the leaching process. The Hg extraction rate generally increased with decreasing pH value, which suggested that the environmental risk of FGD gypsum increased during the multipurpose utilization processes, resulted from severe acid rain. The released Hg from FGD gypsum used in this study exhibited biphasic kinetics. Hg in FGD gypsum samples not only appeared in the leachate but also re-emitted into the air. The Hg reduction kinetics followed the pseudo-first-order kinetic model well. Our results provide the theoretical understanding for the co-removal of highly soluble oxidized Hg in WFGD systems and also in the recycling of the FGD gypsum. [Copyright &y& Elsevier]

Zirconocene bis(perfluorobutanesulfonate) [Cp2Zr(OSO2C4F9)2·2H2O] was successfully synthesized by treatment of Cp2ZrCl2 with C4F9SO3Ag, and was found to have the nature of air-stability, water tolerance, high thermal stability and strong Lewis acidity. This complex showed high catalytic efficiency for the synthesis of α-aminophosphonates via Kabachnik–Fields reaction of aldehydes/ketones, amines and diethyl phosphite under mild and solvent-free conditions. Furthermore, it can be reused without loss of activity in a test of five cycles. Compared with our previously reported complex of Cp2Zr(OSO2C8F17)2·3H2O·THF, this complex showed better catalytic activity. [ABSTRACT FROM AUTHOR]

Soil biogeochemical processes and the ecological stability of wetland ecosystems under global warming scenarios have gained increasing attention worldwide. Changes in the capacity of microorganisms to maintain stoichiometric homeostasis, or relatively stable internal concentrations of elements, may serve as an indicator of alterations to soil biogeochemical processes and their associated ecological feedbacks. In this study, an outdoor computerized microcosm was set up to simulate a warmed (+5°C) climate scenario, using novel, minute-scale temperature manipulation technology. The principle of stoichiometric homeostasis was adopted to illustrate phosphorus (P) biogeochemical cycling coupled with carbon (C) dynamics within the soil-microorganism complex. We hypothesized that enhancing the flux of P from soil to water under warming scenarios is tightly coupled with a decrease in homeostatic regulation ability in wetland ecosystems. Results indicate that experimental warming impaired the ability of stoichiometric homeostasis (H) to regulate biogeochemical processes, enhancing the ecological role of wetland soil as an ecological source for both P and C. The potential P flux from soil to water ranged from 0.11 to 34.51 mg m−2 d−1 in the control and 0.07 to 61.26 mg m−2 d−1 in the warmed treatment. The synergistic function of C-P acquisition is an important mechanism underlying C∶P stoichiometric balance for soil microorganisms under warming. For both treatment groups, strongly significant (p<0.001) relationships fitting a negative allometric power model with a fractional exponent were found between n-HC∶P (the specialized homeostatic regulation ability as a ratio of soil highly labile organic carbon to dissolved reactive phosphorus in porewater) and potential P flux. Although many factors may affect soil P dynamics, the n-HC∶P term fundamentally reflects the stoichiometric balance or interactions between the energy landscape (i.e., C) and flow of resources (e.g., N and P), and can be a useful ecological tool for assessing potential P flux in ecosystems. [ABSTRACT FROM AUTHOR]

Abstract: An air-stable Lewis acidic binuclear complex of bis(ethylcyclopentadienyl)zirconium perfluorooctanesulfonate (1a) was successfully synthesized by the reaction of (CH3CH2Cp)2ZrCl2 with C8F17SO3Ag. The complex 1a was characterized by different techniques and found to have the nature of air-stability, water tolerance, thermal-stability, and strong Lewis-acidity. In addition, its solubility was higher than that of our previously reported uninuclear zirconocene bis(perfluorooctanesulfonate). This complex showed high catalytic efficiency, good recyclability, and reusability in the one-pot three-component aza-Friedel–Crafts reactions of indoles with aldehydes and N,N-dimethylaniline. The yields of the corresponding 3-diarylmethyl indoles are higher than those from the traditional Lewis acidic catalysts. [Copyright &y& Elsevier]

Abstract: Air-stable binuclear complex of bis(methylcyclopentadienyl)zirconium perfluorooctanesulfonate (1a) was successfully synthesized by the reaction of (CH3Cp)2ZrCl2 with C8F17SO3Ag. The compound 1a was characterized by different techniques and found to have the nature of air-stability, water tolerance, thermally-stability and strong Lewis-acidity. In addition, its solubility was higher than that of our previously reported uninuclear zirconocene bis(perfluorooctanesulfonate). It showed high catalytic efficiency in the Friedel–Crafts acylation of alkyl aryl ethers and the Mannich reaction and could be reused. [Copyright &y& Elsevier]

The effects of the combination of silane functionalized hollow glass beads (silanized HGBs), acid functionalized carbon nanotubes (oxidized CNTs), and short carbon fibers (SCFs) on the tensile properties of epoxy (EP) resin were investigated. The combined utilization of silanized HGBs, oxidized CNTs and SCFs led to a pronounced synergy in the tensile properties of the SCF/HGB/CNT/EP composites. The composites exhibited greater tensile strength and Young's modulus than the neat EP, clearly. The mechanism of such synergetic effect was analyzed by tensile fracture studies using SEM. In addition, by analyzing the DSC curves, the curing temperatures of the composites were obtained. [ABSTRACT FROM PUBLISHER]

Highlights: [•] Fe0-Fe3O4 nanocomposites are embedded in polyvinyl alcohol/sodium alginate beads;. [•] Acidification and reduction after bead molding greatly improve beads performance;. [•] High stability, Cr(VI) removal efficiency and reusability of these beads;. [•] Easy and complete separation after reaction. [Copyright &y& Elsevier]

Highlights: [•] Arsenic removal performance of SSFs containing HBC and Fe-HBC (50% w/w) is studied. [•] Over 99% and 98% arsenic removals were achieved in SSF(a) and SSF(b) under oxic-environment. [•] Two steps in situ mechanism is proposed to convert As(III) into As(V) and subsequent adsorption. [•] Low levels of influent co-occurring ions did not significantly interfered arsenic removal. [•] Filter with low-cost adsorbents could be proposed as feasible and efficient method for arsenic removal. [ABSTRACT FROM AUTHOR]

The suppressed ion chromatography (IC) and molybdenum blue methods were used to comparatively evaluate phosphorus (P) concentrations. Most of the P was more resistant to hydrolysis in ion chromatography as compared to the molybdenum blue method. However, P analysis by IC is more liable to be interfered than the molybdenum blue method because of the presence of high bivalent and trivalent metal ions. Polyvalent metal ions interfere with organic P hydrolysis or the release of P from colloids during P investigation, which leads to a difference ofortho-phosphate concentrations determined by IC and molybdenum blue methods. During the environmental samples analysis, theortho-phosphate obtained by the IC method was usually less than that obtained by the molybdenum blue method. [ABSTRACT FROM AUTHOR]

Highlights: [•] Pd/Fe-Fe3O4 nanocomposites showed synergy effects on 2,4-DCP dechlorination. [•] Weak acidic condition and high temperature favored 2,4-DCP dechlorination. [•] Common dissolved anions and cations were found to affect 2,4-DCP dechlorination. [•] HA adsorbed on nFe3O4-Pd/Fe would inhibit 2,4-DCP dechlorination. [•] High stabilities and durable reactivity were observed in consecutive experiments. [ABSTRACT FROM AUTHOR]

Highlights: [•] Sensitivity analysis of energy performance is performed for residential envelope. [•] EETP method is introduced to calculate cooling and heating energy use. [•] Shading coefficient and window to wall ratio are the most vital factors in summer. [•] Wall heat transfer coefficient and shape coefficient have crucial effect in winter. [•] Wall heat transfer coefficient and window to wall ratio weight the most in a year. [ABSTRACT FROM AUTHOR]

The influence of quiescent molten-state annealing process on the phase structure and morphology of poly(propylene)/poly(ethylene-co-octene) blends with co-continuous morphology was studied using scanning electron microscopy (SEM). The structure parameter called characteristic length ( L) was calculated by the pattern analysis of SEM micrographs to describe morphological variation with annealing time during molten-state annealing process under quiescent condition. Moreover, the potential fractal behavior of the phase structure and morphology of PP/PEOc = 50/50 blend during the process were discussed. The histograms of P( L/ L) obtained at various annealing time fell on a master curve, demonstrating the self-similar growth of the phase structure of the blends during quiescent molten-state annealing process. [ABSTRACT FROM AUTHOR]

[Display omitted] • Combining PFS&PAC coagulation is proposed to remove ppb-level Sb(V). • Enhanced Sb(V) removal is achieved with presence of dispersive black UD. • Combining PFS&PAC coagulation also removes turbidity caused by dispersive dye. • The removed Sb(V) is bound with O atom originated from PFS hydrolysis. • Flocs derived from combining PFS&PAC can adsorb much more Sb(V) in 30 min. Antimony (Sb) is a typical contaminant in textile wastewater due to its extensive use in fabric production. Although Fe coagulant shows good performance towards Sb in simulated condition, co-existing components such as dye, coexisting ion, and humic acid (HA) in actual textile wastewater would hinder its application. This study proposes a combination of poly ferric sulfate and poly aluminum chloride (PFS&PAC) to remove ppb-level Sb(V) from both simulated and actual textile matrix with presence of typical dispersive dye. By optimizing the operating parameters, maximum Sb(V) removal efficiency of 95.0% is observed with coexistence of 100 mg L−1 dispersive black UD at pH 3, with dosage of 200 mg L−1 PFS and 100 mg L−1 PAC. The response surface methodology indicates that nitrate and chloride have negligible effect on the Sb(V) removal capacity, while HA and phosphate inhibit Sb(V) removal. When compared with PFS, combining PFS&PAC coagulation also reduces the turbidity caused by dispersive black UD in both simulated (from 450 to 22 NTU) and actual textile wastewater (from 116 to 42 NTU). The XPS spectra of flocs suggests that Sb(V) can be bounded with O atom. Aging test suggests the PAC addition retards transformation of flocs from amorphous ferrihydrite to crystalline phases, thus providing more active adsorption sites for Sb(V) removal with presence of competing dispersive dye. Newly produced flocs derived from combining PFS&PAC coagulation can adsorb 63% Sb(V) in 30 min, which is 2.3 folds than that of PFS only. [ABSTRACT FROM AUTHOR]

Cr(VI) is a toxic pollutant and its reduction to relatively less toxic Cr(III) can solve this problem to a greater extent. In the present study, coupled reduction–sorption of Cr(VI) in aqueous solutions using limonite was investigated as a function of pH, limonite dose and particle size. Results demonstrated that the smaller limonite particle size and low pH aqueous medium favored high Cr(VI) removal. Significant Cr(VI) removal (>55±1%) was achieved with 100–200mesh, whereas only 25±0.7% and 10±0.5% removals were attained using 30–40mesh and 20–30mesh, respectively, after 2h reaction. Acid pH proved beneficial and the complete Cr(VI) removal was observed at pH <4.0 compared to that of 10±0.5% at pH9.0. Moreover, above 53±2.5% of Cr(VI) removal rates were maintained in the first three batch experiment runs and then drastically decreased to below 5±0.3% in experiment Run-7. The Brunauer–Emmett–Teller (BET) surface area and sorption capacity of limonite were 35.22m2 g−1 and 10.03mgg−1, respectively. The reaction mechanism demonstrated that under acidic aqueous medium, the dissolved Fe(II) and S(II) on limonite surface reacted with Cr(VI) and formed Cr3S4 and Cr5Si3 precipitates. But the resultant precipitates on limonite surface hindered further Cr(VI) removal and passivated, affirmed in XRD and ESEM analyses. This study suggested that limonite can be used for the effective removal of Cr(VI) from contaminated water environments. [ABSTRACT FROM AUTHOR]

The transient state of the phase morphology of polypropylene with poly(ethylene-co-1-octene) blends during melt mixing are investigated by the pattern analysis of scanning electron microscope (SEM). The results show that morphology develops mainly at the initial stages of mixing. During the intermediate mixing stage, a dynamic equilibrium is established between breakup and coalescence of domains. The mixing time required for reaching equilibrium stage reduces as shear rate increases. The fractal analysis indicates that the development of the dispersed phase during melt mixing process evolves with dynamical self-similarity partly through the competitions of break-up and coalescence of dispersed phase. [ABSTRACT FROM AUTHOR]

Abstract: Palladium/Iron (Pd/Fe) nanoparticles were prepared by using ultrasound strengthened liquid phase reductive method to enhance dispersion and avoid agglomeration. The dechlorination of 2,4-dichlorophenol (2,4-DCP) by Pd/Fe nanoparticles was investigated to understand its feasibility for an in situ remediation of contaminated groundwater. Results showed that 2,4-DCP was first adsorbed by Pd/Fe nanoparticles, then quickly reduced to o-chlorophenol (o-CP), p-chlorophenol (p-CP), and finally to phenol (P). The induction of ultrasound during the preparation of Pd/Fe nanoparticles further enhanced the removal efficiency of 2,4-DCP, as a result, the phenol production rates increased from 65% (in the absence of ultrasonic irradiation) to 91% (in the presence of ultrasonic irradiation) within 2h. Our data suggested that the dechlorination rate was dependent on various factors including Pd loading percentage over Fe0, Pd/Fe nanoparticles availability, temperature, mechanical stirring speed, and initial pH values. Up to 99.2% of 2,4-DCP was removed after 300min reaction with these conditions: Pd loading percentage over Fe0 0.3wt.%, initial 2,4-DCP concentration 20mgL−1, Pd/Fe dosage 3gL−1, initial pH value 3.0, and reaction temperature 25°C. The degradation of 2,4-DCP followed pseudo-first-order kinetics reaction and the apparent pseudo-first-order kinetics constant was 0.0468min−1. [Copyright &y& Elsevier]

Highlights: [•] Enhanced catalytic dechlorination of 2,4-dichlorophenoxyacetic acid. [•] Synergistic technology combined nZVI with electrochemistry. [•] Palladium loading and current density had a greater impact on efficiencies. [•] nZVI promoted the generation of electron and enhanced the dechlorination. [Copyright &y& Elsevier]

This work was aimed at studying the phase structure and evolution of polypropylene (PP)/poly(ethylene-1-octene) copolymer (PEOc) blends with droplet/matrix morphology using scanning electron microscopy (SEM) during quiescent molten-state annealing process. The structure parameters, such as the area diameter, d, and number average diameters, D, of the dispersed phase in PP/PEOc blends were calculated by pattern analysis of SEM images. Moreover, the potential fractal behavior of the phase structure and morphology of PP/PEOc = 80/20 blend during the process was discussed. The histograms of $$ P\left( {{d_p \left/ {{{{\overline{d}}_p}}} \right.}} \right) $$ obtained at various annealing time fell on a master curve, demonstrating the self-similar growth of the phase structure of the blends during quiescent molten-state annealing process. [ABSTRACT FROM AUTHOR]

Abstract: In this study a systematic investigation of two specified MWCNTs-Pd/Fe nanocomposites to remove 2,4-dichlorophenol (2,4-DCP) is presented. Two specified Multi-Walled Carbon Nanotubes (MWCNTs), i.e., 60–100nm and 10–20nm were introduced in nZVI synthesis in order to improve its adsorption–dechlorination efficiency. Both MWCNTs-Pd/Fe nanocomposites showed excellent adsorption efficiencies for phenols and followed the sequential order; 2,4-DCP>p-CP>o-CP>P. Batch sorption experiments including kinetics and isotherm were also intensively investigated. Significantly high 2,4-DCP removal was observed after 1min when it reached to 49.7% and 53.2%, then continuously increased up to 95.2% and 77.7% after 5h at 0.20wt.% Pd loading by 60–100nm and 10–20nm MWCNTs-Pd/Fe nanocomposites, respectively. However, stronger dechlorination and weaker adsorption was found in 60–100nm MWCNTs-Pd/Fe nanocomposites. Moreover, an integrated approach of physical adsorption by 60–100nm MWCNTs and chemical reduction by Pd/Fe nanoparticles to remove 2,4-DCP was successfully achieved. The property of quick adsorption of targeted pollutants and steady release of dechlorination products enhance the applicability of this process for an in situ pollution remediation measures. [Copyright &y& Elsevier]

Sulfate in groundwater has been previously shown to change the reactivity of Fe0 in permeable reactive barriers for reducing chlorinated organics. To better understand the effect and mechanism of SO, the degradation of 1,1,1-trichloroethane (TCA) by Fe0 in unbuffered aqueous solutions with and without SO was investigated. In a Fe0-TCA-H2O system with initial pH of 2.0 to 10.0, the maximum removal rate of TCA was achieved at the initial pH 6.0 with pseudo-first-order constant Kobs 9.0 × 10−3/min. But in a Fe0-TCA-Na2SO4-H2O system, the removal rate of TCA decreased remarkably with a reduction in Kobs to 1.0 × 10−3/min, and the pH varied from 6.0 to 9.6, indicating an inhibition of TCA dehydrochlorination by SO. Sulfate remarkably inhibited TCA degradation via changing the route of Fe0 dissolution. It accelerated the dissolution of Fe0 and transformed the intermediate form Fe(OH)ads to Fe2(SO4)ads, which weakened the affinity between Fe and TCA, and thus depressed the degradation of TCA by Fe0. [ABSTRACT FROM AUTHOR]

Abstract: This study describes the chromium (VI) removal in aqueous solution by nanoscale zero-valent iron (nZVI)-Fe3O4 nanocomposites, which were prepared by a novel in situ reduction method. The effects of several factors, including ionic strength, temperature, co-existing anions and cations and natural organic matters were evaluated. The ionic strength was found to be insignificant to the removal efficiency, while temperature was critical. With the increase in temperature from 10–40°C, 32% removal efficiency increased within 2h from 49.96%. Most anions hindered the reaction, especially in high concentration, such as and , causing a drop of the removal efficiency from 66.48% to 57.47% and 59.93% respectively. In contrast, both cations and moderate natural organic matter facilitated the removal of Cr(VI). It is noteworthy that calcium hardness can greatly promote the reaction, 100% removal efficiency was achieved within 90min and the rate constant k 2 reached 0.528gmg−1 min−1 after adding 40mgL−1 Ca2+, which was ten times more than that in other cases. Possible mechanism was presented, and TEM, SEM and FITR analyses were used to verify these speculations. Hopefully, these results can contribute to a better development of the water treatment facilitates for nZVI-Fe3O4 composites, maintaining its high efficiency in real aqueous environment. [Copyright &y& Elsevier]

Abstract: Global warming is increasingly challenging for wetland ecological function. A temperature controlled microcosm system was developed to simulate climate change scenarios of an ambient temperature (control) and an elevated temperature (+5°C). The effects and associated mechanisms of warming on phosphorus (P) fluxes at the sediment–water interface of six subtropical wetlands were investigated. The results indicated that P fluxes were generally enhanced under the experimental warming as measured by higher P concentrations in the porewater and overlying water as well as higher benthic P fluxes. The release of P from sediment to porewater occurred more strongly and quickly in response to experimental warming compared to the subsequent upward transfer into overlying water. The average accumulative benthic P output from the tested wetlands under the experimental warming was greater by 12.9μgcm−2 y−1 (28%) for total P and 8.26μgcm−2 y−1 (25%) for dissolved reactive P, compared to the ambient scenarios. Under warming the redistribution of P fractions in sediments occurred with greater NH4Cl–P and lower BD–P (extracted by a bicarbonate buffered dithionite solution) accompanied by greater NaOH–P. The higher temperature enhanced total phospholipid fatty acids. A shift in the microbial community was also observed with a relative dominance of fungi (a 4.7% increase) and a relative decline (by 18%) in bacterial abundance, leading to the higher secretion of phosphatase. Comparing between wetlands, the potential P fluxes in the nutrient-enriched wetlands were less impacted by warming than the other wetland types investigated. Thus wetlands characterized by low or medium concentrations of P in sediments were more susceptible to warming compared to P-rich wetlands. [Copyright &y& Elsevier]

Abstract: With the extensive utilization and disposal of flue gas desulfurization (FGD) gypsum, Hg0 re-emission and Hg2+ dissolution could cause severe atmospheric and groundwater contaminations. The present study employed two precipitating agents: sodium dithiocarbamate (DTCR) and 2,4,6-trimercaptotiazine, trisodium salt monohydrate (TMT) to prevent mercury in FGD gypsum from releasing into the environment as Hg0 and Hg2+. The results indicated that in the presence of DTCR and TMT, Hg2+ in leachate decreased to nearly 10%, while the amount of released Hg0 declined by over 2/3. Hence, it demonstrated an apparent effect of precipitants on the inhibition of Hg2+ dissolution and Hg0 re-emission. However, precipitation efficiencies represented better inhibitive performance of DTCR than that of TMT. Further increase of initial pH value and the precipitant dosage had an outstanding effect on the decline of total dissolved Hg2+, released Hg0 and Hg2+ remaining in leachate. Thus, in some severe conditions such as acid rain prone areas, the stabilization of mercury in FGD gypsum from dissolving and releasing could be extraordinarily controlled by the addition of DTCR and TMT, which is highly promising for future applications. [Copyright &y& Elsevier]

Abstract: A small solar energy collector was run to heat lignocellulosic hydrolyzates through an exchanger, and the heated hydrolyzate was concentrated by vacuum membrane distillation (VMD). Under optimal conditions of velocity of 1.0m/s and 65°C, glucose rejection was 99.5% and the flux was 8.46Lm−2 h−1. Fermentation of the concentrated hydrolyzate produced 2.64 times the amount of ethanol as fermentation using the original hydrolyzate. The results of this work indicated the possibility to decrease the thermal energy consumption of lignocellulosic ethanol through using VMD. [Copyright &y& Elsevier]

Abstract: Ni/Fe bimetallic nanoparticles were synthesized for treatment of Aroclor 1242, in order to evaluate their applicability for in situ remediation of groundwater and soil contaminated by polychlorinated biphenyls (PCBs). Our experimental results indicate that the total PCB concentration changed during the reduction of 3,5-dichlorobiphenyl (PCB 14), and biphenyl was produced as the final product. Initially, the concentration of 3-chlorobiphenyl (PCB 2) was increased in the prophase reaction and then slowly decreased, suggesting that Aroclor 1242 was first adsorbed by Ni/Fe nanoparticles, and then, the higher chlorinated congeners were converted gradually to the lower chlorinated congeners, and finally to biphenyl. The dechlorination efficiency of Aroclor 1242 reached approximately 80% at 25°C in just 5h, then 95.6% and 95.8% in 10h and 24h, respectively. The study revealed that high Ni/Fe nanoparticle dosage and high Ni content in Ni/Fe nanoparticles favor the catalytic dechlorination reaction. Moreover, a comparison of different types of catalysts on the dechlorination of Aroclor 1242 indicated that Ni/Mg and Mg powders showed a greater reactivity than Ni/Fe and Fe nanoparticles, respectively. [Copyright &y& Elsevier]

A simple, rapid and sensitive liquid chromatography tandem mass spectrometry method is presented for the simultaneous determination of oleanolic acid, p-coumaric acid, ferulic acid, kaemperol and quercetin in rat plasma. Glycyrrhetinic acid was used as an internal standard, and sample pretreatment consisted of a liquid–liquid extraction. Chromatographic separation was achieved on a Gemini 110A C18 column (50 × 2.0 mm i.d., 5 µm) by gradient elution with a mobile phase consisting of methanol, acetonitrile and 0.01% formic acid in water. Tandem mass spectrometric detection was conducted using multiple reaction monitoring under negative ionization mode. Calibration curves offered linear ranges of two orders of magnitude with r > 0.99. The method was validated in terms of matrix effect, intra-day and inter-day precision, accuracy, linearity, specificity and stability. The relative standard deviation of intra-day and inter-day variations ranged from 2.66 to 14.74% and 1.9 to 14.55%. No substantial endogenous interference from blank plasma was observed. The method has been successfully applied to a pharmacokinetic study of Oldenlandia diffusa extract after oral administration in rats. [ABSTRACT FROM PUBLISHER]

Abstract: Water pollution caused by ammonia nitrogen has attracted a great attention as its toxicity affects both the environment and human health. The objective of this paper was to investigate the adsorption behavior of NH4 +-N from aqueous solution by activated carbons prepared from rice husk. The physico-chemical properties of the activated carbon were characterized by Brunauer-Emmett-Teller (BET) test, Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). It was found that the NH4 +-N adsorption on the rice husk derived carbons was dependent on adsorbent dosage and solution pH. The adsorption kinetics and isotherms of NH4 +-N by rice husk carbon were also investigated, and good correlation coefficients were obtained for the pseudo-second order kinetic equation. Dubinin-Radushkevitch (D-R) adsorption isotherm model could better describe the adsorption behavior of NH4 +-N on the rice husk carbon. Calculated by D-R model, the adsorption course of NH4 +-N on the rice husk carbon was favored chemical ion-exchange mechanism. Moreover, the activated carbon adsorbed NH4 +-N was highly fertilizer conservation especially for the nitrogen element. It was proposed that the amount of removed NH4 +-N from aqueous solutions would increase evidently treated by rice husk carbon if combined with biological method. [Copyright &y& Elsevier]