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1.
An immobilized clay composite (BEN–PVAG) on a glass plate (GP) was fabricated using bentonite powder (BEN) and glutaraldehyde cross-linked polyvinyl alcohol (PVAG) as the adsorbent and adhesive, respectively. The immobilized bentonite composite (BEN–PVAG) was characterized using SEM, EDX, FTIR, and BET analysis. The adsorption capacity of BEN–PVAG was examined using methylene blue (MB) as the model pollutant. The results indicated that the adsorption of MB onto BEN–PVAG obeyed pseudo-second-order kinetics. In addition, the adsorption of MB by the immobilized BEN–PVAG was controlled by intra-particle diffusion. In contrast, the adsorption of MB by the suspended BEN–PVAG composite was dominated by film diffusion. The immobilized BEN–PVAG was then applied as the adsorbent sub-layer for the fabrication of P-25TiO2/BEN–PVAG/GP bilayer system where P-25TiO2 was deposited as the top layer. The fabricated bilayer system exhibited synergistic photocatalytic-adsorptive removal of MB upon irradiation with a light source, while experiment in the dark yielded only adsorption process. The rate of the synergistic photocatalytic-adsorptive removal of MB by the P-25TiO2/BEN–PVAG/GP was 5.3 times faster than the suspended P-25TiO2. The result implied the positive impact of the BEN–PVAG adsorbent sub-layer on the immobilized P-25TiO2 photocatalyst. Most important, the immobilized P-25TiO2/BEN–PVAG/GP provided a convenient reuse of the catalyst over time where the treated water could be directly discharged without the need of filtration.  相似文献   

2.
This study investigated the performance of UV light active TiO2 and UV–visible light active WO3/TiO2 nanoparticles as air purifying materials that can be potentially applied to urban green infrastructures such as rain gardens and pervious pavements. Using a laboratory-scale continuous gas flow photoreactor, the removal efficiency of gaseous nitrogen oxide (NO x ) by two different photocatalytic nanoparticles coated on natural zeolites and pervious concrete blocks was evaluated. The results showed that the TiO2- and WO3/TiO2-coated zeolites are excellent photoactive materials providing enhanced air purification function (~95% removal efficiency of NO x ) under UV and UV–visible light irradiation, respectively. In contrast, both of the TiO2- and WO3/TiO2-coated pervious concrete blocks showed a measurable NO x removal (~60%) only under UV irradiation, whereas the visible light activity of the WO3/TiO2-coated concrete block was significantly reduced (~20%) mainly due to the decrease in the photocatalytic reaction sites for visible light. This study revealed the potential utility of photocatalytic nanoparticles in improving urban air quality, in the form of the surface component of various urban infrastructures.  相似文献   

3.
After more than a decade of multidisciplinary studies of the Central American subduction zone mainly in the framework of two large research programmes, the US MARGINS program and the German Collaborative Research Center SFB 574, we here review and interpret the data pertinent to quantify the cycling of mineral-bound volatiles (H2O, CO2, Cl, S) through this subduction system. For input-flux calculations, we divide the Middle America Trench into four segments differing in convergence rate and slab lithological profiles, use the latest evidence for mantle serpentinization of the Cocos slab approaching the trench, and for the first time explicitly include subduction erosion of forearc basement. Resulting input fluxes are 40–62 (53) Tg/Ma/m H2O, 7.8–11.4 (9.3) Tg/Ma/m CO2, 1.3–1.9 (1.6) Tg/Ma/m Cl, and 1.3–2.1 (1.6) Tg/Ma/m S (bracketed are mean values for entire trench length). Output by cold seeps on the forearc amounts to 0.625–1.25 Tg/Ma/m H2O partly derived from the slab sediments as determined by geochemical analyses of fluids and carbonates. The major volatile output occurs at the Central American volcanic arc that is divided into ten arc segments by dextral strike-slip tectonics. Based on volcanic edifice and widespread tephra volumes as well as calculated parental magma masses needed to form observed evolved compositions, we determine long-term (105 years) average magma and K2O fluxes for each of the ten segments as 32–242 (106) Tg/Ma/m magma and 0.28–2.91 (1.38) Tg/Ma/m K2O (bracketed are mean values for entire Central American volcanic arc length). Volatile/K2O concentration ratios derived from melt inclusion analyses and petrologic modelling then allow to calculate volatile fluxes as 1.02–14.3 (6.2) Tg/Ma/m H2O, 0.02–0.45 (0.17) Tg/Ma/m CO2, and 0.07–0.34 (0.22) Tg/Ma/m Cl. The same approach yields long-term sulfur fluxes of 0.12–1.08 (0.54) Tg/Ma/m while present-day open-vent SO2-flux monitoring yields 0.06–2.37 (0.83) Tg/Ma/m S. Input–output comparisons show that the arc water fluxes only account for up to 40 % of the input even if we include an “invisible” plutonic component constrained by crustal growth. With 20–30 % of the H2O input transferred into the deeper mantle as suggested by petrologic modeling, there remains a deficiency of, say, 30–40 % in the water budget. At least some of this water is transferred into two upper-plate regions of low seismic velocity and electrical resistivity whose sizes vary along arc: one region widely envelopes the melt ascent paths from slab top to arc and the other extends obliquely from the slab below the forearc to below the arc. Whether these reservoirs are transient or steady remains unknown.  相似文献   

4.
In this study, the photocatalytic degradation of Congo red has been investigated in N-doped TiO2 (N-TiO2) aqueous suspensions under visible light irradiation. Visible light-active N-TiO2 was successfully prepared at three different weight contents (2.5, 5, and 7%) employing sol–gel method. It was able to harvest the visible irradiation with wavelength suitable for activation. X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectrometer, diffused reflectance UV–Vis spectroscopy, nitrogen adsorption Brunauer–Emmert–Teller, Raman spectroscopy, photoluminescence and X-ray photoelectron spectrometer were used to characterize the doped catalyst. The samples had a relatively large specific Brunauer–Emmert–Teller surface areas of about 42 m2 g?1 with average X-ray diffraction crystalline size of 52 nm and showed visible light photocatalytic activity at about 408 nm. The impacts of several operating parameters on the Congo red photodegradation process were examined. Langmuir–Hinshelwood model exhibited pseudo-first-order degradation kinetics. N-TiO2-assisted plausible photodegradation mechanism has been suggested based on the qualitatively detected intermediate compounds.  相似文献   

5.
This study assesses the ability of two low-cost adsorbents made from waste of Rapanea ferruginea treated with ethanol (WRf) and its H2SO4-treated analog (WRf/H2SO4) for the removal of two cationic dyes methylene blue (MB) and crystal violet (CV) from aqueous solutions. The adsorbent was characterized by scanning electron microscopy, Fourier transform infrared spectrometry, thermogravimetric analysis, point of zero charge (pHpzc), specific surface, and functional groups. The adsorption of dye onto the adsorbents was studied as a function of pH solution (2–12), contact time (up to 120 min) and initial concentration (20–120 mg/L), and temperature (25, 35, and 55 °C). The influence of these parameters on adsorption capacity was studied using the batch process. The response surface methodology (RSM) was used in the experimental design, modeling of the process, and optimizing of the variables and was optimized by the response involving Box–Behnken factorial design (15 runs). The results show that the data correlated well with the Sips isotherm. The maximum adsorption capacities of MB and CV onto WRf were found to be 69 and 106 mg/g, and onto WRf/H2SO4, the adsorption capacities were 33 and 125 mg/g, respectively. The kinetic data revealed that adsorption of cationic dyes onto the adsorbents closely follows the pseudo-second-order kinetic model. Regression analysis showed good fit of the experimental data to the second-order polynomial model, with coefficient of determination (R2) values for MB (R2?=?0.9685) and MB (R2?=?0.9832) for WRf and CV (R2?=?0.9685) and CV (R2?=?0.9832) for WRf/H2SO4 indicated that regression analysis is able to give a good prediction of response for the adsorption process in the range studied. The results revealed that waste from R. ferruginea is potentially an efficient and low-cost adsorbent for adsorption of MB and CV.  相似文献   

6.
In this work, permeation of mixed gases H2S/CH4 through commercial polyphenylene oxide (PPO) hollow fiber and poly (ester urethane) urea (PEUU) flat membranes was studied at pressures of 345–689 kPa, at ambient temperature and at 313.15 K. Various H2S concentrations of about 100–5000 ppm in CH4 binary synthetic gas mixtures as well as a real natural gas sample obtained from a gas refinery containing 0.3360 mol.% H2S (equivalent to 3360 ppm) were tested. It was observed that the permeance of components was affected by the balance between competitive sorption and plasticization effects. Separation factors of H2S/CH4 were in the range of 1.3–2.9, 1.8–3.1 and 2.2–4.3 at pressures of 345, 517 and 689 kPa, respectively. In the range of 101–5008 ppm of H2S in CH4, the effect of temperature on the separation factor was nearly negligible; however, permeances of both components of the mixtures increased with temperature. Additionally, the results obtained by PEUU membrane indicated that it was a better choice for hydrogen sulfide separation from H2S/CH4 mixtures than PPO. For PPO membrane, removal of hydrogen sulfide from high-concentration (up to 5008 ppm) binary mixtures of H2S/CH4 was compared with that of low concentration (as low as 101 ppm) through PPO. At concentrations of 101–968 ppm, plasticization was dominant compared with the competitive sorption, while for the H2S feed concentrations of 3048 ppm, the competitive sorption effect was dominant. For H2S concentration of 5008 ppm, the balance between these two effects played an important role for explanation of its trend.  相似文献   

7.
The crystal structure of the unstable mineral alumoklyuchevskite K3Cu3AlO2(SO4)4 [monoclinic, I2, a = 18.772(7), b = 4.967(2), c = 18.468(7) Å, β = 101.66(1)°, V = 1686(1) Å] was refined to R 1 = 0.131 for 2450 unique reflections with F ≥ 4σF hkl. The structure is based on oxocentered tetrahedrons (OAlCu 3 7+ ) linked into chains via edges. Each chain is surrounded by SO4 tetrahedrons forming a structural complex. Each complex is elongated along the b axis. This type of crystal structure was also found in other fumarole minerals of the Great Tolbachik Fissure Eruption (GTFE, Kamchatka Peninsula, Russia, 1975–1976), klyuchevskite, K3Cu3Fe3+O2(SO4)4; and piypite, K2Cu2O(SO4)2.  相似文献   

8.
Amine post-combustion carbon capture technology is based on washing the flue gas with a solvent that captures CO2. Thus, a small fraction of this solvent can be released together with the cleaned flue gas. This release may cause environmental concerns, both directly and indirectly through subsequent solvent degradation into other substances in the atmosphere. The paper presents the ammonia emission from CO2 capture pilot plant (1 tonne CO2 per day) using 40 wt% aminoethylethanolamine solvent, along with the efficiency of the water wash unit. In addition, the temperature effect of lean amine entering the absorber on ammonia emission was studied. Furthermore, the concentrations of other compounds such as SO2, SO3, NO2, CS2 and formaldehyde were monitored. The literature review on the NH3 emission from a pilot plant using aminoethylethanolamine solvent has not been published. The results show that the main source of ammonia emission is the absorber and that emission (in the range 27–50 ppm) corresponds to typical NH3 release from CO2 capture pilot plant using an amine solvent. The emission of amines and amine degradation products is a complex phenomenon which is difficult to predict in novel solvents, and for this reason the significance of new solvents testing in a pilot scale has been highlighted.  相似文献   

9.
Analyses of the specific products of 35SO42? reduction measurements were made in marine sediments in Denmark. We injected tracer quantities of 35SO42? into cores, incubated the cores, and assayed for 35S-labelled acid volatile sulfides. Additionally, we assayed for 35S-labelled elemental sulfur by extraction with CS2, and for 35S-labelled pyrite by reduction with chromium (II). We separately determined that elemental sulfur which formed in situ and that which formed by oxidation during the acid distillation of acid volatile sulfides.In subtidal sediments in Limfjorden, 35S-labelled elemental sulfur and pyrite make up 14–32% of the reduced sulfur formed in short-term (0–48 hours) 35SO42? reduction experiments, at all depths studied (0–15 cm). Labelled elemental sulfur which formed in situ during the incubations at depths below 1 cm made up a fairly constant 5–11% of the total labelled reduced sulfur, from 0–1 cm, it made up 27%. An additional small amount (1–2% from 1–15 cm and 5% from 0–1 cm) of labelled elemental sulfur was formed during the acid-distillation step in our assay for labelled acid-volatile sulndes. Pyrite contained 4–13% of the total labelled reduced sulfur at all depths. Rates of sulfate reduction in Limfjorden were linear over the period 0–48 hours, and 35S-pyrite made up a nearly constant percentage of the 35S-labelled reduced sulfur formed over this time period.Estimates of sulfate reduction rates for Limfjorden which do not include elemental sulfur and pyrite as products are 19% too low. At Kysing Fjord, estimates of sulfate reduction which do not include elemental sulfur and pyrite are 24% to 32% too low. Thus, while previously published data on sulfate reduction in similar environments are probably low, they are not greatly in error.  相似文献   

10.
The transition between rutile and α-PbO2 structured TiO2 (TiO2II) has been investigated at 700–1,200 °C and 4.2–9.6 GPa. Hydrothermal phase equilibrium experiments were performed in the multi-anvil apparatus to bracket the phase boundary at 700, 1,000, and 1,200 °C. The equilibrium phase boundary is described by the equation: P (GPa)=1.29+0.0065 T ( °C). In addition, growth of TiO2II was observed in experiments at 500 and 600 °C, although growth of rutile was too slow to bracket unambiguously the equilibrium boundary at these temperatures. Water was not detected in either rutile or TiO2II, and dry synthesis experiments at 1,200 °C were consistent with the phase boundary determined in the fluid-bearing experiments, suggesting that the equilibrium is unaffected by the presence of water. Our bracket of the phase boundary at 700 °C is consistent with the reversed, dry experiments of Akaogi et al. (1992) and the reversals of Olsen et al. (1999). The new data suggest that the phase boundary is linear, in agreement with Akaogi et al. (1992), but in striking contrast to the phase diagram inferred by Olsen et al. (1999). The natural occurrence of TiO2II requires formation pressures considerably higher than the graphite–diamond phase boundary.  相似文献   

11.
It is demonstrated that single titanium dioxide (TiO2) has high potential for photodegradation of pollutants. However, it is still far from becoming an effective photocatalyst system, due to issues of adsorption process, separation, as well as dissolution. Therefore, this study highlights the high adsorption capacity, simplified separation, and the promising stability of TiO2(SY) (synthesized via sol–gel method) photocatalyst, fabricated using chitosan–TiO2(SY) and supported by glass substrate (Cs–TiO2(SY)/glass substrate) photocatalysts. Chitosan (Cs), with abundant –R–NH and NH2 groups, promotes the adsorption sites of methyl orange (MO) and OH groups for major attachment to TiO2(SY). Meanwhile, the glass substrate increases stability and assists separation of the photocatalysts. Initially, nano-TiO2(SY) has been characterized using high-resolution transmission electron microscope. Cs–TiO2(SY)/glass substrate was fabricated via dip-coating. The distribution and interface between the photocatalytic components were characterized by Fourier transform infrared absorption spectroscopy, UV–Vis diffuse reflectance spectroscopy, field emission scanning electron microscopy, and energy-dispersive spectrometer. UV–Vis analysis of the multilayer photocatalyst (2, 4, 6, and 8 layers) was further carried out by the adsorption–photodegradation, with MO as model of pollutant. Seventy percent of the total removal of MO via optimized eight layers of photocatalyst was achieved within 1 h of UV irradiation. The adsorption photocatalyst achieved 50 % with no exposure to UV light for 15 min of irradiation. It is concluded that suitable photocatalytic conditions and sample parameters possessing the multilayer photocatalyst of Cs–TiO2(SY) are beneficial toward the adsorption–photodegradation process in wastewater treatment.  相似文献   

12.
Stability and phase relations of coexisting enstatite and H2 fluid were investigated in the pressure and temperature regions of 3.1–13.9 GPa and 1500–2000 K using laser-heated diamond-anvil cells. XRD measurements showed decomposition of enstatite upon heating to form forsterite, periclase, and coesite/stishovite. In the recovered samples, SiO2 grains were found at the margin of the heating hot spot, suggesting that the SiO2 component dissolved in the H2 fluid during heating, then precipitated when its solubility decreased with decreasing temperature. Raman and infrared spectra of the coexisting fluid phase revealed that SiH4 and H2O molecules formed through the reaction between dissolved SiO2 and H2. In contrast, forsterite and periclase crystals were found within the hot spot, which were assumed to have replaced the initial orthoenstatite crystals without dissolution. Preferential dissolution of SiO2 components of enstatite in H2 fluid, as well as that observed in the forsterite H2 system and the quartz H2 system, implies that H2-rich fluid enhances Mg/Si fractionation between the fluid and solid phases of mantle minerals.  相似文献   

13.
Crystals of hydronium jarosite were synthesized by hydrothermal treatment of Fe(III)–SO4 solutions. Single-crystal XRD refinement with R1=0.0232 for the unique observed reflections (|Fo| > 4F) and wR2=0.0451 for all data gave a=7.3559(8) Å, c=17.019(3) Å, Vo=160.11(4) cm3, and fractional positions for all atoms except the H in the H3O groups. The chemical composition of this sample is described by the formula (H3O)0.91Fe2.91(SO4)2[(OH)5.64(H2O)0.18]. The enthalpy of formation (Hof) is –3694.5 ± 4.6 kJ mol–1, calculated from acid (5.0 N HCl) solution calorimetry data for hydronium jarosite, -FeOOH, MgO, H2O, and -MgSO4. The entropy at standard temperature and pressure (So) is 438.9±0.7 J mol–1 K–1, calculated from adiabatic and semi-adiabatic calorimetry data. The heat capacity (Cp) data between 273 and 400 K were fitted to a Maier-Kelley polynomial Cp(T in K)=280.6 + 0.6149T–3199700T–2. The Gibbs free energy of formation is –3162.2 ± 4.6 kJ mol–1. Speciation and activity calculations for Fe(III)–SO4 solutions show that these new thermodynamic data reproduce the results of solubility experiments with hydronium jarosite. A spin-glass freezing transition was manifested as a broad anomaly in the Cp data, and as a broad maximum in the zero-field-cooled magnetic susceptibility data at 16.5 K. Another anomaly in Cp, below 0.7 K, has been tentatively attributed to spin cluster tunneling. A set of thermodynamic values for an ideal composition end member (H3O)Fe3(SO4)2(OH)6 was estimated: Gof= –3226.4 ± 4.6 kJ mol–1, Hof=–3770.2 ± 4.6 kJ mol–1, So=448.2 ± 0.7 J mol–1 K–1, Cp (T in K)=287.2 + 0.6281T–3286000T–2 (between 273 and 400 K).  相似文献   

14.
The carbon molecular sieves (CMSs) prepared by carbonaceous materials as precursors are effective in CO2/N2 separation. However, selectivity of these materials is too low, since hydrocarbon cracking for developing the desired microporosity in carbonaceous materials has not been done effectively. Hence, in this study, cobalt and nickel impregnation on the precursor was conducted to introduce catalysts for hydrocarbon cracking. Cobalt and nickel impregnation, carbonization under N2 atmosphere, and chemical vapor deposition (CVD) by benzene were conducted on the extruded mixtures of activated carbon and coal tar pitch under different conditions to prepare CMSs. The best CMS prepared by carbon deposition on the cobalt-impregnated samples exhibited CO2 adsorption capacity of 54.79 mg/g and uptake ratio of 28.9 at 0 °C and 1 bar. In terms of CO2 adsorption capacity and uptake ratio, CMSs prepared by carbon deposition on non-impregnated and cobalt-impregnated samples presented the best results, respectively. As benzene concentration and CVD time increased, equilibrium adsorption capacity of CO2 decreased, and uptake ratio increased. Cobalt was found to be the best catalyst for benzene cracking in the CVD process.  相似文献   

15.
Phase equilibria in the join CaMgSi2O6-CaFeAlSiO6-CaTiAl2O6 have been determined in air at 1 atm by the ordinary quenching method. Clinopyroxeness, forsterite, perovskite, magnetitess, spinelss, hibonite and an unknown phase X are present at liquidus temperatures (ss: solid solution). At subsolidus temperatures the following phase assemblages were encountered; clinopyroxeness+perovskite, clinopyroxeness +perovskite+spinelss, clinopyroxeness +perovskite+melilite (+anorthite), clinopyroxeness +perovskite+melilite+spinelss+anorthite, clinopyroxeness +perovskite+anorthite+spinelss, and clinopyroxeness +perovskite+anorthite+hibonite. At subsolidus temperatures the single phase field of clinopyroxeness extends up to 19 wt.% CaTiAl2O6. Even in the field of clinopyroxeness+perovskite, the TiO2 content in clinopyroxeness continues to increase and attains 9.2 wt.% TiO2 with 24.8 wt.% Al2O3. An interesting fact is that unusual clinopyroxenes which contain more AlIV than SiIV are present in the CaFe-AlSiO6-rich region. The liquid coexisting with pyroxene is richer in Ti, Al, and Fe3+ than the coexisting pyroxene. The clinopyroxenesss coexisting with liquid contain less TiO2, Al2O3 and Fe2O3 than those crystallized at subsolidus temperatures. The petrological significance of the join and the crystallization of Ti- and Al-rich clinopyroxenes are discussed on the basis of the experimental results of the join.  相似文献   

16.
Undoped and Ni-doped TiO2 nanoparticles are synthesized using sol–gel technique. The physical, structural, optical and thermal properties of the samples are investigated using X-ray powder diffraction, Fourier transform infrared spectroscopy, transmittance electron microscopy, UV–visible diffuse reflectance and thermogravimetric analysis. The photocatalytic activity of the samples is investigated by the photocatalytic degradation of phthalate esters. Phthalate esters have been considered as endocrine disrupting compounds. Ni-doped TiO2 samples show better photocatalytic activity as compared to undoped TiO2 sample. The greater photocatalytic activity of doped samples as compared to undoped TiO2 can be attributed to the production of more number of electron–hole pairs in doped samples.  相似文献   

17.
To enhance the overall efficiency of oil and grease removal in wastewater coated N-doped TiO2 photocatalytic polyscales were fabricated through sol–gel technique. The materials fabricated were characterized using powder X-ray diffraction, Fourier transmission infrared spectroscopy, scanning electron microscopy, and UV–Vis spectroscopy. In order to enhance degradation efficiency of organic pollutant under natural sun light, shifting of absorption range of TiO2 to visible spectrum, various modifications such as surface modification and size optimization were carried out by doping of nitrogen under sol–gel processes. To ease recovery of suspended catalysts from aqueous media, the coated N-doped TiO2 were prepared by decorating photocatalytic particles onto suitable substrates. N-doped TiO2 polyscales with desired functionalities were coated onto the spherical supporting substrates using a binding agent. The photocatalytic treatment studies clearly indicated the considerable level of the oil and grease and other organic pollutants removal from wastewater (up to 85–90 % ± 2) using coated N-doped TiO2 under natural sunlight as an alternative driving energy source. Removal of oil and grease along with other organic pollutants in wastewater using coated N-doped TiO2 polyscales is a versatile, economical, and environmental friendly technique due to the ease of handling and recovery, utilization of natural sunlight which is renewable energy source.  相似文献   

18.
WO3-modified TiO2 polyscale crystals were fabricated successfully using the hydrothermal technique. The as-prepared samples were characterized using powder X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, photoluminescence spectroscopy and UV–vis spectroscopy. The photocatalytic application of these synthesized samples was confirmed by photocatalytic degradation of fast green dye solution under sunlight and UV irradiation. The degradation efficiency was analyzed by measuring the parameters such as percent transmittance, chemical oxygen demand and percent decomposition of the dye solution. It was noted that the photodegradation efficiency of the samples varies with added amounts of WO3 content. The highest photodegradation efficiency was obtained using 2WT sample where the pace of decomposition was 70.5% under UV light and 81.3% under sunlight.  相似文献   

19.
A low-cost visible light-driven silver/titanium oxide/expanded perlite (Ag/TiO2/EP) as a floating plasmonic photocatalyst is fabricated by a simple hydrolysis method. Photocatalytic properties of Ag/TiO2/EP have been studied by scanning electron microscope, X-ray diffraction, UV–Vis (DRS), EDAX, FTIR, chemiluminescence, photoluminescence and X-ray photoelectron spectroscopy methods. The photocatalytic activity of resulting Ag/TiO2/EP with different Ag contents (3 and 5%) was evaluated by its ability to degrade furfural solution under visible light irradiation. The Ag/TiO2/EP exhibits wide absorption in the visible light region and shows visible light-driven photocatalytic activities in furfural degradation compared with TiO2/EP photocatalyst. The Ag/TiO2/EP (5%) was the best concentration of photocatalyst dosage with almost 80% furfural degradation under visible light. The antibacterial character of Ag/TiO2/EP with different Ag contents has been tested against Escherichia Coli under visible light. The photocatalytic activity of Ag/TiO2/EP can be attributed to the plasmonic effect of silver in the separation of photoinduced electrons and holes in resulting photocatalyst. The Ag/TiO2/EP (5%) as a floating photocatalyst combined with its ability to absorb visible light makes it of significant interest for the purification of industrial wastewater.  相似文献   

20.
In order to model the processes of formation of the highly alkaline (potassic) melts during the partial melting of the eclogite nodules in kimberlites, experiments on the melting of the model and natural eclogites in presence of the H2O-CO2 and H2O-CO2-KCl fluids at 5 GPa and 1200 and 1300°C are performed. A comparative analysis of the phase relations in the systems with H2O-CO2 and H2O-CO2-KCl demonstrate that KCl in the fluid equilibrated with eclogites intensifies their melting. It is related to both high Cl concentration in the forming silicate melt (2.0–5.5 wt %) and its enrichment in K2O owing to the K-Na exchange reactions with the immiscible chloride melt. Because of these reactions, the K2O/Cl ratio in the melts increases with the KCl content in the system and reaches 2.5–3.5 in the silicate melts coexisting with the immiscible chloride liquid. However, the ratio KCl/(H2O + CO2 + KCl) in the fluid does not influence on the ratio K2O/Cl in the melts. Thus, the solubility KCl in the melts, apparently, does not depend on presence of the H2O-CO2 fluid, at least, within the concentration range used in the experiments (up to 20 wt %). The experiments show that the deliberated chloride liquid is necessary to form the potassium-rich chlorine-bearing silicate melts during the eclogite melting. It corresponds to the KCl content in the system above 5 wt %.  相似文献   

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