Advanced Materials Research Vols. 356-360

Abstract: A kind of new adsorption material for wastewater treatment was made of fly ash as the main composition, with addition of sodium silicate, cement and pore forming material as the accessory materials, etc. Three kinds of practical wastewater were treated by using the new material, they were printing and dyeing wastewater, papermaking wastewater and coking wastewater, respectively. The results showed that removal COD efficiencies of the three kinds of wastewater were 57.89%, 71.43%, 80%, respectively, removal color efficiencies were 90%, 92%, 92%, respectively. The new developed material was mainly used for advanced treatment of the effluent water after biochemical process. It will be a substitute for activated carbon materials and have preferable application prospect.

Abstract: A kind of 4A zeolite, which was modified by magnesium chloride and aluminum chloride, was used to treatment phosphorus wastewater. The effect of several parameters on phosphorus removal was also investigated, including zeolite dosage, pH, phosphorus concentration and the adsorption time. The results showed that, under the conditions of pH 7, the amount of modified 4A zeolite 0.05g, reaction time 15min, room temperature, the removal efficiency of phosphorus with initial concentration 2mg/L reached 98%. The SEM analysis explained that crystalline structure of 4A zeolite has changed after modification, thus resulted in the improvement of adsorption capacity. What’s more, the phosphorus removal mechanism was also discussed.

Abstract: A new visible-light-driven plasmonic photocatalyst Ag/AgCl/TiO_2-XC_X was prepared by a two-step synthesis process. The bandgap of the synthesized sample was 2.87 eV. In the degradation of methyl orange (MO) solution under the visible light (l>420 nm), the Ag/AgCl/TiO_2-X C_X shows higher photocatalytic activity than TiO_2-X C _X . The apparent ratio constant (kapp) value of Ag/AgCl/TiO_2-XC_X was about 9.7 times that TiO_2-XC_X.

Abstract: Carbon materials possess special structural and fascinating functions. The use of biomass raw material to produce a variety of carbon materials can reduce the cost of production, and also achieve the sustainable development of carbon materials. A series of biomass carbon adsorbent were prepared by controlling the different carbonization temperatures (100 ~ 700 °C) using rice husk as the representatives of biomass, and the structure of these obtained biomass carbon were characterized by FT-IR. Adsorption properties of p-chlorophenol on the biomass carbon were also investigated. Results shown that the C/H and C/O values were decreased with the increasing carbonization temperatures, with the increasing of aromatic fractions in the biomass carbon materials. p-Chlorophenol was significantly adsorbed on the surface of these biomass carbon, the higher adsorption capacity was found in the biomass carbon produced with higher carbonization temperatures. The obtained results can be used for the further research in the study of adsorption properties and mechanism of biomass carbon in wastewater treatment.

Abstract: The core-nanoshell composite materials doped with Sm were prepared by a solid-state reaction method. The core is magnetic fly-ash hollow cenosphere, and the shell is the nanosized ferrite doped with Sm. The thermal decomposition process of the sample was investigated by thermogravimetric analysis-differential scanning calorimetry ( TG- DSC ). The morphology and components of the composite materials were investigated by the X-ray diffraction analysis ( XRD ), scanning electron microscope ( SEM ) and energy disperse spectroscopy ( EDS ). The microwave absorption property was investigated by vector network analyzer ( VNA ). The results indicated that the exchange-coupling interaction happens between ferrite of magnetic fly-ash hollow cenosphere and nanosized ferrite coating. The exchange-coupling interaction enhances magnetic loss of composite materials. So, in the frequency between 1 MHz and 1 GHz, the absorbing effectiveness of the core-nanoshell composite absorbers can achieve –32 dB, it is better than single material and is consistent with requirements of the microwave absorbing material at the low-frequency absorption.

Abstract: ZnO nanoparticles were modified by polyaniline (PANI) using ‘in situ’ chemical oxidative polymerization method. The morphology, structure, and light absorption properties of PANI-ZnO composites were examined by powder X-ray diffraction (XRD), transmission electron microscopy (TEM) and UV–vis spectra. UV–vis spectra reveal that PANI-ZnO composites showed stronger absorption than neat ZnO under the whole range of visible light. New characteristic peaks were found in PANI-ZnO composites according to the X-ray diffraction patterns after hybridization of PANI and ZnO, which indicating that there was a strong interaction between PANI and ZnO nanoparticles. The resulting PANI-ZnO composites exhibit significantly higher photocatalytic activity than that of neat ZnO for degradation of anthraquinone dye (reactive brilliant blue KN-R) aqueous solution under visible light irradiation (λ > 420 nm).

Abstract: A polyaniline supported titanium dioxide photocatalyst was prepared by an impregnation-hydrothermal process and characterized by powder X-ray diffraction, transmission electron microscopy and UV-visible spectroscopy. It was found that the TiO₂ nanoparticles were well dispersed on the surface of the polyaniline and the photocatalyst has a stronger absorption compared with that of pure TiO₂ over the whole of the visible spectrum. The photocatalyst exhibited higher photocatalytic activity than pure TiO₂ for the photodegradation of solutions of the anthraquinone dye, reactive brilliant blue KN-R, under visible light irradiation.

Abstract: Two catalysts, MnOx and ceria modified MnOx were prepared by deposition-precipitation method and used for low-temperature selective catalytic reduction (SCR) with NH₃ in the presence of SO₂. The catalysts were characterized by X-ray diffraction (XRD), surface area measurement (BET) and thermal gravimetry analysis(TG). The deactivation of MnOx and MnOx-CeO₂ by SO₂ was observed during SCR process. It was found that the resistance to SO₂ could be greatly enhanced for Ce modified MnOx. It was because that the formation of Mn(SO₄)x was prevented and the depositions of (NH₄)₂SO₄ and NH₄HSO ₄ were significantly inhibited with the doping of ceria.

Abstract: In this paper, one-dimensional ZnS nanostructures were fabricated in a conventional tube furnace by physical vapor deposition method using commercial ZnS powder as the starting materials. The morphologies, microstructures of the products were characterized. The results revealed that the products showed different morphology in different deposition temperature area. The growth mechanisms of the products were also discussed. The nanowires and triangular nanosheets formed via a vapor-liquid-solid process, while the nanobelts formed via a vapor-solid process. The key factors which influenced the morphologies of the products were discussed.

Abstract: The use of surface oxidized covellite (CuS), namely mixed phase copper sulphide (CuS and CuSO₄) was studied for the removal of mercury from aqueous solution under the effect of various reaction parameters (pH, time, Hg(II) concentration). From batch sorption studies, the equilibrium data revealed that the sorption behaviour of Hg(II) onto mixed phase copper sulphide follows well with Langmuir isotherm and the maximum sorption capacity (Q_max) determined ≈ 400mg Hg(II) /g of sorbent. Meanwhile, all the unreacted and reacted mixed phase copper sulphides were also characterized by Powder XRD, SEM and XPS techniques. The results indicated that the sorption of Hg(II) onto mixed phase copper sulphide occurs initially through the dissolution of surface oxidized CuSO₄ layer. After that, the surface complexation product formed and sorbed onto the surface of CuS. These outcomes suggest the potential ability of CuS in removing Hg(II) even if the CuS layer is being surrounded by oxidized layer of CuSO₄.