Advanced Materials Research Vols. 356-360

Abstract: Spinning effluents (SE) from dry-spun acrylic fiber manufacturing are hard to degrade due to the containing of vast dimethyl formamide (DMF). Activated carbon, ion exchange and Fenton oxidation were applied to solve this problem. Coconut-shell-based activated carbon exhibited a better performance than the coal-based and nut-shell-based ones did. At the optimal dosage of 1g/L, pH=6 and 30 °C, the removal of COD and DMF were respectively 84.39% and 66.14%. Ion exchange resins are rated as NKA-9 > D301R > D201 > 201×7 respected to the performance, and the optimum COD and DMF removal were 82.31% and 68.76% at the NKA-9 dosage of 0.22 g, pH=7 and 30°C. The most appropriate treatment process appeared to be Fenton. COD and DMF were finally reduced to 23.29 mg/L and 23.43 mg/L, with removal rates of 90.23% and 79.43% respectively. This optimum efficiency was obtained at c(H₂O₂)/c(Fe²⁺) of 14:1, pH=3, 50 °C, and an oxidation time of 3 h.

Abstract: Two kinds of SnS₂ materials were prepared through the hydrothermal route, respectively using thioacetamide (TAA) and thiourea as the sulfur source. The as-prepared SnS₂ samples were characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM) and N₂-sorption. The results showed that the SnS₂ sample prepared with TAA had a lengthening shape, a smaller size and surface area, but a better adsorption of rhodamine B (RhB). X-ray photoelectron spectroscopy (XPS) analysis was used to confirm that there was an interaction between RhB molecule and SnS₂ contributing to the strong adsorption of RhB.

Abstract: A series of V₂O₅/WO₃/TiO₂ plate catalysts were prepared via the incipient wetness impregnation method, with the V₂O₅ content of 0.68 wt%, 1.01 wt%, 1.19 wt%, 1.5 wt% and the WO₃ loading of 4.8 wt%, 6.2 wt%, 7.9 wt%, 9.2 wt%, respectively. Selective catalytic reduction of nitric oxide by ammonia (NH₃-SCR) experiments were performed to investigate the effects of the several factors on the performance of the catalysts, including the V₂O₅, WO₃ and MoO₃ content in the catalysts and the O₂ concentration in the flue gas. The results indicated that as the rising of the V2O5 content, the SCR activity of the V₂O₅/WO₃/TiO₂ catalysts was firstly increased and then slightly decreased, with the best activity obtained at the V₂O₅ content of 1.19 wt%. As the increasing of the WO₃ content, the activity was firstly increased slightly and then almost kept constant. Furthermore, the loading of the MoO₃ on the V₂O₅/WO₃/TiO₂ plate catalysts would bring negative effects to the catalytic activity. In addition, the capability of the catalysts would slightly increase as the O₂ concentration rising up to 7%, and then became stable at higher O₂ concentrations.

Abstract: The objective of this study is to immobilize Pb, Cu, and Zn in a multi-metal contaminated soil using triple superphosphate fertilizer (TSP) and phosphate rock tailing (PR) materials, alone and in combination. The treatment effectiveness was evaluated with a column leaching experiment under simulated rainfall conditions. More than 90% of Pb and Cu were stabilized in the upper layer soil (0-10cm) in both untreated and P-treated soil columns. However, the significant downward migration of Zn was observed in either untreated or P-treated column soil profiles though the transport was inhibited by P treatments. In the untreated soil, 27.2% of Zn migrated down to the subsurface soil (10-20cm), while there were 7.45%, 13.0%, and 11.2% of Zn transported down in the TSP, PR, and PR+TSP treatments, respectively. Phosphate reduced the leaching of Pb and Cu from the contaminated soils, with reduction of Pb and Cu in the leachate by up to 71.2% and 34.8%, respectively. However, Zn leaching was enhanced by P treatments except for TSP. The results indicated that triple superphosphate fertilizer and phosphate rock tailing were effective in immobilizing Pb followed by Cu, but less for Zn in a multi-metal contaminated soil.

Abstract: New green theory is put forward that indoor air pollution is controlled by overall process based on the residential interior decoration and air pollution status in China, as indoor air quality becomes important more and more. According to the concept of healthy house to control indoor air pollution through four steps that are green interior design, selecting environmental materials, green decoration and green ornament safe, healthy and environmental green home could be realized.

Abstract: Experiments were performed on the packed tower with 150mm diameter and 2800mm high to study the wet flue gas desulfurization continuously. The results shows that the suitable conditions for the SO₂ absorption process of 0.3mol•L^-1 ethylenediamine/phosphoric acid and ethylenediamine/boric acid solutions: pH value was 6.0～7.0, liquid-gas ratio was 0.82L•m^-3. The import SO₂ concentration and the flue gas flow were separately at 500×10^-6～3100×10^-6 and 110m³•h^-1～150m³•h^-1, the desulfurization efficiency exceeded 97%. Under the same conditons, ethylenediamine/boric acid has a better desulfurization and was more suitable for the flue gas desulfurization in a wider fluctuation.

Abstract: A series of binuclear metal (II) phthalocyanine hexasulphonates, (M-M)Pc, including (Co-Co)Pc, (Co-Zn)Pc, (Co-Mn)Pc, (Zn-Zn)Pc, (Zn-Mn)Pc and (Mn-Mn)Pc were synthesized and immobilized on nanocrystalline TiO2 thin films. The nanocrystalline TiO₂ thin film was characterized by SEM, XRD and profilometer. The catalytic activity of various (M-M)Pc/nanocrystalline TiO₂ thin films was evaluated by the degradation of methylene blue (MB) with air as the oxidant under visible light irradiation and dark condition. The results indicated that the prepared nanocrystalline TiO₂ thin film had good crystalline and uniform particle size distribution. According to the degradation results of MB, various homo/hetero (M-M)Pc can sensitize nanocrystalline TiO₂ thin films and improve their photocatalytic activity under visible light irradiation. The catalytic activity of hetero (M-M)Pc/nanocrystalline TiO₂ thin films were more effective than that of homo (M-M)Pc under both visible light irradiation and dark condition, and the air purging was essential in degradation of MB. Therefore, these (M-M)Pc/nanocrystalline TiO₂ thin films can be applied to the degradation of MB as a promising catalyzer.

Abstract: The vertical and horizontal distribution of NPEOn and their metabolites of NP and NPEnC in the Upper Nansi Lake, North China were investigated using LC-MS and LC-MS/MS methods, sampling at three sites (St.1, St.2 and St.3) along the water flow direction. The total content of NPEOn (n=1–15) bound onto the sediment of this lake changed in the range of 60.7–631.5 μg/kg-dry with the horizontal flow direction and the vertical direction of the sediment cores with sediment thickness up to 35 cm. Compared to the presence levels of all detected NPEOn species, the content of NP was much higher, falling in 26.5–1,998.4 μg/kg-dry. A general increasing trend of the NP content along the water flow direction of this lake was revealed. NPEnC showed a roughly increasing trend from the upstream to the downstream, with the total concentrations being obviously lower than NPEOn and NP and falling in 2.13–23.1 μg/kg-dry. The short chain NPEOn dominant in NPEO mixtures in these sedimentary cores indicated that this lake received some effluents from STPs, and the sewage treatment ratio is relatively low in this area. Furthermore, the computed magnitudes of NPEO _1-2/NPEO_1-15, NP/NPEO _1-15 and NPEC _1-10/NPEO _1-15 suggested that the non-oxidative hydrolytic transformation seemed to be a major process occurring within the sediment phase of Nansi Lake, while the oxidative hydrolytic transformation pathway was probably less involved.

Abstract: Hybrid biofilm reactor has become a technically as well as economically feasible option for treatment of industrial wastewater. This article presents a critical review of some basic mathematical biofilm models. Mainly focus on the development and the solution of these models. The aim is to find a reasonable and simple model of hybrid biofilm reactor under aerobic and anoxic conditions and to simulate the decontamination of petrochemical wastewater.

Abstract: Given the low cost of their components and their demonstrated reliable efficiencies, dye-sensitized techniques based on the titanium dioxide (TiO₂) thin films have received much research attention in the past decade. The d_{Subscript text}ye/TiO₂ thin films were prepared on glass fibers substrate by a dip-coating method combined with a sol-gel process and the photocatalytic of acetone was investigated in this study. The natural botanical dye of Gardenia jasminoides with absorption reflection intensity in 410-460 nm of liquid extraction was used to improve the photo absorbability under illumination of visible light source. Degradation of acetone under 420 nm light illumination was conducted to evaluate the photocatalytic ability of the dye/TiO₂ thin films. The SEM images evidence that fibers existed in the dye/nano-TiO₂ composites. The dye/TiO₂ thin films catalyst prepared in the laboratory sho_{Subscript text}wed photocatalytic performance with the degradation efficiency of 55% under 420 nm. A few percentages increase in removal efficiency when compared with the dye less TiO₂ thin films.