Advanced Materials Research Vols. 233-235

Abstract: A kind of bamboo char with high specific surface area has been studied as the absorption material of the activated carbon electrodes, and the electrosorptive deionization ability of the as-obtained electrodes for elimination of metal ions in tap water has been examined under certain direct voltage. The effects of the distance between the elect rode plates, and the numbers of the electrode plates have been investigated in detail. The results show that the electrodes exhibit the optimal deionization ability over 2 cm of distance between the electrode plates and 4 couples of the elect rode plates. The reverse wash treatment indicates that the activated carbon electrodes can be cycle used. The efficiency order of the electrosorptive deionization of different metal ions on the activated carbon electrode has been summarized as follows: Pb²⁺＞Cu²⁺＞Cr³⁺＞Cd²⁺.

Abstract: A study of the modified diatomite prepared by the PAM coated on the surface of the raw diatomite and applied to treat the simulated wastewater with intensive concentration of lead ions [Pb(Ⅱ)]. Pb(Ⅱ) has been considered as one of some significantly toxic heavymetals (Cd,Cr,Pb, Mn,Cu,Zn,et al) contaminated the surfacewaters. The results indicated that modification could enhance the diatomite and acidic heavymetal wastewater’s compatibility; Obtained that modified diatomite’s saturated adsorption capacity could reach 66.15~ 68.95mg/g, superior to raw one; At the same time, the comparation of four common adsorbents and modified diatomite’s adsorption capacity under some given conditions showed: modified diatomite > zeolite > vermiculite > raw diatomite > red soil; Observed by SEM, PAM molecule arrayed on the diatomite’s surface smoothly that improved its interior structure and the charge on the surface, even enhanced the sedimentation performance of the diatomite in heavymetal wastewater.

Abstract: A new method using aluminum oxide (Al₂O₃) as solid-phase extraction coupled with atomic absorption spectrum(AAS) was proposed. The adsorption behavior of Al₂O₃ nanoparticles towards Cd²⁺ was investigated by AAS, and the adsorption pH, isotherms as well as capacities were obtained. It was found that the adsorption rates of Cd^­­­­2+ was more than 98% in pH 8.50~10.00. The adsorption equilibrium data of Cd²⁺ were well fitted with the Langmuir isothermal equation. The kinetic experimental data correlated well with the pseudo-second-order kinetic model. Adsorption enthalpy of standard (DH^q) was 5.23 kJ mol^-1, which indicated that adsorption reaction was an endothermal process in the range of being studied temperature. It was sufficient for 1.0mol L^–1 HCl to elute Cd²⁺ on Al₂O₃ nanoparticles and recovery rate was more than 95%.

Abstract: In this experiment, we use the removal rate of COD as index to optimize membrane composition and operating parameters formula by 3 stage countercurrent liquid membrane extraction and also study the influence of different water to emulsion R_ew on COD removal rate .The experiments showed that R_ew and the external phase pH have significant effects on the removal rate of COD and the total removal rate of COD reached 85.3% when R_ew=1:1.0 under the condition of 3 stage countercurrent extraction.

Abstract: In this paper, azo dye Acid Red B (ARB) simulation of wastewater was treated with persulfuric acid. By conducting the comparative experiments of the catalysts and analyzing their catalytic mechanisms, the promotion effect of catalysts on the reaction was ranked as: AgNO₃>Ag₂SO₄>CoCl₂>CoSO₄>FeSO₄>FeCl₂; in addition, optimum reaction conditions were attained: ARB concentration of 200mg/L, the reaction time 1h, temperature 25°C, oxidant dosage 15mL/L and 6.5×10^-5mol/L with catalyst of AgNO₃, under which the decolorization rate of ARB was up to 100%, and COD removal rate was up to 72%.

Abstract: Clean development mechanism is one way of cooperation between developed and developing countries to decrease greenhouse gases emission in the “Kyoto Protoco1”. An advanced technology of Japan Mitsubishi Corporation was introduced to Kaifeng Jinkai Chemical Engineering to reduce the emission of N₂O by improving nitric acid production installation. This can not only reduce the greenhouse gases emission, reduce nitric acid production costs and create considerable economic efficiency to enterprise but also promote clean development mechanism and make great contribution to the world environmental protection.

Abstract: 3-D Fluorescence Spectrometry analysis and sorption experiments of Acenaphthene (Acp), one of the polycyclic aromatic hydrocarbons (PAHs), were carried on in this paper. Under the experimental conditions, the optimized excitation/emission wavelength (λex/λem) was 280/320nm. The correlative coefficient of 0.998 and the relative standard deviation of 4.03%(n=5) could be obtained over the linear ranges of 0.025mg/L~1mg/L for the calibration curve. The sorption tests of Acp to surface sediment in Chongqing Section of the Yangtze River showed that the sorption isotherms were fitted with different types of model, including traditional linear partition model and Freundlich model. According to the fitted value of model, the sorption behaviors of Acp to the surface sediment was not affected by the single sorption mechanism but the combined action of linear partition process and surface sorption.

Abstract: Cement industry bear the brunt in the tide of resisting global warming because of large carbon dioxide emission. Five low-carbon measures and implementation approach to Chinese cement industry was put forward: Increasing industrial concentration degree and developing new dry process cement; Processing waste in cement kilns and reducing the use of raw materials and fuels; Increasing the amount of admixture in cement; Producing cement from calcium oxide content solid waste; Taking energy-saving measures such as cogeneration and grinding technology.

Abstract: Catalytic combustion of volatile organic compounds (VOCs) is a high efficient and low-polluted technique. In this paper, the palladium-based combustion catalysts on cordierite honeycomb ceramics (CHC) substrate without interlayer film — Pd/CHC, were prepared by electroless plating method, and the effect of preparing conditions for the catalysts on the catalytic performance of toluene combustion was mainly studied. The optimal conditions were confirmed as follows: plating bath temperature is 60°C, plating time is 30min, palladium salt concentration is 0.2g/L, and calcination temperature after plating is 500°C. Finally, the stability test further indicated that the Pd/CHC catalyst prepared by the optimal electroless plating conditions has good catalytic stability.

Abstract: Hydrotalcites (HT-X) of different Mg/Al ratio (X is Mg/Al molar ratio, 3 and 4) was synthesized by co-precipitation method. Calcined HTLCs (CHT-X) at 500°C have been shown to recover their original layered structure by taking up chloride ion from aqueous solution. Adsorption of chloride by CHT-X was investigated in batch mode. The kinetics study showed that the pseudo-second-order kinetics model could be used to describe the adsorption process satisfactorily. The equilibrium isotherm showed that the Langmuir model gave a better fit to the experimental data than the Freundlich model. The maximum adsorption capacity of CHT-3 was 83.33 mg/g; CHT-4 was 90.09 mg/g .The samples of different Mg/Al ratio have different crystallite size, thus showing different adsorption capacity. As the Mg/Al ratio increases from 3 to 4; the electric charge density between the layers becomes weaker; the interlayer spacing increases; the sample shows greater adsorption capacity. The HT-X where characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), electron dispersive X-ray analysis (EDX).