Advanced Materials Research Vols. 518-523

Abstract: ^{Superscript textSuperscript text}The concentration of six potential carcinogenic compounds (3-Methylcholanthrene, Dibenz(a,h)acridine, Dibenz(a,i)acridine, Dibenzo(a,e)pyrene, Dibenzo(a,h)pyrene, Dibenzo(a,i)pyrene ) in the urban air of Dalian, China were monitored from November 2009 to March 2010 with active high-volume sampler. They were detected in gaseous phase and particulate phase, respectively. The total concentration of them was 563.2 pg m^-3, and they were mainly found in particulate phase with the concentration of 540.5 pg m^-3 while the concentration in the gas phase only was 22.7 pg m-3. The concentration of them changed apparently in different month.

Abstract: Mercury distribution and stable isotope composition in solid samples of two coal-fired power plants in Guizhou province were determined. Results shown electrostatic precipitator (ESP) has mercury removal efficiency between 29.53% to 58.41%, and wet flue gas desulfurization (WFGD) between 12.29% to 58.60%, mercury removal efficiency of ESP and WFGD mainly depends on the coal properties. Most mercury (70% to 88%) in coal was captured by the combination of ESP+WFGD. Mercury in fly ash and gypsum were much heavier in isotope composition compared to the coal, hints mercury escaped into atmosphere was enriched in lighter mercury isotopes.

Abstract: The effect of different hydraulic retention time on the removal of COD, nitrogen and phosphorous when influent COD was 1000 mg/L were carried out by establishing simulation model with the help of mathematical simulation software BioWin3.0 on the computer and adjusting the parameters continuously combined with the actual operation of anaerobic sewage treatment technology, then compared and analyzed the effect of the simulated effluent and the actual effluent. The results showed that the model established by mathematical simulation software BioWin3.0 can reflect the actual operation conditions of sewage treatment.

Abstract: The wastewater treatment plants (WWTPs) in small towns are of dispersed locations, small scale and difficult management, thus joint WWTPs operation is a recommended operation mode for those WWTPs. Site selection for central plant plays a crucial role in promoting the reliability and efficiency in joint WWTPs operation. Multiobjective models to maximize the reliability and minimize the cost of the central plant were developed, and primary objective function was applied to obtain the solution of the models. And we presented an example to illustrate the application of the proposed models.

Abstract: Hierarchical FeZSM-5 microspheres were prepared in the presence of 3-aminopropyltriethoxysilane (APTES) in the synthesis system. The structure and morphology of the synthesized zeolites have been characterized by XRD, SEM, and N₂ adsorption techniques. The hierarchical FeZSM-5 shows a much better catalytic performance in the direct decomposition of N₂O, compared to FeZSM-5 synthesized without APTES.

Abstract: This study focused on the comparisons between nitrogen and phosphorus removal rates from the simulated wastewater using various kinds of aquatic plants (4 emergent and 3 floating plants). Results showed that aquatic plants has a significant effect on the removal of NO3--N and TP, but has a less effect on NH4+-N. Among the four emergent plants, the order of NO3--N removal capacities was: S. sagittifolia > S. tabernaemontani > T. latifolia > A. calamus. But for TP, the order was: T. latifolia > A. calamus > S. tabernaemontani > S. sagittifolia. To the floating plants, the order of NO3--N and TP removal capacities were: E. crassipes > P. stratiotes. The ANOVA analyses showed that there was a significant difference between planted treatments and unplanted treatment for the removal of NO3--N and TP. The study suggests that the treatment of simulated wastewater using the aquatic macrophytes was effective in the removal of nutrients.

Abstract: In the present study a lab-scale biofilm reactor was monitored for approximately 6 months to evaluate the use of ratios of carbon to nitrogen (C/N), pH and hydraulic retention time(HRT) levels as monitoring parameters in order to optimize nitrate removal from groundwater. The results indicated it was possible to operate the biofilm system at high denitrification rates and relatively low HRT of 8 hours.

Abstract: The process of gasoline vapor adsorption by an activated carbon or a silica gel was simulated using Aspen Adsorption Simulation software and the adsorption isothermal model of the expanded Langmuir. Meanwhile, an experiment of the dynamic adsorption of gasoline vapor was designed. Two key parameters in the dynamic adsorption process, i.e., the vapor concentration from the adsorption bed and the temperature change in the bed, were calculated and ,measured, respectively. The simulation results agreed well with the experimental data. This showed that the simulation method using the adsorption isothermal model is suitable for the research and design of gasoline vapor adsorption process.

Abstract: Kaohsiung and Pintung are the first regions were set into action of total quantity control zones for air quality in Taiwan. Cap and trade programs have built for the particle matters (PM10), sulfur oxides (SOx), nitrogen oxides (NOx) and Volatile Organic Compounds (VOCs) in 2010. The offset ratio was designed as 1.0 or 1.2 various on the offset sources. The fixed offset ratio setting is suitable for PM10, SOx, and NOx since their characters are unitary. However, VOCs include a variety of chemicals, some of which may have short- or long-term adverse health effects. Even the same pollutant trading amount cannot guarantee the same health risk or environmental impacts. It would induced the highly uncertainty of air quality for the fixed offset ratio system. This study therefore tried to create a new methodology based on the pollutant impact strength of health and environment for determining the offset ratio of VOCs. An equation for calculating the offset ratio of VOCs was proposed and evaluated by case study. The elasticity of weighting determination was remained to the decision makers for confronting the various environmental improving targets.

Abstract: The oxidative degradation of azo dye Reactive Red 2BF in aqueous solution by using potassium ferrate (Ⅵ) was studied. The initial concentration of wastewater 100 mg/L, pH 4.0, reaction time 20 min, and the dosage of potassium ferrate was 0.9 g/L. Under the optimal conditions, the decolorizing rate of Reactive Red 2BF and the COD removal rate were 99.9% and 73.3%.