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ABSTRACT: In this study, the characterizations of soot from ceramic furnace flue gas were studied using environmental scanning electron microscopy, energy dispersive spectroscopy, particle size distribution, specific surface area measurements, crystal characterizations and organic pollutant analysis. Soot particles were mainly spherical nanoparticles with diameters less than 100 nm. However, the particles could be aggregated into larger ones with a median diameter of 3.66 μm. Nanometer pores with diameters ranging 2-4 nm were also detected in the soot particles. Because of their large surface areas and pore volumes, other pollutants in the environment can be adsorbed to soot particles potentially making them more hazardous. Several elements, including C, O and Pb, were detected in the soot, but only small amounts of crystalline materials were observed. This is because most of the detected carbon and metals/metal oxides/metal salts were amorphous. Approximately 90 different organic pollutants were detected in the soot, including aromatic compounds and other hydrocarbons. Because of the carcinogenic properties of aromatic compounds and the photochemical effects of hydrocarbons, soot could have serious health and environmental impacts. The results suggest that soot particles are hazardous material and urgently need to be controlled.
Journal of hazardous materials 11/2011; 199-200:272-81. · 4.14 Impact Factor
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ABSTRACT: Black carbon (BC) particles were removed from experimental flue gas by the surfactant solutions of sodium dodecylbenzene sulfonate (SDBS), hexadecyl trimethyl ammonium bromide (CTAB), fatty alcohol polyoxyethylene ether-9 (AEO-9) and polyoxy ethrlene nonyl phinyl ether-10 (TX-10), as well as AEO-9-SDBS, AEO-9-CTAB and SDBS-CTAB, in a new type of umbrella plate scrubber. Among the four independent surfactants, AEO-9 has the lowest surface tension, 35.9 mN/m, which resulted in the highest BC removal ratio among the alone surfactants. The experimental conditions were as follows: dust concentration = 3000 mg/m3; gas velocity = 14 m/s; liquid-gas ratio = 0.80 l/m3; and gas flow = 400 m3/h. When the mole ratio of the mixed surfactants was 1:1, the lowest surface tension could be detected among the studied mixed surfactants. According to the molecular interaction parameters (beta) and the mole ratio of surfactant 1 in the mixture (x1), the synergistic effects of AEO-9-SDBS and SDBS-CTAB solutions were obviously higher than those of AEO-9-TX-10 and AEO-9-CTAB. Therefore, AEO-9-SDBS solution had the lowest surface tension among the mixtures due to its beta < 0 and x1 = 0.85. The mixture solution of AEO-9-SDBS (1:1 mole ratio, 0.2 mmol/l) yielded the highest BC removal ratio, about 99.8%, and it was about 12% higher than that of only water, which was about 87.9%. The calculated critical micelle concentration was almost the same as that of the experimental concentration when the related equation was corrected by beta.
Environmental Technology 34(1-4):101-11. · 1.41 Impact Factor
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ABSTRACT: Surfactant solutions were propounded to remove fine and hydrophobic carbon black particles from coal-fired flue gas. The adsorption mechanisms between sodium dodecyl benzene sulfonate (SDBS, an anionic surfactant) and carbon black particles in suspension were investigated. The influence of inorganic salt (NaCl) was also considered. As results showed, hydrophobic interactions contributed to the strong adsorption between SDBS and carbon black particles in the absence of NaCl, and adding NaCl affected the adsorption process. The adsorption amount of SDBS significantly increased when NaCl was added into the SDBS solution; however, when SDBS was in low concentration, the amount of adsorbed SDBS, which was responsible for the shift of zeta potentials, varied little under different concentrations of NaCl. This indicated that the adsorption of SDBS was mainly caused by hydrophobic interaction and Na+ could not change the adsorption of SDBS on adsorption site when SDBS was in low concentration. Moreover, the adsorbed SDBS and Na+ were retained in the Stern layer.
Environmental Technology 34(1-4):201-7. · 1.41 Impact Factor
