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ABSTRACT: Digested sewage sludge gasification in supercritical water was studied. Influences of main reaction parameters, including temperature (623-698 K), pressure (25-35 Mpa), residence time (10-15 min) and dry matter content (5-25 wt%), were investigated to optimize the gasification process. The main gas products were methane, carbon monoxide, carbon dioxide and traces of ethene, etc. Results showed that 10 wt% dry matter content digested sewage sludge at a temperature of 698 K and residence time of 50 min, with a pressure of 25 MPa, were the most favorable conditions for the sewage sludge gasification and carbon gasification efficiencies. In addition, potassium carbonate (K(2)CO(3)) was also employed as the catalyst to make a comparison between gasification with and without catalyst. When 2.6 g K(2)CO(3) was added, a gasification efficiency of 25.26% and a carbon gasification efficiency of 20.02% were achieved, which were almost four times as much as the efficiencies without catalyst. K(2)CO(3) has been proved to be effective in sewage sludge gasification.
Waste management & research : the journal of the International Solid Wastes and Public Cleansing Association, ISWA. 01/2013;
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ABSTRACT: Selective catalytic reduction (SCR) of NO by urea loaded on rayon-based activated carbon fibre (ACF) and CeO2/ACF (CA) was studied at ambient temperature (30 degrees C) to establish a basic scheme for its reduction. Nitric oxide was found to be reduced to N2 with urea deposited on the ACF and CA. When oxygen was present, the greater the amount of loaded urea (20-60%), the greater the NO(x) conversions, which were between 72.03% and 77.30%, whereas the NO(x) conversions were about 50% when oxygen was absent. Moreover, when the urea was loaded on CA, a catalyst containing 40% urea/ACF loaded with 10% CeO2 (UCA4) could yield a NO(x) conversion of about 80% for 24.5 h. Based on the experimental results, the catalytic mechanisms of SCR with and without oxygen are discussed. The enhancing effect of oxygen resulted from the oxidation of NO to NO2, and urea was the main reducing agent in the SCR of loaded catalysts. ACF-C was the catalytic centre in the SCR of NO of ACF, while CeO2 of urea-loaded CA was the catalytic centre.
Environmental Technology 06/2012; 33(10-12):1331-7. · 1.41 Impact Factor
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ABSTRACT: Small non-coding RNAs (sRNAs) are important post-transcriptional regulators in prokaryotes and have been demonstrated to participate in most of the cellular processes. SraG is an sRNA found in several enterobacterial species, but its targets have not been characterized. Here, we compared the protein expression patterns between the wild-type and an sraG-depleted mutant of Yersinia pseudotuberculosis by proteomic analysis. Sixteen proteins were up- or downregulated, and the negative regulatory role of SraG associated with the YPK_1206-1205 operon was confirmed. A region in the coding sequence of YPK_1206 was further demonstrated to be required for this negative regulation.
FEMS Microbiology Letters 03/2012; 331(1):37-43. · 2.04 Impact Factor
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ABSTRACT: Direct cloning of PCR fragments by TA cloning or blunt end ligation are two simple methods which would greatly benefit high-throughput (HTP) cloning constructions if the efficiency can be improved. In this study, we have developed a ribosomal binding site (RBS) switching strategy for direct cloning of PCR fragments. RBS is an A/G rich region upstream of the translational start codon and is essential for gene expression. Change from A/G to T/C in the RBS blocks its activity and thereby abolishes gene expression. Based on this property, we introduced an inactive RBS upstream of a selectable marker gene, and designed a fragment insertion site within this inactive RBS. Forward and reverse insertions of specifically tailed fragments will respectively form an active and inactive RBS, thus all background from vector self-ligation and fragment reverse insertions will be eliminated due to the non-expression of the marker gene. The effectiveness of our strategy for TA cloning and blunt end ligation are confirmed. Application of this strategy to gene over-expression, a bacterial two-hybrid system, a bacterial one-hybrid system, and promoter bank construction are also verified. The advantages of this simple procedure, together with its low cost and high efficiency, makes our strategy extremely useful in HTP cloning constructions.
PLoS ONE 01/2012; 7(11):e50142. · 4.09 Impact Factor
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ABSTRACT: Total suspended particle (TSP) collected at the fifth floor of House Dust in Hunan University, China, was analyzed in terms of microscopic morphology and chemical composition. The fine particles (50 nm-2 μm) in the TSP were analyzed by a high-resolution transmission electron microscope equipped with an energy-dispersive X-ray analyzer (HRTEM/EDS). Results showed that the particles were in shapes of plate, irregular and agglomerate. Based on EDS results, these fine particulate matter was primarily composed of Fe-rich (35.82-61.29%), Ca-rich (30.18-36.77%) and Si-rich (18.95-32.28%) particles. Other elements mainly including Mg (0.47-4.97%), Al (0.45-14.57%), S (0.45-4.73%), K (1.13-2.13%) and Zn (0.67-3.85%) were also observed. The sources analysis indicated that the HRTEM particles mainly originated from coal combustion, traffic emission, vehicles exhaust emission and fugitive soil or cement particulate matter. The coarse particles (4-50 μm) were detected by environmental scanning electron microscopy coupled with energy-dispersive X-ray detector (ESEM/EDS). Based on a simple algorithm, ESEM particles were categorized into five groups: C-bearing (46.15%, 67% and 86.98%), Si + Ca-bearing (21.48 + 11.80%, 16.51 + 10.81% and 16.32 + 10.62%), Si + Al-bearing (20.06 + 12.40%, 20.16 + 11.22% and 15.31 + 11.25%), Si-bearing (34.40%, 26.92% and 27.15%) particles and aggregates, most of which exhibit obvious crystalline structure, and these ESEM particles mainly derived from vehicles exhaust emission, coal combustion, soil, and biomass burning, while the aggregates are indicative of atmospheric reaction progress. HRTEM/EDS and ESEM/EDS are mutual complementary in analyzing the characteristic and determining the sources of TSP.
Environmental Monitoring and Assessment 12/2011; 184(11):6693-707. · 1.40 Impact Factor
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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: The Al2O3,which has large specific surface area and is used as carrier,was prepared by sol-gel method in this study. Series catalysts of MnOx, CeO2 plus MnOx supported on Al2O3 by isometric impregnation method. The SCR denitrification experimental conditions were as follows: NH3 as reductive agent, certain gas velocity and suitable ratio of gas mixed was setup. Furthermore, the experiments of BET, XRD and SEM were also carried out respectively in order to obtain physicochemical properties of the prepared catalysts. The experimental results showed that the loading of active component and calcination temperature made a big difference to the catalysts' performance. With appropriate addition of CeO2, MnOx/Al2O3 exhibits better activity and stability. For MnOx/Al2O3, the catalytic activity on NO was greatly influenced by its loaded content, and 7% MnOx/Al2O3 showed superior catalytic activity among the MnOx/Al2O3. The addition of CeO2 could greatly improve the dispersibility of MnOx on the carrier and increase its catalytic activity. The 4% CeO2 addition was the optimum loaded mass precent. Forthermore, 550 degrees C is the best calcination temperature, as MnOx formed different crystalline phases with temperature, at the same time, the addition of CeO2 could affect MnOx crystalline phase. The catalytic mechanism of SCR on NO was also discussed.
Huan jing ke xue= Huanjing kexue / [bian ji, Zhongguo ke xue yuan huan jing ke xue wei yuan hui "Huan jing ke xue" bian ji wei yuan hui.] 08/2011; 32(8):2240-6.
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ABSTRACT: The influence of some experimental factors on removal efficiency of nitric oxide (NO) under the condition of liquid-phase oxidation with UV/H2O2, such as H2O2 concentration, solution temperature, initial pH, NO concentration, illumination condition, O2 content and gas flow rate, were investigated by employing orthogonal experiments and single factor experiments. The results showed that NO could be efficiently removed by the aqueous oxidation technology with UV/H2O2 system, and the highest NO removal rate was about 80%. Moreover, H2O2 concentration, temperature and initial pH had varying degree effects on purifying NO-containing gas, whereas NO removal rate were more affected by H2O2 concentration and temperature. The single factor experimental results showed that high NO removal rate could be obtained when H2O2 concentration was 0.2 mol/L and the initial pH was 6-7. H2O2 concentration and initial pH should be maintained at an appropriate level or the production of *OH could be restricted, which would result in lower NO removal rate. The optimum operation temperature was 40 degrees C, which is lower than common operating temperature (50 degrees) for the wet scrubber. Enlarging the illumination strength and O2 content could improve the NO removal rate. Furthermore, the NO removal rate was also controlled by the area and coefficient of gas-liquid mass transfer.
Huan jing ke xue= Huanjing kexue / [bian ji, Zhongguo ke xue yuan huan jing ke xue wei yuan hui "Huan jing ke xue" bian ji wei yuan hui.] 04/2011; 32(4):949-54.
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ABSTRACT: Survival in acidic environments is important for successful infection of gastrointestinal pathogens. Many bacteria have evolved elaborate mechanisms by inducing or repressing gene expression, which subsequently provide pH homeostasis and enable acid survival. In this study, we employed comparative proteomic analysis to identify the acid-responsive proteins of a food-borne enteric bacterium, Yersinia pseudotuberculosis. The expression level of eight proteins involved in carbohydrate metabolism was up- or downregulated over twofold at pH 4.5 compared with pH 7.0. The role of a global transcriptional regulator catabolite repressor/activator Cra was further studied in this acid survival process. lacZ-fusion analysis showed that expression of cra was repressed under acidic pH. Deletion of the cra gene increased acid survival by 10-fold, whereas complementation restored the wild-type phenotype. These results lead us to propose that, in response to acidic pH, the expression of cra gene is downregulated to increase acid survival. This is the first study to demonstrate the regulatory role of Cra in acid survival in an enteric bacterium.
FEMS Microbiology Letters 01/2011; 317(2):190-5. · 2.04 Impact Factor
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ABSTRACT: The catalysts were prepared by activated carbon fiber (ACF) loaded different contents of NiO and NiO-CeO2, Urea was loaded on the prepared catalysts as reductant. The experiments of selective catalytic reductions (SCR) of NO were carried out from 30 to 120 degrees C. The experiments of SEM, BET and XRD of the samples were also carried out selectively to study the catalysts properties, respectively. The experimental results showed that the loaded mass fraction of NiO could greatly affect the catalytic activity of the catalysts. 10% NiO catalyst activity and activity stability were both higher than that of the others, and it could yield about 50% removal efficiency of NO at 90 degrees C. With the loaded mass increasing, the catalytic activity was obviously decreased. And furthermore, the catalyst of 5% NiO-5% CeO2/ACF had the best catalytic activities on SCR NO and stability among the prepared NiO-CeO2/ACF catalysts, and its NO removal efficiency was over 55% at 110 degrees C. When the loaded mass increased, the similar phenomenon was observed, which was due to the decreasing of specific surface area of the catalysts. The metal oxides, loaded on ACF, were the catalytic centers in this study. Moreover, 5% CeO2-5% NiO/ACF had the highest catalytic activity than 10% CeO2/ACF and 10% NiO/ ACF. Therefore, there should be synergistic effect between CeO2 and NiO. Finally, the catalytic mechanism of SCR on NO at low temperature was discussed.
Huan jing ke xue= Huanjing kexue / [bian ji, Zhongguo ke xue yuan huan jing ke xue wei yuan hui "Huan jing ke xue" bian ji wei yuan hui.] 11/2010; 31(11):2575-81.
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ABSTRACT: Surfactants increase wetting, solubilization of carbon black and reduce interfacial tension between surfactants and carbon black are very important for the wet removal of furnace smoke. Calculated hydrophile-lipophile balance value (HLB), critical micelle concentration (CMC) and Gibbs-free-energy (deltaG0(mf)) of mixed surfactants solution generated on the basis of selected mathematical models. The CMC of AEO-9, SDBS solution at different ratios and smoke removal efficiency at the CMC were gained by experiments. The relation among HLB, CMC and deltaG0(mf) in mixed surfactants were analyzed. At last, new mathematic models were established about them. The results showed that the calculated data had good agreement with the experimental data. HLB was linearly correlate with ln [CMC]. There was a quadratic relationship between deltaG0(mf) and smoke removal efficiency. The reducing CMC could effectively increase HLB value and solubility, while the deltaG0(mf) and surface tension were both decreased, which could form micelles more spontaneously and enhance smoke removal significantly.
Huan jing ke xue= Huanjing kexue / [bian ji, Zhongguo ke xue yuan huan jing ke xue wei yuan hui "Huan jing ke xue" bian ji wei yuan hui.] 10/2010; 31(10):2541-6.
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ABSTRACT: Enteric bacteria have developed various survival systems that protect against acid stress. In this study, an aspartate-dependent acid survival system is characterized in Yersinia pseudotuberculosis. The expression of aspartase (AspA) was confirmed to be increased at acidic pH by proteomic and lacZ fusion analyses. Addition of aspartate increased acid survival of the wild type but not the aspA knockout mutant. AspA increases acid survival by producing ammonia as demonstrated by mutation and in vitro enzyme activity analyses. This is the first demonstration that an enzyme involved in aspartate metabolism plays a role in acid survival in an enteric bacterium.
FEBS letters 04/2010; 584(11):2311-4. · 3.54 Impact Factor
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ABSTRACT: Plant infection models provide certain advantages over animal models in the study of pathogenesis. However, current plant models face some limitations, e.g., plant and pathogen cannot co-culture in a contained environment. Development of such a plant model is needed to better illustrate host-pathogen interactions.
We describe a novel model plant system for the study of human pathogenic bacterial infection on a large scale. This system was initiated by co-cultivation of axenic duckweed (Lemna minor) plants with pathogenic bacteria in 24-well polystyrene cell culture plate. Pathogenesis of bacteria to duckweed was demonstrated with Pseudomonas aeruginosa and Staphylococcus aureus as two model pathogens. P. aeruginosa PAO1 caused severe detriment to duckweed as judged from inhibition to frond multiplication and chlorophyll formation. Using a GFP-marked PAO1 strain, we demonstrated that bacteria colonized on both fronds and roots and formed biofilms. Virulence of PAO1 to duckweed was attenuated in its quorum sensing (QS) mutants and in recombinant strains overexpressing the QS quenching enzymes. RN4220, a virulent strain of S. aureus, caused severe toxicity to duckweed while an avirulent strain showed little effect. Using this system for antimicrobial chemical selection, green tea polyphenols exhibited inhibitory activity against S. aureus virulence. This system was further confirmed to be effective as a pathogenesis model using a number of pathogenic bacterial species.
Our results demonstrate that duckweed can be used as a fast, inexpensive and reproducible model plant system for the study of host-pathogen interactions, could serve as an alternative choice for the study of some virulence factors, and could also potentially be used in large-scale screening for the discovery of antimicrobial chemicals.
PLoS ONE 01/2010; 5(10):e13527. · 4.09 Impact Factor
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ABSTRACT: OmpR has been demonstrated to negatively regulate the expression of the flagellar master operon flhDC in a wide variety of bacterial species. Here we report the positive regulation of flhDC expression by OmpR in Yersinia pseudotuberculosis. A sigma(70)-dependent promoter was identified by primer extension analysis and an active region with two conserved OmpR-binding sites around the flhDC promoter was confirmed. To confirm the regulation of flhDC expression by OmpR, flhDC as well as the downstream flagellar genes fliA, flgD, flgA, flgM, fliC and flaA were fused to lacZ, and decreased expression of all these genes in an ompR mutant (Delta ompR) was detected. Furthermore, Delta ompR was defective in bacterial motility and flagella synthesis. This defect was due to the low level of expression of flhDC in Delta ompR since overproduction of FlhDC in Delta ompR restored bacterial motility. The importance of two conserved OmpR-binding sites around the flhDC promoter region in the regulation of flhDC expression by OmpR was demonstrated by the fact that mutation of either one or both sites significantly decreased the promoter activity in the wild-type but not in Delta ompR. The binding of OmpR to these two sites was also demonstrated by DNA mobility shift assay. The possible mechanism underlying this positive regulation in Y. pseudotuberculosis is discussed. To our knowledge, this is the first report to demonstrate that OmpR positively regulates flhDC expression.
Microbiology 08/2009; 155(Pt 11):3622-31. · 3.06 Impact Factor
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ABSTRACT: Yersinia pseudotuberculosis is an enteric bacterium which must overcome the acidic stress in host organs for successful colonization, but how this bacterium survives in acidic conditions remains largely unknown. In the present study, the importance of OmpR in acid survival of Y. pseudotuberculosis YpIII was confirmed by the fact that mutation of ompR (strain DeltaompR) greatly reduced cell survival at pH 4.5 or lower. To characterize the regulatory role of OmpR in this acid survival process, proteomic analysis was carried out to compare YpIII at pH 7.0 and pH 4.5 with DeltaompR at pH 7.0, and urease components were revealed to be the main targets for OmpR regulation. Addition of urea to the culture medium also enhanced acid survival of YpIII but not DeltaompR and urease activity was significantly induced by acid in YpIII but not in DeltaompR. Each of the seven components of the YpIII urease gene cluster was fused to a lacZ reporter and their expression was dramatically decreased in a DeltaompR background; this supports the notion that OmpR positively regulates urease expression. Furthermore, gel shift analysis revealed that OmpR binds to the deduced promoter regions of three polycistronic transcriptional units (ureABC, ureEF and ureGD) in the urease cluster, suggesting that the regulation of OmpR to urease components is direct. Taken together, these data strongly suggest that OmpR activates urease expression to enhance acid survival in Y. pseudotuberculosis.
Microbiology 06/2009; 155(Pt 8):2522-31. · 3.06 Impact Factor
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ABSTRACT: The active carbon fiber (ACF) loaded different contents of La2O3 catalysts were prepared, and their catalytic activities and durability for the purification of NO were investigated, and for comparison, those of ACF and HNO3/ACF for the title reaction were also investigated. The orthogonal experiment results showed that the best volume fraction of oxygen in the mixed gas was 5%, and the best air speed of mixed gas was 5000 m3 (m3 x h)(-1). The catalytic experiment results showed that the activity of HNO3/ACF was better than that of ACF when the temperature was below 414.08 degrees C, but the activity durability of HNO3/ACF was inferior than that of ACF. The activity and the activity durability of ACF could be markedly increased when it was loaded La2O3 catalyst, the activity center of the catalyst was La2O3, and the La2O3 catalyst best load amount was 20%, the activity of 20% La2O3/ACF would above 95% when the temperature was higher than 350 degrees C, and its activity durability was about 8 h, which was superior than most of the catalysts that had been reported. The results of FT-IR and TG experiments also showed that the NO purification principle of ACF and HNO3/ACF was different from that of La2O3/ACF, when NO was purified by La2O3/ACF, the competition reactions took place between CO and NO.
Huan jing ke xue= Huanjing kexue / [bian ji, Zhongguo ke xue yuan huan jing ke xue wei yuan hui "Huan jing ke xue" bian ji wei yuan hui.] 12/2008; 29(11):3280-4.
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ABSTRACT: To compare the efficacy and safety of a single ceftriaxone injection with 10-day oral amoxicillin in the treatment for children's acute otitis media.
This study was a prospective, comparative, open randomized, multicenter trial. In the ceftriaxone group, a single dose sodium ceftriaxone (50 mg/kg, total dose < 1 g) was injected. In the amoxicillin group, the oral amoxicillin [40 mg/(kg.d), tid] was used for 10 days. Totally 236 cases aged from 0.5 to 12 years were enrolled and 212 cases completed the study. These patients were followed up twice and clinical signs and symptoms were recorded, otoscopy, peripheral blood WBC count, hearing test (pure tone test) and tympanography were performed.
In the ceftriaxone group, 103/106 cases were cured or improved (97.17%), while in the amoxicillin group 96/106 cases were cured or improved (90.57%) (P < 0.05). Ceftriaxone was significantly better than amoxicillin in the treatment. Totally 4 cases had side effects such as papular skin rash, urticaria around mouth, skin pigmentation, two cases in the ceftriaxone group and other two cases in the amoxicillin group. There was no significant difference between the 2 groups in side effects.
Ceftriaxone injection was significantly better than ten-day oral amoxicillin for treatment of acute otitis media in children. The single dose regimen with ceftriaxone seems to be a good choice for children, particularly for.
Zhonghua er ke za zhi. Chinese journal of pediatrics 02/2003; 41(2):135-8.
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ABSTRACT: A series of Mn/Al2O3, La-Mn/Al2O3 and Fe-La-Mn/Al2O3 catalysts were prepared by an impregnation method and investigated for selective catalytic reduction of NO with NH3 at low temperature. The experimental results revealed that NO conversion over La-Mn/Al2O3 was obviously improved after La doping. Addition of Fe increased both NO conversion and the resistance to H2O and SO2. The catalyst Fe0.04La0.03Mn0.06/Al2O3 with a load mass of MnO2 = 6%, La2O3 = 3% and Fe2O3 = 4% exhibited relatively high catalytic activity and yielded 98% NO conversion at 260 degrees with a space velocity of 15,000 h(-1). Meanwhile, the catalytic activity was slightly decreased in the presence of H2O and SO2. Moreover, the catalysts were characterized by N2 adsorption measurement, X-ray diffraction and X-ray photoelectron spectroscopy. The results showed that the doping of La enhanced the dispersion and oxidation states of Mn on the surface of Al2O3. On the surface of the Fe0.04La0.03Mn0.06/Al2O3 catalyst, La was highly dispersed and a mixed oxidation state of Mn existed, while iron ions were only in the Fe3+ state. The mechanism of selective catalytic reduction over these catalysts is also discussed. In this experiment, metal oxides loaded on the support were catalytic centres which served as electron transfer during NO reduction. The electron transfer between Mn3+ and Fe3+ might also exist and the mixture oxidation states of Mn on the surface of the Fe0.04La0.03Mn0.06/Al2O3 catalyst contributed to the SCR activity.
Environmental Technology 34(1-4):81-90. · 1.41 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
