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Neergaard Haahr posted an update 1 year, 7 months ago
The pulsed magnetic field (PMF) was adopted for the enhancement of lipid in Chlorella vulgaris. The average biomass and lipid content in outdoor conditions were found to be 0.315 g.L-1 and 20-25% respectively. The effect of magnetic flux density in the range of 600-900 mG on biomass production and lipid content was studied. A magnetic flux density of 700 mG at 1Hz for 4 h per day was found to be optimum, which yielded a maximum dry cell weight of 0.61 g.L-1, two-fold than the normal condition, with a lipid content of 55.2%. FTIR analysis evidenced that the PMF treatment increased the active oxygen, which could be attributed to the enhancement of growth and lipid of C. vulgaris.In this work, a series of spindle-like CeO2 supports with different contents of surface oxygen vacancies were fabricated by an in-situ atmosphere thermal pyrolysis method. Due to the unique surface physicochemical properties of the modified CeO2 supports, the interaction between Pt and CeO2 can be regulated during the synthesis of the Pt/CeO2 catalyst. The abundant oxygen vacancies on the CeO2 support could preferentially trap Pt2+ ions in solution during the Pt impregnation process and enhance the Pt-CeO2 interaction in the subsequent reduction process, which results in the strongest Pt-O-Ce bonds formed on the PCH catalysts successfully (0.6% Pt loading on the CH support, which generated by thermal pyrolysis of Ce(OH)CO3 under H2 atmosphere). The strong Pt-O-Ce bond would trigger abundant surface oxygen species generated and enhanced the lattice oxygen species transfer from CeO2 supports to Pt nanoparticles. It was crucial to boosting the toluene catalytic activity. Therefore, the PCH catalyst exhibits the highest activity for toluene oxidation (T10 = 120 °C, T50 = 138 °C, and T90 = 150 °C with WHSV = 60,000 mL g-1 h-1) and remarkable durability and water resistance among all catalysts. We also conclude that the Pt-O-Ce bond may be the active site for toluene oxidation by calculating the turnover frequencies (TOFPt-O-Ce) value for all Pt/CeO2 catalysts. Moreover, the DFT calculation indicates that the Pt/CeO2 catalyst with a strong Pt-O-Ce bond possesses the lowest oxygen absorption energy and higher CO tolerance ability, which leads to excellent catalytic performance for toluene and CO catalytic oxidation.The hydrophobicity properties of dissolved organic matter (DOM) found in tropical peat water has an impact on the formation of carcinogenic DBPs such as trihalomethanes-4 (THM4) and haloacetic acids-5 (HAA5). This study was conducted to determine the effect of microbubble ozonation on changes in DOM fraction and its effect on the formation of THM4 and HAA5. Alum coagulation and activated carbon adsorption were carried out to reduce the DOM concentration before microbubble ozonation. Microbubble ozonation was carried out at acidic (pH 5.5), neutral (pH 7) and alkaline (pH 8.5) conditions to determine the effect of pH. Coagulation and adsorption of activated carbon were successful in reducing the presence of the hydrophobic acid fraction (HPOA) in peat water completely, but the transphilic (TPH), charged hydrophilic (HPIC) and neutral hydrophilic (HPIN) fractions remained in the water. Microbubble ozonation succeeded in decreasing the presence of TPH fraction but increased the formation of HPIC and HPIN. The degradation of the TPH fraction resulted in reduced formation of chlorinated THM4 and HAA5 (C-THM4 and C-HAA5). On the other hand, the formation of HPIC and HPIN fractions increased the formation of brominated THM4 and HAA5 (B-THM4 and B-HAA5) after the final chlorination process.A three-dimensional electrochemical reactor with Ti/SnO2-Sb/β-PbO2 anode and granular activated carbon (3DER-GAC) particle electrodes were used for degradation of 2,4-dichlorophenol (2,4-DCP). Process modeling and optimization were performed using an orthogonal central composite design (OCCD) and genetic algorithm (GA), respectively. Ti/SnO2-Sb/β-PbO2 anode was prepared by electrochemical deposition method and then its properties were studied by FESEM, EDX, XRD, Linear sweep voltammetry and accelerated lifetime test techniques. The results showed that lead oxide was precipitated as highly compact pyramidal clusters in the form of β-PbO2 on the electrode surface. In addition, the prepared anode had high stability (170 h) and oxygen evolution potential (2.32 V). A robust quadratic model (p-value 0.99) was developed to predict the 2,4-DCP removal efficiency in the 3DER-GAC system. Under optimal conditions (pH = 4.98, Na2SO4 concentration = 0.07 M, current density = 35 mA cm-2, GAC amount = 25 g and reaction time = 50 min), the removal efficiency of 2,4-DCP in the 3DER-GAC system and the separate electrochemical degradation process (without GAC particle electrode) were 99.8 and 71%, respectively. At a reaction time of 80 min, the TOC removal efficiencies in the 3DER-GAC and the separate electrochemical degradation system were 100 and 57.5%, respectively. Accordingly, the energy consumed in these two systems was calculated to be 0.81 and 1.57 kWh g-1 TOC, respectively. Based on the results of LC-MS analysis, possible degradation pathways of 2,4-DCP were proposed. Trimerization and ring opening reactions were the two dominant mechanisms in 2,4-DCP degradation.Sulfamethoxazole (SMX), recognized as emerging pollutant, has been frequently detected in aquatic environment. Thymidine order However, effects induced by SMX and the underneath mechanism on non-target aquatic organisms, marine mussels (Mytilus galloprovincialis), are still largely unknown. In present study, marine mussels were exposed to SMX (nominal concentrations 0.5, 50 and 500 μg/L) for 6 days, followed by 6 days depuration and responses of antioxidant defenses, e.g. superoxide dismutase (SOD), catalase (CAT) and glutathione-S-transferase (GST), etc., at transcriptional, translational and functional levels were evaluated in two vital tissues, gills and digestive glands. Results showed SMX can be accumulated in mussels while the bio-accumulative ability was low under the experimental condition. A systemic but not completely synchronous antioxidant defense at different levels upon SMX exposure. The transcriptional alteration was more sensitive and had the potential to be used as early warning of SMX induced ecotoxicity. Complementary function of antioxidant enzymes with specific alteration of metabolism related gene (gst) suggested that further researches should focused on SMX metabolism and SMX induced effects simultaneously.

