Advanced Materials Research Vols. 113-116

Abstract: Activated carbon (AC) electrodes to electrosorption NaCl from aqueous solution were modified. The electrodes were characterized using scanning electron micrograph (SEM), nitrogen adsorption and cyclic voltammetry. The electrosorption removal efficiency is improved by 3 M HNO3 modification due to increased hydrophilic groups enhance adsorption of inorganic ion. The electrosorption removal efficiency is decreased by 15 M HNO3 modification due to the combined effects of increased hydrophilic groups and decreased average pore size. The improvement of electrosorption performance by TiO2 nanoparticles modification due to TiO2 nanoparticles boned with the polar groups works as electrosorption sites with enhanced adsorption strength. The reversal operation mode is better than non-reversal operation mode for electrosorption application.

Abstract: P-, N-doped titania were synthesized by the direct hydrothermal method, which phosphorus from phosphoric acid and the following nitridation from urea solution. The resulting materials were characterized by XRD, XPS analysis, and their photocatalytic activities were tested by the solar light irradiation. N-doping titania resulted in the band-gap narrowing with improved photocatalytic activity. However, the phosphated titania exhibited higher photocatalytic activity than the N-doped one, but with larger band-gap energy.

Abstract: This study mainly analyzed the factors that affected the mechanical properties of laminated veneer lumber（LVL）. To increase the mechanical properties, metal mesh was inserted into LVL that made of fast-growing timber. Effects of different factors were evaluated on the mechanical properties of LVL, several enhancement modes of metal mesh were designed to reinforce the LVL. Then, the mechanical properties (modulus of rupture and modulus of elasticity) of the LVL specimens were measured by static bending test. The results of different enhancement modes were analyzed and compared to investigate the effects of different factors. The position of metal mesh and the mesh number of metal mesh make significant effects on the MOE; the type of metal mesh and the angle of metal mesh-wood grain do not have any obvious effects on the MOE. The type of metal mesh and the position of metal mesh make significant effects on the MOR; the mesh number of metal mesh and the angle of metal mesh-wood grain do not have any obvious effects on the MOR.

Abstract: Phosphor-doped titania nanoparticles were synthesized by a one step hydrothermal method. These samples which prepared by hydrothermal method exist in anatase phase has much higher photocatalytic activity for methylene blue (MB) degradation. In addition, MB degradation performance of the hydrothermal ones is also superior to that of the commercial P25. The resulting materials were characterized by X-ray diffraction (XRD), nitrogen physical adsorption at 77 K, X-ray photoelectron spectroscopy (XPS), etc. It can conclude the hydrothermal method proves to be more suitable to improve the photocatalytic performance.

Abstract: Phosphor-doped titania nanoparticles were synthesized by a one step method, which were prepared by conventional calcination method. These samples have much higher photocatalytic activity for methylene blue degradation. The resulting materials were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), etc. Moreover, we use high P/TiO2 molar ratio to get the most suitable proportion for the synthesis of P-doped titania photocatalyst.

Abstract: Photoelectrochemical degradation of cyanuric acid occurred when the applied potential exceeded 2 V by using Ti electrodes and TiO2 suspension in 0.3 M NaCl solution. The removal increased drastically when the applied potential was more than 5 V. The addition of HCO3- ion could accelerate photoelectrochemical degradation of cyanuric acid. An optimum removal of 85% was achieved when HCO3- ion concentration increased to 0.05 M. Further increase of HCO3- ion led to the decrease of removal, due to consumption of hydroxyl radicals and other oxidizing species by excessive bicarbonate. Photocatalytic oxidation had no capacity on degrading cyanuric acid whether in NaHCO3 aqueous solution or in the solution containing both Cl- and HCO3- ions.

Abstract: Phosphor and nitrogen co-doped titania were prepared by hydrothermal method with phosphorous acid and ammonia as the P and N sources, respectively. The resulting materials were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS). Phosphor and nitrogen co-doped titania give a higher photocatalytic activity in the degradation of methylene blue (MB) under solar light irradiation. It was evidenced that the incorporation of P and N in the anatase titania lattice in the form of O–Ti–N, O–P–N, and Ti–O–P linkages. After photocatalytic properties studies, we can conclude that N, P codoped titania exhibit the further enhanced photocatalytic activity.

Abstract: A new porous material, lignin woodceramics (WCS), was successfully prepared with enzymatic hydrolysis (EH) lignin as its raw material, through modifying, mixing with lignin, drying, moldings, and sintering. Its yields, hardness and microstructure were analyzed. Because of the phenolic structure of EH lignin, which is similar to phenol- formaldehyde (PF) resin, the yields of mass, diameter, and thickness was almost the same with those of the samples made of PF resin treated material. The hardness of the product with 20% (w/w) the modified lignin in dosage was 30% higher than that of control, and it was also better than that of the sample made of PF resin to original EH lignin of 5: 95. SEM analysis showed that the plant tissue was largely strengthened by PF resin through swelling, filling and covering, but modified lignin worked not as efficiently as PF resin to strengthen WCS. However, this new material, EH lignin WCS, does not rely on phenol and will have a promising future.

Abstract: In order to investigate ecotoxicity effect of 2,4-dinitrotoluene (2,4-DNT) to freshwater fish(Brocarded carp), the acute toxicity test and the sub-lethal expriment were conducted in lab. The acute toxicity test show that 96h LC50 value of 2,4-DNT to Brocarded carp is 19.67 mg/L. Its toxicity rating is moderately toxic to fish. Based on the result of the acute toxicity test, fish was exposed to different concentrations (1/2LC50, 1/4LC50, 1/16LC50, 1/256LC50, surface water standard concentration) and killed at 3, 7, 10 and 14 day after exposure. The activities of Superoxide Dismutase (SOD) and Catalase (CAT) in liver tissue were analyzed. The results indicated the activities of SOD and CAT were inhibited from the third day in all treatment groups at post-exposure, they were lower than those of the control group (p＜0.01). The SOD and CAT activities of the control group were stable during 14-days. The CAT and SOD activities had the same changing trend and they were unstable under the pollution stress. The CAT enzyme was more sensitive than SOD enzyme under pollution stress. The results demonstrate that the SOD and CAT activities of liver in Brocarded Carp might be the promising biomarker of 2,4-DNT exposure to freshwater fish. Therefore it is suggested that the couple index of SOD and CAT could be used as biomarker of nitroaromatics compounds, when their pollutions affected living beings in aquatic environment.

Abstract: Polychlorinated biphenyls (PCBs) are Persistent Organic Pollutants (POPs). This experiment screened a halophilic bacterium from the deep sea sediments, which could grow at the salinity of 15%, and designated as B2.6. The cells of this strain were rod shaped, Gram negative, motile. Growth of this bacterium in the presence of PCBs, as the sole source of carbon and energy, and the experiment indicated that at 30°C when pH value is between 7 and 8, inoculation amount is 5mL, the concentration of PCBs is below 3mg•L-1, and the ratio of degradation could reach 90% at 72h. The traditional morphology, physiological and biochemical properties as well as identified system of Biolog were applied to the bacterial classification. The pattern of PCBs-degrading enzyme production of strain B2.6 was continuous synthesis.