Applied Mechanics and Materials Vols. 295-298

Abstract: To study the effects of substrate materials on the photocatalytic activity, TiO₂ films were immobilized on the inner wall surface of ceramic, glass and stainless steel tubes by sol-gel method. X-ray diffraction (XRD) results indicated that the crystal form of TiO₂ were all anatase type with theoretical particle size of 15 nm. According to the X-ray photoelectron spectroscopy (XPS) results, appearance of the element Na was observed which would decrease the photocatalytic activity. Scanning electron microscope (SEM) photos showed that the film coating on the ceramic and glass were even and uniform with thickness of about 300 nm and practical particle size of 20 nm to 100 nm. However, the film coating on stainless steel was hackly which would lead to diffraction of lights. The degradation rate constants of methylene blue (MB) with initial concentration of 5 mg.L^-1 were 0.049 min^-1、0.029 min^-1 and 0.023 min^-1 with films coating on ceramic, stainless steel and glass tubes respectively. Degraded with TiO² film coating on ceramic tube, the according rate constants of phenol were 0.37, 0.14, 0.04 and 0.02 min^-1 for initial concentration of 2, 10, 50 and 100 mg.L^-1 respectively.

Abstract: In order to study the effect of organic matter on the heavy metals leachability from municipal solid waste incineration (MSWI) bottom ash. In the project, the composted sewage sludge (CS) rich in organic matter was mixed with MSWI bottom ash in a certain proportion. e exudation test, determination of the leaching liquid pH, dissolved organic carbon and humus concentration, and the concentration of heavy metals. And the combination of CS and BA in organic compounds and metal content, calculate metal leaching rate. According to the experimental results, analysis of dissolved organic matter and humic acid concentrations and Cu and Cr leaching concentration, showed that when CS mixture ratio of 20%, organic matter and humic substances concentration and Cu and Cr leaching concentrations are highly linear correlation.

Abstract: Humidity control paper board comprising natural polymer derivatives, porous natural minerals, inorganic salts, natural moisturizing material and paper was prepared by simple physical blending and its humidity control properties were tested. The moisture adsorption and desorption rate are 0.82 g/7h.g-1 and 0.71 g/7h.g-1, respectively. The adsorbed moisture amount is 0.85 g/g. It can maintain the relative humidity (RH) range between 50% and 60% within 20 min at 25 °C. Above all, the prepared paper board shows pronounced humidity control properties and the preparation technology is simple, which is feasible for production in large scale.

Abstract: Hydrotalcite (LDHs) / MC nylon 6 composites were prepared by in- situ intercalation polymerization, followed by morphology and mechanical properties’ characterization of composites. FTIR shows that chemical structure of the molecular chain of the MC nylon 6 is not changed with adding hydrotalcite; SEM reveales that LDHs (2.5, wt-%) has good dispersion and compatibility in the MC nylon 6 matrixes; but when the amount of LDHs is excessive, the composites show obvious phase separation phenomenon. Hydrotalcite can significantly improve the mechanical properties of the composites. When the amount of hydrotalcite reaches 2.5% (wt-%), the composite has best comprehensive mechanical performance. Comparing with untreated MCPA6, the tensile strength and notched Izod impact strength are respectively increased by 68 % and 53 %.

Abstract: The Thermal Decomposition Kinetics of Mg(OH)2 Modified with Sodium Dodecyl Benzene Sulfonate (SDBS) by the Liquid Phase Method Was Investigated Using Differential Thermal Analysis and Thermo Gravimetric (DTA-TG) at Different Heating Rates. the Results Show that the Mg(OH)₂ Modified with SDBS Is Mg(OH)₂ with Hexagonal Phase Structure. the Average Apparent Activation Energy of the Decomposition Stages of Mg(OH)₂ Modified with SDBS Was Calculated Using the Doyle-Ozawa and Kissinger Methods as 169.13 Kj•mol-1. the Reaction Order and Frequency Factor Can Be Also Determined by Kissinger Method. the Kinetics Equations of Reaction Were Deduced as Dα/dt = (5.71×10¹²/β) e^-20340/T (1-α)^1.52.

Abstract: In this paper we used the excess sludge of municipal sewage treatment plant as raw material, ZnCl2 as activator, and adopted the traditional activated carbon production process to prepare sludge activated carbon adsorbent. Then characterized the structure and determined the performance of sludge activated carbon adsorbent prepared at the activation temperature of 600°C, in a period of 90min, N2 as protecting gas, in a ratio of dry sludge and activator of 5:2. The results show that sludge activated carbon adsorbent with ZnCl2 as activator has the adsorption performance through the evidence of BET, SEM and XRD. The maximal iodine value of the adsorbent is more than 380 mg/g, and it has good adsorption performance for H2S. And there is good correlation between the structure and the performance of sludge activated carbon adsorbent.

Abstract: The corn stalk/montmorillonite(CS/MMT) nanocomposite was prepared by a solution intercalation technique. The effects of the initial pH value of Pb2+ solution, contact time and the dosage of adsorbent on the adsorption capacitiy of CS/MMT nanocomposite for Pb2+ were investigated. The adsorption kinetics and isotherms of nanocomposite were also studied. The results indicated that with the initial pH value increasing, the adsorption capacity of the CS/MMT nanocomposite increased. Compared with the adsorption capacity of CS (6.32 mg/g), the nanocomposite exhibited the higher adsorption capacity (31.95 mg/g). The adsorption behaviors of CS/MMT nanocomposite showed that the adsorption kinetics was in accorded with pseudo-second-order equation and the adsorption isotherms followed the Langmuir and Freundlich equation.

Abstract: In order to combine the microbial metabolism characteristics in biological aerated filter (BAF) with the adsorption and ion-exchange ability of natural clinoptilolite to treat sanitary wastewater, the experiment use clinoptilolite powder as main materials to prepare the large specific surface and high porosity spherical compound filter material by adding adhesive and pore-forming agent etc and get better effect on sanitary wastewater treatment.The static adsorption test showed that the adsorb ratios of ammonia-nitrogen is 58.5% when the compound filter material dosage was 100g/L, NH3-N concentration was 100mg/L and the contact time was 40min.The cure fitting of the adsorption isotherm of NH3-N on the compound filter material could be well described by the Langmuir formula and the coefficient of determination is 0.99216.

Abstract: In this paper graphene is used to improve absorption rate of nano-titanium dioxide under visible light, meanwhile titanium dioxide is doped with superparamagnetism nano-powder of γ-Fe2O3 to modify the recovery of the photocatalyst. Gradually the increasing content of grapheme promotes the removal efficiency and correspondingly. Excitation condition is reduced and the photocatalysis property under visible light is improved and recycle rate of the titanium dioxide is effective promoted after the dispose. The effect of photocatalytic degradation of methylene blue is used to evaluate the photocatalytic activity. The methylene blue degradation rate raised from 53.4% to 85.9% with the increasing graphene load from 5% to 20% under visible light. The degradation efficiency of methylene blue decreased to 15% without the graphene load. The recovery rate of the photocatalyst can achieve 95% above. Graphene oxide works as the electron acceptor and photosensitizer to efficiently enhance the dye photodecomposition.

Abstract: TerraZyme is a completely different and new material for constructing road compared to the traditional road construction materials. Through the indoor and field tests of TerraZyme solidification soil, the road performance (e.g., unconfined compression strength, CBR value，modulus of resilience, hydraulic conductivity etc) of TerraZyme solidification soil was analyzed systematically. Meanwhile, the changing patterns in the case of various construction technology and different maintenance conditions were discussed. Then, the quality control index and measure for construction were presented. By validating the adaptability of TerraZyme solidification technology in engineering practice, it showed that the technology of TerraZyme solidification soil have many advantages such as no pollution, simple and convenient construction, higher solidified strength, good water stability and lower cost. Therefore, it can be broadly popularized and applied in the engineering practice.