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We applied LDHs to modify the bitumen by melt blending, and studied the viscoelasticity of LDHs modifi ed bitumen by means of dynamic shear rheometer（DSR）. The creep test was used to evaluate the viscoelastic behavior. The experimental results indicated that, due to the addition of the LDHs, the viscoelastic properties of modifi ed bitumen were superior to those of pristine bitumen. Therefore, the LDHs would be an alternative to modifi ers used in the bitumen to improve the UV-aging resistance during the service of asphalt pavement.

Dynamic rheological properties of asphalt modified by Supramolecular UV resistant material—layered double hydroxides（LDHs） was studied by means of the dynamic shear rheometer（DSR） test.Two typical base asphalts were chosen and modified by 2 different LDHs contents.DSR tests were performed on the original samples,samples after exposed to outdoor and samples after the artificial accelerated UV aging tests respectively to analyze the rheological properties.It is found that when the LDHs content is between 3wt% and 5wt% of asphalt weight,the high temperature performance and fatigue resistant property of the modified asphalt become better,the UV aging resistance properties are improved.

A series of Cu/Co/Cr nanocomposites with different Cu/Co/Cr molar ratios were obtained by calcination of Cu/ Co/Cr hydrotalcites precursors, which were prepared by a co-precipitation reaction. X-ray diffraction, inductively coupled plasma analysis, and transmission electron microscopy were used to characterize the structure, composition, and mor- phology of Cu/Co/Cr nanocomposites. The results show that Cu/Co/Cr nanocomposites have both CuCr204 and CoCr204 spinel phase. The particle size of Cu/Co/Cr nanocomposites is 15-20 nm and the specific surface area is 95-115 m2/g. Cu/ Co/Cr nanocomposites were used as new catalysts for improving thermal decomposition of ammonium perchlorate （AP）. Their catalytic activities were investigated using differential thermal analysis and thermal gravimetric analyzer coupled with an online mass spectrometer. The results show that the decomposition temperature of AP lowered 132-146℃ by adding 4 wt% Cu/Co/Cr nanocomposites. Catalytic activities of the prepared nanocomposites depend on the calcinations temperature and addition amount of corresponding nanocomposites. The possible catalytic mechanism of Cu/Co/Cr nanocomposites was also studied and discussed.

Wastewater containing chloride ions is often discharged fi＇om landfills, tanning industries, and pickling industries. The high salt content in the wastewater can give rise to corrosion of waste pipes and pose problems to treatment systems, particularly biological units. Chloride induced is a well-known problem, especially where de-icing salts, chloride-containing admixtures or chloride-contaminated aggregate are incorporated into the concrete. Hydrotalcite （HT） is a class of anionic layered clays which can be described as containing brucite-like layers and positively-charged sheets. The general formula is [Mgl-xAlx（OH）2]x＋（CO3）x/2×4H2O, where x is equal to the ratio of Al^3＋/（Mg^2＋＋Al^3＋） with a value varying in the range of 0.17-0.50. HT calcined （thermally treated） within a certain temperature range （CHT） has been shown to reconstruct their original layered structure in the presence of aqueous solution of appropriate anions. Therefore, the CHT are good adsorbents for removal of toxic anions from wastewater. This work primarily focuses on investigation of the removal of chloride by CHT, taking it into account the effects of calcined temperature, Mg/Al molar ratio of HT, and temperature on dechlorination. It was found that dechlorination capacity of CHT-500 ℃ is higher than that calcined at other temperatures, and CLDH with an Mg/Al ratio of 4 has marked ability to adsorb anions. The dechlorination capacity of CHT decreased with the rise of temperature, indicating that the process is exothermic in nature. And the data of isotherms fitted well to the linearly transformed Langrnuir equation. The thermodynamic parameters were calculated from equilibrium isotherms. The negative AGO value indicates the spontaneity of the dechlorination process.

An appropriate concentration of fluoride in drinking water is required to prevent dental cavities, but long-term ingestion of water that contains more than a suitable level of fluoride can cause bone disease and mottling of the teeth. Fluoride ions can be found in wastewater from the fluoride chemical industry, as well as the semiconductor, metal processing, fertilizer, and glass-manufacturing industries. The discharge standard for fluoride in industrial wastewater in China is 10 mg/L. Efficient treatment of fluoride-containing wastewater is therefore of major concern in China, following the rapid development of the fluoride chemical industry. Several methods have been used to remove fluoride from water, such as adsorption, chemical precipitation, electrodialysis, ion exchange and electrochemical processes. Layered double hydroxides （LDHs） are anionic clays with high anion exchange capacities which are effective adsorbents for removal of a variety of anionic pollutants. LDHs have been studied as potential adsorbents for removing toxic anionic species such as CrO4^2-, TcO4^-, SeO3^2-, pesticides, and anionic surfactants from aqueous systems. One of the main attractions of using LDHs for fluoride removal, is that unlike other chemical treatment methods, no chemical sludge should be produced. In the present study, an attempt was made to investigate the mechanism of fluoride removal by LDHs under different conditions using batch methods. In addition, the release of fluoride adsorbed on LDHs by treatment with an aqueous solution of Na2CO3 was studied. The residual fluoride was found to be 10 mg/L in a solution with an initial concentration of 1000 mg/L, which meets the discharge standard for fluoride in industrial wastewater in China.