A series of micro-mesoporous Zr-SiO2 composites with nanoscale domains were prepared by using ionic liquid (IL) as a template at 373 K in only 3 h with one-step. The synthesized Zr-SiO2 materials ...were characterized by N2 adsorption-desorption, scanning electron microscopy, transmission electron microscopy, powder X-ray diffraction, Fourier transform infrared spectroscopy, diffuse reflectance UV-Vis spectroscopy, thermogravimetric analysis and temperature program desorption technologies. The results show that the synthesized composite materials possess nanoparticle with a mean diameter of about 100 nm and a large surface area more than 1000 m2/g, and the hierarchically porous structure is preserved after removing template by calcination at high temperature and treating in boiling water for 72 h. The heteroatom of zirconium has been successfully incorporated into the structure framework and/or has been highly dispersed on the surface of materials. The prepared materials contain moderate to strong acid sites and the surface acid site concentration is 0.18-0.42 sites/nm2. The amount of strong acid sites increases with a decrease of Si/Zr ratio, which leads to increased temperature for removing IL templates.
Environmental accidents occur frequently in China in recent years. A quick estimation of the extent and distribution of contamination after environmental accidents is important for immediate ...treatment of the contaminated sites. This paper proposed a methodology to estimate the velocity and maximum infiltration depth of NAPL after spill accidents to provide quick and quantitative information for the emergency treatment of the site. The proposed methodology uses only the basic information of the accident: contaminant type and its properties, groundwater level, soil type and average properties, and estimated infiltration area. By comparing the maximum infiltration depth of NAPL with the depth to groundwater, one can identify whether there is an immediate threat to groundwater. If there is such a danger, proper measures should be taken within the suggested time frame to prevent NAPL from entering the saturated zone.
A series of micro-mesoporous Zr–SiO
2 composites with nanoscale domains were prepared by using ionic liquid (IL) as a template at 373 K in only 3 h with one-step. The synthesized Zr–SiO
2 materials ...were characterized by N
2 adsorption–desorption, scanning electron microscopy, transmission electron microscopy, powder X-ray diffraction, Fourier transform infrared spectroscopy, diffuse reflectance UV–Vis spectroscopy, thermogravimetric analysis and temperature program desorption technologies. The results show that the synthesized composite materials possess nanoparticle with a mean diameter of about 100 nm and a large surface area more than 1000 m
2/g, and the hierarchically porous structure is preserved after removing template by calcination at high temperature and treating in boiling water for 72 h. The heteroatom of zirconium has been successfully incorporated into the structure framework and/or has been highly dispersed on the surface of materials. The prepared materials contain moderate to strong acid sites and the surface acid site concentration is 0.18–0.42 sites/nm
2. The amount of strong acid sites increases with a decrease of Si/Zr ratio, which leads to increased temperature for removing IL templates.
Environmental issues associated with disposal of processed oil shale tailings and various chemical wastes from the Maoming Petrochemical Company in landfills near Maoming, China, are reviewed. Soil, ...water, and oil shale tailing samples were analyzed. Soil and groundwater are contaminated by oil shale tailing chemicals to various degrees, depending on the distance from tailings. Soil and groundwater acidification, high levels of heavy metals and sulfate in soil and groundwater, and organic contamination of soil (mainly with PAHs retained in soil) were detected. Remediation requirements for the landfill are discussed.
Soil slurry reactor technology is one of the effective methods for treating PAHs contaminated soil. In this paper, removal of high molecular weight PAHs, Indeno (1,2,3-cd) pyrene (Inp), was studied ...in soil slurry reactors with isolated bacteria from PAHs contaminated soil. The factors affecting Inp biodegradation and the optimal conditions were investigated using orthogonal experimental design (L9(34)). The highest degradation efficiency of Inp was 50.71% after the incubation of 12 days. The most significant influencing factors were aeration rate, water to soil ratio and salinity, while pH was less significant. The optimal conditions for Inp degradation in soil slurry reactor was: aeration rate 120L/h, water to soil ratio 2:1, salinity 10%, pH=6.
Environmental pollution from solid waste landfillings (SWLs) is of major concern to both the environmentalists and to individual citizens. The necessity for studying on contaminant generation and ...control is becoming more urgent in view of the risks associated with such sites.
An oil shale tailing at Maoming, South China, was chosen as our study case. Soil samples, water samples and oil shale tailings were collected from the site and analyzed for their compositions. The analytical results revealed that the soil and groundwater were contaminated to various degrees by several chemicals or pollutants from the oil shale tailings. The major environmental problems associated with the site were acidification of soil and groundwater, high content of heavy metals and sulfate in soil and groundwater and organic contamination of soil, in particular, finding of carcinogenous benzoa pyrene other PAHs.
Statistical and geochemical methods were applied to reveal the sources of contaminants. Soil and groundwater contamination were correlated obviously with the oil shale waste disposal. The nearer the sampling sites to the tailing, the heavier the soil and groundwater were contaminated. The different water samples composition had same chemical characteristics. The soil and water samples were analyzed for 16 PAHs (USEPA priority pollutants). It indicated that PAHs were retained mostly in the soil, which consisted of mainly naphthalene, fluorene, phenanthrene and anthracene. Analysis for PAHs source revealed that they were also from the oil shale tailing.
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