Papers by Author: Na Gu

Abstract: ZnO/SnO₂/montmorillonite that could flocculate and restrict the growth of Microcystis aeruginosa used as a probe of cyanobacterial was prepared and characterized by means of XRD and TEM. In ZnO/SnO₂/montmorillonite, ZnO and SnO₂ nanoparticles disperse on montmorillonite surface. The determinations of chlorophyll a levels and total soluble protein content demonstrate that ZnO/SnO₂/montmorillonite has stronger flocculation effect on Microcystis aeruginosa compared with natural montmorillonit under visible light, and has a good photocatalytic degradation effect on Microcystis aeruginosa under UV irradiation. Under UV, 96.79% removal efficiency is achieved for Microcystis aeruginosa in 1h using 50mg.L^-1 ZnO/SnO₂/montmorillonite. The synergy of absorption flocculation and photocatalysis of ZnO/SnO₂/montmorillonite promotes the removal of Microcystis aeruginosa.

Abstract: A kind of water-based material which can absorb mine gas and suppress gas explosion was designed for the purpose of keeping the coal mine safe. The anionic surfactant sodium dodecyl sulfate (SDS) was used as the main gas absorbent according to the micelle solubilization of surfactant, and castor oil was used as absorption enhancer in this material. Methane was regarded as a model of mine gas. The volume fraction of methane absorption was measured by head space gas chromatography. The state of the aggregates in the material was observed by transmission electron microscopy. The explosion suppression effect was tested by self-made explosion chamber which can simulate gas explosion. Also the methane absorption rate of the water-based material was tested in practice of coal mine. The results showed that the maximum volume fraction of methane absorption of the SDS + castor oil aqueous solution can reach up to 12.65%; with the addition of castor oil, the structure of aggregates in SDS aqueous solution system changed from spherical to lamellar, so it can provide greater non-polar microenvironment for methane; the water-based material can lower the maximum explosion pressure to some extent when it was sprayed into the explosion chamber in atomization condition before ignition; field test on methane absorption showed that the methane absorption ratio can reach up to 16.7%, which is much higher than the experimental value.

Abstract: This paper aims to design a sort of aqueous atomization absorbing material which can absorb mine gas under coal mine to decrease the methane concentration and reduce the explosion hazard. The material was composed of water as matrix, Span 80 as methane absorbent, and inorganic salt as additive. Methane the main component of mine gas was used as model of mine gas. The influence of concentration of inorganic salt on absorption and the effect of different compound materials made of Span 80 and inorganic salt on absorption were studied using Head Space Gas Chromatography to determine the content of methane absorbed. Explosion chamber was used as experiment system to simulate mine gas explosion. The explosion suppression effects of absorbing materials were studied preliminarily in explosion chamber using the maximum explosion pressure and residual methane content after explosion as parameters. The results indicate that the absorbing material can absorb more methane than water and can partly inhibit the explosion of the mixture of methane and air.

Abstract: Water Storage and Controlled-release Film (WSCF) material is a kind of composite film which can form a “small reservoir” in the soil to meet the need of plant growth when packed with water and embedded in soil around tree roots. Coated water-transmitting fiber is a kind of functional fiber which has effect of transmitting water in WSCF material. Different coated water-transmitting fibers were prepared by treating natural fiber using colloidal composite materials made of polyvinyl alcohol and inorganic clay such as Common clay, Kaolin or Bentonite. Furthermore, the water-transmitting capacity and surface morphology of coated water-transmitting fibers were studied by thermal multi-analyzer, instrument for quick moisture measure and SEM. The results show that coated water-transmitting fiber with continuous and compact surface has better water-transmitting capacity than those with uneven surface and the addition amount of clay also can affect the water-transmitting capacity of coated fiber. Additionally, coated water-transmitting fibers can regulate water transferring according to the variation of temperature or soil humidity.