MIL-53(Fe) was successfully prepared and deposited on the surface carboxylated polyester (PET) fiber by an optimized conventional solvothermal or industrialized high temperature pressure exhaustion (HTPE) process to develop a PET fiber supported MIL-53(Fe) photocatalyst ([email protected]) for the degradation of polyvinyl alcohol (PVA) in water under light emitting diode (LED) visible irradiation. On the basis of several characterizations, [email protected] was tested for the photocalytic ability and degradation mechanism. It was found that temperature elevation significantly enhanced the formation and deposition of MIL-53(Fe) with better photocatalytic activity. However, higher temperature than 130°C was not in favor of its photocatalytic activity. Increasing the number of surface carboxyl groups of the modified PET fiber could cause a liner improvement in MIL-53(Fe) loading content and photocatalytic ability. High visible irradiation intensity also dramatically increased photocatalytic ability and PVA degradation efficiency of [email protected] Na2S2O8 was used to replace H2O2 as electron acceptor for further promoting PVA degradation in this system. [email protected] prepared by HTPE process showed higher MIL-53(Fe) loading content and slightly lower PVA degradation efficiency than that prepared by solvothermal process at the same conditions. These findings provided a practical strategy for the large-scale production of the supported MIL-53(Fe) as a photocatalyst in the future. 相似文献
Antu County in the Changbai Mountains is an important source of mineral water, but there is a lack of research on the source of groundwater characteristic components, affecting the protection of water resources. This study obtained hydrochemical and isotopic data (28 groups in total, April and September in 2019) by summarizing research and sampling data in order to identify the formation process of characteristics. The formation mechanism of the characteristic components was revealed using geostatistical, isotopic, and hydrogeochemical inversion simulations. The results show that the metasilicic acid is a common component of groundwater water chemistry in the study area. The water body primarily receives stable recharge from low-mineralized precipitation with ages ranging from 27.7 to 38.4 years and recharge elevations ranging from 1160 to 2393 m, providing ample time for water–rock interaction. The dissolution of olivine, pyroxene, albite, and other siliceous minerals is the source of characteristic components, and deep faults and deep basalt heat flow are the key conditions for the formation of metasilicic acid. When low-mineralized precipitation recharges the underground aquifer, it dissolves the silica-aluminate and silicon-containing minerals in the surrounding rocks through the water–rock action under the effect of CO2, causing a large amount of metasilic acid to dissolve into the groundwater and forming metasilic acid-type mineral water.
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