Environment-friendly nano-catalysts capable of activating peroxymonosulfate (PMS) have received increasing attention recently. Nevertheless, traditional nano-catalysts are generally well dispersed and difficult to be separated from reaction system, so it is particularly important to develop nano-catalysts with both good catalytic activity and excellent recycling efficiency. In this work, magnetically recoverable Fe3O4-modified ternary CoFeCu-layered double hydroxides (Fe3O4/CoFeCu-LDHs) was prepared by a simple co-precipitation method and initially applied to activate PMS for the degradation of Rhodamine B (RhB). X-ray diffraction (XRD), fourier transform infrared spectrometer (FT-IR), scanning electron microscope (SEM), transmission electron microscopy (TEM), Brunauer-Emmett-Teller method (BET), and vibrating sample magnetometer (VSM) were applied to characterize morphology, structure, specific surface area and magnetism. In addition, the effects of several key parameters were evaluated. The Fe3O4/CoFeCu-LDHs exhibited high catalytic activity, and RhB degradation efficiency could reach 100% within 20 min by adding 0.2 g/L of catalyst and 1 mmol/L of PMS into 50 mg/L of RhB solution under a wide pH condition (3.0-7.0). Notably, the Fe3O4/CoFeCu-LDHs showed good super-paramagnetism and excellent stability, which could be effectively and quickly recovered under magnetic condition, and the degradation efficiency after ten cycles could still maintain 98.95%. Both radicals quenching tests and electron spin resonance (ESR) identified both HO? and SO4?? were involved and SO4?? played a dominant role on the RhB degradation. Finally, the chemical states of the sample's surface elements were measured by X-ray photoelectron spectroscopy (XPS), and the possible activation mechanism in Fe3O4/CoFeCu-LDHs/PMS system was proposed according to comprehensive analysis. 相似文献
Environmental Fluid Mechanics - Based on the mechanism of landslide dam failure caused by overtopping, a simplified mathematical model for simulating dam breach overtopping flow processes was... 相似文献
Environmental Chemistry Letters - Global water pollution by organic dyes and metals may be solved by adsorption. In particular, hydrogel adsorbents display unique... 相似文献
Environmental Science and Pollution Research - In this present study, a novel indirect Z-scheme TiO2@g-C3N4@biochar (TiO2@g-C3N4@BC) composite photocatalyst was successfully fabricated and... 相似文献
Environmental Science and Pollution Research - By revealing the temporal and spatial differentiation of China’s regional tourism carbon emissions and its decoupling relationship with tourism... 相似文献
Power technology innovation has been positioned as an effective way to contribute to China’s carbon productivity. However, limited empirical evidence exists on the impact of power technology innovation on carbon productivity. Thus, based on the annual panel dataset of 30 China’s provinces from 2001 to 2019, this study explored whether and how power technology innovation promotes or impedes the improvement of carbon productivity. First, carbon productivity in the framework of total factor was calculated based on the metafrontier Malmquist-Luenberger productivity index. Second, the effect of power technology innovation on carbon productivity was investigated using the spatial Durbin model. And we also examined whether heterogeneous power technology innovations have a synergistic effect on carbon productivity. Third, influence mechanism of power technology innovation affecting carbon productivity was identified. Results show that (1) there are notable differences in China’s provincial carbon productivity, which is characterized by the spatial correlation. (2) Local power technology innovation has a promotion effect on carbon productivity in both local and neighboring provinces. Moreover, the promotion effect of breakthrough power technology innovation is stronger than that of incremental power technology innovation. (3) Catching-up Effect and Innovation Effect are important transmission channels through which power technology innovation improves carbon productivity. Finally, policy recommendations are provided.
Perfluorooctane sulfonate (PFOS), as a potential persistent organic pollutant, has been widely detected in water environments, and has become a great concern in recent years. PFOS is very stable and difficult to decompose using conventional techniques. Sorption may be an attractive method to remove it from water. In this study, the molecularly imprinted polymer (MIP) adsorbents were prepared through the polymerization of 4-vinylpyridine under different preparation conditions in order to remove perfluorooctane sulfonate (PFOS) from water. The MIP adsorbents using perfluorooctanoic acid (PFOA) as the template had good imprinting effects and could selectively remove PFOS from aqueous solution. The sorption behaviors including sorption kinetics, isotherms, and effect of pH, salt, and competitive anions were investigated. Experimental results showed that the sorption of PFOS on the MIP adsorbents was very fast, pH-dependent, and highly selective. The achieved fast sorption equilibrium within 1 h was attributed to the surface sorption on the fine adsorbents. The sorption isotherms showed that the sorption selectivity of PFOS on the MIP adsorbents decreased at high PFOS concentrations, which may be due to the double-layer sorption and the formation of PFOS micelles on the sorbent surface. The sorption of PFOS on the MIP adsorbents was mainly dominated by the electrostatic interaction between the protonated vinylpyridine on the adsorbent surface and the anionic PFOS. The prepared MIP adsorbents can potentially be applied in water and wastewater treatment for selective removal of PFOS. 相似文献