Material
with special wettability for oil/water separation has
drawn more and more attention, since the oil spill accidents and industrial
processing are growing in frequency and in volume. A superhydrophilic
and underwater superoleophobic mesh was prepared by introducing Co
3
O
4
on a stainless steel mesh, through a simple
hydrothermal process and subsequent calcination. The as-prepared Co
3
O
4
mesh can not only separate various oil/water
mixtures with high efficiency and high flux, but also work effectively
in harsh environment such as highly acidic, alkaline, and salty solutions.
Moreover, the Co
3
O
4
mesh can still retain good
separation performance after 40 abrasion cycles with sandpaper. The
outstanding anticorrosion and antiabrasion behaviors make the Co
3
O
4
mesh promising for oil/water separation even
in harsh environment.
A constructed wetland system, consisting of a surface-flow wetland cell connected in series with three vertical subsurface-flow wetland cells, was tested for treatment of domestic sewage from rural families in southern China. Diatomite, vermiculate, zeolite and hydrotalcite, were used, respectively, as filler adsorbents in the sequenced subsurface-flow cells for adsorption of organic, cationic and anionic pollutants. Selected trees, shrubs and annual herbs were planted to form a wetland plant community. The total treatment capacity, hydraulic loading rate and water retention time were 2 m 3 /d, 0.5 m/d and 48 h, respectively. Experimental data obtained from a year operation confirmed that the treatment process followed the dynamic pathway of pollutant transformation. The constructed system was effective to remove TSS, COD Cr and BOD 5 and their effluent concentrations met the first grade of the discharge standards legislated in China. The removal rates of TN, NH 3 -N and TP were relatively lower, and their effluent concentrations fell within the range between the first and second grade of the standards. An increase in initial pollutant loading and a decrease in temperature in winter caused apparent accumulation of TN, NH 3 -N and TP in the system. Discharge of sludge at adequate intervals was shown to be effective to enhance the treatment efficiency.
Volatile organic compounds (VOCs) are a great threat to the health of human beings, and developing catalysts with prominent activity and stability to eliminate them are highly desired. In this work, carbon-based Pt catalysts toward lowtemperature benzene catalytic combustion were prepared through a photodeposition strategy using three-dimensional expanded graphite (EG), bulk graphite, and active carbon as supports. It was found that the Pt/EG catalyst demonstrated the best catalytic performance for benzene oxidation (T 100 = 180 °C) under a high flow rate of 120,000 h −1 . Brunauer−Emmett−Teller, scanning electron microscopy, transmission electron microscopy, thermogravimetric analysis, Fourier transform infrared, X-ray photoelectron spectroscopy, electrochemical impedance spectroscopy, and temperature-programmed decomposition techniques were applied to explore the structure−activity relationship. The results indicated that the adsorption capacity and the electron transfer property caused by the Pt nanoparticles and EG support led to a good catalytic performance. Moreover, the 0.5 Pt/EG catalyst also showed excellent stability, good water resistance properties, and high recyclability, which can be used as a promising candidate for practical VOC catalytic combustion.
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