By investigating the nitrogen concentrations in effluents of the horizontal subsurface-flow constructed wetlands under the conditions of different kinds of substrates, residence time and heights, as well as the nitrog...
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ISBN:
(纸本)9781424491728
By investigating the nitrogen concentrations in effluents of the horizontal subsurface-flow constructed wetlands under the conditions of different kinds of substrates, residence time and heights, as well as the nitrogen concentrations changes along the flow in the wetlands, the nitrogen removal routes in the wetlands were analyzed. The results demonstrated that the wetland system with zeolites demonstrated greater efficiency in the removal of nitrogen. There was a higher nitrogen removal rates at the bottom of the wetland system owing to an aerobic-anoxic environment. In that a more efficient reoxygenation was attained at the front of the system, it achieved a higher nitrogen removal rates.
A fast and simple procedure based on matrix solid-phase dispersion was carried out for the extraction of three kinds of lignans, including podophyllotoxin, 4'-demethylpodophyllotoxin and podophyllotoxin glucoside,...
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A fast and simple procedure based on matrix solid-phase dispersion was carried out for the extraction of three kinds of lignans, including podophyllotoxin, 4'-demethylpodophyllotoxin and podophyllotoxin glucoside, from the dried roots of Sinopodophyllum emodi Wall. After extraction, the lignans were determined by LC. The main experimental parameters, including type of dispersant, type of clean-up absorbent and type and volume of elution solvent, were examined and optimized. Compared with reflux extraction, the proposed method is simpler, faster and more efficient.
A modified ASTM G 65 rubber wheel test was used in wet and dry conditions using 220 nm titania particles and 368 μm sand particles, respectively. Both tests were conducted on WC-CoCr coatings produced with two powder...
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