作    者：宗恩敏
影响因子：2.599
刊物名称：J mater SCI
出版年卷：2017,52:7294–7310

文章摘要：A new carboxylated multi-walled carbon nanotubes adsorbent modified with lanthanum hydroxide (MWCNTs-COOH-La) was prepared, characterized and investigated for phosphate removal in batch experiments. The maximum adsorption capacity of the MWCNTs-COOH-La was 48.02 mg P g-1 according to Langmuir model. Structural characterizations demonstrated that the MWCNTs-COOH-La was successfully synthesizedandLa specieswaspresent in the formofLa(OH)3.Batchexperiments were performed under various conditions (e.g., initial concentrations, temperature,pH, co-existing ions) to investigate the removal of phosphate by MWCNTs-COOH-La. Equilibrium data agreed very well with the Langmuir model, suggesting that the adsorption feature was monolayer. The adsorption behaviors of phosphate were described better by the pseudo-second-order, indicating that the adsorption behaviors were mainly ascribed to chemic-sorption. Phosphate adsorption varied slightly at pH 3–7, butdecreased significantly at higherpHvalues.Phosphate adsorption was slightly influenced by solution ionic strength.Ahigh selectivity ofphosphate was also observed in the presence of co-existing anions (exceptCO3 2-). The underlyingmechanism for the specific adsorption of phosphate byMWCNTs-COOH-La was fully analyzed by X-ray diffraction, Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy technologies. The above results revealed that the hydroxyl groups were involved in the sorption of phosphate and LaPO4 was formed during the adsorption process. This study implied that MWCNTs-COOH-La might be an alternatively viable and promising adsorbent for removal of phosphate from aqueous solution.

全文链接