1. Lanthanum oxide nanorods for enhanced phosphate removal from sewage: A response surface methodology study.
- Author
-
Fang L, Wu B, Chan JKM, and Lo IMC
- Subjects
- Adsorption, Nanotubes, Photoelectron Spectroscopy, Water chemistry, X-Ray Diffraction, Lanthanum chemistry, Phosphates chemistry, Sewage chemistry, Water Pollutants, Chemical chemistry, Water Purification methods
- Abstract
Lanthanum-based adsorbents are ideal candidates for phosphate removal because of their excellent affinity to phosphate. However, their application in the removal of trace-levels of phosphate from sewage is still unsatisfactory due to the limited adsorption capacity and inadequate optimization of the operational parameters. To overcome these drawbacks, we have developed a novel lanthanum hydroxide (LH), using a facile precipitation and hydrothermal process that involves a nanorod-like structure with the lengths ranging from 124 to 1700 nm, depending on the La/OH molar ratio. The phosphate adsorption capacity of the developed LH is up to 170.1 mg-P g
-1 in synthetic water, while a slightly lower adsorption capacity of 111.1 mg-P g-1 is observed in a sewage sample. A polynominal model consisting of three variables (i.e. dosage, reaction time and initial phosphate concentration) for predicting efficiency of phosphate removal has been successfully developed using a face-centred central composite design (CCD)-based methodology. The results also suggest a strong interactive effect of the dosage with the phosphate concentration, and reaction time, which can significantly affect the optimization of the phosphate removal by LH. Both X-ray photoelectron spectroscopy and X-ray diffraction studies indicate that the inner sphere complexation of phosphate with LH is probably the major mechanism governing phosphate removal., (Copyright © 2017 Elsevier Ltd. All rights reserved.)- Published
- 2018
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