Efficient removal of methylene blue from aqueous solutions by an ordered mesoporous HPMo-SiO2

Abstract

2016): Efficient removal of methylene blue from aqueous solutions by an ordered mesoporous HPMo-SiO 2 , Desalination and Water Treatment, A B S T R A C TAn ordered mesoporous HPMo-SiO 2 was synthesized and used as an adsorbent for removal of methylene blue (MB) from aqueous solutions. The morphology and structures of the material were characterized by scanning electron microscope and transmission electron microscopy. The removal process was systematically investigated under various conditions such as pH value, shaking time, the initial concentration of MB. Adsorption process was closely fitted with pseudo-second-order model and Langmuir isotherm equations. The maximum adsorption capacity for MB was 87.8 mg g −1 at 293 K. The results of thermodynamics studies (ΔG˚< 0, ΔH˚> 0, ΔS˚> 0) showed the adsorption progress was spontaneous and endothermic. Besides, quantitative desorption of MB from HPMo-SiO 2 could be achieved with methanol containing over 25% acetic acid.

Ordered mesoporous silicon doped with HPMo‐SiO 2 solid phase extraction of trace Pb prior to flame atomic absorption spectrometry determination

“…3 b . A hydrogen bonding interaction and a dehydration reaction may form between –OH groups of the surface of HPMo‐SiO 2 [11] and –COOH groups in Pb(OOC‐C 6 H 4 ‐COOH) 2 , which makes HPMo‐SiO 2 exhibit good selectivity toward Pb.…”

“…The preparation method and characterisation of HPMo-SiO 2 were as the same of our previous work [11]. A series of buffer solutions such as potassium acid phthalate (KHP), Britton-Robinson (B-R) (containing phosphoric acid, acetic acid and boric acid, each with a concentration of 0.04 mol l −1 ) and 0.1 mol l −1 hydrochloric acid-sodium hydroxide (HCl-NaOH) were used for pH adjustment, respectively.…”

“…A selective adsorption behaviour of Pb has been studied by mesoporous silica SBA‐15 based on surface molecularly imprinting technique. Although the selectivity of the molecularly imprinting method is excellent, the preparation method is not so simple as compared with a sol–gel method [11]. Up to now, few materials such as mesoporous silica doped with heteropolyacids have been used as adsorbents for preconcentration/separation of Pb from real samples.…”