Rapid and Efficient Removal of Microcystins by Ordered Mesoporous Silica

Abstract

To alleviate the environmental and health threats from water resources polluted by large-sized microcystins (MCs), we demonstrate for the first time that ordered mesoporous silica materials with large pore sizes of 2-12 nm can be used as adsorbents for rapid and efficient removal of MCs. The obvious correlations between adsorption performance of MCs and physicochemical properties of adsorbents including pore mesostructure, texture and size, and surface chemistry have been well established. Accordingly, an excellent candidate, mesoporous silica SBA-15 templated from Pluronic P123 has been sorted out, exhibiting extremely rapid rate (one minute) as well as high capacities of 5.99 and 13 mg g(-1) for removing high-concentration MC-LR and MC-RR, respectively, which are much higher than that of other silica-based adsorbents reported previously. The adsorption performance can be further improved from 50 to 95% at around pH 4 by grafting positively charged and/or hydrophobic groups onto pore surface of SBA-15. Furthermore, thermodynamic and kinetic evaluations provide additional valuable information for a better understanding of the adsorption process. Given the excellent adsorption performance, it is expected that mesoporous silica materials with unique characteristics are attractive for actual applications in removal of MCs from wastewater.

Enhanced nitrobenzene adsorption in aqueous solution by surface silylated MCM-41

“…It was reported that MCM-41 displayed a quite short equilibrium time (even less than 1 min) to reach its maximum capacity for nitrobenzene adsorption [3], which is crucial for its practical application. Similarly, quick equilibrium was also observed for other organic pollutants adsorption such as pharmaceuticals [5], microcystins [6] using ordered mesoporous silica adsorbents. However, MCM-41 has a relatively low adsorption capacity for the removal of nitrobenzene.…”

An Efficient Reusable Mesoporous Solid-Based Pd Catalyst for Selective C2 Arylation of Indoles in Water

“…33 The IEP value shifts toward higher pH values of approximately 4.5 in the presence of the nitrogen-containing functional group (8.5ODDMA-MP) due to the inherent electropositive nature of quaternary ammonium salts. 34 With a further increase in nitrogen content, the samples exhibit increased IEP values of 4.8 and 5.3 for 11.5ODDMA-MP and 13ODDMA-MP, respectively.…”

Mechanisms and Factors Influencing Adsorption of Microcystin-LR on Biochars

“…By contrast, BC-300 exhibits low carbon content (70.1 %), high H/C ratio (0.617), and low specific surface area (only 4.1 m 2 g −1 ), indicating that some wood organic residues remain on the structure of BC-300 after incomplete carbonization ). The three-dimensional size of MCLR was reported as 1.9 nm×1.5 nm×1.1 nm (Teng et al 2013). Therefore, the micropore regions (pore size <2 nm) may be unavailable for MCLR adsorption because the second widest dimension of MCLR (1.7× 1.5=2.55 nm) is 1.7 times larger than 2 nm (Xiao et al 2012).…”