Removal of BTX using granular octyl-functionalized mesoporous silica nanoparticle

• A functionalized MSN was granulated with calcium alginate.
• The granulation improved the hydraulic conductivity to be used in the field.
• The granule retained highly-ordered mesoporous structure for efficient BTX removal.

An octyl-functionalized and surfactant-containing mesoporous silica nanoparticle (MSN) was granulated with calcium alginate. The authors investigated the feasibility of the granular MSN as an adsorbent for BTX (benzene, toluene and xylenes). The granulation increased the mean particle size from 1.16 μm to 1.41 mm, therefore improved hydraulic conductivity from 1.7 × 10−4 to 0.16 cm/s. The granular MSN maintained uniform mesoporous structure and high BTX adsorption capacity, which were comparable with those of the powdered MSN. The following trend in adsorption equilibrium onto the granular functionalized mesoporous silica was observed: p-xylene > toluene ≒ benzene. The granulation enabled the column adsorption experiment, which is closer to the field situation compared to the batch test. The decrease of temperature raised the amount of removed amount of xylene in the column experiments. We envision that the granular octyl-functionalized MSN could serve as an efficient adsorbent for BTX from aqueous phase.