Utilization of rice husk silica as adsorbent for BTEX passive air sampler under high humidity condition

Abstract

Selective adsorbent of benzene, toluene, ethylbenzene, and xylenes (BTEX) was developed based on mesoporous silica materials, RH-MCM-41. It was synthesized from rice husk silica and modified by silane reagents. The silane reagents used in this study were trimethylchlorosilane (TMS), triisopropylchlorosilane (TIPS), and phenyldimethylchlorosilane (PDMS). Physiochemical properties of synthesized materials were characterized by small-angle X-ray diffraction (XRD), Fourier-transformed infrared spectroscopy (FTIR), and surface area analysis. Materials packed in passive air sampler were tested for BTEX uptake capacity. The tests were carried out under an influence of relative humidity (25 to 99 %). Overall, RH-MCM-41 modified by TMS outperformed compared to those modified by other silane agents. The comparative BTEX adsorption on this material and commercial graphitized carbon black was reported.

Sustainable Removal of BTEX Gas Using Regenerated Metal Containing SiO2

“…The benzene removal efficiency with Fe 2 O 3 -Mn 2 O 3 /SiO 2 increased from 69% to 87% when the dosage increased from 0.1 g to 0.5 g. While ethylbenzene and xylene showed 100% removal with both catalysts (2 g L −1 catalyst dosage at 20 min), benzene showed 92–93% removal efficiency, which was the lowest adsorption capacity among the BTEX component. The interaction between BTEX and catalyst surface is contributed to by van der Waals’ force, which is dependent on the molecular weight (78.12 g mol −1 for benzene, 92.15 g mol −1 for toluene, and 106.17 g mol −1 for ethylbenzene and xylene) [ 21 , 22 ]. The higher the molecular weight, the more the adsorption capacity increases.…”

“…Konggidinata et al conducted the BTEX adsorption on mesoporous carbon and found the adsorption capacity to follow the order of xylenes > ethylbenzene > toluene > benzene due to the different solubility of gases [ 22 ]. Areerob et al carried the adsorption performance of BTEX with silica-based material, and the performance was proportional to their hydrophobicity and molecular weight [ 21 ]. Thus, the interaction between BTEX and catalyst surface is contributed by van der Waals’ force, which is dependent on the molecular weight (78.12 g mol −1 for benzene, 92.15 g mol −1 for toluene, and 106.17 g mol −1 for ethylbenzene and xylene) [ 21 , 22 ].…”

“…Areerob et al carried the adsorption performance of BTEX with silica-based material, and the performance was proportional to their hydrophobicity and molecular weight [ 21 ]. Thus, the interaction between BTEX and catalyst surface is contributed by van der Waals’ force, which is dependent on the molecular weight (78.12 g mol −1 for benzene, 92.15 g mol −1 for toluene, and 106.17 g mol −1 for ethylbenzene and xylene) [ 21 , 22 ]. The higher the molecular weight, the more the adsorption capacity increases.…”

Recent Progress on the Development of Engineered Silica Particles Derived from Rice Husk

“…Sodium silicate solution was added to the surfactant mixture (CTAB and LE-4) dissolved in an aqueous solution at 80 • C. Then, the mixed solution was titrated using acetic acid until the pH reached 10, and heated at 100 • C for 48 h. After filtration and washing, the final product was obtained by calcination at 550 • C. The obtained MCM-48 silica showed a bicontinuous I a3d cubic phase with a surface area of 1124 m 2 g −1 and a main pore size of 3.9 nm. Morphological properties, such as the surface area, pore volume, and main pore size of the rice husk-derived MCM-41 and MCM-48 silica reported to date are summarized in Table 1 [81][82][83][84][85][86][87][88][89][90][91][92][93][94][95]. SBA-15 is one of the most common types of mesoporous silica and was first developed at the University of California [96].…”

Eco-friendly and facile synthesis of size-controlled spherical silica particles from rice husk

“…12 In particular, various studies have investigated the production of nanostructured silica with well-defined mesopores through bottomup process using a rice husk-derived silicate solution. 4,[20][21][22][23][24][25][26][27][28] However, some critical problems are yet to be solved, including the following: (i) Synthetic methods are complex; the steps include the acid leaching of rice husk, pyrolysis, silicate extraction in alkaline media, and reprecipitation with hazardous reagents (e.g., ammonia, sulfuric acid, and hydrochloric acid) (Fig. 1).…”