Preparation Of Water-Resistant Silica Gel Material And Study On Its Adsorption Properties For Two-Component VOCs

With the expansion of industrialization and the widespread use of chemicals, the emissions of volatile organic compounds (VOC) increasing day by day, caused great harm to the environment and human health, and thus widespread concerned. Current treat technology for the emissions of volatile organic is abundant, adsorption is one of them which is more economical and more effective, and the performance of adsorbents played an important role in this method.In this dissertation, the preparation conditions for water-resistant silica gel was studied. First, inorganic silicon and aluminum salt was mixed under acidic conditions, obtained aluminum-containing silicone gel, and then the gel went through series of process under controlled conditions:the base immersing, acid immersing, washing, the surface active agent immersing, drying and so on, getting water-resistant silicone material. The orthogonal experiment method has been used to obtain the optimization process conditions that influence the preparation of silica gel with specific surface area and pore volume as indicators; We use FTIR, BET and other means to characterize the adsorption properties of the material and the atomic replacement in the skeleton. The experimental results of this study show that water-resistance of the prepared silica gel is well, the replacement of aluminum on silicon occurs in the skeleton structure, and the silica gel has a larger surface area and pore volume.The water-resistant material obtained was used for single component and two component adsorption of volatile organic compounds to study the dynamic adsorption behavior of toluene, xylene, acetone and ethyl acetate. Gas chromatography was used to detect the continuous variation of concentration for volatile organic compounds, characterize their adsorption breakthrough curves. The GC experimental results show that single component adsorption of acetone and ethyl acetate on water-resistant silica gel is good, the breakthrough time is longer, saturated adsorption amount is larger, while the single component adsorption of toluene and xylene is not good, which is controled by particle internal diffusion process. The absorption results of two components acetone and toluene show acetone play a role that bring toluene into the internal pore, so both of acetone and toluene adsorption enhance, and the breakthrough time gets longer, while the replacement of toluene by acetone occurring in the adsorption process. The adsorption curves of two components toluene and xylene show the toluene and xylene adsorption on water-resistant silica gel gets weakened at the same time, the internal diffusion of xylene in the silica gel particle is more difficult.