Designed Synthesis Of Amino-functionalized Absorbents And Application In Wastewater Treatment

Industrial heavy metal pollution has become a serious environmental and sanitaryproblem all over the world in recent years. Heavy metals can accumulate throughout the foodchain from organisms living in water and may also affect human beings. Functionalizedporous materials have received considerable attention because of their large BET surface,controllable narrow pore size distribution, thermal and mechanical stability, and featuringhigh functionality. These materials are known to be promising candidates for the use incatalysis, electrochemistry, biochemistry and drug controlled release system, and especially inadsorption. In this study, we introduced the synthesis, characterization and performance ofheavy metal adsorption of the amino-functionalized mesoporous materials.The main research work is as follows:1. Mesoporous amino-functionalized adsorbents with developed frameworks werefacilely synthesized using polymeric polymethylhydrosiloxane (PMHS), tetraethylortho-silicate (TEOS) and amino-organoalkoxysilane as co-precursors via a one-step sol-gel methodin absence of traditional surfactant agents. The as-prepared materials were characterized byN2adsorption-desorption, SEM, TEM, elemental analysis, FT-IR, solid state NMR and TGA.The N2sorption and TEM results indicate that the amino-functionalized mesoporous withamino organic moieties in the framework are in three-dimensional wormhole-like porestructures with narrow pore size distribution and large the specific surface area and porevolume. In addition, the results from FT-IR, elemental analysis, solid state NMR and TGAresults reveal that a certain amount of amino moieties have been effectively introduced intothe mesostructured samples via co-condensation of siliceous species. The loadings of aminomoieties of the amino-functionalized gels could be tuned by adjusting the molar ratio oforganoalkoxysilane/silica in the synthesis system.2. The heavy metal adsorption experiments have been examined for Cu(Ⅱ), Pb(Ⅱ),Ni(Ⅱ), Cd(Ⅱ) and Zn(Ⅱ) from aqueous solution employing batch method. The results ofadsorption towards metal ions implies that the mesostructure amino-functionalized adsorbents show a largely favorable affinity to these heavy metal ions, especially to Pb(Ⅱ) undersimulated conditions and the adsorption amount with increasing of the amino-functionalizedmoieyies amount in the adsorbents. Furthermore, the results showed that the adsorptioncapacity of the multi-amino-functionalized adsorbents was higher than that of themono-amino-functionalized counterparts, illustrating a good potential for environmentalremediation in virtue of the combination of selective adsorption performance and large-scalesynthesis character.