关键词: 改性方法;石墨烯;改性有机膨润土;颗粒吸附剂;Cr(Ⅵ)

Abstract: Graphene modified organobentonite granules(OTAC-GMBG/M、OTAC-GMBG/U)were prepared by using graphene and octadearyl dimethyl ammonium chloride(OTAC)as modifier together, under the conditions of microwave and ultrasonic respectively.The granules were conducted by mixing with polyvinyl alcohol(PVA)as binder and starch as pore former under roasting.The samples were characterized by EDS,FTIR, SEM, XRD, and BET to confirm how the process of modification would affect the internal structure of GMBG.The adsorption of the granulated absorbent on Cr(Ⅵ)was investigated.The result shows that graphene and organobentonite composite uniformly and the key bond are formed between the framework of organobentonite.The microwave modification is selected as the pore structure of OTAC-GMBG/M is evidently improved by granulation.The basal spacing of OTAC-GMBG/M has increased from 1.265 nm to 2.708 nm,the surface area go up to 51.3482 m2· g-1.At 50 ℃,the removal rate of OTAC-GMBG/M on Cr(Ⅵ)could reach 96.54%under the following conditions:the pH value is 6,the adsorption time is 30 min,the dosage is 1 g· 100 mL-1.

Key words: modification method;graphene;modified organobentonite;granulated absorbent;Cr(Ⅵ)