[Sorption of phenol and nitrobenzene in water by CTMAB/CPAM organobentonites].

A series of cetyltrimethyl amonium bromide bentonite (C-Bt), cationic polyacrylamide bentonite (P-Bt) and composite organobentonite (C/P-Bt) were synthesized by modifying bentonite with cetyltrimethyl ammonium bromide (CTMAB) and/or cationic polyacrylamide (CPAM). The basal spacings of the obtained organobentonites were analyzed with XRD. The sorption capacities of phenol and nitrobenzene to these organobentonites from water were examined. The results showed that the basal spacing values of C/P-Bt were larger than those of C-Bt and P-Bt, which indicated a simultaneous intercalation of bentonite interlayers by CTMAB and CPAM. The sorption capacity of C/P-Bt was better than that of C-Bt. Under the same equilibrium concentration (7 045 mg/L for phenol and 409 mg/L for nitrobenzene) , the sorbed amounts of phenol and nitrobenzene on 60C/4% P-Bt were 150 and 69 mg/g, which enhanced 26% and 28% respectively comparing with those on 60C-Bt. Furthermore, the sorption capacity of 60C/4% P-Bt was better than the sum of 60C-Bt and 4% P-Bt, and the sorbed amounts of phenol and nitrobenzene enhanced 22% and 26% respectively, showing an obvious synergistic sorption effect. An explanation for these results was that the arrangement model of CTMAB within the C/P-Bt interlayers was affected by CPAM, which led to the formation of organic phase with better affinity to the organic compounds. This novel organobentonites may have wide applications in organic pollution control.