改性膨润土的制备及其对苯酚吸附特性研究

Study on Preparation of Modified Bentonite and Its Adsorption Properties to Phenol

以复合十六烷基三甲基溴化铵(CTAB)和二乙基二硫代氨基甲酸钠(DDTC)为改性剂、钠基膨润土(SMB)为原料,制备了不同配比的复合有机改性膨润土,并对其进行了红外光谱(FTIR)和扫描电镜(SEM)表征,发现CTAB和DDTC插层于膨润土的片层结构表面,不同配比的复合改性剂对膨润土的改性效果存在差异.通过改性前和不同配比改性下吸附剂对含苯酚废水的吸附效果对比表明:改性后膨润土对废水中苯酚的吸附效果明显好于改性前.改性剂DDTC/CTAB的摩尔比为2∶1时的改性对苯酚的吸附效果最好,对该配比下的吸附时间、用量以及吸附等温方程的研究发现,处理含90mg·L-1的苯酚废水时,吸附时间为0.5h,复合有机吸附剂用量为26.4g·L-1,吸附效果最好,且吸附过程符合Freundlich方程(R2>0.97).

The modified bentonite organic composite adsorbents were obtained with CTAB （cetyltrimethy ammonium bromide） and DDTC （sodium diethyldithiocarbamate） as compound modifier and SMB （sodium bentonite） as raw materials.Those adsorbents were characterized by FT-IR and SEM,respectively,indicating that CTAB and DDTC were both intercalated into the interlayer of bentonite successfully,and diverse mole ratios of DDTC and CTAB showed different modification effects on bentonite.Additionally,the results of the adsorbents treating phenol wastewater indicate that the adsorption effect of modified bentonite adsorbents is significantly better than that of unmodified one,and obviously,when the mole ratio of DDTC and CTAB comes to 2：1,the adsorption effect is best.Further study of the adsorption time,adsorbent dosage and isothermal adsorption equation shows clearly that the optimal time is 0.5 h and the adsorbent dosage is 26.4 g L^-1 for 90 mg L^-1 of wastewater.Satisfactorily,the adsorption process is in accordance with Freundlich equation.