乙酸膨润土对孔雀石绿的吸附去除

Malachite green adsorption on acetic acid bentonite

为提高膨润土对染料的吸附性能,制备了有机酸改性膨润土-乙酸膨润土（AAB）。对AAB进行了N2-BET、FTIR和XRD表征分析,同时考察了影响乙酸膨润土（AAB）去除孔雀石绿（MG）的主要因素,并进行了吸附动力学和吸附等温模型研究。研究结果表明,乙酸分子已成功负载在天然膨润土（RB）上,AAB的比表面积为45m2/g;层间距为1.721nm;在实验条件下,用0.4g/L的吸附剂处理300mg/L的MG,MG的脱色率达到99%;p H值为1~12时,AAB对MG的脱色率均达到97%以上;低浓度的十二烷基苯磺酸钠（SDBS）能提高AAB对MG的去除率,而加入十六烷基三甲基溴化铵（CTAB）会产生很强的抑制作用;AAB对MG的吸附符合Langmuir模型,Langmuir吸附容量高达1250mg/g;MG在AAB上的吸附先是一个快速吸附阶段,然后逐渐到达吸附平衡,符合准二级动力学模型。总之,AAB环保无毒,在MG去除方面具有用量低、适应p H值范围广、吸附容量大和吸附快速的优势。

In order to improve the dyes adsorption properties of bentonite,organic acid modified bentonite（AAB）was prepared. AAB were characterized by N2-BET,FTIR and XRD. In addition,main influencing factors of malachite green（MG） removal by AAB were investigated,with the adsorption isotherms and adsorption kinetics of MG on AAB were also studied. The results showed that the specific surface area of AAB was 45m2/g;the acetic acid molecule was successfully loaded on raw bentonite（RB）,with the interlamellar spacing was 1.721 nm. Under experimental conditions,decolorizing rate reached 99% when the adsorption dosage for 300mg/L MG with 0.4g/L AAB. The decolorizing rate of MG by AAB remained more than 97% within the initial p H 1—12 range. MG adsorption on AAB can be improved by low concentration sodium dodecyl benzene sulfonate（SDBS）. On the other hand,cetyl trimethyl ammonium bromide（CTAB） suppressed MG adsorption on AAB obviously. MG adsorption on AAB followed Langmuir model and the Langmuir adsorption capacity was 1250mg/g. The adsorption process of MG was a fast adsorption stage,then gradually reached the adsorption equilibrium,which can be described by pseudo-second-order model. In summary,AAB is an environmental friendly absorbent for MG removal follow with low adsorbent dosage,rapid adsorption rate,a broad p H rang and high adsorption capacity.