溴化十六烷基吡啶改性沸石对水中甲基橙的吸附

采用溴化十六烷基吡啶(CPB)对天然沸石进行改性制备得到了CPB改性沸石,通过批量吸附实验考察了CPB改性沸石对水中阴离子染料甲基橙的去除作用。结果表明,天然沸石对水中甲基橙的吸附能力很差,而CPB改性沸石则可以有效吸附去除水中的甲基橙。CPB改性沸石对水中甲基橙的吸附能力随CPB负载量的增加而增加,CPB负载量最大的改性沸石对水中甲基橙的吸附能力最强。双分子层CPB改性沸石对水中甲基橙的去除率随吸附剂投加量的增加而增加,而CPB改性沸石对水中甲基橙的单位吸附量则随吸附剂投加量的增加而降低。双分子层CPB改性沸石对水中甲基橙的吸附平衡数据可以采用Langmuir等温吸附模型加以描述。根据Langmuir模型计算得到的CPB负载量为341 mmol/(kg沸石)的双分子层CPB改性沸石对水中甲基橙的最大吸附容量为63.7 mg/g(303 K和pH 7)。准二级动力学模型适合用于描述双分子层CPB改性沸石对水中甲基橙的吸附动力学过程。pH和反应温度对双分子层CPB改性沸石吸附水中甲基橙的影响较小。以上结果说明,双分子层CPB改性沸石适合作为一种吸附剂用于去除废水中的甲基橙。

Adsorption of methyl orange from aqueous solution on cetylpyridinium bromide (CPB)-modified zeolite

Cetylpyridinium bromide (CPB)-modified zeolites with different coverage types were prepared by loading different amounts of CPB on natural zeolites, and they were used as adsorbents to remove methyl orange (MO) from aqueous solution. The effect of various parameters such as CPB loading amounts, adsorbent dosage, solution pH, reaction temperature, initial adsorbate concentration, and contact time on MO adsorption onto CPB-modified zeolites was investigated using batch method. Results showed that the natural zeolite had negligible affinity for MO in aqueous solution, while the CPB-modified zeolites exhibited much higher MO removal efficiency than the natural zeolite. The MO adsorption capacity for CPB-modified zeolite increased with increasing CPB loading amount. The MO removal efficiency of bilayer CPB-modified zeolite increased with increasing adsorbent dosage, while the amount of MO adsorbed decreased with increasing adsorbent dosage. The equilibrium adsorption data of MO on bilayer CPB-modified zeolite could be described by the Langmuir isotherm model. Based on the Langmuir isotherm model, the predicted maximum MO adsorption capacity for bilayer CPB-modified zeolite with CPB loading amount of 341 mmol/(kg zeolite) was found to be 63.7 mg/g at 303 K and pH 7. The adsorption kinetic data of MO on bilayer CPB-modified zeolite followed a pseudo-second-order kinetic model. Solution pH and reaction temperature had little influence on MO adsorption onto bilayer CPB-modified zeolite. Results of this study indicate that bilayer CPB-modified zeolite is a promising adsorbent for the removal of MO from wastewater.