【摘要】 采用反相乳液交联法制备了活性炭负载壳聚糖的新型复合树脂,研究了该树脂对亚硝酸盐氮(NO2--N)的吸附性能.结果表明,复合树脂表面具有发达的微孔,与壳聚糖树脂相比,活性炭的加入使复合树脂的堆积密度、骨架密度和孔度参数值略有降低.壳聚糖复合树脂的吸附量远大于活性炭与壳聚糖树脂简单机械组合的吸附量.当温度低于40℃时,吸附类型是以静电引力为主要作用力的物理吸附,树脂对NO2--N的吸附选择性会受共存阴离子浓度及其所带负电荷数的影响,吸附平衡时间约为60min,平衡吸附量计算值为0.479mg/g,吸附速率较快,吸附量较小;当温度高于40℃时,吸附类型为化学吸附,吸附热力学特性为吸热、自发、熵增,吸附平衡时间约为90min,平衡吸附量计算值为0.700mg/g,吸附速率下降,但吸附量增大.化学吸附和物理吸附的等温方程符合Freundlich模型,二者的吸附速率方程都更符合二级吸附速率模型.更多还原

【Abstract】 A novel composite resin of chitosan supported by activated carbon was prepared using the emulsification cross-linking technique.The adsorption properties of the resin for NO-₂-N were studied.It is found that there are many developed micropores on the surface of the resin.Due to the addition of activated carbon,the bulk density,skeleton density and void ratio of composite resin are lower than those of the chitosan resin.The adsorption capacity of chitosan composite resin is much greater than the simple compounding made up of activated carbon and chitosan resin.When the temperature is lower than 40℃,the adsorption is a physisorption process primarily caused by electrostatic attraction.The adsorption selectivity of composite resin for NO-₂-N is affected by the concentration and negative charge number of co-existing anions.The adsorption reachs equilibrium in 60 min with a calculated equilibrium capacity of 0.479 mg/g.The adsorption velocity is high while the adsorption capacity is low.When the temperature is higher than 40℃,the adsorption is a chemisorption process which is endothermic,spontaneous and entropy increasing.The adsorption reached equilibrium in 90 min with a calculated equilibrium capacity of 0.700 mg/g.The adsorption velocity drops while the adsorption capacity increases.The chemisorption and physisorption isotherm equations are conformed to the Freundlich model,and the adsorption process accords with second-order kinetic rate mode.更多还原