胶原纤维固化杨梅单宁对Mo(Ⅵ)的吸附  

Adsorption of Mo(Ⅵ) on Collagen Fiber Immobilized Bayberry Tannin

作　　者：王茹[1] 廖学品[1] 曾滔[2] 彭娜[2] 石碧[1] 

机构地区：[1]四川大学皮革化学与工程教育部重点实验室,四川成都610065 [2]四川大学化学工程学院,四川成都610065

出　　处：《林产化学与工业》2008年第2期21-26,共6页Chemistry and Industry of Forest Products

基　　金：国家杰出青年基金(20325619);四川省应用基础研究(2007J13-092)

摘　　要：研究了胶原纤维固化杨梅单宁(IBT)这一新型吸附材料对Mo6+的吸附特性。实验表明,温度对吸附容量影响不大,而pH值对吸附容量有显著影响,Mo6+的吸附容量随pH值降低而增加,表明其吸附机理是吸附剂与聚钼阴离子之间的静电结合。当Mo6+的初始质量浓度为100.0mg/L、吸附剂用量0.100g、温度为303K、pH值2.0时,IBT对Mo6的吸附量为82.4mg/g。Freundlich方程可以很好地描述IBT对Mo6+的吸附等温线。动力学研究表明,初始吸附速率很快,吸附达到平衡的时间约为600min,其吸附动力学可很好地用拟二级速率方程描述,计算所得的平衡吸附量与实测值误差很小。解吸实验表明,0.02mol/LEDTA溶液能使吸附剂再生,并能循环使用。选择性吸附研究表明,在酸性(pH值2.0)条件下,IBT对Mo6+的吸附率大于95%,而对Ni2+和Cu2+的吸附率低于5%,可用于Mo6+-Ni2+和Mo6+-Cu2+二元混合溶液中Mo6+的分离和提取。The adsorption behaviors of Mo^6＋ on collagen fiber immobilized bayberry tannin（ IBT）, a new kind of adsorbent, were investigated. It was found that the influence of temperature on adsorption capacity of Mo^6＋ is insignificant, but the effect of pH value on the adsorption was remarkable. The adsorption capacity of Mo^6＋ was increased with the decrease of pH value. These facts implies that adsorption is based on electrostatic association between adsorbent and polymeric anions of Mo^6＋. At pH value 2.0 and 303 K, the adsorption capacity of Mo^6＋ on 0. 100 g adsorbent was 82.4 mg/g in 100 mL of 100.0 mg/L Mo^6＋ solution. The adsorption isotherms can be well described by Freundlich equation. The adsorption rate of the adsorbent to Mo^6＋ was very fast at the beginning, and reached adsorption equilibrium around 600 min. The adsorption kinetics can be well described by the pseudo- second-order-rate model and the adsorption capacities calculated by this model are very close to those experimentally determined. The adsorbent can be regenerated by using 0.02 mol/L sodium ethylenediamine-tetraacetate （ EDTA-Na4 ） as resorption agent after adsorption of Mo^6＋. The adsorbent also showed satisfactory adsorption selectivity to Mo^6＋ in Mo^6＋-Ni^2＋ and Mo^6＋-Cu^2＋ mixture solutions at pH value 2.0, because these metal ions have different adsorption mechanisms on IBT and therefore, to be adsorbed at different pH value ranges.

关 键 词：杨梅单宁 固化单宁 Mo^6+ 胶原纤维 吸附机理 

分 类 号：TQ94[化学工程]