NEW CORRELATION METHOD OF LIQUlD-PHASE ADSORPTION EQUILIBRIUM BY FRONTIER ORBITAL THEORY

1.液相吸附数据库实验结果表明，该树脂对芳烃的吸附量较大，其取代基为供电子基团。另一方面，发现吸附的具有吸电子基团的芳烃的量很少。含供电子基团的芳香族化合物在活性炭上的液相吸附和脱附均表现出滞后现象。另一方面，具有吸电子基团的芳香族化合物没有表现出滞后。2.液相吸附亲和系数的关联将水溶液中的烃类在活性炭和合成吸附剂上的吸附作用视为HOMO和LUMO的混合作用，根据前线轨道理论和半经验分子轨道计算，提出了估算吸附能的方法。结果表明，在液相吸附过程中，电荷转移相互作用起着重要的作用，用D-R方程确定的亲合系数可以用某些吸附质的吸附能与参比吸附剂的吸附能之比来关联。3.表面改性对液相吸附和解吸特性的影响活性炭和石墨经氧化处理后，对芳香族化合物的吸附量减少。而湿式氧化则改善了脱附特性。考虑到吸附能因氧化作用而发生的变化，解释了活性炭表面官能团对吸附和脱附特性的影响。结果表明，吸电子基团的表面修饰有利于提高合成吸附剂的吸附量。

1.Data-Base for Liquid Phase AdsorptionThe experimental results showed that the amounts of the aromatic hydrocarbons adsorbed were large, whose substituting groups were electron-donating. On the other hand, it was found that the amounts of the aromatic hydrocarbons with electron-attracting groups adsorbed were small. Aromatic compounds with electron donation groups showed the hysteresis of adsorption and desorption in the liquid phase on activated carbon. On the other hand, aromatic compound with electron attracting groups showed no hysteresis. No hysteresis was detected for all adsorbates on the synthetic adsorbents.2.Correlation of Affinity Coefficient in Liquid-Phase AdsorptionThe adsorptive interaction of hydrocarbons in aqueous solution on the activated carbon and the synthetic adsorbents was regarded as a mixing of HOMO and LUMO.The method to estimate the adsorption energy was proposed according to the frontier orbital theory and the semi-empirical molecular orbital calculation. It was found that the charge transfer interaction plays an important role in liquid-phase adsorption and the affinity coefficient determined by D-R equation can be correlated by the ratio of adsorption energy of some adsorbate to that of the reference adsorbent. The prediction method of adsorption equilibrium was proposed.3.Effect of Surface Modification on Adsorption and Desorption Characteristics in Liquid-PhaseWhen activated carbon and graphite were oxidized, the amount adsorbed of aromatic compounds were decreased. The desorption characteristic, however, was improved by wet oxidation. The influence of surface functional groups of the carbon on adsorption and desorption characteristics was explained taking into account the change of adsorption energy by oxidation. It was deducted that the surface modification with electron-attracting groups is useful to increase the amount adsorbed on synthetic adsorbents.