This paper investigated the effects of β-cyclodextrins (β-CD) and its two derivatives, hydroxypropyl-β-cyclodextrin (HPCD) and carboxymethyl-β-cyclodextrin (CMCD), on the solubility and biodegradation of 2-nitrophenyl by an Acinetbacter sp. Results showed that β-CD,HPCD and CMCD could not be utilized by Acinetbacter sp. as sole carbon source and none of the CDs had toxic effects on the growth of the bacteria in the experiments; all the CDs could enhance the apparent solubility and accelerate the biodegradation of 2-nitrobipheny. It showed that biodegradation-accelerating effects of CDs on 2-nitrobiphenyl were correlated with their solubility-enhancing effects. Among three CDs investigated,CMCD had the most obvious effects both on the apparent solubility and the biodegradation, followed by β-CD and HPCD.
研究了添加羟丙基-β-环糊精(HP--βCD)和羟丙基-γ-环糊精(HP--γCD)对土壤中的2-硝基联苯在1 h内的解吸动力学的影响.随着环糊精添加质量浓度的增加,2-硝基联苯的最大质量浓度和解吸速率均比对照显著增加.2-硝基联苯的水相质量浓度C与时间t之间符合曲线方程:C=Cma′x(1-e-kt),其中,Cma′x是最大解吸质量浓度,解吸速率常数k=0.159 1 m in-1.根据由溶解度曲线计算的环糊精对2-硝基联苯的包合平衡常数Ks以及2-硝基联苯在土壤中的吸附平衡方程,推导了2-硝基联苯的最大解吸浓度的估算式,当HP--βCD与土壤中初始吸附的2-硝基联苯的摩尔比大于等于3.09时(对于HP--γCD,摩尔比须大于等于10.47),估算值与实测值很接近,此式可用来估算使2-硝基联苯达到最佳解吸率所需的环糊精的最小用量.
