采用深海中温菌Wangia profunda(SM-A87)的胞外多糖对对硝基苯胺进行吸附试验。分别用热分析仪、FTIR和Zeta电位仪对胞外多糖进行表征分析,并研究了吸附时间、胞外多糖用量、pH和温度等方面对其吸附规律的影响。结果表明:胞外多糖可有效去除水中的对硝基苯胺。20℃时,0.1g/L的SM-A87胞外多糖吸附处理50mL初始浓度为15mg/L的对硝基苯胺水样120min后,对硝基苯胺的最大吸附率可达91%;Langmuir、Freundlich、Redlich-Peterson等温方程和准二级动力学方程均能较好地描述SM—A87胞外多糖吸附对硝基苯胺的热力学及动力学过程,由Langmuir方程得到SM—A87胞外多糖对对硝基苯胺的最大吸附量为769.2mg/g(30℃)。
Biosorption of p-nitroaniline by exopolysaccharide (EPS) from the deep-sea mesophilic bacterium Wangia profunda (SM-A87) was studied. The SM-A87 EPS was characterized by DSC/TGA, FTIR and Zeta potential. The influence of contact time,SM-A87 EPS dosage, pH and temperature were investigated by batch adsorption experiments. The results showed that SM- A87 EPS was particularly effective at removal of p-nitroaniline from aqueous solution. The adsorption ratio of p-nitroaniline could reach 91%, under the condition of 20 ℃, p-nitroaniline concentration of 15 mg/L, EPS dosage of 0.1 g/L and equilibrium time of 120 min. The equilibrium data at different temperatures fitted all the Langmuir, Freundlich and Redlich-Peterson models well. The maximum adsorption capacity of p-nitroaniline was calculated to be 769.2 mg/g (30 ℃) according to the Langmuir model. Compared with the pseudo-first-order kinetic model, the biosorption kinetics for p-nitroaniline can be well described by the pseudo-second-order kinetic model.