Abstract:

Biosorption of pnitroaniline by exopolysaccharide (EPS) from the deepsea mesophilic bacterium Wangia profunda (SMA87) was studied. The SMA87 EPS were respectively 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 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 at 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.

Key words:  Wangia profunda SMA87; exopolysaccharide; pnitroaniline;biosorption