摘要
The adsorption ofEscherichia coli and Staphylococcus aureus on chaff and WMDP （waste of molasses dates production） has been studied. FTIR spectra were employed to investigate the adsorption ofEscherichia coli and Staphylococcus aureus on surfaces. Adsorption of bacteria resulted in obvious shifts of some infrared bands of adsorbents. The adsorption isotherms ofEscherichia coli on two surfaces and Staphylococcus aureus on WMDP, are of L-curve type according to Giles classification. However, type H isotherm was observed in the adsorption of S. aureus on chaff. The adsorption isotherms of bacteria on the examined adsorbents conformed to the Langmuir and Temkin equations. The adsorption of bacteria was studied at different temperatures （10, 25 and 40 ℃）, the thermodynamic parameters （AH, AS and AG） have also been calculated and it has been found that the adsorption process of bacteria was exothermic in nature. The number of bacteria adsorbed on surfaces was decreased with the increase of sodium chloride concentration. The amount of bacteria cells adsorbed was increased in the presence of different cations and followed the sequence： FeCl3 〉 CaCl2 〉 KCl 〉 NaCl. The pseudo-first order and pseudo-second order models for describing the kinetic data were applied and it was found that the process was well described by pseudo-second order model. The desorption studies indicated that the bacteria were strongly retained by two adsorbents.
