Abstract:
Kinetics of Spirulina attachment on Polyethylene Terephthalate (PET) was investigated in this work by batch systems. Spirulina platensis strain BP, a non-fixing nitrogen cyanobacteria, was selected in the experiments. Study factors affecting attachment were age of Spirulina platensis which included lag, early log, mid log, late log and stationary phase and substrate concentration of various formulation which were Zarrouk's medium 1X, 0.3X and 0.1X. The suspended algal cell in solution without PET was employed as control. The results showed that Spirulina attachment rate was effected by concentration of Zarrouk's medium. Specific log growth rate of Spirulina platensis in control with Zarrouk's medium 1X, kG (0.0403 d-1) was close to specific build up mass rate of that on PET, kM (0.0400 d-1). When reducing the concentration of substrate, kG in control was slightly lower but kM on PET including growth and attachment was obviously higher (0.0295 and 0.1094 d-1 respectively). Increase of specific build up mass rate on PET in low substrate result from higher attachment rate. This implied that the attachment of Spirulina platensis on PET was accelerated when substrate concentration was limited. The attachment rate constant of Spirulina platensis on PET in Zarrouk's medium 0.3X and 0.1X were 0.0408 and 0.0597 d-1, respectively.