Study on the physiology and degradation of dye with immobilized algae

Immobilization of chlorella (pyrenoidosa) with calcium alginate was carried out. Both algal growth and physiological activity increased after immobilization. Algal size and initial density have little influence on cell growth and physiological activity. Algal cell division inside the support was restricted without bubbling air containing 2% CO2. Individual algal cell increased and algal distribution inside the support was not homogeneous, indicating that within the support the resistance of mass transfer of CO2 was the limiting factor for the growth and cell division of immobilized algae. After bubbling 2% CO2, algal growth, the cell division considerably increased and individual cell size restored normally. Study of the degradation of dye (direct brown NM) by immobilized algae was better than that of free algae. Bubbling air containing 2% CO2 in the culture solution was more favorable for increasing decolorization rate. Preliminary study of co-immobilization of algae plus bacterium illustrated that the addition of bacterium increased the anabolic activity of algae, thus increased the decolorization capacity if immobilized algae for dye.