Posted on 09 Jun 2014
Development of Algal Culture by Using Waste of Steel Industry
The feasibility study of microalgal cultivation by using the nutrients from iron industrial wastewater was performed. Seven species of microalgae which are Chlorella sp. TISTR 8990 Chlorella sp. TISTR 8991 Chlorella sp. IFRPD 1162 Chlorella sarakiniana DMKU 522 Chlorella protothecoides UTEX 25 Ankistrodesmus sp. and Scenedesmus sp. were studied. The preliminary study was performed in mixed wastewater which used as algal growth medium. Unfortunately, no microalgae could grow on this defined medium. Thus, the acclimatization of these microalgae has been done in Horikoshi basal medium mixed with 5% v/v wastewater, pH 6.0 for 14 days. The result showed that there were 4 species including Chlorella sp. TISTR 8990 Chlorella sp. TISTR 8991 C. sarakiniana DMKU 522 and C. protothecoides UTEX 25 could be acclimatized satisfactorily. Thus, these 4 species would be potentially used for next step which were acclimatized in 150 ml Horikoshi basal medium mixed with 5% v/v wastewater, pH 6.0 for 10 days. There were used as algal starter for the 1st fed-batch cultivation which had the same conditions as described previously. The 2nd fed-batch cultivation was done after 10 days of the 1st fed-batch cultivation. The Horikoshi basal medium mixed with 5% v/v wastewater was added into the culture from the 1st fed-batch cultivation to provide the working volume at 150 ml. The 2nd fed-batch cultivation was performed for 10 days. The results showed that the C. protothecoides UTEX 25 which cultivated in the Horikoshi basal medium mixed with 5% v/v wastewater grew satisfactorily comparing with control condition (no mixed wastewater added). Moreover, it showed more potential than the other strains. However, the limitations of fed-batch growth that contains the Horikoshi basal medium mixed with wastewater were found during the cultivation. As compared with the acclimatized batch cultivation, the specific rate of growth which calculated from the fed-batch condition showed the low values and the precipitation of microalgae in the 2nd fed-batch cultivation was also found. Moreover, the specific rate of growth which calculated from the 2nd fed-batch cultivation was also found to be lower than obtained from the 1st fed-batch cultivation. In conclusion, the microalgae had the possibility to cultivate in the medium which added with nutrients from iron industrial wastewater. However, the stage of acclimatization is needed, as well as, the consideration of the algal starter and the other factors which effect on promotion and inhibition the microalgal growth are necessary.2012 SEAISI Seminar
