DEVELOPMENT OF INTEGRATED BIOREMEDIATION AND ANAEROBIC DIGESTION PROCESS USING 3 rd GENERATION FEEDSTOCK

ABSTRACT The possibility of microalgae nitrogen treatment was tested in biogas digester wastewater. In this work, Chlorella pyrenoidosa was cultivated in biogas digester wastewater as a nutrient source. The growth kinetics of the algae as well as the bioremediation effect on the waste water was studied at different environmental conditions. The microalgae, Chlorella pyrenoidosa can utilize the nitrogen content present in biogas digester wastewater as a substrate for its growth. The growth of microalgae was found to follow the Monod growth model satisfactorily. Under the different condition in biogas waste water medium of microalgae, a maximum biomass of 3.75 gm/l and 1.5 gm/l was obtained in fifteen days. The net specific growth rate of microalgae Chlorella pyrenoidosa was found to be 0.1 D -1 . The growing algae also removed 92.8 % of nitrate nitrogen (NO 3 -N) at 19± 2 º C and 76 % at 30 ± 2 º C from the biogas wastewater. Treated Biogas waste water can be further used for the anaerobic digestion of algal biomass for the production of biogas. Anaerobic co-digestion of cultured microalgae and cow dung is to be done with treated water to maintain C\N ratio and to optimize the yield of biogas. This suggests that the cultivation of C. pyrenoidosa in biogas wastewater would be efficient, saving water as well as producing digestible biomass. Thus, on one hand the biogas waste water is being treated and on the other, the alga is showing substantial growth