Microalgal species growing on piggery wastewater as a valuable candidate for nutrient removal and biodiesel production

Six microalgal species were examined in this study to determine their effectiveness in the coupling of piggery wastewater treatment and biodiesel production. The dry biomasses of Ourococcus multisporus, Nitzschia cf. pusilla, Chlamydomonas mexicana, Scenedesmus obliquus, Chiorella vulgaris, and Micractinium reisseri were 0.34 +/- 0.08, 0.37 +/- 0.13, 0.56 +/- 0.35, 0.53 +/- 0.30, 0.49 +/- 0.26, and 0.35 +/- 0.08 g dwt/L, respectively. The highest removal of nitrogen (62%), phosphorus (28%), and inorganic carbon (29%) were achieved by C mexicana. In the absence of microalgae, the spontaneous precipitation of phosphorus, calcium, and inorganic carbon occurred at slightly alkaline pH. The highest lipid productivity and lipid content (0.31 +/- 0.03 g/L and 33 +/- 3%, respectively) were found in C mexicana. The fatty acid compositions of the studied species were mainly palmitic, linoleic, a-linolenic, and oleic. The results of our study suggest that C mexicana is one of the most promising candidates for simultaneous nutrient removal and high-efficient biodiesel production. (C) 2012 Elsevier Ltd. All rights reserved.This work was supported by the Korea Institute of Energy Research, the Senior Researchers program (the National Research Foundation of Korea, 2010-0026904), the Brain Korea-21 (BK-21) program, the Brain Pool program by the Korean Federation of Science and Technology Societies (KFSTS, Grant number: 11-150-152-1600-1658), the Global Research Laboratory (GRL) Program of the National Research Foundation of Korea (NRF, Grant number: 2010-00248) of the Korea Ministry of Education, Science & Technology (MEST), and the Eco-Innovation project (Global-Top project, 2012001090001) of the Korea Ministry of Environment