CHEMICAL ENGINEERING TRANSACTIONS VOL. 45, 2015 A publication of The Italian Association of Chemical Engineering www.aidic.it/cet Guest Editors: Petar Sabev Varbanov, Jiří Jaromír Klemeš, Sharifah Rafidah Wan Alwi, Jun Yow Yong, Xia Liu Copyright © 2015, AIDIC Servizi S.r.l., ISBN 978-88-95608-36-5; ISSN 2283-9216 DOI:10.3303/CET1545233 Please cite this article as: Tan C.H., Chech W.Y., Tau C.L., Show P.L., Juan J.C., Chang J.-S., 2015, Algae cultivation in wastewater for biodiesel – a review, Chemical Engineering Transactions, 45, 1393-1398 DOI:10.3303/CET1545233 1393 Algae Cultivation in Wastewater for Biodiesel – A Review Chung Hong Tan a , Wai Yan Cheah b , Tau Chuan Ling b , Pau Loke Show* ,a,c , Joon Ching Juan d,e , Jo-Shu Chang f,g,h a Department of Chemical and Environmental Engineering, Faculty of Engineering, University of Nottingham Malaysia Campus, Jalan Broga, 43500 Semenyih, Selangor Darul Ehsan, Malaysia. b Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia. c Manufacturing and Industrial Processes Division, Faculty of Engineering, Centre for Food and Bioproduct Processing, University of Nottingham Malaysia Campus, Malaysia. d Laboratory of Advanced Catalysis and Environmental Technology, School of Science, Malaysia. e Nanotechnology& Catalysis Research Centre (NANOCAT), University of Malaya, 50603 Kuala Lumpur, Malaysia. f University Center for Bioscience and Biotechnology, National Cheng Kung University, Tainan 701, Taiwan. g Department of Chemical Engineering, National Cheng Kung University, Tainan 701, Taiwan h Research Center for Energy Technology and Strategy, National Cheng Kung University, Tainan 701, Taiwan. PauLoke.Show@nottingham.edu.my Global concern for energy security and environmental sustainability has put a great prominence towards alternative energy resources, substituting the rapidly-depleting fossil fuels. Fossil fuels have been a major contributing factor for greenhouse gas production, leading to global warming. Hence, biofuels have been greatly researched in hopes to replace fossil fuels. One remarkable biofuel producer is microalgae, due to their high biomass productions, high cellular lipid accumulation, as well as the ability to sequester carbon dioxide from waste gas and remove pollutants from wastewater. Integration of wastewater as the medium for algal cultivation offers a green and cost-effective way for sustainable biofuel production. The zero-cost palm oil mill effluent (POME) in Malaysia will be an option for microalgae cultivation due to the high concentrations of nitrogen and phosphorus. Microalgae are able to survive in wastewater by utilizing the nutrients for growth. This has the potential to achieve economical microalgae production for bioenergy, while promoting environmental sustainability. 1. Introduction The global primary energy consumption has increased by 2.3 % in 2013, compared to 1.8 % in 2012. Energy consumption rose far more rapidly than its production in 2013, despite a stagnant global economic. World-wide energy consumption is predicted to increase by 49 % from 2007 to 2035 due to the demands from the expanding world population, economic growth and social pressures. It is expected that this may exhaust natural resources, such as petroleum, natural gas and coal. The sustained use of fossil fuels has been implicated as a major contributing factor for the greenhouse gas production. Alternative energy sources, such as biofuels, have to be in place to reduce the dependence on fossil fuels. Microalgae will be the next remarkable biofuel source, due to their rapid growth rate and low nutrient requirement, compared to other oil crops such as oil palm, soybean and rapeseed. Moreover, microalgae are capable of producing 15 – 300 times more oil than traditional crops on per unit area of land. Microalgae have been observed as suitable for biodiesel production due to their high growth rate coupled with a considerable amount of lipid accumulation. Most microalgae exhibit oil contents of 20 – 50 % on dry-cell weight basis (Chisti, 2007). Table 1 shows the comparison between all three generations of biofuels.