Acid Pretreatment of Sago Wastewater for Biohydrogen Production Noor Illi Mohamad Puad, Nurainin Farhan Abd Rahim and Azlin Suhaida Azmi E3S Web Conf., 34 (2018) 02012 Published online: 19 March 2018 DOI: 10.1051/e3sconf/20183402012