Application of Dual Coagulant (Alum + Barley) in Removing Colour from Leachate Nur Shaylinda Mohd Zin and Zulazimie Azraff Zulkapli MATEC Web Conf., 103 (2017) 06002 Published online: 05 April 2017 DOI: 10.1051/matecconf/201710306002