Mercury Removal from Wastewater Using Palm Oil Fuel Ash Imla Syafiqah Mohd Salleh, Nor Akmalina Mustazar and Hafizuddin Wan Yussof MATEC Web of Conferences, 150 (2018) 02007 Published online: 23 February 2018 DOI: 10.1051/matecconf/201815002007